JP5079113B2 - Cleaning system and cleaning method - Google Patents

Description

  The present invention relates to a cleaning system and a cleaning fluid cleaning method for cleaning an object to be cleaned contained in a cleaning chamber using a cleaning fluid of either a supercritical fluid or a subcritical fluid.

  There is a cleaning system in which the pressure of carbon dioxide gas used for the next cleaning is increased in advance simultaneously with the cleaning of an object to be cleaned (see Patent Document 1). The cleaning system includes a pressurizing pump that raises the pressure of the carbon dioxide gas, a heater that heats the carbon dioxide gas, a cleaning chamber that circulates a supercritical fluid made from the carbon dioxide gas and cleans an object to be cleaned, It is formed of a contamination separation chamber connected to a cleaning chamber and a storage tank connected to a pressure pump. The supercritical fluid not only removes dirt on the surface of the object to be cleaned, but also removes dirt that penetrates into the object to be cleaned and permeates the object to be cleaned. In this cleaning system, during the cleaning of the object to be cleaned contained in the cleaning chamber, the pressure of the carbon dioxide gas used for the next cleaning is increased by a pressurizing pump, and the carbon dioxide gas pressurized to a predetermined pressure is stored. Store temporarily in tank.

  After cleaning the object to be cleaned, the pressure regulating valve is opened to allow the supercritical fluid to flow out from the cleaning chamber to the contamination separation chamber. After the pressure of the fluid in the cleaning chamber is reduced, the object to be cleaned is taken out from the cleaning chamber. After removing the object to be cleaned from the cleaning chamber, the next object to be cleaned is put into the cleaning chamber, and pressurized carbon dioxide gas is sent from the storage tank to the heater to create a supercritical fluid. Is distributed in the washing room. This cleaning system uses the carbon dioxide gas temporarily stored in the storage tank to create a supercritical fluid and distributes the fluid to the cleaning chamber to clean the object to be cleaned. Compared with the case of making a supercritical fluid starting from the above, the cleaning processing time can be shortened.

JP-A-8-97021

  In order to remove the object to be cleaned from the cleaning chamber after flowing the supercritical fluid through the cleaning chamber and cleaning the object to be cleaned, the pressure of the supercritical fluid in the cleaning chamber is reduced to atmospheric pressure. It is necessary to return the supercritical fluid to the normal fluid. In the cleaning system disclosed in the above publication, when the object to be cleaned is removed from the cleaning chamber, the pressure control valve is opened at once, and the supercritical fluid is allowed to flow out of the cleaning chamber into the contamination separation chamber, so that the pressure of the fluid in the cleaning chamber is increased. Is returned to atmospheric pressure, the pressure of the supercritical fluid in the cleaning chamber drops irregularly. When the pressure of the supercritical fluid drops irregularly, the density of the fluid in the cleaning chamber decreases rapidly before and after the critical point, and the object to be cleaned is caused by the rapid density change of the supercritical fluid that has penetrated into the object to be cleaned. There are cases where damage such as deformation, expansion, and foaming is received.

  An object of the present invention is to provide a cleaning system and a cleaning method capable of preventing a rapid density change of a cleaning fluid in a cleaning chamber and preventing an object to be cleaned after being cleaned from being damaged.

The first premise of the present invention for solving the above-mentioned problem is
An airtight structure cleaning chamber for cleaning a three-dimensional filter having a first surface, a second surface, and a side surface extending between the surfaces by flowing a cleaning fluid of either a supercritical fluid or a subcritical fluid; A cleaning container having an inlet for allowing the cleaning fluid to flow into and an outlet for allowing the cleaning fluid to flow out of the cleaning chamber; a first control valve capable of adjusting the amount of the cleaning fluid flowing out of the cleaning chamber; The cleaning system cleans the filter by allowing fluid to flow from the first surface to the second surface of the filter housed in the cleaning chamber.

  As a feature of the present invention in the first premise, the cleaning container includes a covering material that is installed in the cleaning chamber and covers the filter, and a pipe material that is installed in the cleaning chamber and extends from the covering material and is connected to the outlet. A central portion that covers the entire surface of the filter so as to be separated from one of the first surface and the second surface of the filter, and a peripheral edge that is positioned outward in the circumferential direction of the side surface of the filter and covers the entire side surface A space for collecting the cleaning fluid flowing from the first surface to the second surface of the filter and guiding the cleaning fluid to the pipe member, between the surface of the filter and the central portion of the covering material. In the cleaning system, after cleaning the filter accommodated in the cleaning chamber, the cleaning fluid is gradually discharged from the cleaning chamber through the first control valve while controlling the flow rate of the cleaning fluid in the first control valve. Gradually lower the pressure of the cleaning fluid in the cleaning chamber Run the body pressure decreasing means, is to reduce the density of the washing fluid cleaning chamber substantially constant downward slope by the fluid pressure decreasing means.

  As an example of the cleaning system of the present invention, in the cleaning system, a supercritical fluid or a subcritical fluid is heated by heating to a temperature of 30 to 120 ° C. while pressurizing carbon dioxide gas to a pressure of 5.0 to 30.0 MPa. In the fluid pressure decreasing means, the pressure of the cleaning fluid is decreased at a pressure reduction rate of 0.5 MPa / h to 10.0 MPa / h in a range of ± 5.0 MPa across the critical pressure of the cleaning fluid.

  As another example of the cleaning system of the present invention, the cleaning system includes a heater capable of adjusting the temperature of the cleaning container. In the cleaning system, the temperature of the heater is adjusted after cleaning the filter accommodated in the cleaning chamber. First temperature control means for controlling the temperature of the cleaning container is executed, and the temperature of the cleaning fluid in the cleaning chamber is gradually lowered with a substantially constant downward gradient by the first temperature control means.

  As another example of the cleaning system of the present invention, the cleaning system preheats the cleaning fluid flowing into the cleaning chamber, and the amount of the cleaning fluid preheated by the preheating tank can be adjusted to the cleaning chamber. In the cleaning system, after the filter accommodated in the cleaning chamber is cleaned, the preheated cleaning fluid is passed through the second control valve while controlling the flow rate of the cleaning fluid in the second control valve. An inflow control means for gradually flowing into the cleaning chamber from the preheating tank is executed, and the temperature of the cleaning fluid in the cleaning chamber is gradually lowered with a substantially constant downward gradient by the inflow control means.

  As another example of the cleaning system of the present invention, in the cleaning system, after the filter housed in the cleaning chamber is cleaned, second temperature control means for controlling the temperature of the preheating tank is executed, and cleaning is performed by the second temperature control means. The temperature of the cleaning fluid in the room is gradually lowered with a substantially constant downward gradient.

  As another example of the cleaning system of the present invention, the cleaning system includes a heater capable of adjusting the temperature of the cleaning container. In the cleaning system, the temperature of the heater is adjusted after cleaning the filter accommodated in the cleaning chamber. Third temperature control means for controlling the temperature of the cleaning container is executed, and the temperature of the cleaning fluid in the cleaning chamber is kept substantially constant by the third temperature control means.

  As another example of the cleaning system of the present invention, the cleaning system preheats the cleaning fluid flowing into the cleaning chamber, and the second adjusts the inflow amount of the cleaning fluid preheated by the preheating tank into the cleaning chamber. In the cleaning system, after the filter accommodated in the cleaning chamber is cleaned, the preheated cleaning fluid is preheated via the second control valve while controlling the flow rate of the cleaning fluid in the second control valve. An inflow control means for gradually flowing from the tank into the cleaning chamber is executed, and the temperature of the cleaning fluid in the cleaning chamber is kept substantially constant by the inflow control means.

  As another example of the cleaning system of the present invention, in the cleaning system, after the filter housed in the cleaning chamber is cleaned, fourth temperature control means for controlling the temperature of the preheating tank is executed, and cleaning is performed by the fourth temperature control means. The temperature of the cleaning fluid in the room is kept substantially constant.

  As another example of the cleaning system of the present invention, the pipe material is formed of a first portion located on the outlet side and a second portion branched from the first portion into a plurality of portions and connected to a plurality of portions of the covering material. .

  As another example of the cleaning system of the present invention, the cleaning chamber is provided with a breathable pedestal on which the filter is placed in a state in which either one of the first surface and the second surface of the filter is in contact, In the cleaning system, the filter is positioned between the covering material and the pedestal, and the cleaning fluid flows through substantially the entire area of the filter by the rectifying action of the pedestal.

  As another example of the cleaning system of the present invention, in the cleaning system, a plurality of inlets through which the cleaning fluid flows into the cleaning chamber are formed.

  The second premise of the present invention for solving the above-described problem is that a cleaning fluid, either a supercritical fluid or a subcritical fluid, is circulated to form a first surface and a second surface and a side surface extending between the surfaces. A cleaning container having an airtight structure cleaning chamber for cleaning a three-dimensional structure filter, an inlet for allowing the cleaning fluid to flow into the cleaning chamber, and an outlet for allowing the cleaning fluid to flow out of the cleaning chamber, and a cleaning fluid flowing out of the cleaning chamber In this cleaning method, the filter is cleaned by allowing a cleaning fluid to flow from the first surface toward the second surface of the filter housed in the cleaning chamber.

  The feature of the present invention in the second premise includes a covering material in which the cleaning container is installed in the cleaning chamber and covers the filter, and a pipe material that is installed in the cleaning chamber and extends from the coating material and is connected to the outlet, A central portion that covers the entire surface of the filter so as to be separated from one of the first surface and the second surface of the filter, and a peripheral portion that covers the entire side surface of the filter on the outer side in the circumferential direction. And a space for collecting the cleaning fluid flowing from the first surface of the filter toward the second surface and guiding the cleaning fluid to the tube material is formed between the surface of the filter and the central portion of the covering material. In the cleaning method, after the filter accommodated in the cleaning chamber is cleaned, the cleaning fluid is gradually discharged from the cleaning chamber through the first control valve while cleaning the flow rate of the cleaning fluid in the first control valve. Gradually reduce the pressure of the cleaning fluid in the room, thereby The density of the cleaning fluid cleaning chamber is to reduce substantially constant downward slope.

  As an example of the cleaning method of the present invention, a supercritical fluid or a subcritical fluid is produced by heating carbon dioxide gas to 30 to 120 ° C. while pressurizing carbon dioxide gas to 5.0 to 30.0 MPa. The pressure of the cleaning fluid is reduced at a depressurization rate of 0.5 MPa / h to 10.0 MPa / h within a range of ± 5.0 MPa across the critical pressure of the fluid.

  As another example of the cleaning method of the present invention, the cleaning method includes a heater capable of adjusting the temperature of the cleaning container. In the cleaning method, the temperature of the heater is adjusted after cleaning the filter accommodated in the cleaning chamber. The temperature of the cleaning vessel is controlled, thereby gradually decreasing the temperature of the cleaning fluid in the cleaning chamber with a substantially constant downward gradient.

  As another example of the cleaning method of the present invention, the cleaning method includes a preheating tank that preheats the cleaning fluid flowing into the cleaning chamber and a flow rate of the cleaning fluid preheated by the preheating tank that can be adjusted to the cleaning chamber. In the cleaning method, after the filter accommodated in the cleaning chamber is cleaned, the preheated cleaning fluid is passed through the second control valve while controlling the flow rate of the cleaning fluid in the second control valve. The temperature of the cleaning fluid in the cleaning chamber is gradually lowered with a substantially constant downward gradient by gradually flowing from the preheating tank into the cleaning chamber.

  As another example of the cleaning method of the present invention, in the cleaning method, after the filter housed in the cleaning chamber is cleaned, the temperature of the preheating tank is controlled, whereby the temperature of the cleaning fluid in the cleaning chamber is reduced to a substantially constant downward gradient. And gradually decrease.

  As another example of the cleaning method of the present invention, the cleaning method includes a heater capable of adjusting the temperature of the cleaning container. In the cleaning method, the temperature of the heater is adjusted after cleaning the filter accommodated in the cleaning chamber. The temperature of the cleaning container is controlled, thereby keeping the temperature of the cleaning fluid in the cleaning chamber substantially constant.

  As another example of the cleaning method of the present invention, the cleaning method includes a preheating tank that preheats the cleaning fluid flowing into the cleaning chamber and a flow rate of the cleaning fluid preheated by the preheating tank that can be adjusted to the cleaning chamber. In the cleaning method, after the filter accommodated in the cleaning chamber is cleaned, the flow rate of the cleaning fluid in the second control valve is controlled, and the preheated cleaning fluid is preheated via the second control valve. The temperature of the cleaning fluid in the cleaning chamber is kept substantially constant by gradually flowing from the tank into the cleaning chamber.

  As another example of the cleaning method of the present invention, in the cleaning method, after the filter housed in the cleaning chamber is cleaned, the temperature of the preheating tank is controlled, thereby maintaining the temperature of the cleaning fluid in the cleaning chamber substantially constant. .

  As another example of the cleaning method of the present invention, the pipe material is formed of a first portion located on the outlet side and a second portion branched from the first portion into a plurality of portions and connected to a plurality of portions of the covering material. .

  As another example of the cleaning method of the present invention, the cleaning chamber is provided with a breathable pedestal on which the filter is placed with either one of the first surface and the second surface of the filter in contact with each other, In the cleaning method, the filter is positioned between the covering material and the pedestal, and the cleaning fluid flows through substantially the entire area of the filter by the rectifying action of the pedestal.

    As another example of the cleaning method of the present invention, in the cleaning method, a plurality of inflow ports through which the cleaning fluid flows into the cleaning chamber are formed.

  According to the cleaning system of the present invention, the cleaning container includes a covering material that covers the inlet and outlet and the filter, and a pipe material that connects to the outlet, and a central portion that covers the entire surface of the filter and the entire side surface of the filter. And a space for collecting the cleaning fluid flowing from the first surface of the filter toward the second surface and guiding the cleaning fluid to the pipe member is formed between the surface of the filter and the central portion of the covering material. Therefore, the cleaning fluid can surely flow from the first surface to the second surface of the filter, and the generation of the cleaning fluid that does not flow through the filter can be prevented. Can prevent wasteful consumption. The cleaning system can reliably clean the entire filter using the cleaning fluid. After cleaning the filter, the cleaning system controls the flow rate of the cleaning fluid in the first control valve, and gradually discharges the cleaning fluid from the cleaning chamber through the first control valve to gradually increase the pressure of the cleaning fluid in the cleaning chamber. Since the fluid pressure decreasing means for decreasing the pressure is executed and thereby the density of the cleaning fluid in the cleaning chamber is decreased with a substantially constant downward gradient, the pressure of the cleaning fluid does not decrease irregularly in the cleaning chamber. It is possible to prevent a rapid density change before and after the critical point of the cleaning fluid that has permeated the liquid. Since this cleaning system can prevent deformation, expansion, foaming, and the like of the filter due to a rapid density change of the cleaning fluid, the filter after cleaning is not damaged.

  A supercritical fluid or subcritical fluid is produced by heating carbon dioxide gas to a temperature of 30 to 120 ° C. while pressurizing carbon dioxide gas to a pressure of 5.0 to 30.0 MPa, and sandwiches the critical pressure of the cleaning fluid ± 5. Since the cleaning system that reduces the pressure of the cleaning fluid at a pressure reduction rate of 0.5 MPa / h to 10.0 MPa / h in the range of 0 MPa slowly reduces the pressure of the cleaning fluid at the pressure reduction rate, the cleaning system penetrates the inside of the filter. The rapid density change before and after the critical point of the washed fluid can be prevented, and the washed filter can be reliably prevented from being damaged.

  A heater that can adjust the temperature of the cleaning container is included. After the filter is cleaned, first temperature control means for controlling the temperature of the cleaning container by adjusting the temperature of the heater is executed, and the temperature of the cleaning fluid in the cleaning chamber is reduced. In the cleaning system that gradually decreases at a constant downward gradient, the temperature of the cleaning fluid in the cleaning chamber can be reliably decreased at a substantially constant downward gradient by the first temperature control means. It is possible to prevent sudden changes in temperature of the cleaning fluid due to regular reduction, and it is possible to prevent sudden changes in density before and after the critical point of the cleaning fluid that has penetrated into the filter. It can be surely prevented from receiving.

  A preheating tank for preheating the cleaning fluid flowing into the cleaning chamber; and a second adjustment valve capable of adjusting an inflow amount of the cleaning fluid preheated by the preheating tank into the cleaning chamber; While controlling the flow rate of the cleaning fluid in the valve, an inflow control means for gradually flowing the preheated cleaning fluid from the preheating tank into the cleaning chamber through the second control valve is executed, and the temperature of the cleaning fluid in the cleaning chamber is controlled. In a cleaning system that gradually decreases with a substantially constant downward gradient, the temperature of the cleaning fluid in the cleaning chamber can be reliably decreased with a substantially constant downward gradient by the inflow control means. It is possible to prevent a sudden temperature change of the cleaning fluid due to the regular decrease, and a sudden density change before and after the critical point of the cleaning fluid that has penetrated into the filter. Can be prevented, the filter after cleaning can be reliably prevented from being damaged.

  After the filter is cleaned, the second temperature control means for controlling the temperature of the preheating tank is executed, and the cleaning system for gradually reducing the temperature of the cleaning fluid in the cleaning chamber with a substantially constant downward gradient is cleaned by the second temperature control means. Since the temperature of the cleaning fluid in the room can be reliably lowered with a substantially constant downward gradient, it is possible to prevent a rapid temperature change of the cleaning fluid caused by irregularly reducing the temperature of the cleaning fluid in the cleaning chamber. The rapid density change before and after the critical point of the cleaning fluid that has permeated into the filter can be prevented, and the filter after cleaning can be reliably prevented from being damaged.

  A heater that can adjust the temperature of the cleaning container is included. After the filter is cleaned, third temperature control means for controlling the temperature of the cleaning container by adjusting the temperature of the heater is executed, and the temperature of the cleaning fluid in the cleaning chamber is reduced. Since the cleaning system that keeps constant can maintain the temperature of the cleaning fluid in the cleaning chamber after the cleaning at a predetermined temperature by the third temperature control means, it is possible to prevent a rapid temperature change of the cleaning fluid in the cleaning chamber. In addition, it is possible to prevent an abrupt density change before and after the critical point of the cleaning fluid that has permeated into the filter, and to reliably prevent the filter after cleaning from being damaged. This cleaning system can dry the filter after cleaning in the cleaning chamber by maintaining the temperature of the cleaning fluid in the cleaning chamber at a predetermined temperature.

  A preheating tank that preheats the cleaning fluid flowing into the cleaning chamber; and a second adjustment valve that adjusts an inflow amount of the cleaning fluid preheated by the preheating tank into the cleaning chamber. Inflow control means for gradually flowing the preheated cleaning fluid from the preheating tank into the cleaning chamber via the second control valve is executed while controlling the flow rate of the cleaning fluid in the cleaning chamber. The cleaning system that keeps constant can maintain the temperature of the cleaning fluid in the cleaning chamber after cleaning at a predetermined temperature by the inflow rate control means, and can prevent a rapid temperature change of the cleaning fluid in the cleaning chamber. At the same time, it is possible to prevent sudden changes in density before and after the critical point of the cleaning fluid that has penetrated into the filter, and reliably prevent damage to the filter after cleaning. Door can be. This cleaning system can dry the filter after cleaning in the cleaning chamber by maintaining the temperature of the cleaning fluid in the cleaning chamber at a predetermined temperature.

  After cleaning the filter, the cleaning system that executes the fourth temperature control means for controlling the temperature of the preheating tank and keeps the temperature of the cleaning fluid in the cleaning chamber substantially constant is the cleaning chamber after the cleaning by the fourth temperature control means. Since the temperature of the cleaning fluid can be maintained at a predetermined temperature, a rapid temperature change of the cleaning fluid in the cleaning chamber can be prevented, and the rapid density before and after the critical point of the cleaning fluid that has penetrated into the filter A change can be prevented and it can prevent reliably that the filter after washing | cleaning receives a damage. This cleaning system can dry the filter after cleaning in the cleaning chamber by maintaining the temperature of the cleaning fluid in the cleaning chamber at a predetermined temperature.

  A cleaning system in which a pipe material is formed of a first portion located on the outlet side and a second portion branched from the first portion into a plurality of portions and connected to a plurality of locations of the covering material, The pipe can be collected from a plurality of locations of the covering material, and the cleaning fluid having a substantially uniform flow rate can be passed through the entire region of the filter, and the entire region of the filter can be reliably cleaned.

  A breathable pedestal on which the filter is placed in a state where either one of the first surface and the second surface of the filter is in contact is installed in the cleaning chamber, and the filter is located between the covering material and the pedestal, The cleaning system in which the cleaning fluid flows almost the entire area of the filter by the rectifying action of the pedestal allows the cleaning fluid to flow through the filter while the cleaning fluid is evenly distributed throughout the pedestal by the fluid resistance of the pedestal having the rectifying action. Therefore, the cleaning fluid can surely flow from substantially the entire area of the first surface of the filter to the entire area of the second surface, and has a high cleaning function for the filter. This cleaning system can reliably clean the entire filter using the cleaning fluid.

  A cleaning system that has multiple inlets that allow the cleaning fluid to flow into the cleaning chamber can discharge the cleaning fluid from the multiple inlets and evenly apply to multiple parts of the filter. A flow rate of cleaning fluid can be allowed to flow. This cleaning system can reliably clean the entire filter using the cleaning fluid.

  According to the cleaning method of the present invention, the cleaning container includes a covering material that covers the inflow port, the outflow port, and the filter, and a pipe material that is connected to the outflow port, and the covering material covers the entire surface of the filter and the entire side surface of the filter. And a space for collecting the cleaning fluid flowing from the first surface of the filter toward the second surface and guiding the cleaning fluid to the pipe member is formed between the surface of the filter and the central portion of the covering material. Therefore, the cleaning fluid can surely flow from the first surface to the second surface of the filter, and the generation of the cleaning fluid that does not flow through the filter can be prevented. Can prevent wasteful consumption. The cleaning method can reliably clean the entire filter using a cleaning fluid. In the cleaning method, after cleaning the filter, the flow rate of the cleaning fluid in the first control valve is controlled, and the cleaning fluid is gradually discharged from the cleaning chamber through the first control valve to gradually increase the pressure of the cleaning fluid in the cleaning chamber. This reduces the density of the cleaning fluid in the cleaning chamber with a substantially constant downward gradient, so that the pressure of the cleaning fluid does not decrease irregularly in the cleaning chamber, and the criticality of the cleaning fluid that has penetrated into the interior of the filter. A sudden density change before and after the point can be prevented. This cleaning method can prevent deformation, expansion, foaming, and the like of the filter due to a sudden change in density of the cleaning fluid, so that the filter after cleaning is not damaged.

  Supercritical fluid or subcritical fluid is produced by heating carbon dioxide gas to 30 to 120 ° C. while pressurizing carbon dioxide gas to 5.0 to 30.0 MPa, and in the range of ± 5.0 MPa across the critical pressure of the cleaning fluid In the cleaning method in which the pressure of the cleaning fluid is decreased at a pressure reduction rate of 0.5 MPa / h to 10.0 MPa / h, the pressure of the cleaning fluid is slowly decreased at the pressure reduction rate. A rapid density change before and after the critical point can be prevented, and the filter after cleaning can be reliably prevented from being damaged.

  A heater that can adjust the temperature of the cleaning container is included.After cleaning the filter, the temperature of the cleaning fluid in the cleaning chamber is gradually adjusted to a substantially constant downward slope by adjusting the temperature of the heater and controlling the temperature of the cleaning container. In the cleaning method for reducing the temperature, the temperature of the cleaning fluid in the cleaning chamber can be reliably decreased with a substantially constant downward slope by adjusting the temperature of the heater and controlling the temperature of the cleaning container. In addition to preventing rapid changes in the temperature of the cleaning fluid due to irregularly decreasing the temperature of the cleaning fluid, it is also possible to prevent rapid changes in density before and after the critical point of the cleaning fluid that has penetrated into the filter. It is possible to reliably prevent the filter from being damaged.

  A preheating tank for preheating the cleaning fluid flowing into the cleaning chamber; and a second control valve capable of adjusting an inflow amount of the cleaning fluid preheated by the preheating tank into the cleaning chamber. While controlling the temperature, the flow rate of the cleaning fluid in the second control valve is controlled, and the preheated cleaning fluid is gradually introduced from the preheating tank into the cleaning chamber via the second control valve, thereby cleaning the cleaning fluid in the cleaning chamber. The cleaning method for gradually lowering the temperature of the cleaning fluid at a substantially constant downward slope gradually reduces the temperature of the cleaning fluid in the cleaning chamber by causing the preheated cleaning fluid to flow gradually from the preheating tank into the cleaning chamber via the second control valve. Since the temperature can be reliably lowered with a certain downward gradient, it is possible to prevent a rapid temperature change of the cleaning fluid caused by irregularly decreasing the temperature of the cleaning fluid in the cleaning chamber. Both can be prevented abrupt density change before and after the critical point of the cleaning fluid that has penetrated into the interior of the filter, the filter after cleaning can be reliably prevented from being damaged.

  A cleaning method that gradually decreases the temperature of the cleaning fluid in the cleaning chamber with a substantially constant downward slope by controlling the temperature of the preheating tank after cleaning the filter accommodated in the cleaning chamber controls the temperature of the preheating tank. As a result, the temperature of the cleaning fluid in the cleaning chamber can be surely lowered with a substantially constant downward gradient, so that a sudden change in the temperature of the cleaning fluid caused by irregularly decreasing the temperature of the cleaning fluid in the cleaning chamber is prevented. In addition, it is possible to prevent an abrupt density change before and after the critical point of the cleaning fluid that has permeated into the filter, and to reliably prevent the filter after cleaning from being damaged.

  A cleaning method including a heater capable of adjusting the temperature of the cleaning container, cleaning the filter, and controlling the temperature of the cleaning container by adjusting the temperature of the heater, thereby maintaining the temperature of the cleaning fluid in the cleaning chamber substantially constant. Since the temperature of the cleaning fluid in the cleaning chamber after cleaning can be maintained at a predetermined temperature by controlling the temperature of the cleaning container by adjusting the temperature of the heater, a rapid temperature change of the cleaning fluid in the cleaning chamber In addition, it is possible to prevent a rapid change in density before and after the critical point of the cleaning fluid that has permeated into the filter, and it is possible to reliably prevent the filter after cleaning from being damaged. In this cleaning method, the temperature of the cleaning fluid in the cleaning chamber is maintained at a predetermined temperature, so that the cleaned filter can be dried in the cleaning chamber.

  A preheating tank for preheating the cleaning fluid flowing into the cleaning chamber; and a second adjustment valve capable of adjusting an inflow amount of the cleaning fluid preheated by the preheating tank into the cleaning chamber; While controlling the flow rate of the cleaning fluid in the valve, the temperature of the cleaning fluid in the cleaning chamber is kept substantially constant by gradually flowing the preheated cleaning fluid from the preheating tank into the cleaning chamber via the second adjustment valve. In the cleaning method, the temperature of the cleaning fluid in the cleaning chamber after cleaning can be maintained at a predetermined temperature by gradually flowing the preheated cleaning fluid from the preheating tank into the cleaning chamber via the second control valve. In addition to preventing sudden changes in temperature of the cleaning fluid in the cleaning chamber, it is also possible to prevent rapid changes in density before and after the critical point of the cleaning fluid that has penetrated into the filter. Filter after cleaning can be reliably prevented from being damaged. In this cleaning method, the temperature of the cleaning fluid in the cleaning chamber is maintained at a predetermined temperature, so that the cleaned filter can be dried in the cleaning chamber.

  After cleaning the filter, the cleaning method for controlling the temperature of the preheating tank to keep the temperature of the cleaning fluid in the cleaning chamber substantially constant is that the cleaning fluid in the cleaning chamber after cleaning is controlled by controlling the temperature of the preheating tank. Since the temperature of the cleaning fluid can be maintained at a predetermined temperature, it is possible to prevent a rapid change in temperature of the cleaning fluid in the cleaning chamber and to prevent a rapid change in density before and after the critical point of the cleaning fluid that has penetrated into the filter. It is possible to reliably prevent the filter after cleaning from being damaged. This cleaning system can dry the filter after cleaning in the cleaning chamber by maintaining the temperature of the cleaning fluid in the cleaning chamber at a predetermined temperature.

  A cleaning method in which a pipe material is formed from a first part located on the outlet side and a second part branched from the first part into a plurality of parts and connected to a plurality of parts of the covering material, The pipe can be collected from a plurality of locations of the covering material, and the cleaning fluid having a substantially uniform flow rate can be passed through the entire region of the filter, and the entire region of the filter can be reliably cleaned.

  A breathable pedestal on which the filter is placed in a state where either one of the first surface and the second surface of the filter is in contact is installed in the cleaning chamber, and the filter is located between the covering material and the pedestal, The cleaning method in which the cleaning fluid flows through substantially the entire area of the filter by the rectifying action of the pedestal allows the cleaning fluid to flow through the filter while the cleaning fluid is evenly distributed throughout the pedestal by the fluid resistance of the pedestal having the rectifying action. Therefore, the cleaning fluid can surely flow from substantially the entire area of the first surface of the filter to the entire area of the second surface, and has a high cleaning function for the filter. In this cleaning method, the entire filter can be reliably cleaned using a cleaning fluid.

  In the cleaning method in which a plurality of inflow ports for allowing the cleaning fluid to flow into the cleaning chamber are formed, the cleaning fluid can be discharged from the plurality of inflow ports and uniformly applied to a plurality of parts of the filter. A flow rate of cleaning fluid can be allowed to flow. In this cleaning method, the entire filter can be reliably cleaned using a cleaning fluid.

The block diagram of the washing | cleaning system shown as an example. The top view of the washing | cleaning container shown as an example which abbreviate | omitted the lid | cover. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2 with the lid attached. Those perspective views which show an example of a base, a coating | covering material, and a pipe material. The figure which shows an example of the time-sequential change of the temperature of the washing | cleaning fluid in a washing chamber after washing | cleaning to-be-washed | cleaned material, a pressure, and a density.

  The details of the cleaning system and the fluid density control method according to the present invention will be described below with reference to the accompanying drawings, taking filter cleaning as an example. FIG. 1 is a configuration diagram of a cleaning system 10 shown as an example. The cleaning system 10 is preferably used for cleaning the used air filter 26 (object to be cleaned) after filtering the gas and cleaning the used liquid filter 26 (object to be cleaned) after filtering the liquid. (See FIGS. 2 and 3). For cleaning the filters 26, either a supercritical fluid or a subcritical fluid is used. The objects to be cleaned by the cleaning system 10 include not only the filter 26 but also all objects to be cleaned that can be cleaned by the supercritical fluid or the subcritical fluid.

  The cleaning system 10 includes a cylinder 11 containing liquefied carbon dioxide, a pump 12 that pressurizes the carbon dioxide gas to a predetermined pressure, a heater 13 that heats the carbon dioxide gas to a predetermined temperature, and the temperature of the cleaning fluid. The preheating tank 14 is kept constant, the cleaning container 15 that houses and cleans the filter 26, the cooling / decompression device 16 that cools and depressurizes the cleaning fluid, and the controller 17. The cylinder 11, the pump 12, the heater 13, the preheating tank 14, the cleaning container 15, and the cooling and decompressing device 16 are connected via a pipe line 18. An adjustment valve 57 and a flow meter 19 are attached to a pipe line 18 extending between the heater 13 and the preheating tank 14. A control valve 20 (second control valve) is attached to the pipe line 18 that extends between the preheating tank 14 and the cleaning container 15, and the pipe line 18 that extends between the cleaning container 15 and the cooling pressure reducing device 16 includes An adjustment valve 21 (first adjustment valve) is attached. A heater 22 is attached to the preheating tank 14, and a thermometer 23, a pressure gauge 24, and a heater 25 are attached to the cleaning container 15.

  Carbon dioxide gas supplied from the cylinder 11 flows into the pump 12 through the pipe 18 and is pressurized to a pressure of 5.0 to 30.0 MPa by the pump 12 and then flows into the heater 13 to be heated. By being heated to a temperature of 30 to 120 ° C. by the vessel 13, the cleaning fluid becomes either a supercritical fluid or a subcritical fluid. The cleaning fluid is forcibly sent from the heater 13 to the preheating tank 14 via the pump 12, supplied from the preheating tank 14 to the cleaning container 15, and flows into an airtight structure cleaning chamber 38 described later. The cleaning fluid that has flowed out of the cleaning container 15 is cooled and depressurized by the cooling and decompression device 16 to return to the non-supercritical or non-subcritical normal fluid, and the normal fluid flows again into the pump 12 through the pipe line 18. The normal fluid becomes cleaning fluid again by the pump 12 and the heater 13. During the cleaning of the filter 26, cleaning fluid and normal fluid circulate through the system 10. During the cleaning of the filter 26, the inflow amount of the cleaning fluid into the cleaning chamber 38 is adjusted by the pump 12 and the adjustment valve 20, and the outflow amount of the cleaning fluid from the cleaning chamber 38 is adjusted by the adjustment valve 21. Although not shown, the cleaning system 10 is provided with a filtration device that filters impurities contained in the circulating cleaning fluid or normal fluid. The filtration device is installed in a pipe line 18 extending between the cooling pressure reducing device 16 and the pump 12.

  The pump 12, the heater 13, the adjustment valve 57, the flow meter 19, the heater 22, the adjustment valve 20, the thermometer 23, the pressure gauge 24, the heater 25, the adjustment valve 21, and the cooling pressure reducing device 16 have interfaces (wired or wireless). Via the controller 17. The pump 12, the heater 13, the flow meter 19, the control valves 20 and 21, the heaters 22 and 25, the thermometer 23, and the pressure gauge 24 together with the controller 17 set the flow rate, temperature, and pressure of the cleaning fluid during cleaning within the target value range. The control element of the feedback control is made to coincide with. The controller 17 is a computer having a central processing unit (CPU or MPU) and a storage device. The controller 17 has a built-in large-capacity hard disk, and although not shown, a keyboard, a display, and a printer are connected via an interface (wired or wireless).

  In the internal address file of the storage device, a cleaning program for executing the cleaning of the filter 26 in this system 10 is stored, and further, a fluid density control program for executing each means after the cleaning of the filter 26 is stored. Yes. The central processing unit of the controller 17 starts each program stored in the internal address file of the storage device based on the control by the operating system, executes the cleaning of the filter 26 according to the cleaning program, and performs the filter according to the fluid density control program. 26 After the cleaning, each means such as fluid pressure decreasing means, first to fourth temperature control means, inflow amount control means, etc. is executed. During operation of the system 10, the flow rate of the cleaning fluid flowing through the pipe line 18 is constantly input to the controller 17 via the flow meter 19, and the temperature of the cleaning fluid in the cleaning chamber 38 is always input via the thermometer 23. In addition, the pressure of the cleaning fluid in the cleaning chamber 38 is always input via the pressure gauge 24. The controller 17 is constantly supplied with a flow rate of the cleaning fluid passing through the valve mechanism of the valve 20 (a flow rate of the cleaning fluid flowing into the cleaning chamber) from a flow meter (not shown) attached to the control valve 20. The flow rate of the cleaning fluid that passes through the valve mechanism of the valve 21 (the flow rate of the cleaning fluid that flows out from the cleaning chamber) is constantly input from a flow meter (not shown) attached to 21.

  2 and 3 are a top view of the cleaning container 15 shown as an example in which the lid 31 is omitted, and a cross-sectional view taken along line 3-3 in FIG. 2 with the lid 31 attached, and FIG. FIG. 4 is a perspective view showing an example of 44, a covering material 45, and a pipe material 46. 2 and 3, the vertical direction is indicated by an arrow A (only in FIG. 3), the radial direction is indicated by an arrow B, and the circumferential direction is indicated by an arrow C (only in FIG. 2). The air filter 26 or the liquid filter 26 is accommodated in the airtight structure cleaning chamber 38 of the cleaning container 15 shown in FIGS.

  These filters 26 have a function of removing impurities present in the gas or liquid, and purify the gas or liquid. The filter 26 is classified according to performance. A pre-filter for removing coarse impurities, a medium-performance filter or a high-performance filter for removing fine impurities, a HEPA filter or a ULPA filter for removing extremely fine impurities, There are chemical filters that remove chemical substances. Examples of the air filter 26 include a separator type air filter and a mini-pleat type air filter. The air filter 26 is mainly used as an air conditioning filter, an air cleaning filter, an exhaust treatment filter, or a vehicle air conditioner filter. The liquid filter 26 is used as a filter for a water purifier or a filter for a membrane device using osmotic pressure.

  The illustrated air filter 26 and liquid filter 26 are used by being housed in a filter housing or a filter cartridge using glass fiber, adsorbent, or synthetic resin fiber as a filter medium. These filters 26 have a three-dimensional structure folded into a bellows, and are hexahedrons having a rectangular upper surface 27 and a lower surface 28 and four rectangular side surfaces 29 (peripheral surfaces) extending between the upper and lower surfaces 27, 28. is there. In addition to the filter having a three-dimensional structure, the filter to be cleaned by the cleaning system 10 includes a substantially flat filter, and further includes a filter whose upper and lower surfaces are circular, elliptical, or polygonal. .

  Examples of the adsorbent include activated carbon and a ceramic porous body. Synthetic resin fibers include polypropylene, polyester, polyether sulfone, polysulfone, nylon 6, polyphenylene sulfide, and the like. Examples of the filter medium include those in which an adsorbent such as granular activated carbon or granular ceramic porous material is supported between fibers, and those in which an adsorbent such as granular activated carbon or porous porous ceramic body is interposed between overlapping fiber aggregates. . The cleaning fluid, either supercritical fluid or subcritical fluid, has the property of gas and liquid, and easily enters the fine gaps of the filter medium forming the filter 26 to remove dirt adhering to the filter medium surface. It dissolves easily, and easily penetrates into the filter medium and easily dissolves dirt that has penetrated into the filter medium. By using the cleaning fluid, not only can the dirt adhered to the surface of the filter medium be removed, but also the dirt that has entered the filter medium can be removed.

  The cleaning container 15 includes a container body 30 and a lid 31, and a clamp 32 that fixes the lid 31 to the body 30. The container body 30 has a substantially cylindrical shape that is long in the vertical direction, and includes a bottom wall 33, a peripheral wall 34 that extends upward from the periphery of the bottom wall 33, and a circular upper opening 35. Concave portions 36 and convex portions 37 that are alternately arranged in the circumferential direction are formed on the upper outer peripheral surface of the peripheral wall 34. An airtight structure cleaning chamber 38 surrounded by a bottom wall 33 and a peripheral wall 34 is formed inside the container body 30. The bottom wall 33 is formed with five inlets 39 through which the cleaning fluid flows into the cleaning chamber 38 and outlets 40 through which the cleaning fluid flows out of the cleaning chamber 38. The inflow port 39 and the outflow port 40 pass through the bottom wall 33 and communicate with the outside of the container body 30 from the cleaning chamber 38. The inflow port 30 is connected to the pipeline 18 extending from the control valve 20, and the outflow port 40 is connected to the pipeline 18 extending from the container body 30. The lid 31 has a circular planar shape, and has an upper and lower surface and a peripheral surface extending between the upper and lower surfaces. On the peripheral surface of the lid 31, similarly to the container body 30, concave portions (not shown) and convex portions 41 that are alternately arranged in the circumferential direction are formed. When the lid 31 is placed on the container main body 30, the peripheral edge of the lid 31 comes into contact with the upper portion of the peripheral wall 34, and the upper opening 35 of the main body 30 is closed by the lid 31. The clamp 32 has a ring shape, and has concave portions 42 and convex portions 43 that are alternately arranged in the circumferential direction on the inner peripheral surface thereof.

  The airtight structure cleaning chamber 38 has a cylindrical shape and a predetermined volume that can accommodate the filter 26. In the cleaning chamber 38, a pedestal 44 on which the filter 26 is placed, a covering material 45 that covers the filter 26, and a hollow tube 46 through which the cleaning fluid flows are installed. The base 44, the covering material 45, and the pipe material 46 are made of a metal such as stainless steel, aluminum, or iron. The pedestal 44 is formed of a square rectifying plate 48 in which a plurality of through holes 47 are formed at equal intervals, and leg portions 49 extending downward from the periphery of the rectifying plate 48. The leg portion 49 is in contact with the bottom wall 33. The lower surface 28 of the filter 26 is in contact with the rectifying plate 48. The current plate 48 is spaced upward from the bottom wall 33, and a space 50 is formed between the bottom wall 33 and the current plate 48. The pedestal 44 may be formed of a rectangular wire mesh through which the cleaning fluid easily passes and leg portions extending downward from the periphery of the wire mesh. The five inflow ports 39 are located below the filter 26 with the pedestal 44 interposed therebetween, and protrude into a space 50 formed between the bottom wall 33 and the pedestal 44. One of the inflow ports 39 is located at the center of the pedestal 44, and the other four are located at locations where the length dimension between the leg portions 49 of the pedestal 44 is divided into two.

  The covering material 45 includes a peripheral edge portion 51 located on the outer side in the circumferential direction of the four side surfaces 29 (peripheral surfaces) of the filter 26 and a central portion 52 spaced upward from the upper surface 27 of the filter 26. The central portion 52 has a quadrangular planar shape, and its area is substantially the same as that of the upper surface 27 of the filter 26 or slightly larger than that of the upper surface 27 of the filter 26 and covers the entire upper surface 27 of the filter 26. The peripheral edge portion 51 extends downward from the peripheral edge of the central portion 52, has a vertical dimension larger than that of the side surface 29 of the filter 26, and covers the entire side surface 29 of the filter 26. Although it is preferable that there is no gap between the peripheral edge portion 51 of the covering material 45 and the side surface 29 of the filter 26, a slight gap may be formed depending on the size of the filter 26. A space 53 is formed between the upper surface 27 of the filter 26 and the central portion 52 of the covering material 45 to collect the cleaning fluid flowing through the filter 26 and guide the cleaning fluid to the tube material 46. A space 54 excluding 53 is formed.

  The tube material 46 is formed of a first portion 55 located on the outlet 40 side and a second portion 56 branched from the first portion 55 into five. The first portion 55 is connected to the outlet 40, extends upward from the outlet 40, extends horizontally in the radial direction toward the central portion 52 of the central portion 52 of the covering material 45, and further, the central portion of the central portion 52. It extends slightly downward. The second portion 56 is connected to the central portion of the central portion 52 of the covering material 45 and is connected to four corner portions (a plurality of locations) of the central portion 52. The second portion 56 extends horizontally in the radial direction from the first portion 55 toward the corner portion of the central portion 52, and then extends downward at the corner portion of the central portion 52.

  An example of the procedure for cleaning the used air filter 26 and liquid filter 26 using the cleaning container 15 is as follows. The filter 26 is placed in the airtight structure cleaning chamber 38, and the filter 26 is placed on the pedestal 44 with the lower surface 28 of the filter 26 in contact with the rectifying plate 48, and then the covering material 45 is placed on the filter 26. The upper surface 27 and the side surface 29 of the filter 26 are covered. The entire upper surface 27 and the entire side surface 29 of the filter 26 are covered with the covering material 45, and are located between the pedestal 44 and the covering material 45. After the filter 26 is installed in the cleaning chamber 38, the lid 31 is placed on the upper part of the peripheral wall 34 of the main body 30 with the convex portion 37 of the container main body 30 and the convex portion 41 of the lid 31 being aligned with each other. The upper opening 35 of the main body 30 is closed. Next, the convex portion 43 of the clamp 32 is inserted between the concave portion 36 of the container body 30 and the concave portion of the lid 31, and the clamp 32 is fitted into the peripheral wall 34 of the main body 30 and the peripheral surface of the lid 31, and then the clamp 32. Is rotated in the circumferential direction so that the convex portions 37 and 40 of the main body 30 and the lid 31 and the convex portion 43 of the clamp 32 are arranged in the vertical direction. When the convex portions 37 and 40 of the container body 30 and the lid 31 and the convex portion 43 of the clamp 32 are arranged in the vertical direction, the lower surface of the lid 31 is pressed against the upper portion of the peripheral wall 34 of the main body 30, and the lid 31 is brought into close contact with the main body 30. The cleaning chamber 38 can be sealed. After closing the upper opening 35 of the container body 30 with the lid 31, the cleaning system 10 is started.

  When the cleaning system 10 is activated, the controller 17, the pump 12, the heater 13, the preheating tank 14, the heaters 22 and 25, the valve mechanisms of the valves 20 and 21, the cooling pressure reducing device 16 are operated, and the flow meter 19 and thermometer 23, the pressure gauge 24, and the flow meters of the adjustment valves 20 and 21 start measurement, and carbon dioxide gas is supplied from the cylinder 11 to the pipe 18. The carbon dioxide gas becomes a cleaning fluid of either a supercritical fluid or a subcritical fluid by the pump 12 and the heater 13, and the cleaning fluid enters the cleaning chamber 38 from the inlet 39 as indicated by an arrow L1 in FIG. In addition to flowing in, it flows out of the cleaning container 15 from the outlet 40 through the pipe 46. During the cleaning of the filter 26, the controller 17 keeps the valve mechanism of the adjustment valve 57 fully open. During the cleaning of the filter 26, the controller 17 controls the pump 12 and the regulating valves 20 and 21 to maintain the flow rate of the cleaning fluid flowing through the pipe line 18 at a target value, and the amount of cleaning fluid flowing into the cleaning chamber 38 and the cleaning flow. The outflow amount of the cleaning fluid from the chamber 38 is maintained at the target value, and the pressure of the cleaning fluid in the cleaning chamber 38 is maintained at the target value. Further, the controller 17 controls the amount of heat of the heater 13, the amount of heat of the heater 22 of the preheating tank 14, and the amount of heat of the heater 25 attached to the container 15 to keep the temperature of the cleaning fluid in the cleaning chamber 38 at the target value. . In addition, each target value stored in the storage device of the controller 17 can be changed at any time by inputting the target value from the keyboard.

  The central processing unit of the controller 17 causes the flow rate of the cleaning fluid circulating through the system 10 during the cleaning of the filter 26 to be out of the target value range, and the amount of the cleaning fluid flowing into the cleaning chamber 38 or the cleaning fluid from the cleaning chamber 38 is reduced. When the outflow amount deviates from the target value, the output of the pump 12 and the valve mechanisms of the valves 20 and 21 are adjusted to return the flow rate, inflow amount, and outflow amount of the cleaning fluid within the target value range. When the pressure of the cleaning fluid circulating through the system 10 is out of the target value range during cleaning of the filter 26, the central processing unit adjusts the output of the pump 12 and the valve mechanism of the valves 20 and 21 to adjust the pressure of the cleaning fluid. Return to within the target value range. When the temperature of the cleaning fluid in the cleaning chamber 38 deviates from the target value range during cleaning of the filter 26, the central processing unit is attached to the container 15 and the amount of heat of the heater 13, the amount of heat of the heater 22 of the preheating tank 14, and the container 15. The amount of heat of the heater 25 is adjusted to return the temperature of the cleaning fluid in the cleaning chamber 38 to the target value range.

  The cleaning fluid that has flowed into the cleaning chamber 38 from the inlet 39 hits the rectifying plate 48 of the pedestal 44, and is evenly distributed over the entire rectifying plate 48 due to the fluid resistance of the rectifying plate 48, then passes through the through holes 47, and the lower surface of the filter 26. 28 enters the inside of the filter 26 (filter medium gap) from substantially the entire area 28 and flows from the lower surface 28 toward the upper surface 27. The cleaning fluid cleans the filter 26 by removing dirt adhered to the filter medium through the gaps of the filter medium forming the filter 26, and further penetrating the inside of the filter medium to remove dirt contaminated into the filter medium. The cleaning fluid that has flowed out of the upper surface 27 of the filter 26 is collected in a space 53 that serves as a flow path for the cleaning fluid, flows through the space 53 toward the tube 46 as indicated by an arrow L2 in FIG. Sucked. The cleaning fluid reaches the outlet 40 through the pipe 46, flows out of the cleaning container 15 from the outlet 40, then flows into the cooling decompression device 16 through the valve 21, and is cooled and decompressed by the cooling decompression device 16. And return to normal fluid.

  After the impurities contained in the normal fluid are filtered by the filtering device, the normal fluid becomes the cleaning fluid again by the pump 12 and the heater 13 and flows into the cleaning chamber 38 of the cleaning container 15. During the cleaning of the filter 26, the cycle of returning the cleaning fluid to the normal fluid by the cooling pressure reducing device 16 and returning the normal fluid to the cleaning fluid by the pump 12 and the heater 13 is repeated, and the normal fluid and the cleaning fluid are forced by the pump 12. The cleaning fluid is constantly circulated through the cleaning chamber 38 while being circulated. Here, the cleaning time of the filter 26 differs depending on the filter to be cleaned, and is about 5 to 120 minutes. Although the cleaning time is stored in advance in the storage device of the controller 17, the cleaning time stored in the storage device can be changed at any time by inputting the cleaning time from the keyboard.

FIG. 5 is a diagram illustrating an example of time-series changes in the temperature, pressure, and density of the cleaning fluid in the cleaning chamber 38 after the filter 26 is cleaned. In FIG. 5, the density ρ (kg / m ³ ) of the cleaning fluid is displayed on the left vertical axis, and the temperature T (° C.) and the pressure P (MPa) of the cleaning fluid are displayed on the right vertical axis. The time t (min) is displayed on the horizontal axis of FIG. As shown in FIG. 5, the cleaning fluid immediately after cleaning the filter 26 has a density ρ of about 840 kg / m ³ , a temperature T of about 40 ° C., and a pressure P of about 20 MPa. The normal fluid for removing the filter 26 from the cleaning chamber 38 has a density ρ of 1.82 kg / m ³ , a temperature T when the temperature of the cleaning fluid is gradually decreased, about 20 ° C., and a constant temperature of the cleaning fluid. When held, the temperature T is about 40 ° C. and the pressure P is 0.1 MPa. After cleaning the filter 26, the controller 17 activates the fluid density control program stored in the storage device to automatically execute the fluid density control, and reduces the density of the cleaning fluid in the cleaning chamber 38 to a substantially constant value. The cleaning fluid in the cleaning chamber 38 is returned to the normal fluid by lowering with a gradient and setting the density of the cleaning fluid below the critical point. In the system 10, after the controller 17 returns the cleaning fluid in the cleaning chamber 38 to the normal fluid, the clamp 32 is removed, the lid 31 is opened, and the cleaned filter 26 is removed from the cleaning chamber 38.

  The fluid density control for reducing the density of the cleaning fluid in the cleaning chamber 38 with a substantially constant downward gradient is performed by controlling the pump 12, the preheating tank 14, the adjusting valves 20, 21, 57, and the heaters 22, 25 based on the control of the controller 17. Use to do. An example of fluid density control performed by the cleaning system 10 is as follows. When the cleaning fluid is circulated in the system 10 for a predetermined time, the central processing unit of the controller 17 determines that the cleaning of the filter 26 is completed, and automatically executes fluid density control. Specifically, the central processing unit simultaneously executes the fluid pressure decreasing means, the first temperature control means, the inflow amount control means, and the second temperature control means, and the temperature of the cleaning fluid in the cleaning chamber 38 is reduced to a substantially constant downward gradient. And the density of the cleaning fluid in the cleaning chamber 38 is gradually decreased with a substantially constant downward gradient. The execution time of the fluid pressure decreasing means, the first temperature control means, the inflow amount control means, and the second temperature control means is in the range of 10 minutes to 6 hours.

  When the cleaning time of the filter 26 elapses, the central processing unit of the controller 17 determines that the cleaning of the filter 26 is completed, stops the operation of the pump 12 and the operation of the heater 13, and the valve mechanism of the adjustment valve 57. Is closed, and the flow path 18 extending between the heater 13 and the preheating tank 14 is blocked to prevent the cleaning fluid from flowing from the heater 13 to the front. The central processing unit controls the valve mechanism (flow rate) of the valve 21 to adjust the outflow amount of the cleaning fluid flowing out from the cleaning chamber 38, and gradually discharges the cleaning fluid from the cleaning chamber 38 to clean the cleaning chamber 38. The pressure of the fluid is gradually reduced (fluid pressure decreasing means). The central processing unit controls the temperature of the tank 14 by adjusting the heater 22 (heat amount) of the preheating tank 14 in parallel with the fluid pressure decreasing means (tank temperature increase / decrease control: second temperature control means), thereby The temperature of the cleaning fluid in the cleaning chamber 38 is gradually lowered with a substantially constant downward gradient. The central processing unit is parallel to the fluid pressure decreasing means and controls the valve mechanism (flow rate) of the valve 20 to adjust the amount of the cleaning fluid flowing into the cleaning chamber 38 from the tank 14. The preheated cleaning fluid is gradually introduced (inflow control means). Further, the central processing unit controls the temperature of the container 15 by adjusting a heater 25 (heat amount) attached to the cleaning container 15 in parallel with the fluid pressure decreasing means (container temperature increase / decrease control: first temperature control). Means), whereby the temperature of the cleaning fluid in the cleaning chamber 38 is gradually lowered with a substantially constant downward gradient. The central processing unit gradually decreases the temperature of the cleaning fluid in the cleaning chamber 38 with a substantially constant downward gradient by simultaneously executing the first temperature control means, the inflow amount control means, and the second temperature control means. In the first temperature control means, the inflow amount control means, and the second temperature control means, the central processing unit performs feedback control in which each element of setting, adjustment, operation, and detection forms a closed loop. Note that the control operation of the feedback control is PID control.

  In the fluid pressure decreasing means, the central processing unit of the controller 17 sets the pressure of the cleaning fluid to 0.5 MPa / h to 10.0 MPa / h in a range of ± 5.0 MPa across the critical pressure (about 7.3 MPa) of the cleaning fluid. The pressure is reduced at a reduced pressure rate. Preferably, the pressure of the cleaning fluid is decreased at a pressure reduction rate of 1.0 MPa / h to 5.0 MPa / h in a range of ± 5.0 MPa across the critical pressure of the cleaning fluid. More preferably, the pressure of the cleaning fluid is decreased at a pressure reduction rate of 1.0 MPa / h to 5.0 MPa / h within a range of ± 7.5 MPa across the critical point of the cleaning fluid. In FIG. 5, the pressure of the cleaning fluid is decreased at a pressure reduction rate of 1.0 MPa / h to 5.0 MPa / h while the pressure of the cleaning fluid is decreased from 10 MPa to 5 MPa. When the depressurization rate of the cleaning fluid pressure is less than 0.5 MPa / h, the gradient of the descending gradient of the fluid density becomes small, and the density of the cleaning fluid in the cleaning chamber 38 cannot be reduced within a predetermined time. Cleaning efficiency decreases. When the depressurization rate of the cleaning fluid pressure exceeds 10.0 MPa / h, the cleaning fluid in the cleaning chamber 38 undergoes a rapid density change before and after the critical point, whereby the filter 26 and the filter components are deformed, expanded, It may receive damage such as foaming.

  An example of the second temperature control means is as follows. In the second temperature control means, the central processing unit of the controller 17 measures the temperature of the cleaning fluid in the cleaning chamber 38 so that the temperature of the cleaning fluid in the cleaning chamber 38 gradually decreases with a substantially constant downward gradient. Feedback control is performed to increase or decrease the temperature of the tank 14 by adjusting the heater 22 of the preheating tank 14 in the range of 0 to 100 ° C. An example of the inflow amount control means is as follows. In the inflow control means, the central processing unit of the controller 17 adjusts the valve mechanism of the control valve 20 to control the flow rate of the cleaning fluid in the valve 20, and a predetermined ratio of the cleaning fluid with respect to the volume of the cleaning chamber 38 from the preheating tank 14. It flows into the cleaning chamber 38. The ratio of the cleaning fluid to the volume of the cleaning chamber 38 is in the range of 10% / h to 200% / h. The central processing unit measures the opening degree of the valve mechanism of the adjustment valve 20, and performs feedback control to increase or decrease the opening degree of the valve mechanism so that the ratio of the cleaning fluid falls within the above range. An example of the first temperature control means is as follows. In the first temperature control means, the central processing unit of the controller 17 measures the temperature of the cleaning fluid in the cleaning chamber 38 so that the temperature of the cleaning fluid in the cleaning chamber 38 gradually decreases with a substantially constant downward gradient. Feedback control for adjusting the heater 25 in the range of 0 to 100 ° C. to increase or decrease the temperature of the cleaning container 15 is performed.

During execution of the fluid density control, the cleaning fluid gradually flows from the preheating tank 14 into the cleaning chamber 38 while the temperature of the tank 14 and the temperature of the cleaning container 15 rise or fall, and the cleaning fluid in the cleaning chamber 38 Gradually flows out of the cleaning chamber 38 and flows into the cooling pressure reducing device 16. In this cleaning system 10, the central processing unit of the controller 17 executes the fluid pressure decreasing means, the first temperature control means, the inflow amount control means, and the second temperature control means, as shown in FIG. The temperature of the cleaning fluid gradually decreases at a substantially constant downward gradient, and the density of the cleaning fluid existing in the cleaning chamber 38 gradually decreases at an approximately constant downward gradient. When the execution time of these means elapses, the pressure of the cleaning fluid returns to the atmospheric pressure, the density of the cleaning fluid decreases below the critical point, and the cleaning fluid returns to the normal fluid. The normal fluid in the cleaning chamber 38 after performing the fluid density control has a density ρ of 1.82 kg / m ³ , a temperature T of about 20 ° C., and a pressure P of 0.1 MPa.

  In the cleaning system 10, in the fluid density control, the controller 17 executes the fluid pressure decreasing means, the first temperature control means, the inflow control means, and the second temperature control means at the same time. The one temperature control means may be executed simultaneously, and the controller 17 may execute the fluid pressure decreasing means, the first temperature control means, and the inflow amount control means simultaneously. The controller 17 may simultaneously execute the fluid pressure decreasing means, the first temperature control means, and the second temperature control means.

  In the cleaning system 10, the pressure reduction rate in the fluid pressure decreasing means is in the above range, and the pressure of the cleaning fluid is slowly decreased before and after the critical pressure of the cleaning fluid, so that the pressure of the cleaning fluid is irregular in the cleaning chamber 38. The density of the cleaning fluid in the cleaning chamber 38 can be decreased with a substantially constant downward gradient, and the cleaning fluid that has penetrated into the filter 26 or the filter component member has an abrupt before and after the critical point. Density change can be prevented. In addition, since the cleaning system 10 executes the first temperature control unit, the inflow amount control unit, and the second temperature control unit, the temperature of the cleaning fluid in the cleaning chamber 38 is decreased with a substantially constant downward gradient. The temperature of the cleaning fluid in the cleaning chamber 38 does not rapidly decrease, and a rapid temperature change of the cleaning fluid in the cleaning chamber 38 can be prevented, and a rapid density change before and after the critical point of the cleaning fluid is ensured. Can be prevented. Since the cleaning system 10 can prevent deformation, expansion, foaming, and the like of the filter 26 and the filter constituent members due to a rapid density change of the cleaning fluid, the filter 26 and the filter constituent members after cleaning are surely damaged. Can be prevented.

  Another example of fluid density control executed by the cleaning system 10 is as follows. When the cleaning fluid is circulated in the system 10 for a predetermined time, the central processing unit of the controller 17 determines that the cleaning of the filter 26 is completed, and automatically executes fluid density control. Specifically, the central processing unit simultaneously executes the fluid pressure decreasing means, the third temperature control means, the inflow amount control means, and the fourth temperature control means to keep the temperature of the cleaning fluid in the cleaning chamber 38 substantially constant. Meanwhile, the density of the cleaning fluid in the cleaning chamber 38 is gradually decreased with a substantially constant downward gradient. The execution time of the fluid pressure decreasing means, the third temperature control means, the inflow amount control means, and the fourth temperature control means is in the range of 10 minutes to 6 hours.

  When the cleaning time of the filter 26 elapses, the central processing unit of the controller 17 determines that the cleaning of the filter 26 is completed, stops the operation of the pump 12 and the operation of the heater 13, and the valve mechanism of the adjustment valve 57. Is fully closed. The central processing unit controls the valve mechanism (flow rate) of the valve 21 to adjust the outflow amount of the cleaning fluid flowing out from the cleaning chamber 38, and gradually discharges the cleaning fluid from the cleaning chamber 38 to clean the cleaning chamber 38. The pressure of the fluid is gradually reduced (fluid pressure decreasing means). The central processing unit controls the temperature of the tank 14 by adjusting the heater 22 (amount of heat) of the preheating tank 14 in parallel with the fluid pressure decreasing means (tank temperature increase / decrease control: fourth temperature control means), thereby The temperature of the cleaning fluid in the cleaning chamber 38 is kept substantially constant. The central processing unit is parallel to the fluid pressure decreasing means and controls the valve mechanism (flow rate) of the valve 20 to adjust the amount of the cleaning fluid flowing into the cleaning chamber 38 from the tank 14. The preheated cleaning fluid is gradually introduced (inflow control means). Further, the central processing unit controls the temperature of the container 15 by adjusting a heater 25 (heat quantity) attached to the cleaning container 15 in parallel with the fluid pressure decreasing means (container temperature increase / decrease control: third temperature control). Means), thereby keeping the temperature of the cleaning fluid in the cleaning chamber 38 substantially constant. The central processing unit keeps the temperature of the cleaning fluid in the cleaning chamber 38 substantially constant by simultaneously executing the third temperature control unit, the inflow amount control unit, and the fourth temperature control unit. In the third temperature control means, the inflow amount control means, and the fourth temperature control means, the central processing unit performs feedback control in which each element of setting, adjustment, operation, and detection forms a closed loop. Note that the control operation of the feedback control is PID control.

  In the fluid pressure decreasing means, the central processing unit of the controller 17 sets the pressure of the cleaning fluid to 0.5 MPa / h to 10.0 MPa / h in a range of ± 5.0 MPa across the critical pressure (about 7.3 MPa) of the cleaning fluid. The pressure is reduced at a reduced pressure rate. Preferably, the pressure of the cleaning fluid is decreased at a pressure reduction rate of 1.0 MPa / h to 5.0 MPa / h in a range of ± 5.0 MPa across the critical pressure of the cleaning fluid. More preferably, the pressure of the cleaning fluid is decreased at a pressure reduction rate of 1.0 MPa / h to 5.0 MPa / h within a range of ± 7.5 MPa across the critical point of the cleaning fluid.

  An example of the fourth temperature control means in the fluid density control is as follows. In the fourth temperature control means, the central processing unit of the controller 17 measures the temperature of the cleaning fluid in the cleaning chamber 38, and the heater of the preheating tank 14 so that the temperature of the cleaning fluid in the cleaning chamber 38 becomes substantially constant. Feedback control is performed to increase or decrease the temperature of the tank 14 by adjusting 22 within a range of 0 to 100 ° C. An example of the inflow control means in this fluid density control is as follows. In the inflow control means, the central processing unit of the controller 17 adjusts the valve mechanism of the control valve 20 to control the flow rate of the cleaning fluid in the valve 20, and a predetermined ratio of the cleaning fluid with respect to the volume of the cleaning chamber 38 from the preheating tank 14. It flows into the cleaning chamber 38. The ratio of the cleaning fluid to the volume of the cleaning chamber 38 is in the range of 10% / h to 200% / h. The central processing unit measures the opening degree of the valve mechanism of the adjustment valve 20, and performs feedback control to increase or decrease the opening degree of the valve mechanism so that the ratio of the cleaning fluid falls within the above range. An example of the third temperature control means in the fluid density control is as follows. In the third temperature control means, the central processing unit of the controller 17 measures the temperature of the cleaning fluid in the cleaning chamber 38 and sets the heater 25 to 0 so that the temperature of the cleaning fluid in the cleaning chamber 38 becomes substantially constant. Feedback control is performed to increase or decrease the temperature of the cleaning container 15 by adjusting the temperature within the range of 100 ° C.

During execution of the fluid density control, the cleaning fluid gradually flows from the preheating tank 14 into the cleaning chamber 38 while the temperature of the tank 14 and the temperature of the cleaning container 15 rise or fall, and the cleaning fluid in the cleaning chamber 38 Gradually flows out of the cleaning chamber 38 and flows into the cooling pressure reducing device 16. In the cleaning system 10, the central processing unit of the controller 17 executes the fluid pressure decreasing means, the third temperature control decreasing means, the inflow amount controlling means, and the fourth temperature control means, as shown in FIG. The density of the cleaning fluid existing in the cleaning chamber 38 gradually decreases with a substantially constant downward gradient while the temperature of the cleaning fluid in the cleaning chamber 38 is kept substantially constant. When the execution time of these means elapses, the pressure of the cleaning fluid returns to the atmospheric pressure, the density of the cleaning fluid decreases below the critical point, and the cleaning fluid returns to the normal fluid. The normal fluid in the cleaning chamber 38 after performing the fluid density control has a density ρ of 1.82 kg / m ³ , a temperature T of about 40 ° C., and a pressure P of 0.1 MPa.

  In the cleaning system 10, in the fluid density control, the controller 17 simultaneously executes the fluid pressure decreasing means, the third temperature control means, the inflow amount controlling means, and the fourth temperature control means. The three temperature holding means may be executed simultaneously, and the controller 17 may simultaneously execute the fluid pressure decreasing means, the third temperature holding means, and the inflow amount control means. Further, the controller 17 may simultaneously execute the fluid pressure decreasing means, the third temperature holding means, and the fourth temperature holding means.

  The cleaning system 10 executes the third temperature holding unit, the inflow amount control unit, and the fourth temperature holding unit, thereby holding the temperature of the tank 14 and the temperature of the container 15 at a predetermined temperature, Since the temperature of the cleaning fluid is kept substantially constant, a change in the temperature of the cleaning fluid in the cleaning chamber 38 can be prevented, and the cleaning fluid that has penetrated into the filter 26 and the filter constituent member has a sudden change before and after the critical point. A change in density can be reliably prevented. Since the cleaning system 10 can prevent deformation, expansion, foaming, and the like of the filter 26 and the filter component due to a rapid density change of the cleaning fluid, it is ensured that the filter 26 and the filter component after cleaning are damaged. Can be prevented. The cleaning system 10 can dry the object to be cleaned in the cleaning chamber 38 by maintaining the temperature of the cleaning fluid in the cleaning chamber 38 at a predetermined temperature.

  In the cleaning container 15 used in the cleaning system 10, the covering material 45 covers the entire area of the upper surface 27 and the entire side surface 29 of the filter 26, and a space 53 serving as a flow path for the cleaning fluid flowing through the filter 26 is formed in the filter 26. Since it is formed between the upper surface 27 and the central portion 52 of the covering material 45, the cleaning fluid can surely flow from the lower surface 28 of the filter 26 toward the upper surface 27. The cleaning container 15 can prevent generation of the cleaning fluid that does not flow through the filter 26, and can prevent wasteful consumption of the cleaning fluid. The cleaning container 15 allows the cleaning fluid to flow through the filter 26 while evenly distributing the cleaning fluid over the entire rectifying plate 48 due to the fluid resistance of the rectifying plate 48 having a rectifying action. It is possible to reliably flow from substantially the entire lower surface 28 toward almost the entire upper surface 27, and has a high cleaning function for the filter 26.

  In the cleaning container 15 used in the system 10, the peripheral edge portion 51 of the covering material 45 is positioned outward in the circumferential direction of the side surface 29 (circumferential surface) of the filter 26 having a three-dimensional structure and covers the entire side surface 29. Even in the filter 26 having a three-dimensional structure, the cleaning fluid can be surely passed through substantially the entire region. The cleaning container 15 has a second portion 56 in which the pipe material 46 branches from the first portion 55 into five branches and is connected to a plurality of locations in the central portion 52 of the covering material 45, so that the cleaning fluid flowing through the filter 26 is covered. The pipes 46 can be collected from a plurality of locations of the material 45, and a substantially uniform flow rate of the cleaning fluid can be passed through the entire area of the filter 26. In the cleaning container 15, the cleaning fluid inlet 39 is formed below the center portion of the central portion 52 of the covering material 45, and further below the position where the length of one side of the peripheral portion 51 of the covering material 45 is divided into two. Thus, the cleaning fluid can be discharged from the five inlets 39 and uniformly applied to a plurality of portions of the filter 26, so that a substantially uniform flow rate of the cleaning fluid can be passed over substantially the entire area of the filter 26.

  In this cleaning system 10, carbon dioxide gas is used as a raw material for the cleaning fluid, but water or methanol can be used in addition to the carbon dioxide gas as a raw material for the cleaning fluid. When water is used as a raw material for the cleaning fluid, the pressure is increased to 22.1 MPa or more by the pump 12 and the temperature is heated to 374 ° C. or more by the heater 13. When methanol is used as a raw material for the cleaning fluid, the pressure is increased to 7.9 MPa or more by the pump 12 and the temperature is heated to 239 ° C. or more by the heater 13.

DESCRIPTION OF SYMBOLS 10 Cleaning system 11 Cylinder 12 Pump 13 Heater 14 Preheating tank 15 Cleaning container 16 Cooling decompression device 17 Controller 20 Control valve (2nd control valve)
21 Control valve (first control valve)
26 Filter (object to be cleaned)
38 Airtight structure cleaning room book

Claims (22)

An airtight structure cleaning chamber for cleaning a three-dimensional filter having a first surface and a second surface and a side surface extending between the surfaces by flowing a cleaning fluid of either a supercritical fluid or a subcritical fluid; A cleaning container having an inlet for allowing the cleaning fluid to flow into the chamber and an outlet for allowing the cleaning fluid to flow out of the cleaning chamber, and a first control valve capable of adjusting the amount of the cleaning fluid flowing out of the cleaning chamber In the cleaning system for cleaning the filter by flowing the cleaning fluid from the first surface to the second surface of the filter accommodated in the cleaning chamber,
The cleaning container includes a covering material that is installed in the cleaning chamber and covers the filter, and a pipe material that is installed in the cleaning chamber and extends from the coating material and is connected to the outflow port. A central portion that covers the entire area of the filter and is spaced from either one of the first surface and the second surface of the filter, and a peripheral portion that is located on the outer side in the circumferential direction of the side surface of the filter and covers the entire side surface of the filter. A space for collecting the cleaning fluid flowing from the first surface to the second surface of the filter and guiding the cleaning fluid to the pipe member, and a surface of the filter and a central portion of the covering material. Formed between
In the cleaning system, after cleaning the filter accommodated in the cleaning chamber, the cleaning fluid is gradually discharged from the cleaning chamber through the first control valve while controlling the flow rate of the cleaning fluid in the first control valve. And a fluid pressure decreasing means for gradually decreasing the pressure of the cleaning fluid in the cleaning chamber is executed, and the density of the cleaning fluid in the cleaning chamber is decreased at a substantially constant downward gradient by the fluid pressure decreasing means. Cleaning system.   In the cleaning system, the supercritical fluid or the subcritical fluid is formed by heating carbon dioxide gas to a temperature of 30 to 120 ° C. while pressurizing carbon dioxide gas to a pressure of 5.0 to 30.0 MPa, The cleaning system according to claim 1, wherein the means reduces the pressure of the cleaning fluid at a pressure reduction rate of 0.5 MPa / h to 10.0 MPa / h in a range of ± 5.0 MPa across the critical pressure of the cleaning fluid.   The cleaning system includes a heater capable of adjusting the temperature of the cleaning container. In the cleaning system, after cleaning the filter accommodated in the cleaning chamber, the temperature of the cleaning container is adjusted by adjusting the temperature of the heater. 3. The cleaning system according to claim 1, wherein a first temperature control unit that controls the cleaning fluid is executed, and the temperature of the cleaning fluid in the cleaning chamber is gradually decreased with a substantially constant downward gradient by the first temperature control unit.   The cleaning system includes a preheating tank for preheating cleaning fluid flowing into the cleaning chamber, and a second adjustment valve capable of adjusting an inflow amount of the cleaning fluid preheated by the preheating tank into the cleaning chamber, In the cleaning system, after cleaning the filter housed in the cleaning chamber, the preheated cleaning fluid is supplied to the preheating tank via the second control valve while controlling the flow rate of the cleaning fluid in the second control valve. The cleaning system according to claim 3, wherein an inflow amount control unit that gradually flows into the cleaning chamber from the cleaning chamber is executed, and the temperature of the cleaning fluid in the cleaning chamber is gradually decreased with a substantially constant downward gradient by the inflow amount control unit.   In the cleaning system, after the filter housed in the cleaning chamber is cleaned, second temperature control means for controlling the temperature of the preheating tank is executed, and the cleaning fluid in the cleaning chamber is controlled by the second temperature control means. The cleaning system according to claim 4, wherein the temperature is gradually lowered with a substantially constant downward gradient.   The cleaning system includes a heater capable of adjusting the temperature of the cleaning container. In the cleaning system, after cleaning the filter accommodated in the cleaning chamber, the temperature of the cleaning container is adjusted by adjusting the temperature of the heater. The cleaning system according to claim 1 or 2, wherein third temperature control means for controlling the temperature is executed, and the temperature of the cleaning fluid in the cleaning chamber is maintained substantially constant by the third temperature control means.   The cleaning system includes a preheating tank that preheats the cleaning fluid flowing into the cleaning chamber, and a second adjustment valve that adjusts an inflow amount of the cleaning fluid preheated by the preheating tank into the cleaning chamber, In the system, after the filter housed in the cleaning chamber is cleaned, the preheated cleaning fluid is removed from the preheating tank via the second control valve while controlling the flow rate of the cleaning fluid in the second control valve. The cleaning system according to claim 6, wherein an inflow amount control unit that gradually flows into the cleaning chamber is executed, and the temperature of the cleaning fluid in the cleaning chamber is maintained substantially constant by the inflow amount control unit.   In the cleaning system, after the filter housed in the cleaning chamber is cleaned, fourth temperature control means for controlling the temperature of the preheating tank is executed, and the cleaning fluid in the cleaning chamber is controlled by the fourth temperature control means. The cleaning system according to claim 7, wherein the temperature is maintained substantially constant.   The said pipe material is formed from the 1st part located in the said outflow port side, and the 2nd part branched from the said 1st part into two or more and connected to several places of the said coating | covering material. 8. The cleaning system according to any one of 8.   The cleaning chamber is provided with a breathable pedestal on which the filter is placed in a state in which one of the first surface and the second surface of the filter is in contact with the filter. The cleaning system according to any one of claims 1 to 9, wherein the cleaning system is located between the covering material and the pedestal, and the cleaning fluid flows through substantially the entire area of the filter by a rectifying action of the pedestal.   11. The cleaning system according to claim 1, wherein a plurality of inflow ports through which the cleaning fluid flows into the cleaning chamber are formed in the cleaning system. An airtight structure cleaning chamber for cleaning a three-dimensional filter having a first surface and a second surface and a side surface extending between the surfaces by flowing a cleaning fluid of either a supercritical fluid or a subcritical fluid; A cleaning container having an inlet for allowing the cleaning fluid to flow into the chamber and an outlet for allowing the cleaning fluid to flow out of the cleaning chamber, and a first control valve capable of adjusting the amount of the cleaning fluid flowing out of the cleaning chamber A cleaning method for cleaning the filter by allowing the cleaning fluid to flow from the first surface to the second surface of the filter housed in the cleaning chamber,
The cleaning container includes a covering material that is installed in the cleaning chamber and covers the filter, and a pipe material that is installed in the cleaning chamber and extends from the coating material and is connected to the outflow port. A central portion that covers the entire area of the filter and is spaced from either one of the first surface and the second surface of the filter, and a peripheral portion that is located on the outer side in the circumferential direction of the side surface of the filter and covers the entire side surface of the filter. A space for collecting the cleaning fluid flowing from the first surface to the second surface of the filter and guiding the cleaning fluid to the pipe member, and a surface of the filter and a central portion of the covering material. Formed between
In the cleaning method, after cleaning the filter accommodated in the cleaning chamber, the cleaning fluid is gradually discharged from the cleaning chamber through the first control valve while controlling the flow rate of the cleaning fluid in the first control valve. A cleaning method characterized by gradually reducing the pressure of the cleaning fluid in the cleaning chamber, thereby decreasing the density of the cleaning fluid in the cleaning chamber with a substantially constant downward gradient.   The supercritical fluid or the subcritical fluid is produced by heating carbon dioxide gas to 30 to 120 ° C. while pressurizing the carbon dioxide gas to 5.0 to 30.0 MPa, and the cleaning method sandwiches the critical pressure of the cleaning fluid. The cleaning method according to claim 12, wherein the pressure of the cleaning fluid is reduced at a pressure reduction rate of 0.5 MPa / h to 10.0 MPa / h in a range of ± 5.0 MPa.   The cleaning method includes a heater capable of adjusting the temperature of the cleaning container. In the cleaning method, after cleaning the filter accommodated in the cleaning chamber, the temperature of the cleaning container is adjusted by adjusting the temperature of the heater. 14. The cleaning method according to claim 12, wherein the temperature of the cleaning fluid in the cleaning chamber is controlled to gradually decrease at a substantially constant downward gradient.   The cleaning method includes a preheating tank for preheating the cleaning fluid flowing into the cleaning chamber, and a second adjustment valve capable of adjusting an inflow amount of the cleaning fluid preheated by the preheating tank into the cleaning chamber, In the cleaning method, after the filter housed in the cleaning chamber is cleaned, the preheated cleaning fluid is removed from the preheating tank via the second control valve while controlling the flow rate of the cleaning fluid in the second control valve. The cleaning method according to claim 14, wherein the cleaning fluid is gradually introduced into the cleaning chamber, thereby gradually decreasing the temperature of the cleaning fluid in the cleaning chamber with a substantially constant downward gradient.   16. The cleaning method according to claim 15, wherein after the filter housed in the cleaning chamber is cleaned, the temperature of the preheating tank is controlled, thereby gradually decreasing the temperature of the cleaning fluid in the cleaning chamber with a substantially constant downward gradient. The cleaning method described.   The cleaning method includes a heater capable of adjusting the temperature of the cleaning container. In the cleaning method, after cleaning the filter accommodated in the cleaning chamber, the temperature of the cleaning container is adjusted by adjusting the temperature of the heater. The cleaning method according to claim 12 or 13, wherein the cleaning method controls the temperature of the cleaning fluid in the cleaning chamber to be substantially constant.   The cleaning method includes a preheating tank for preheating the cleaning fluid flowing into the cleaning chamber, and a second adjustment valve capable of adjusting an inflow amount of the cleaning fluid preheated by the preheating tank into the cleaning chamber, In the cleaning method, after the filter housed in the cleaning chamber is cleaned, the preheated cleaning fluid is removed from the preheating tank via the second control valve while controlling the flow rate of the cleaning fluid in the second control valve. The cleaning method according to claim 17, wherein the cleaning fluid is gradually allowed to flow into the cleaning chamber, thereby maintaining the temperature of the cleaning fluid in the cleaning chamber substantially constant.   19. The cleaning method according to claim 18, wherein after cleaning the filter housed in the cleaning chamber, the temperature of the preheating tank is controlled to thereby maintain the temperature of the cleaning fluid in the cleaning chamber substantially constant. .   The said pipe material is formed from the 1st part located in the said outflow port side, and the 2nd part branched from the said 1st part into two or more and connected to several places of the said coating | covering material. 19. The cleaning method according to any one of 19.   The cleaning chamber is provided with a breathable pedestal on which the filter is placed in a state in which either one of the first surface and the second surface of the filter is in contact with the filter. The cleaning method according to any one of claims 12 to 20, wherein the cleaning fluid is located between the covering material and the pedestal, and the cleaning fluid flows through substantially the entire area of the filter by a rectifying action of the pedestal. The cleaning method according to any one of claims 12 to 21, wherein in the cleaning method, a plurality of inflow ports through which the cleaning fluid flows into the cleaning chamber are formed.

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