JP5351807B2 - Vacuum valve unit - Google Patents

Description

  The present invention relates to a vacuum valve unit used in a vacuum sewage collecting system that sucks sewage in sewage by opening a vacuum valve with a suction pipe and transfers it to a vacuum pump station installed in a sewage treatment plant or the like.

  FIG. 1 is a diagram showing a configuration example of this type of conventional vacuum valve unit. In FIG. 1, reference numeral 1 is sewage. The tip of the suction pipe 3 is inserted into the waste water 1, and the rear end of the suction pipe 3 is connected via a vacuum valve 4 to a line 5 (vacuum system) communicating with the vacuum tank. The vacuum valve 4 includes a diaphragm 4b and a spring 4a for biasing the diaphragm 4b in the piston chamber 4c.

  Reference numeral 11 denotes a control device. The control device 11 includes a casing 12, and the casing 12 has a structure in which a large diameter portion 12a and a small diameter portion 12b are integrated. The large-diameter portion 12a is provided with a partition wall 15 through which a shaft (shaft) 14 penetrates at the center, and is divided into left and right chambers. The left chamber is divided into a first chamber 17 and a second chamber 18 by a first diaphragm 16 provided in the center, and the right chamber is divided into a third chamber 20 and a fourth chamber by a second diaphragm 19 provided in the center. It is divided into chambers 21. The small-diameter portion 12b is divided into left and right chambers by a partition wall 22, the left chamber communicates with the fourth chamber 21, and the right chamber is partitioned into a fifth chamber 24 and a sixth chamber 25 by a partition wall 23. Yes.

  A valve body 13 is fixed to the tip of the shaft 14, and the valve body 13 is disposed in the sixth chamber 25. The rear end of the shaft 14 is fixed to the central portion of the first diaphragm 16. The shaft 14 passes through the partition wall 15, and the second diaphragm 19 is inserted (the diaphragm 19 is fixed to the shaft 14), and further passes through the partition wall 22 and the partition wall 23. A seal mechanism (not shown) is provided in a penetrating portion where the shaft 14 penetrates the partition wall 15, and a seal mechanism (not shown) is provided in a penetrating portion penetrating the partition wall 22. Is provided with a through hole 23 a that is opened and closed by the valve body 13. Reference numeral 28 denotes a spring that pushes the second diaphragm 19 to the left.

  A magnet 29 is provided at a position facing the rear end of the shaft 14 on the rear end wall of the casing 12. The sixth chamber 25 is provided with a shaft seal 30 having an air release hole 30a. The atmosphere opening hole 30 a communicates with the atmosphere and is opened and closed by the valve body 13. The shaft 14 is urged by a spring 28 in a direction in which the valve body 13 is separated from the atmosphere opening hole 30a.

  The suction pipe 3 is provided with pressure detection holes 9, 10 at a predetermined vertical distance, the pressure detection hole 9 communicates with the fourth chamber 21 through a pipe 31, and the pressure detection hole 10 is formed through a pipe 32 with a third chamber 20. Communicate with. In the sewage basin 1, a pressure sensor pipe 2 for converting a change in the level of sewage into a change in pressure is disposed. The pressure sensor pipe 2 communicates with the first chamber 17 through a pipe 33. The second chamber 18 communicates with the atmosphere through a hole 34. The fifth chamber 24 communicates with the line 5 through a pipe 35, and the sixth chamber 25 communicates with the piston chamber 4 c of the vacuum valve 4 through a pipe 36.

  In the vacuum valve unit configured as described above, when the level of sewage in the sewage mass 1 rises and the pressure in the pressure sensor pipe 2 rises, the pressure is transmitted to the first chamber 17 in the control device 11 through the pipe 33. As a result, the first diaphragm 16 overcomes the elastic force of the spring 28 and the magnetic attractive force of the magnet 29 and moves to the right to push the shaft 14, the valve body 13 abuts against the shaft seal 30, and opens the air opening hole 30 a. close up. Then, the vacuum is transmitted from the line 5 through the pipe 35 to the fifth chamber 24 and the sixth chamber 25, and further to the piston chamber 4 c of the vacuum valve 4. Thereby, the valve body 6 of the vacuum valve 4 is pulled up.

  When the first diaphragm 16 is pushed by the pressure of the pressure sensor tube 2 and the shaft 14 starts to move, the elastic force of the spring 28 increases as the shaft 14 moves, but the magnetic attractive force of the magnet 29 decreases rapidly (moves). Therefore, the shaft 14 moves to the moving end, that is, to the position where the valve body 13 closes the atmosphere opening hole 30a.

  When the valve body 6 of the vacuum valve 4 is pulled up, the line 5 and the suction pipe 3 communicate with each other, so that the sewage begins to be sucked, and the sewage is transported through the suction pipe 3 while being mixed with the air taken in from the air suction pipe 8. The At this time, a differential pressure is generated between the pressure detection hole 9 and the pressure detection hole 10, and this is transmitted to the fourth chamber 21 and the third chamber 20 through the pipes 31 and 32. This differential pressure becomes a force for pushing the second diaphragm 19 to the right, and the valve body 13 is further pushed to the right via the shaft 14. Even if the water level of the sewage drops and the pressure difference between the first chamber 17 and the second chamber 18 disappears, the sewage flows in the suction pipe 3 because of the differential pressure between the fourth chamber 21 and the third chamber 20. The valve body 13 remains pressed to the right side.

  When the water level of the sewage is further lowered and the lower end of the suction pipe 3 sucks air, the pressure difference between the pressure detection hole 9 and the pressure detection hole 10 disappears, so that the second diaphragm 19 is pushed to the left by the spring 28. The valve body 13 is pressed to the left side to close the through hole 23a of the partition wall 23. As a result, the atmosphere flows into the sixth chamber 25, and the atmosphere flows into the piston chamber 4 c of the vacuum valve 4 through the pipe 36, and the valve body 6 of the vacuum valve 4 is returned by the elastic force of the spring 4 a, The body 7 between the pipe 3 and the line 5 is closed, and the communication between the suction pipe 3 and the line 5 is blocked.

Japanese Patent Laid-Open No. 10-60995

  When the vacuum valve 4 is suddenly closed during suction of sewage due to accidental disconnection of the pipe 36 during operation of the vacuum valve 4 (suction of sewage), the internal pressure is applied to the suction side of the vacuum valve 4. Occurs, so-called water hammer occurs. When the water hammer is generated, there is a problem that the connection between the vacuum valve 4 and the suction pipe 3 is disconnected or the sewage enters the inside of the control device 11 through the pipes 31 and 32 and the vacuum valve 4 cannot be reactivated.

  Further, at the moment when the vacuum valve 4 is activated and the valve body 6 is opened, the air in the pipes 31 and 32 is first sucked, and then the sewage in the sewage 1 is sucked. At this time, since the pipes 31 and 32 have a negative pressure, sewage enters the pipes 31 and 32, and the pressure inside the control device 11 may act in the direction of closing the vacuum valve 4, and a water hammer is generated. There was something to do.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a vacuum valve unit used in a vacuum sewage collection system, which can prevent sewage from entering a control device. .

  In order to achieve the above-described object, one aspect of the present invention is arranged between a suction pipe whose tip is disposed in a sewage basin, a vacuum system for transferring sewage by a vacuum suction force, and the suction pipe. A vacuum valve, a first differential pressure detection pipe connected to a predetermined height of the suction pipe, and a second differential pressure connected to a height lower than a connection position of the first differential pressure detection pipe A detection pipe, a mechanical control device that operates based on the pressure in the first differential pressure detection pipe and the second differential pressure detection pipe, and controls opening and closing of the vacuum valve; and the first differential pressure A flexible tube for connecting the detection tube and the second differential pressure detection tube and the control device, respectively, on the side of the first differential pressure detection tube and the second differential pressure detection tube, 1 connection nozzle and 2nd connection nozzle are provided, respectively. Fine the second connection nozzle are vacuum valve unit, characterized in that connected to the flexible tube.

In a preferred aspect of the present invention, the first differential pressure detection tube and the second differential pressure detection tube are provided with a first atmospheric opening and a second atmospheric opening, respectively. To do.
In a preferred aspect of the present invention, a plurality of the second atmosphere opening ports are provided.
In a preferred aspect of the present invention, the flow rate of the air flowing from the first atmosphere opening port during sewage transfer is configured to be equal to or less than the flow rate of the air flowing from the second atmosphere opening port during sewage transfer. It is characterized by.
In a preferred aspect of the present invention, the first connection nozzle and the second connection nozzle are provided obliquely upward.
In a preferred aspect of the present invention, a convex portion is provided on the inner surface of the first differential pressure detection tube at a position below the first connection nozzle.

In a preferred aspect of the present invention, the connection portion of the first differential pressure detection tube to the suction tube is an inclined tube.
In another aspect of the present invention, a suction pipe having a tip disposed within the sewage basin, a vacuum valve disposed between the suction system and a vacuum system for transferring sewage by a vacuum suction force, and the suction pipe A first differential pressure detection pipe connected to a predetermined height; a second differential pressure detection pipe connected to a height lower than a connection position of the first differential pressure detection pipe; and the first A mechanical control device that operates based on the pressure in the differential pressure detection pipe and the second differential pressure detection pipe and controls the opening and closing of the vacuum valve; the first differential pressure detection pipe and the second differential A vacuum valve unit comprising: a flexible tube that connects the pressure detection tube and the control device, and the connection portion of the first differential pressure detection tube to the suction tube is an inclined tube. It is.

According to the present invention, since the flow of sewage in the differential pressure detection pipe has a momentum in the pipe line direction, the momentum flowing to the connection nozzle connected to the side is cut off. Therefore, even if a water hammer occurs, it is possible to prevent sewage from entering the control device, and the operation of the control device can be kept normal.
In addition, by providing the first atmospheric opening and the second atmospheric opening in the first differential pressure detection pipe and the second differential pressure detection pipe, respectively, even when a water hammer occurs, the differential pressure detection pipe is provided. The sewage that has flowed in is discharged to the outside through these open air openings. Therefore, infiltration of sewage into the control device can be reliably prevented.

It is a schematic diagram which shows the structural example of the conventional vacuum valve unit. It is a mimetic diagram showing a vacuum valve unit concerning one embodiment of the present invention. It is sectional drawing which shows the modification of the differential pressure | voltage detection tube shown in FIG. FIG. 6 is a cross-sectional view showing another modification of the differential pressure detection tube shown in FIG. 2. FIG. 10 is a cross-sectional view showing still another modification of the differential pressure detection tube shown in FIG. 2.

Hereinafter, a vacuum valve unit according to an embodiment of the present invention will be described with reference to the drawings.
In FIG. 2, the configuration of the vacuum valve 4 and the control device 11 is the same as the configuration shown in FIG. Further, the configuration and operation of the vacuum valve unit not specifically described are the same as the configuration and operation shown in FIG.

  The vacuum valve unit has a suction pipe 50 whose tip is disposed in the sewage basin 1. The suction pipe 50 is connected to a line (vacuum system) 5 through a vacuum valve 4. The line 5 communicates with a vacuum station (not shown) composed of a vacuum tank, a vacuum pump, and the like, and the sewage in the sewage 1 is sucked into the suction pipe 50 by the vacuum suction force generated in the line 5. ing. The vacuum valve 4 is arranged between the suction pipe 50 and the line 5. The suction pipe 50 is connected to the upstream coupling 40 of the vacuum valve 4, and the line 5 is connected to the downstream coupling 41 of the vacuum valve 4. The pressure sensor pipe 2 is configured separately from the suction pipe 50. The tip of the pressure sensor pipe 2 is disposed in the sewage tank 1 as with the suction pipe 50. The pressure sensor tube 2 and the vacuum valve 4 are connected to the control device 11 via flexible tubes 63 and 66, respectively. The line 5 and the fifth chamber 24 of the control device 11 communicate with each other via a flexible tube 65.

  A first differential pressure detection pipe 51 and a second differential pressure detection pipe 52 are connected to the suction pipe 50. The suction pipe 50, the first differential pressure detection pipe 51, and the second differential pressure detection pipe 52 are integrally formed and communicate with each other. The first differential pressure detection tube 51 and the second differential pressure detection tube 52 extend in the vertical direction, and their lower ends are connected to the side portion of the suction tube 50. The connection position between the second differential pressure detection pipe 52 and the suction pipe 50 is lower than the connection position between the first differential pressure detection pipe 51 and the suction pipe 50.

  A first atmospheric pressure release nozzle 51A extending in the vertical direction is provided at the upper end of the first differential pressure detection pipe 51, and the inside and outside of the first differential pressure detection pipe 51 through the first atmospheric pressure release nozzle 51A. And communicate with each other. Further, a first connection nozzle 51 </ b> B extending in the horizontal direction is provided near the upper end of the first differential pressure detection tube 51. The first connection nozzle 51B is provided on the side portion of the first differential pressure detection pipe 51, and is located below the first atmosphere release nozzle 51A. The lower end of the flexible tube 61 is connected to the first connection nozzle 51 </ b> B, and the upper end of the flexible tube 61 is connected to the fourth chamber 21 of the control device 11. On the other hand, the first atmosphere release nozzle 51A is not connected to the flexible tube, and the inside of the first differential pressure detection tube 51 is opened to the atmosphere via the first atmosphere release nozzle 51A.

  Similarly, a second atmospheric pressure release nozzle 52A extending in the vertical direction is provided at the upper end of the second differential pressure detection tube 52, and the second differential pressure detection tube 52 of the second differential pressure detection tube 52 is passed through the second atmospheric pressure release nozzle 52A. The inside and outside communicate. Further, a second connection nozzle 52B extending in the horizontal direction is provided near the upper end of the second differential pressure detection tube 52. The second connection nozzle 52B is provided on the side portion of the second differential pressure detection pipe 52, and is located below the second atmosphere release nozzle 52A. The lower end of the flexible tube 62 is connected to the second connection nozzle 52 </ b> B, and the upper end of the flexible tube 62 is connected to the third chamber 20 of the control device 11. On the other hand, the second atmosphere release nozzle 52A is not connected to the flexible tube, and the inside of the second differential pressure detection tube 52 is opened to the atmosphere via the second atmosphere release nozzle 52A.

  In the vacuum valve unit configured as described above, when the level of sewage in the sewage mass 1 rises and the pressure in the pressure sensor pipe 2 rises, the pressure is transmitted to the first chamber 17 in the control device 11 through the flexible tube 63. . As a result, the first diaphragm 16 overcomes the elastic force of the spring 28 and the magnetic attractive force of the magnet 29 and moves to the right to push the shaft 14, the valve body 13 abuts against the shaft seal 30, and opens the air opening hole 30 a. close up. Then, the vacuum is transmitted from the line 5 through the flexible tube 65 to the fifth chamber 24 and the sixth chamber 25, and further to the piston chamber 4 c of the vacuum valve 4. Thereby, the valve body 6 of the vacuum valve 4 is pulled up.

  When the first diaphragm 16 is pushed by the pressure of the pressure sensor tube 2 and the shaft 14 starts to move, the elastic force of the spring 28 increases as the shaft 14 moves, but the magnetic attractive force of the magnet 29 decreases rapidly (moves). Therefore, the shaft 14 moves to the moving end, that is, to the position where the valve body 13 closes the atmosphere opening hole 30a. Here, the fifth chamber 24, the sixth chamber 25, the atmosphere opening hole 30 a, and the valve body 13 constitute a vacuum valve opening / closing mechanism that opens and closes the vacuum valve 4.

  When the valve body 6 of the vacuum valve 4 is pulled up, the line 5 and the suction pipe 50 communicate with each other, so that sewage begins to be sucked. A differential pressure is generated between the first differential pressure detection tube 51 and the second differential pressure detection tube 52, and this is transmitted to the fourth chamber 21 and the third chamber 20 through the flexible tubes 61 and 62. This differential pressure becomes a force for pushing the second diaphragm 19 to the right, and the valve body 13 is further pushed to the right via the shaft 14. Even if the water level of the sewage falls and the pressure difference between the first chamber 17 and the second chamber 18 disappears, the sewage flows in the suction pipe 50 because of the differential pressure between the fourth chamber 21 and the third chamber 20. The valve body 13 remains pressed to the right side.

  When the water level of the sewage is further lowered and the lower end of the suction pipe 50 sucks air, the pressure difference between the connection nozzle 51B and the connection nozzle 52B disappears, so that the second diaphragm 19 is pushed to the left by the spring 28, and the valve The body 13 is pressed to the left side and closes the through hole 23 a of the partition wall 23. Thereby, the atmosphere flows into the sixth chamber 25, the atmosphere flows into the piston chamber 4c of the vacuum valve 4 through the flexible tube 66, and the valve body 6 of the vacuum valve 4 is returned by the elastic force of the spring 4a. The body 7 between the suction pipe 50 and the line 5 is closed, and the communication between the suction pipe 50 and the line 5 is blocked.

  When the vacuum valve 4 is suddenly closed during the suction of sewage, an internal pressure is generated on the suction side of the vacuum valve 4 and a so-called water hammer is generated. When the water hammer occurs, the sewage flows from the suction pipe 50 into the differential pressure detection pipes 51 and 52 vigorously. Since this sewage escapes from the air release nozzles 51A, 52A provided at the uppermost portions of the differential pressure detection tubes 51, 52, it is possible to suppress the sewage from moving toward the flexible tubes 61, 62. Since the flow of sewage has a momentum in the pipe direction, the momentum flowing to the connection nozzles 51B and 52B connected to the side portions of the differential pressure detection tubes 51 and 52 is cut off.

  Further, while the vacuum valve 4 is opened and the sewage is being transferred through the suction pipe 50, the negative pressure in the differential pressure detection pipes 51, 52 is relieved because the air is sucked from the respective open air nozzles 51 </ b> A, 52 </ b> A. The Therefore, the sewage is prevented from entering the control device 11 and normal pressure is transmitted to the control device 11. Although the negative pressure in the differential pressure detection pipes 51 and 52 is alleviated, if the difference between the pressure in the first differential pressure detection pipe 51 and the pressure in the second differential pressure detection pipe 52 can be sufficiently secured. There is no problem in the operation of the control device 11.

  In this embodiment, the flow rate of the air flowing into the first differential pressure detection pipe 51 from the first atmospheric release nozzle 51A flows into the second differential pressure detection pipe 52 from the second atmospheric release nozzle 52A. Although it is set to be approximately the same as the flow rate of the atmosphere, in order to sufficiently secure the difference between the pressure in the first differential pressure detection pipe 51 and the pressure in the second differential pressure detection pipe 52, the first The flow rate of the atmosphere flowing into the first differential pressure detection pipe 51 from the atmosphere release nozzle 51A is the same or smaller than the flow rate of the atmosphere flowing into the second differential pressure detection pipe 52 from the second atmosphere release nozzle 52A. That is, the flow rate is preferably equal to or lower than the flow rate of the air flowing into the second differential pressure detection tube 52. In addition, when it is desired to increase the gas-liquid ratio of the fluid passing through the vacuum valve 4, in addition to increasing the diameter of the air suction pipe 8 (see FIG. 1), the air flowing into the second differential pressure detection pipe 52 The flow rate may be larger than the flow rate of the air flowing into the first differential pressure detection tube 51.

  In order to increase the flow rate of the atmosphere flowing into the second differential pressure detection pipe 52, the diameter of the second atmosphere release nozzle 52A may be increased or the length thereof may be shortened. A plurality of open nozzles 52A may be provided, or a small hole may be provided in addition to the second atmosphere open nozzle 52A. Further, an adjustment valve for adjusting the flow rate of the atmosphere may be provided in the second atmosphere opening nozzle 52A.

  As shown in FIG. 3, the connection nozzle 51 </ b> B connected to the control device 11 may be provided obliquely upward. Since the diameter of the connection nozzle 51B is small, it is difficult for sewage to flow down if sewage enters the connection nozzle 51B. By making the connection nozzle 51B diagonal, the sewage can easily flow out of the connection nozzle 51B. For the same reason, the connection nozzle 52B may also be provided obliquely upward.

  Moreover, as shown in FIG. 4, you may provide the convex part 54 in the upstream of the connection nozzle 51B. More specifically, a convex portion 54 may be provided on the inner surface of the first differential pressure detection tube 51 at a position immediately below the connection nozzle 51B. Since the flow of sewage in the first differential pressure detection pipe 51 is inhibited by the convex portion 54, the sewage can be prevented from flowing into the connection nozzle 51B. Similarly, you may provide the convex part 54 in the upstream of the connection nozzle 52B.

  Since the flow path of the first differential pressure detection pipe 51 is shorter than that of the second differential pressure detection pipe 52, a throttle 55 is provided at the connection between the first differential pressure detection pipe 51 and the suction pipe 50. It is difficult for the influence of the water hammer to be transmitted into the first differential pressure detection tube 51. The restrictor 55 is provided on the upper inner surface of the first differential pressure detection tube 51 (the direction drawn by vacuum or the direction toward the water hammer). Such a throttle may be provided in the second differential pressure detection tube 52.

  Further, as shown in FIG. 5, the lower portion of the first differential pressure detection tube 51 is configured by an inclined tube 51C inclined downward toward the suction tube 50, and the first differential pressure detection tube is formed by the inclined tube 51C. You may comprise the connection part to the suction pipe 50 of 51. FIG. As shown in FIG. 2, if the connecting portion between the first differential pressure detection pipe 51 and the suction pipe 50 is a short pipe extending horizontally, sewage will stay in the lower part of the first differential pressure detection pipe 51. Sometimes. By providing the inclined pipe 51 </ b> C as shown in FIG. 5, it is possible to promote the flow of the sewage that tends to stay at the connection portion between the first differential pressure detection pipe 51 and the suction pipe 50 into the suction pipe 50. Similarly, the lower portion of the second differential pressure detection tube 52 is constituted by an inclined tube 52C inclined downward toward the suction tube 50, and the inclined tube 52C leads to the suction tube 50 of the second differential pressure detection tube 52. You may comprise the connection part.

  In addition, as shown in FIG. 5, the suction pipe 50 may be provided with an escape hole 70 for releasing the impact of the water hammer. The escape hole 70 is covered with a flexible material 71 such as a rubber plate whose outer opening end is fixed to the suction pipe 50. When the vacuum valve 4 is in operation, the pressure in the suction pipe 50 decreases, so that the flexible member 71 comes into close contact with the escape hole 70. However, when a water hammer occurs, the flexible material 71 bends to the outside of the suction pipe 50 due to the pressure. The pressure in the suction pipe 50 is released from the escape hole 70 to the outside. In the example of FIG. 5, the escape hole 70 is provided below the second differential pressure detection tube 52. This is because even when the foreign material is sandwiched between the flexible material 71 and the suction pipe 50 and the escape hole 70 is not sufficiently blocked by the flexible material 71 when the vacuum valve 4 is operated, the differential pressure detection pipe 51, This is so as not to affect the differential pressure of 52.

  In the present embodiment, the atmosphere opening nozzles 51A and 52A are provided as the atmosphere opening ports, but the atmosphere is not formed by the shape of the nozzles but by the atmosphere opening holes (through holes) formed at the upper ends of the differential pressure detection tubes 51 and 52. You may comprise an open port. Note that the air opening is not necessarily formed at the upper end of the differential pressure detection pipe, but the impact of the water hammer advances in the pipe line direction, so it is provided at the tip (upper end) of the differential pressure detection pipe 51, 52. preferable.

  The embodiment described above is described for the purpose of enabling the person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the present invention is not limited to the described embodiments, but is to be construed in the widest scope according to the technical idea defined by the claims.

1 Wastewater 2 Pressure sensor tube 3 Suction tube 4 Vacuum valve 5 Line (vacuum system)
6 Valve body 11 Control device 50 Suction pipe 51 First differential pressure detection pipe 52 Second differential pressure detection pipe 51A First atmosphere release nozzle 52A Second atmosphere release nozzle 51B First connection nozzle 52B Second connection Nozzle 51C, 52C Inclined tube 54 Convex 55 Restriction 70 Relief hole

Claims (8)

A suction pipe whose tip is placed in the sewage basin,
A vacuum valve disposed between the suction pipe and the vacuum system for transferring sewage by a vacuum suction force;
A first differential pressure detection pipe connected to a predetermined height of the suction pipe;
A second differential pressure detection tube connected to a height lower than the connection position of the first differential pressure detection tube;
A mechanical control device that operates based on the pressure in the first differential pressure detection tube and the second differential pressure detection tube, and controls opening and closing of the vacuum valve;
A flexible tube connecting the first differential pressure detection tube and the second differential pressure detection tube and the control device, respectively;
A first connection nozzle and a second connection nozzle are respectively provided on the side portions of the first differential pressure detection tube and the second differential pressure detection tube,
The vacuum valve unit, wherein the first connection nozzle and the second connection nozzle are connected to the flexible tube.   The said 1st differential pressure | voltage detection pipe | tube and the said 2nd differential pressure | voltage detection pipe | tube are each provided with the 1st air | atmosphere open port and the 2nd air | atmosphere open port, The said 1st differential pressure | voltage detection tube is provided. Vacuum valve unit.   The vacuum valve unit according to claim 2, wherein a plurality of the second atmosphere opening ports are provided.   The flow rate of the air flowing from the first atmosphere opening port during sewage transfer is configured to be equal to or less than the flow rate of the air flowing from the second atmosphere opening port during sewage transfer. The vacuum valve unit according to claim 2 or 3.   The vacuum valve unit according to any one of claims 1 to 4, wherein the first connection nozzle and the second connection nozzle are provided obliquely upward.   The vacuum valve unit according to any one of claims 1 to 5, wherein a convex portion is provided on an inner surface of the first differential pressure detection tube at a position below the first connection nozzle. .   The vacuum valve unit according to any one of claims 1 to 6, wherein a connection portion of the first differential pressure detection tube to the suction tube is an inclined tube. A suction pipe whose tip is placed in the sewage basin,
A vacuum valve disposed between the suction pipe and the vacuum system for transferring sewage by a vacuum suction force;
A first differential pressure detection pipe connected to a predetermined height of the suction pipe;
A second differential pressure detection tube connected to a height lower than the connection position of the first differential pressure detection tube;
A mechanical control device that operates based on the pressure in the first differential pressure detection tube and the second differential pressure detection tube, and controls opening and closing of the vacuum valve;
A flexible tube connecting the first differential pressure detection tube and the second differential pressure detection tube and the control device, respectively;
The vacuum valve unit according to claim 1, wherein a connecting portion of the first differential pressure detection tube to the suction tube is an inclined tube.

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