CN108889089B - Compressed air drying and purifying process and device - Google Patents

Abstract

In order to solve the technical problem that the existing adsorption drying process and equipment cannot meet the requirements for high-quality battery production, the present invention provides a compressed air drying and purification process and device. The compressed air drying and purification process includes adsorption purification and regeneration links; the regeneration link includes pressure relief, atmospheric heating, dry gas heating, dry gas blowing and cooling, closed cycle cooling and pressure equalization. The invention can continuously output finished gas with a normal pressure dew point of -72°C to (-78)°C and a carbon dioxide content of less than 5ppm for a long time, and can meet the gas requirements for high-quality battery production.

Description

A compressed air drying and purification process and device

Technical field

The invention relates to a compressed air drying and purification process and device.

Background technique

During the production process of lithium batteries, clean product gas with both moisture and carbon dioxide meeting the standards is required. The water and carbon dioxide content in the product gas directly affects the battery life of the lithium battery. Existing battery manufacturers only limit the moisture in the production environment, but ignore the impact of carbon dioxide on battery performance. The existing compressed air post-processing is divided into air separation and conventional adsorption drying. Due to the high investment cost of air separation , so most of them choose the conventional adsorption drying process; the existing dryer design mainly considers the removal of moisture, and can only remove carbon dioxide in the initial stage of switching, and the maintenance time is short, but now high-quality battery production lines need to continuously output moisture (dew point <-70℃) and carbon dioxide (<5ppm) meet the standards of the finished gas, so the existing drying equipment cannot meet the requirements. Some existing adsorption drying processes can remove moisture from compressed air without taking into account the desorption of carbon dioxide. Therefore, the carbon dioxide content in the product gas is high, about 500ppm, which cannot meet the production conditions of high-quality batteries; existing Although some adsorption drying processes take into account the desorption of carbon dioxide, they cannot continuously output finished gas with low carbon dioxide content and cannot meet the production requirements of high-quality batteries.

Contents of the invention

In order to solve the technical problem that the existing adsorption drying process and equipment cannot meet the requirements for high-quality battery production, the present invention provides a compressed air drying and purification process and device.

The technical solution of the present invention is:

A compressed air drying and purification process is special in that it includes the following steps:

1】Use drying tower A for adsorption purification and drying tower B for regeneration

1.1】Adsorption purification

1.1.1] Separate and filter the solid particles and liquid water contained in the raw gas;

1.1.2] Make the gas obtained after step 1.1.1] flow through the drying tower A loaded with the first adsorbent for adsorption drying and purification to remove moisture and carbon dioxide in the gas;

1.1.3] Filter the gas obtained after step 1.1.2] to remove the first adsorbent dust in the gas to obtain the finished gas;

1.1.4] Introduce part of the finished gas obtained after step 1.1.3] into the gas system, and the other part into subsequent links;

1.2】Regeneration

1.2.1】Relieve pressure

If the current pressure in drying tower B is greater than normal pressure, then reduce the pressure in drying tower B to normal pressure and proceed to step 1.2.2];

1.2.2】Dry gas heating

1.2.2.1] Heating the qualified dry gas introduced from the outside and/or the finished gas introduced through step 1.1.4];

1.2.2.2] Introduce the gas obtained from step 1.2.2.1] into the drying tower B to heat and analyze the second adsorbent in the tower, so that the residual moisture and carbon dioxide in the second adsorbent are discharged from the drying tower B along with the hot gas ;

1.2.3】Closed cycle cooling

1.2.3.1】Use a fan to extract the gas in the drying tower B and the pipeline connected to the drying tower B;

1.2.3.2】Cool the gas output from the fan;

1.2.3.3] Introduce the gas obtained in step 1.2.3.2] into the drying tower B, blow and cool the second adsorbent in the drying tower B, and the residual heat of the second adsorbent is discharged from the drying tower B with the hot gas;

1.2.3.4] Cool down the hot gas discharged from drying tower B in step 1.2.3.3];

1.2.3.5] Introduce the gas obtained in step 1.2.3.4] into the fan;

1.2.3.6] Repeat steps 1.2.3.2]-1.2.3.5] to circulate and cool the drying tower B;

1.3】Voltage equalization

Introduce part of the product gas obtained in step 1.4] into the drying tower B to increase the pressure in the drying tower B to the set value;

2】Switch

Switch according to the work requirements. After switching, the drying tower A will be regenerated, and the drying tower B will be subjected to adsorption purification. The principles of adsorption purification and regeneration are the same as step 1].

In order to reduce costs, before step 1.2.2], atmospheric heating is first carried out: the heated atmosphere is sent into the drying tower B loaded with the second adsorbent, and the second adsorbent is heated and analyzed to make the second adsorbent The moisture and carbon dioxide in the adsorbent are discharged from the drying tower B along with the hot gas.

Preferably, the atmospheric heating link is heated until the regeneration outlet temperature is 80-160 degrees Celsius, and the heating duration is at least 1 hour; the dry gas heating link is heated until the regeneration outlet temperature is 120-180 degrees Celsius, and the heating duration is at least 10 minutes.

Preferably, the atmospheric heating link is heated until the regeneration outlet temperature is 80-120 degrees Celsius, and the heating duration is 2-4 hours. The dry gas heating link is heated until the regeneration outlet temperature is 140-160 degrees Celsius, and the heating duration is 1-2 hours.

Preferably, step 1.2.3] close cycle blowing and cooling until the regeneration outlet temperature is 25-40 degrees.

Preferably, in order to further improve the finished gas index, between the step 1.2.2】dry gas heating and step 1.2.3】closed cycle blowing and cooling, a link of dry gas blowing and cooling is added: continuously into the drying tower B Dry gas with qualified water and carbon dioxide indicators is introduced to blow and cool for a set time. During this process, the second adsorbent in drying tower B is cooled and analyzed at the same time.

Preferably, the dry gas blowing and cooling lasts for at least 10 minutes, and the dry gas flow rate is equal to the raw gas flow rate ÷P, where P is the raw gas working pressure.

Further, the switching described in step 3] is through valve switching.

Further, when the raw gas output by the air compressor contains liquid oil, the liquid oil in step 1] should also be separated and filtered.

Further, the first adsorbent and the second adsorbent described in step 1] are both activated alumina + molecular sieve.

The invention also provides a compressed air drying and purifying device, which is special in that it includes a dryer composed of a drying tower A and a drying tower B. Both the drying tower A and the drying tower B are equipped with a device for removing water and carbon dioxide. Adsorbent; the upper and lower ports of the dryer are connected to the upper and lower pipe systems respectively. The upper pipe system is composed of the fourth valve and the eighth valve in parallel and the third and seventh valves in parallel. The lower pipe system It consists of a first valve and a fifth valve connected in parallel and a second valve and a sixth valve connected in parallel;

A fifth connecting pipe is provided between the first valve and the fifth valve. The fifth connecting pipe is provided with a pre-filter, a gas-liquid separator and a pre-water cooler in sequence. The inlet end of the pre-water cooler is the main outlet of the entire device. air inlet;

A seventh connecting pipe is provided between the first valve and the second valve, and a twelfth valve is provided on the seventh connecting pipe;

A sixth connecting pipe is provided between the second valve and the sixth valve, and a fourteenth valve is installed on the sixth connecting pipe;

An eighth connecting pipe is provided between the sixth valve and the fifth valve, and a thirteenth valve is installed on the eighth connecting pipe;

A second connecting pipe is provided between the third valve and the seventh valve. The other end of the second connecting pipe is divided into two branches: the first branch is provided with the 18th valve and the first surface cooler in sequence, and the second branch is A heater, a seventeenth valve and a fan are arranged on the branch road in sequence; the other ends of the first branch road and the second branch road converge at the ninth connecting pipe; a sixteenth valve is provided on the ninth connecting pipe;

A third connecting pipe is provided between the heater and the seventeenth valve, and the third connecting pipe is connected to the first connecting pipe through the twentieth valve; the third connecting pipe is also provided with a tenth connecting pipe connected with it, and the third connecting pipe is connected to the first connecting pipe. The tenth connecting pipe is located between the twentieth valve and the heater; the tenth connecting pipe is provided with a twenty-first valve; a fourth connecting pipe is provided between the seventeenth valve and the fan, and the fourth connecting pipe is provided with The second surface cooler and the fifteenth valve, the other end of the fourth connecting pipe is connected to the sixth connecting pipe;

A first connecting pipe is provided between the fourth valve and the eighth valve, and the outlet end of the first connecting pipe provided with a post-filter is the air outlet of the entire device;

The first connecting pipe is also connected to the second connecting pipe through the nineteenth valve;

The gas-liquid separator, pre-filter and post-filter are respectively connected with a ninth valve, a tenth valve and a twenty-second valve.

Further, it also includes a pre-precision filter for removing liquid oil and a post-precision filter for removing adsorbent dust; along the air flow direction, the pre-precision filter is arranged on the side of the pre-filter. At the rear end, a rear precision filter is arranged at the rear end of the rear precision filter; the outlet end of the rear precision filter is the air outlet of the entire device; the front precision filter and the rear precision filter are respectively An eleventh valve and a twenty-third valve are provided. The pre-precision filter refers to a filter with a precision of less than 1 mg/cubic meter; the post-precision filter refers to a filter with a filtration precision of less than 0.1 micron.

Beneficial effects of the present invention:

1. The invention can continuously output finished gas with a normal pressure dew point of -72°C ~ (-78)°C and a carbon dioxide content of less than 5ppm for a long time, and can meet the gas requirements for high-quality battery production.

2. The present invention reduces investment and operating costs by performing atmospheric heating before dry gas heating.

3. The present invention utilizes the existing dry gas in the tower and pipeline for closed-circulation blowing and cooling, further reducing operating costs and meeting the specifications of the finished gas while consuming only a small amount of finished gas.

4. The present invention further improves the index of the finished gas by adding a dry gas blowing and cooling link between the dry gas heating and the closed cycle blowing and cooling, and by washing the adsorbent with dry gas.

Description of the drawings

Figure 1 is a process flow diagram of the adsorption link according to the embodiment of the present invention.

Figure 2 is a process flow diagram of the regeneration process according to the embodiment of the present invention.

Figure 3 is a schematic diagram of the principle of an air dehydration and carbon dioxide removal device according to an embodiment of the present invention.

Explanation of reference symbols:

1-pre-water cooler, 2-gas-liquid separator, 3-pre-filter, 4-pre-precision filter, 5-post-precision filter, 6-post-filter, 7-heater, 8-first surface cooler, 9-second surface cooler, 10-dryer, 11-upper piping system, 12-lower piping system, 13-fan, 14-air inlet, 15-air outlet;

16-The first connecting pipe, 17-The second connecting pipe, 171-The first branch, 172-The second branch, 18-The third connecting pipe, 19-The fourth connecting pipe, 20-The fifth connecting pipe, 21 -The sixth connecting pipe, 22-the seventh connecting pipe, 23-the eighth connecting pipe, 24-the ninth connecting pipe, 25-the tenth connecting pipe; A1-the first valve, A2-the second valve, A3-the third Valve, A4-the fourth valve, B1-the fifth valve, B2-the sixth valve, B3-the seventh valve, B4-the eighth valve, F1-the ninth valve, F2-the tenth valve, F3-the eleventh valve , F4-twelfth valve, F5-thirteenth valve, F6-fourteenth valve, F7-fifteenth valve, F8-sixteenth valve, F9-seventeenth valve, F10-eighteenth valve, F11-Nineteenth valve, F12-Twentieth valve, F13-Twenty-first valve, F14-Twenty-second valve, F15-Twenty-third valve.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1 and 2, the air dehydration and carbon dioxide removal process provided by this embodiment includes the following steps:

1】Use drying tower A for adsorption purification and drying tower B for regeneration

1.1】Adsorption purification

1.1.1] Separate and filter the solid particles, liquid water and liquid oil contained in the raw gas;

1.1.2] Introduce the gas obtained after step 1.1.1] into the drying tower A loaded with the first adsorbent for adsorption drying and purification to remove moisture and carbon dioxide in the gas; the adsorbent can be activated alumina + molecular sieve ;

1.1.3] Filter the gas obtained after step 1.1.2] to remove the first adsorbent dust in the gas to obtain the finished gas required by the user;

1.1.4] Introduce part of the finished gas obtained after step 1.1.3] into the user's gas system, and the other part into subsequent links;

1.2】Regeneration

1.2.1】Relieve pressure

If the current pressure in drying tower B is greater than normal pressure (i.e. ambient pressure), then relieve the pressure in drying tower B to normal pressure and then proceed to step 1.2.2]; if the current pressure in drying tower B is normal pressure, Then go directly to step 1.2.2];

1.2.2] The atmosphere is heated until the regeneration outlet temperature is 80-120 degrees Celsius, and the heating duration is about 2-4 hours:

The heated atmosphere is fed into the drying tower B loaded with the second adsorbent, and the second adsorbent in the tower is heated and analyzed, so that the moisture and carbon dioxide in the second adsorbent are discharged from the drying tower B along with the hot gas;

1.2.3] Dry gas is heated until the regeneration outlet temperature is 140-160 degrees, and the heating duration is about 1-2 hours:

1.2.3.1] Heating the qualified dry gas introduced from the outside and the finished gas introduced in step 1.1.4];

1.2.3.2] Introduce part of the gas obtained from step 1.2.3.1] into the drying tower B to continue to heat and analyze the second adsorbent in the tower, so that the residual moisture and carbon dioxide in the second adsorbent are discharged from the drying tower along with the hot gas. B discharge;

1.2.4】Dry air blowing and cooling

Continuously introduce qualified dry gas into the drying tower B to blow and cool it for at least 10 minutes. During this process, the adsorbent in the drying tower B is cooled and analyzed at the same time;

1.2.5] Closed cycle blowing and cooling until the regeneration outlet temperature is 25-40 degrees:

1.2.5.1】Use a fan to extract the gas in the drying tower B and the pipeline connected to the drying tower B;

1.2.5.2】Cool the gas output from the fan;

1.2.5.3] Introduce the gas obtained in step 1.2.5.2] into the drying tower B, blow and cool the second adsorbent in the tower, and the residual heat of the second adsorbent is discharged from the drying tower B with the hot gas;

1.2.5.4] Cool down the hot gas discharged from drying tower B in step 1.2.5.3];

1.2.5.5] Introduce the gas obtained in step 1.2.5.4] into the fan;

1.2.5.6] Repeat steps 1.2.5.2]-1.2.5.5] to perform closed cycle cooling of the drying tower B;

1.3】Voltage equalization

Introduce part of the product gas obtained in step 1.1.4 into the drying tower B, so that the pressure in the drying tower B rises to the set value (equivalent to the pressure in the drying tower A);

2】Switch

Switch according to work requirements (since the product gas index continuously output by drying tower A will have a downward trend over time, when the product gas index output by drying tower A is close to the upper limit of the user's required index, it is necessary to switch, using the drying tower B adsorption purification, to ensure that the output product gas indicators during the entire process always meet user requirements), after switching, the drying tower A is regenerated, and the drying tower B is adsorbed and purified. The principle of adsorption purification and regeneration is the same as step 1].

In the present invention, the dry gas with qualified indicators introduced from outside can be non-aqueous, non-toxic inert gas.

Test comparison verification:

The following sets of test data are used to illustrate the purification effect of the present invention, as shown in the following table:

The above data is the test data when the adsorbent is loaded with about 175kg, the inlet air flow is 2Nm ³ /min, the working pressure is 0.4barg, and the inlet air temperature is 12°C. Among them, Test 1 and Test 2 are the existing drying and purification process data, and Test 3 and Test 4 are the drying and purification process data of the present invention. From the above table, it can be seen that CO overflows from the outlet of the existing drying and purification process. The time for _CO2 content to be greater than 5ppm is 2-2.5 hours (single tower adsorption purification), while the time for the _CO2 content to overflow from the outlet of the drying purification process of the present invention is greater than 5ppm is 4-5 hours (single tower adsorption purification), indicating that the present invention It has stronger adsorption and purification capabilities, and can output product gas with a normal pressure dew point of -72~(-78)℃ and a _CO2 content of less than 5ppm for a longer period of time.

As shown in Figure 3, the compressed air drying and purification device provided by the embodiment of the present invention includes a dryer 10 composed of a drying tower A and a drying tower B. The upper and lower ports of the dryer 10 are connected to the upper piping system 11 and the lower port respectively. The pipeline system 12 is connected. The upper pipeline system 11 is composed of the parallel-connected fourth valve A4, the eighth valve B4 and the parallel-connected third valve A3 and the seventh valve B3. The lower pipeline system 12 is composed of the parallel-connected first valve A1 and the fifth valve A1. The valve B1 is connected in parallel with the parallel second valve A2 and the sixth valve B2;

A fifth connecting pipe 20 is provided between the first valve A1 and the fifth valve B1. The fifth connecting pipe 20 is provided with a pre-precision filter 4, a pre-filter 3, a gas-liquid separator 2 and a pre-water cooling device in sequence. Device 1, the inlet end of the front water cooler 1 is the air inlet 14 of the entire device;

A seventh connecting pipe 22 is provided between the first valves A1 and A2, and a twelfth valve F4 is provided on the seventh connecting pipe 22;

A sixth connecting pipe 21 is provided between the second valve A2 and the sixth valve B2, and a fourteenth valve F6 is installed on the sixth connecting pipe 21;

An eighth connecting pipe 23 is provided between the sixth valve B2 and the fifth valve B1, and a thirteenth valve F5 is installed on the eighth connecting pipe 23 (a silencer is installed on the pipe to the right of F5 in Figure 3);

A second connecting pipe 17 is provided between the third valve A3 and the seventh valve B3. The other end of the second connecting pipe 17 is divided into two branches: the first branch 171 is provided with the 18th valve F10 and the 18th valve F10 in sequence. A surface cooler 8, the second branch 172 is provided with the heater 7, the seventeenth valve F9 and the fan 13 in sequence; the other ends of the first branch 171 and the second branch 172 converge at the ninth connecting pipe 24; A sixteenth valve F8 is provided on the ninth connecting pipe 24 (a silencer is installed on the left pipe of F8 in Figure 3);

A third connecting pipe 18 is provided between the heater 7 and the seventeenth valve F9. The third connecting pipe 18 is connected to the first connecting pipe 16 through the twentieth valve F12; the third connecting pipe 18 is also provided with a connecting pipe connected thereto. The tenth connecting pipe 25 is located between the twentieth valve F12 and the heater 7; the tenth connecting pipe 25 is provided with the twenty-first valve F13; and the seventeenth valve F9 is between the fan 13 and the tenth connecting pipe 25. A fourth connecting pipe 19 is provided. A second surface cooler 9 and a fifteenth valve F7 are arranged on the fourth connecting pipe 19 in sequence. The other end of the fourth connecting pipe 19 is connected with the sixth connecting pipe 21;

A first connecting pipe 16 is provided between the fourth valve A4 and the eighth valve B4. The first connecting pipe 16 is provided with a post-filter 6, a post-precision filter 5, and an outlet end of the post-precision filter 5. It is the air outlet 15 of the entire device;

The first connecting pipe 16 is also connected to the second connecting pipe 17 through the nineteenth valve F11;

The gas-liquid separator 2, pre-filter 3, pre-precision filter 4, post-precision filter 5 and post-filter 6 are respectively connected to a ninth valve F1, a tenth valve F2 and an eleventh valve F3. , the twenty-third valve F15 and the twenty-second valve F14. Valves F1, F2, and F3 are blowdown valves, which can remove solid particles, liquid water, and liquid oil entrained in the intake air; valves F14 and F15 are manual blowdown valves, which can remove dust pulverized by the adsorbent and extend the life of the filter element.

The working process of the above compressed air drying and purification device is explained below with reference to Figure 3:

When drying tower A is performing adsorption and purification work, drying tower B is regenerating the adsorbent; after the regeneration of drying tower B is completed, the two drying towers are switched through the valve; after switching, drying tower B is performing adsorption purification work, and drying tower A is regenerating the adsorbent; And so on. Specifically:

1】Adsorption purification of drying tower A and regeneration of drying tower B:

1.1】Adsorption purification:

The normal temperature saturated humid air (raw gas) from the air compressor passes through the pre-water cooler 1, gas-liquid separator 2, pre-filter 3 and pre-precision filter 4 to remove solid particles and liquid water in the raw gas and liquid oil, enters the adsorption tower A through the first valve A1. The adsorption tower A is equipped with an adsorbent for removing moisture and carbon dioxide gas. After desorbing water and carbon dioxide, it passes through the fourth valve A4, post-filter 6 and post-precision After filter 5 removes the adsorbent dust entrained in the gas, it outputs clean air with oil, water, dust, and carbon dioxide all meeting the standards.

1.2】Regeneration:

1.2.1] Pressure relief:

First, use the thirteenth valve F5 to relieve the pressure of the drying tower B in the previous adsorption and purification stage to low pressure, then open the sixth valve B2, the seventh valve B3, and the fourteenth valve F6 to connect the heater 7 and the drying tower B. And the pressure in the related pipelines (the pipelines marked by the solid rectangle in Figure 3) is released to normal pressure.

1.2.2】Atmospheric heating:

Open the sixth valve B2, the fourteenth valve F6, the seventh valve B3, the seventeenth valve F9, the sixteenth valve F8, the fan 13 and the heater 7. The fan 13 inhales the atmosphere, and after being heated by the heater 7, the hot gas Enter drying tower B to heat and analyze the adsorbent in the tower. The heated gas carries the moisture and carbon dioxide in the adsorbent and is discharged to the atmosphere through the sixth valve B2 and the fourteenth valve F6. When the regeneration outlet temperature reaches 80-120 degrees Celsius, close fan 13 and seventeenth valve F9;

1.2.3】Dry gas heating:

Since the residual moisture content of the adsorbent cannot meet the requirements of the residual moisture content index after the fan 13 absorbs the atmospheric air and heats it, it is necessary to take part of the dry air to reheat the adsorbent to meet the continuous output requirements of the adsorbent within the set time during the adsorption stage. Gas, the process of the secondary heating stage is: open the twentieth valve F12, take part of the finished gas (dry gas) into the heater 7 (you can also enter the heater 7 through the dry gas with qualified external indicators through the twenty-first valve F13), Heater 7 continues to work, heating the dry gas to 140-160 degrees Celsius, and then enters drying tower B through the seventh valve B3 to continue heating and analyzing the adsorbent. The heated gas carries the residual moisture in the adsorbent through the sixth valve B2, The fourteenth valve F6 is discharged to the atmosphere;

1.2.4】Dry air blowing and cooling:

After the secondary heating is completed, turn off the heater 7, continue to input dry gas, use the energy stored in the surface of the heater 7 and the adsorbent in the drying tower B to continue to analyze the adsorbent, analyze while cooling, and use dry gas to blow for at least 10 Minutes later, close the 20th valve F12 (when the dry gas with qualified external indicators passes through the 21st valve F13, close the 21st valve F13), and the dry gas cooling is completed.

1.2.5】Closed cycle cooling:

Since the cost of the finished gas is too high, it is not suitable to use dry gas blowing throughout the cooling process. Closed cycle blowing can greatly reduce the energy consumption during the cooling process. The process is: close the sixteenth valve F8, open the fourteenth valve F6, and The fifteenth valve F7 and the eighteenth valve F10 start the fan 13. The fan 13 provides the power source to blow the gas in the drying tower B and related pipes (pipes marked with solid circles in Figure 3) in a closed cycle. Cold, because the fan 13 will generate compression heat during the pressure increase process, a second surface cooler 9 is added at the outlet of the fan 13, using circulating water or chilled water (because the lower the tower body temperature, the dryer, The better the purification index, so it is better to use chilled water). After cooling the gas, it enters the drying tower B through the sixth valve B2. The gas carries the residual heat of the adsorbent in the drying tower B through the seventh valve B3 and the eighteenth valve F10. Entering the first surface cooler 8, use circulating water or chilled water (because the cost of chilled water is high and the fan inlet does not need to be too low, so it is best to use circulating water here) to cool the gas, and then the gas enters the fan again. 13. The second surface cooler 9 and drying tower B use this cycle to cool down drying tower B, and the heat is taken out of the system by circulating water and chilled water. The twentieth valve F12 is a pressure reducing valve. It is considered that during the cooling process, due to thermal expansion and contraction, the pressure in the system will further drop, which is not conducive to the operation of the fan 13 and the cooling speed. It is estimated that the twentieth valve will be added. Valve F12, after the regeneration system pressure drops to the setting value of the twentieth valve F12, the twentieth valve F12 automatically replenishes air.

1.3】Voltage equalization

After the blowing and cooling is completed, since there is no pressure in drying tower B, in order to avoid the impact during switching, the pressure of drying tower B needs to be equalized before switching. The process is: close the sixth valve B2 and the eighteenth valve F10, open the second 10. Valve F12, take part of the dry gas from heater 7 and 7th valve B3 and enter drying tower B. After drying tower B is pressed to a pressure balance with drying tower A, close 20th valve F12 and 7th valve B3 and stop equalization. Press, the device enters the standby stage, waiting for switching.

2】Switch the working state. After switching, drying tower B adsorbs and drying tower A regenerates:

The working status switching between drying tower A and drying tower B is realized through a valve. While the adsorbent in drying tower A is regenerated, the adsorbent in drying tower B is adsorbed. The principle is the same as step 1].

Claims (9)

1. The compressed air drying and purifying process is characterized by comprising the following steps:

1 adsorption purification by drying tower A and regeneration by drying tower B

1.1 adsorption purification

1.1.1, separating and filtering solid particles and liquid water contained in the raw material gas;

1.1.2, allowing the gas obtained after the treatment in the step 1.1.1 to flow through a drying tower A loaded with a first adsorbent for adsorption drying and purification, and removing water and carbon dioxide in the gas;

1.1.3, filtering the gas treated in the step 1.1.2 to remove the dust of the first adsorbent in the gas and obtain the finished gas;

1.1.4, introducing one part of the finished gas obtained after the treatment in the step 1.1.3 into a gas utilization system, and introducing the other part of the finished gas into a subsequent link;

1.2 regeneration

1.2.1 ]

If the pressure in the current drying tower B is greater than normal pressure, unloading the pressure in the drying tower B to normal pressure and then entering a step 1.2.2;

1.2.2 atmospheric heating

Feeding heated air into a drying tower B loaded with a second adsorbent, and heating and analyzing the second adsorbent to ensure that the moisture and carbon dioxide in the second adsorbent are discharged from the drying tower B along with hot gas;

1.2.3 heating of dry gas

1.2.3.1 ] heating the dry gas with qualified indexes introduced from the outside and/or the finished gas introduced through the step 1.1.4);

1.2.3.2 ] introducing the gas obtained by the treatment in the step 1.2.3.1 into the drying tower B to heat and analyze the second adsorbent in the tower, so that residual moisture and carbon dioxide in the second adsorbent are discharged from the drying tower B along with hot gas;

1.2.4 dry gas blowing and cooling

Continuously introducing dry gas with qualified water and carbon dioxide indexes into the drying tower B for cooling and setting time, and analyzing the second adsorbent in the drying tower B while cooling in the process;

1.2.5 closed cycle cooling by blowing

1.2.5.1 ] extracting the gas in the drying tower B and a pipeline connected with the drying tower B by using a fan;

1.2.5.2, cooling the gas output by the fan;

1.2.5.3 ] introducing the gas obtained in the step 1.2.5.2 into the drying tower B, blowing and cooling the second adsorbent in the drying tower B, and discharging the residual heat of the second adsorbent from the drying tower B along with hot gas;

cooling the hot gas discharged from the drying tower B in the step 1.2.5.3;

1.2.5.5 ] introducing the gas from step 1.2.5.4 into the blower;

1.2.5.6 repeating the steps 1.2.5.2 to 1.2.5.5, and circularly cooling the drying tower B;

1.3 Voltage equalizing

Introducing part of the finished product gas obtained in the step 1.1.4 into the drying tower B, and rising the pressure in the drying tower B to a set value;

2 switch over

And (3) switching according to the working requirements, and regenerating the drying tower A, wherein the drying tower B performs adsorption purification, and the adsorption purification and regeneration principles are the same as those of the step (1).

2. The compressed air drying and purifying process according to claim 1, wherein: the atmosphere heating step is to heat to the temperature of the regeneration outlet of 80-160 ℃ for at least 1 hour; and the dry gas heating link is used for heating to the temperature of the regeneration outlet of 120-180 ℃ for at least 1 hour.

3. The compressed air drying and purifying process according to claim 2, wherein: the atmosphere heating link is heated to the temperature of the regeneration outlet of 80-120 ℃ for 2-4 hours, and the dry gas heating link is heated to the temperature of the regeneration outlet of 140-160 ℃ for 1-2 hours.

4. A compressed air drying and purifying process according to claim 3, wherein: and (2) performing closed circulation cooling to a regeneration outlet temperature of 25-40 ℃.

5. The compressed air drying and purifying process according to claim 4, wherein:

the duration of the dry gas blowing and cooling is at least 10 minutes, the flow of the dry gas is equal to the flow rate of the raw material gas/P, and the P is the working pressure of the raw material gas.

6. The compressed air drying and purifying process according to any one of claims 1 to 4, wherein: the switching in step 3 is by a valve.

7. The compressed air drying and purifying process according to any one of claims 1 to 4, wherein: the first adsorbent and the second adsorbent in the step 1 are both activated alumina and molecular sieve.

8. The utility model provides a compressed air drying, purification device which characterized in that: comprises a dryer (10) consisting of a drying tower A and a drying tower B; the drying tower A and the drying tower B are respectively provided with an adsorbent for removing water and carbon dioxide; the upper port and the lower port of the dryer (10) are respectively communicated with an upper pipe system (11) and a lower pipe system (12), the upper pipe system (11) is formed by connecting a fourth valve (A4), an eighth valve (B4) in parallel with a third valve (A3) and a seventh valve (B3) in parallel, and the lower pipe system (12) is formed by connecting a first valve (A1), a fifth valve (B1) in parallel with a second valve (A2) and a sixth valve (B2) in parallel;

a fifth connecting pipe (20) is arranged between the first valve (A1) and the fifth valve (B1), a pre-filter (3), a gas-liquid separator (2) and a pre-water cooler (1) are sequentially arranged on the fifth connecting pipe (20), and the inlet end of the pre-water cooler (1) is an air inlet (14) of the whole device;

a seventh connecting pipe (22) is arranged between the first valve (A1) and the second valve (A2), and a twelfth valve (F4) is arranged on the seventh connecting pipe (22);

a sixth connecting pipe (21) is arranged between the second valve (A2) and the sixth valve (B2), and a fourteenth valve (F6) is arranged on the sixth connecting pipe (21);

an eighth connecting pipe (23) is arranged between the sixth valve (B2) and the fifth valve (B1), and a thirteenth valve (F5) is arranged on the eighth connecting pipe (23);

a second connecting pipe (17) is arranged between the third valve (A3) and the seventh valve (B3), and the other end of the second connecting pipe (17) is divided into two branches: an eighteenth valve (F10) and a first surface cooler (8) are sequentially arranged on the first branch (171), and a heater (7), a seventeenth valve (F9) and a fan (13) are sequentially arranged on the second branch (172); the other ends of the first branch (171) and the second branch (172) are converged on a ninth connecting pipe (24); a sixteenth valve (F8) is arranged on the ninth connecting pipe (24);

a third connecting pipe (18) is arranged between the heater (7) and the seventeenth valve (F9), and the third connecting pipe (18) is communicated with the first connecting pipe (16) through a twentieth valve (F12); a tenth connecting pipe (25) communicated with the third connecting pipe (18) is further arranged on the third connecting pipe, and the tenth connecting pipe (25) is positioned between the twentieth valve (F12) and the heater (7); a twenty-first valve (F13) is arranged on the tenth connecting pipe (25); a fourth connecting pipe (19) is arranged between the seventeenth valve (F9) and the fan (13), a second surface cooler (9) and a fifteenth valve (F7) are sequentially arranged on the fourth connecting pipe (19), and the other end of the fourth connecting pipe (19) is communicated with a sixth connecting pipe (21);

a first connecting pipe (16) is arranged between the fourth valve (A4) and the eighth valve (B4), and the outlet end of the post filter (6) is arranged on the first connecting pipe (16) in sequence to form an air outlet (15) of the whole device;

the first connecting pipe (16) is also communicated with the second connecting pipe (17) through a nineteenth valve (F11);

the gas-liquid separator (2), the pre-filter (3) and the post-filter (6) are respectively connected with a ninth valve (F1), a tenth valve (F2) and a twenty-second valve (F14).

9. The compressed air drying and purifying apparatus according to claim 8, wherein: the device also comprises a front precise filter (4) and a rear precise filter (5) for removing liquid oil; the front precise filter (4) is arranged at the rear end of the front filter (3) along the air flow direction, and the rear precise filter (5) is arranged at the rear end of the rear filter (5); the outlet end of the rear precise filter (5) is an air outlet (15) of the whole device; an eleventh valve (F3) and a twenty-third valve (F15) are respectively arranged on the front precise filter (4) and the rear precise filter (5).