VOCs treatment and recovery device

Abstract

The utility model belongs to the technical field of VOCs treatment, and particularly relates to a VOCs treatment and recovery device. A tail gas main pipe is connected with a tail gas buffer tank, the tail gas buffer tank is connected with a membrane group liquid accumulation tank through a second booster pump and a condenser, a gas outlet of the membrane group liquid accumulation tank is connected with a membrane separator through a filter, a first pressure transmitter and a first booster pump, and the membrane separator is connected with the tail gas buffer tank through an organic gas circulating pipe. The membrane separator is connected with a standby absorption tank through an exhaust pipe and a retreatment pipe, the membrane separator is connected with the atmosphere through the exhaust pipe and a qualified discharge pipe in sequence, the exhaust pipe is provided with a detection hole, the bottom of the tail gas buffer tank and the bottom of the membrane module liquid accumulation tank are connected with a recycled liquid metering tank, and the recycled liquid metering tank is connected with a reaction kettle. By arranging the retreatment pipe on the exhaust pipe and monitoring through the detection hole, when the content of the VOCs exceeds the standard, the tail gas is introduced into the standby absorption tank, and the VOCs in the tail gas are absorbed to reach the standard and then discharged, so that the safety of tail gas emission is further improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of VOCs treatment, and particularly relates to a VOCs treatment and recovery device. Background Art

[0002] In the field of VOCs (volatile organic compounds) treatment and recovery, although the existing treatment devices have achieved certain results, there are still several problems to be solved urgently. First of all, as a key component, the membrane separator often faces the challenge of excessive solid impurities carried by the gas during the treatment process. The accumulation of these impurities on the surface of the membrane module will not only increase the permeation resistance of the membrane, reduce the separation efficiency, but also may cause physical damage to the membrane, such as scratches or perforations, thus accelerating the wear of the membrane, shortening its service life, and increasing the operation and maintenance costs.

[0003] Secondly, in the current treatment process, the gas separated by the membrane separator is often directly discharged. Although it meets the emission standards in most cases, this approach ignores the potential risks during equipment failures or membrane module cleaning suspensions. In these cases, the untreated VOCs-containing waste gas may be directly discharged into the atmosphere, causing environmental pollution.

[0004] In addition, there are also deficiencies in the gas-liquid separation link in the existing technology. After gas-liquid separation, the liquid usually directly enters the reaction kettle to participate in production. However, usually, the recovery of VOCs and the utilization of the recovered liquid cannot be carried out simultaneously due to pressure reasons, affecting the production efficiency.

[0005] To sum up, the current VOCs treatment and recovery devices have deficiencies in aspects such as membrane module protection, waste gas treatment, and gas-liquid separation and metering. These problems limit the overall performance and stability of the devices, and also restrict their wide application in environmental protection and industrial production. Summary of the Utility Model

[0006] The utility model provides a VOCs treatment and recovery device to solve the problems in membrane module protection, waste gas treatment, and gas-liquid separation.

[0007] To solve the above problems, the technical solution of the utility model is as follows:

[0008] The VOCs treatment and recovery device described in the present utility model includes a tail gas main pipe. One end of the tail gas main pipe is connected to a tail gas buffer tank. The tail gas buffer tank is connected to a membrane group liquid accumulation tank through a second pressure transmitter, a second booster pump, and a condenser. The gas outlet of the membrane group liquid accumulation tank is connected to a membrane separator through a filter, a first pressure transmitter, and a first booster pump. A membrane module is provided in the membrane separator. The membrane separator is connected back to the tail gas buffer tank through an organic gas circulation pipe. A vacuum pump is provided on the organic gas circulation pipe. The membrane separator is sequentially connected to a spare absorption tank through an exhaust pipe and a reprocessing pipe, and is sequentially connected to the atmosphere through an exhaust pipe and a qualified discharge pipe. A detection hole is provided on the exhaust pipe. An exhaust main valve, a qualified exhaust valve, and a reprocessing valve are respectively provided on the exhaust pipe, the qualified discharge pipe, and the reprocessing pipe. The bottoms of the tail gas buffer tank and the membrane group liquid accumulation tank are connected to a recovered liquid metering tank through a pipeline. The recovered liquid metering tank is connected to a reaction kettle. The gas outlet pipe at the top of the reaction kettle is connected to the tail gas main pipe.

[0009] The tail gas buffer tank and the membrane group liquid accumulation tank are separately arranged from the recovered liquid metering tank to prevent the application of the recovered liquid and the VOCs recovery from not being able to be carried out simultaneously due to pressure reasons.

[0010] By providing a reprocessing pipe on the exhaust pipe and monitoring through the detection hole, when the VOCs content exceeds the standard, the qualified exhaust valve on the qualified discharge pipe is closed, and the reprocessing valve on the reprocessing pipe is opened to introduce the tail gas into the spare absorption tank. After the VOCs in the tail gas are absorbed to meet the standard, it is discharged, further improving the safety of the tail gas discharge.

[0011] When the second pressure transmitter monitors that the pressure in the tail gas buffer tank reaches the starting pressure, the second booster pump is started for transportation.

[0012] The gas separated by the gas-liquid separation in the membrane group liquid accumulation tank will carry some solid particles due to different processes. After being filtered by the filter, the solid particles are removed, which is beneficial for the membrane module in the subsequent membrane separator to separate, and at the same time can extend the service life of the membrane module. After precipitation and filtration in the membrane group liquid accumulation tank, it needs to be pressurized by the first booster pump again to improve the efficiency and effect of the membrane tissue filtration.

[0013] Further, an exhaust gas flowmeter is provided on the exhaust pipe.

[0014] Further, one-way valves are provided before and after the condenser.

[0015] One-way valves are provided before and after the condenser to prevent the condensed gas-liquid mixture from flowing back.

[0016] Further, a temperature transmitter is provided on the pipeline at the front end of the condenser inlet.

[0017] The temperature of the cooling medium in the condenser and its flow rate can be adjusted according to the temperature of the tail gas monitored by the temperature transmitter on the front pipeline at the inlet of the condenser, so as to reach the required cooling temperature.

[0018] Furthermore, level transmitters are provided in the tail gas buffer tank and the membrane module liquid accumulation tank.

[0019] Furthermore, valves are provided at the bottoms of the tail gas buffer tank and the membrane module liquid accumulation tank.

[0020] When the liquid levels in the tail gas buffer tank and the membrane module liquid accumulation tank reach a certain position, the level transmitters control the valves at the bottoms of the tail gas buffer tank and the membrane module liquid accumulation tank to discharge the VOCs liquid into the recovery liquid metering tank for storage, realizing automatic storage. When production is required, it is pumped into the reaction kettle through the recovery liquid metering tank.

[0021] The organic liquid is metered and then added to the reaction kettle for recycling, reducing material loss.

[0022] Working principle:

[0023] The tail gas containing VOCs from the tail gas main pipe enters the tail gas buffer tank. After reaching the starting pressure, the second pressure transmitter controls the second booster pump to start. The gas is pressurized by the second booster pump to form a high-concentration organic gas. Then, part of the high-concentration organic gas is cooled into a liquid by the condenser. The gas-liquid mixture enters the membrane module liquid accumulation tank through the one-way valve. The organic liquid stays at the bottom of the membrane module liquid accumulation tank. The gas is filtered through the filter to remove solid particles, and the first pressure transmitter controls the first booster pump to pressurize the gas. The gas enters the membrane module in the membrane separator for VOCs separation. Most of the VOCs molecules will be adsorbed on the surface of the membrane module and dissolved. The VOCs dissolved on the membrane surface are adsorbed onto the vacuum central pipe of the membrane module by the continuous vacuum suction applied by the vacuum pump on the organic gas circulation pipe, and are transported back to the tail gas buffer tank through the organic gas circulation pipe for the next cycle. The remaining gas enters the exhaust pipe through the membrane separator, and the flow rate is adjusted by the exhaust flowmeter. The gas is detected through the detection hole. When the gas index reaches the emission standard, the exhaust main valve and the qualified exhaust valve are opened, and the gas is discharged through the exhaust pipe and the qualified discharge pipe. When the gas index does not reach the emission standard, the exhaust main valve and the reprocessing valve are opened, and the gas enters the standby absorption tank through the exhaust pipe and the reprocessing pipe for treatment and then discharged. When the liquid levels in the tail gas buffer tank and the membrane module liquid accumulation tank reach a certain position, the level transmitters control the valves at the bottoms of the tail gas buffer tank and the membrane module liquid accumulation tank to discharge the VOCs liquid into the recovery liquid metering tank for storage, realizing automatic storage. When production is required, it is pumped into the reaction kettle through the recovery liquid metering tank, and the waste gas containing VOCs generated in the reaction kettle enters the tail gas main pipe.

[0024] The beneficial effects of the present utility model are as follows:

[0025] (1) The tail gas buffer tank and the membrane module liquid accumulation tank are separately arranged from the recycled liquid metering tank to prevent the application of the recycled liquid and the VOCs recovery from being unable to proceed simultaneously due to pressure reasons.

[0026] (2) By setting a reprocessing pipe on the exhaust pipe and monitoring through the detection hole, when the VOCs content exceeds the standard, the qualified exhaust valve on the qualified discharge pipe is closed, and the reprocessing valve on the reprocessing pipe is opened to introduce the tail gas into the standby absorption tank. After the VOCs in the tail gas are absorbed up to the standard, they are discharged, further improving the safety of tail gas discharge.

[0027] (3) When the second pressure transmitter monitors that the pressure in the tail gas buffer tank reaches the starting pressure, the second booster pump is started for transportation.

[0028] (4) The gas separated by the gas-liquid separation in the membrane module liquid accumulation tank will carry some solid particles due to different processes. After being filtered by the filter, the solid particles are removed, which is beneficial to the separation of the membrane components of the subsequent membrane separator and can also extend the service life of the membrane components. After precipitation and filtration in the membrane module liquid accumulation tank, it is then pressurized by the first booster pump, effectively improving the efficiency and effect of membrane tissue filtration.

[0029] (5) Check valves are set before and after the condenser to prevent the backflow of the condensed gas-liquid mixture.

[0030] (6) The temperature and flow rate of the cooling medium in the condenser can be adjusted according to the temperature of the tail gas monitored by the temperature transmitter on the front end of the pipeline at the inlet of the condenser to reach the required cooling temperature.

[0031] (7) When the liquid levels in the tail gas buffer tank and the membrane module liquid accumulation tank reach a certain position, the liquid level transmitter controls the valves at the bottoms of the tail gas buffer tank and the membrane module liquid accumulation tank to discharge the VOCs liquid into the recycled liquid metering tank for storage, realizing automatic storage. When production is needed, it is pumped into the reaction kettle through the recycled liquid metering tank. The organic liquid is metered and added to the reaction kettle for recycling, reducing material loss. Description of the Drawings

[0032] The drawings described herein are used to provide a further understanding of the present invention and form a part of the present invention. In the drawings:

[0033] Figure 1 It is a schematic structural diagram of the VOCs treatment and recovery device of the present invention;

[0034] In the figure: 1. Tail gas buffer tank; 2. Condenser; 3. Membrane module liquid accumulation tank; 4. Recycling liquid metering tank; 5. Filter; 6. First pressure transmitter; 7. First booster pump; 8. Membrane separator; 9. Spare absorption tank; 10. Vacuum pump; 11. Organic gas circulation pipe; 12. Reactor; 13. Exhaust pipe; 14. Qualified discharge pipe; 15. Reprocessing pipe; 16. Detection hole; 17. Exhaust main valve; 18. Qualified exhaust valve; 19. Reprocessing valve; 20. Second pressure transmitter; 21. Second booster pump; 22. Temperature transmitter; 23. Exhaust gas flowmeter; 24. Liquid level transmitter. Specific embodiments

[0035] The following provides an understandable description of the present utility model in combination with embodiments.

[0036] In one embodiment, as Figure 1 shown, the VOCs treatment and recycling device includes a tail gas main pipe. One end of the tail gas main pipe is connected to the tail gas buffer tank 1. The tail gas buffer tank 1 is connected to the membrane module liquid accumulation tank 3 through the second pressure transmitter 20, the second booster pump 21, and the condenser 2. The gas outlet of the membrane module liquid accumulation tank 3 is connected to the membrane separator 8 through the filter 5, the first pressure transmitter 6, and the first booster pump 7. A membrane module is provided in the membrane separator 8. The membrane separator 8 is connected back to the tail gas buffer tank 1 through the organic gas circulation pipe 11. A vacuum pump 10 is provided on the organic gas circulation pipe 11. The membrane separator 8 is sequentially connected to the spare absorption tank 9 through the exhaust pipe 13 and the reprocessing pipe 15. The membrane separator 8 is sequentially connected to the atmosphere through the exhaust pipe 13 and the qualified discharge pipe 14. A detection hole 16 is provided on the exhaust pipe 13. An exhaust main valve 17, a qualified exhaust valve 18, and a reprocessing valve 19 are respectively provided on the exhaust pipe 13, the qualified discharge pipe 14, and the reprocessing pipe 15. The bottoms of the tail gas buffer tank 1 and the membrane module liquid accumulation tank 3 are connected to the recycling liquid metering tank 4 through pipelines. The recycling liquid metering tank 4 is connected to the reactor 12. The gas outlet pipeline at the top of the reactor 12 is connected to the tail gas main pipe.

[0037] The tail gas buffer tank 1 and the membrane module liquid accumulation tank 3 are separately arranged from the recycling liquid metering tank 4 to prevent the application of the recycling liquid and the VOCs recycling from not being able to be carried out simultaneously due to pressure reasons.

[0038] By providing a reprocessing pipe 15 on the exhaust pipe 13 and monitoring through the detection hole 16, when the VOCs content exceeds the standard, the qualified exhaust valve 18 on the qualified discharge pipe 14 is closed, and the reprocessing valve 19 on the reprocessing pipe 15 is opened to introduce the tail gas into the spare absorption tank 9. After the VOCs in the tail gas are absorbed to meet the standard, they are discharged, further improving the safety of tail gas discharge.

[0039] When the second pressure transmitter 20 monitors that the pressure in the tail gas buffer tank 1 reaches the starting pressure, the second booster pump 21 is started for transportation.

[0040] The gas that has undergone gas-liquid separation in the membrane module liquid accumulation tank 3 will carry some solid particles due to different processes. After being filtered by the filter 5 to remove the solid particles, it is beneficial for the membrane components of the subsequent membrane separator 8 to perform separation, and at the same time, it can extend the service life of the membrane components. After precipitation and filtration in the membrane module liquid accumulation tank 3, it needs to be pressurized by the first booster pump 7 before it can improve the efficiency and effect of membrane tissue filtration.

[0041] Furthermore, an exhaust gas flowmeter 23 is provided on the exhaust pipe 13.

[0042] Furthermore, check valves are provided before and after the condenser 2.

[0043] Setting check valves before and after the condenser 2 can prevent the condensed gas-liquid mixture from flowing back.

[0044] Furthermore, a temperature transmitter 22 is provided on the pipeline at the front end of the inlet of the condenser 2.

[0045] The temperature and flow rate of the cooling medium in the condenser 2 can be adjusted according to the temperature of the tail gas monitored by the temperature transmitter 22 on the pipeline at the front end of the inlet of the condenser 2 to reach the required cooling temperature.

[0046] Furthermore, a liquid level transmitter 24 is provided in the tail gas buffer tank 1 and the membrane module liquid accumulation tank 3.

[0047] Furthermore, valves are provided at the bottoms of the tail gas buffer tank 1 and the membrane module liquid accumulation tank 3.

[0048] When the liquid levels in the tail gas buffer tank 1 and the membrane module liquid accumulation tank 3 reach a certain position, the liquid level transmitter 24 controls the valves at the bottoms of the tail gas buffer tank 1 and the membrane module liquid accumulation tank 3 to discharge the VOCs liquid into the recovery liquid metering tank 4 for storage, realizing automatic storage. When production is required, it is pumped into the reaction kettle 12 through the recovery liquid metering tank 4.

[0049] The organic liquid is added to the reaction kettle 12 after being metered and recycled to reduce material loss.

[0050] Working principle:

[0051] The tail gas containing VOCs from the tail gas main pipe enters the tail gas buffer tank 1. After reaching the startup pressure, the second pressure transmitter 20 controls the startup of the second booster pump 21. The gas is pressurized by the second booster pump 21 to form a high-concentration organic gas. Then, part of the high-concentration organic gas is cooled into a liquid by the condenser 2. The gas-liquid mixture enters the membrane module liquid accumulation tank 3 through the check valve. The organic liquid stays at the bottom of the membrane module liquid accumulation tank 3. The gas is filtered by the filter 5 to remove solid particles, and the first booster pump 7 is pressurized by the first pressure transmitter 6. The gas enters the membrane module in the membrane separator 8 for VOCs separation. Most VOCs molecules will be adsorbed on the surface of the membrane module and dissolved. The VOCs dissolved on the membrane surface are adsorbed to the vacuum central pipe of the membrane module by the vacuum suction continuously applied by the vacuum pump 10 on the organic gas circulation pipe 11, and are transported back to the tail gas buffer tank 1 through the organic gas circulation pipe 11 for the next cycle. The remaining gas enters the exhaust pipe 13 through the membrane separator 8. The flow rate is adjusted by the exhaust gas flowmeter 23. The gas is detected through the detection hole 16. When the gas index reaches the emission standard, the exhaust main valve 17 and the qualified exhaust valve 18 are opened, and the gas is discharged through the exhaust pipe 13 and the qualified discharge pipe 14. When the gas index does not reach the emission standard, the exhaust main valve 17 and the reprocessing valve 19 are opened, and the gas enters the standby absorption tank 9 through the exhaust pipe 13 and the reprocessing pipe 15 for treatment before being discharged. When the liquid levels in the tail gas buffer tank 1 and the membrane module liquid accumulation tank 3 reach a certain position, the liquid level transmitter 24 controls the valves at the bottoms of the tail gas buffer tank 1 and the membrane module liquid accumulation tank 3 to discharge the VOCs liquid into the recovery liquid metering tank 4 for storage, realizing automatic storage. When production is needed, it is pumped into the reaction kettle 12 through the recovery liquid metering tank 4. The waste gas containing VOCs generated in the reaction kettle 12 enters the tail gas main pipe.

[0052] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment.

[0053] The above description is only for the embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A VOCs treatment and recovery device, characterized in that, It includes an exhaust gas main pipe. One end of the exhaust gas main pipe is connected to an exhaust gas buffer tank (1). The exhaust gas buffer tank (1) is connected to a membrane module liquid accumulation tank (3) through a second pressure transmitter (20), a second booster pump (21), and a condenser (2). The gas outlet of the membrane module liquid accumulation tank (3) is connected to a membrane separator (8) through a filter (5), a first pressure transmitter (6), and a first booster pump (7). A membrane module is provided in the membrane separator (8). The membrane separator (8) is connected back to the exhaust gas buffer tank (1) through an organic gas circulation pipe (11). A vacuum pump (10) is provided on the organic gas circulation pipe (11). The membrane separator (8) is sequentially connected to a spare absorption tank (9) through an exhaust pipe (13) and a reprocessing pipe (15). The membrane separator (8) is sequentially connected to the atmosphere through an exhaust pipe (13) and a qualified discharge pipe (14). A detection hole (16) is provided on the exhaust pipe (13). An exhaust main valve (17), a qualified exhaust valve (18), and a reprocessing valve (19) are respectively provided on the exhaust pipe (13), the qualified discharge pipe (14), and the reprocessing pipe (15). The bottoms of the exhaust gas buffer tank (1) and the membrane module liquid accumulation tank (3) are connected to a recovered liquid metering tank (4) through a pipeline. The recovered liquid metering tank (4) is connected to a reaction kettle (12). The gas outlet pipeline at the top of the reaction kettle (12) is connected to the exhaust gas main pipe.

2. The VOCs treatment and recovery device according to claim 1, characterized in that, An exhaust gas flowmeter (23) is provided on the exhaust pipe (13).

3. The VOCs treatment and recovery device according to claim 1, characterized in that, One-way valves are provided before and after the condenser (2).

4. The VOCs treatment and recovery device according to claim 1, wherein, A temperature transmitter (22) is provided on the pipeline at the front end of the inlet of the condenser (2).

5. The VOCs treatment and recovery device according to claim 1, wherein Level transmitters (24) are provided in the exhaust gas buffer tank (1) and the membrane module liquid accumulation tank (3).

6. The VOCs treatment and recovery device according to claim 5, characterized in that, Valves are provided at the bottoms of the exhaust gas buffer tank (1) and the membrane module liquid accumulation tank (3).

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