VOCS waste gas treatment system

Abstract

The utility model discloses a VOCS waste gas treatment system, and belongs to the technical field of waste gas treatment. The device comprises a filter device, a gas inlet of the filter device is connected with a waste gas source, and a gas outlet of the filter device is connected with a purification device; the purification device is connected with an adsorption unit through an adsorption gas inlet main pipe; the adsorption unit is connected with an exhaust funnel through an adsorption air outlet header pipe; wherein the purification device comprises an ion generator, an ultraviolet lamp tube and a catalyst layer irradiated by the ultraviolet lamp; the adsorption unit comprises an adsorption box and an adsorbent arranged in the adsorption box, and an adsorption fan is arranged between the adsorption box and the exhaust funnel. Powder particles and water mist in waste gas are intercepted through the filter device, then the concentration of VOCs in the waste gas is reduced through the purification device, and finally the VOCs are adsorbed through activated carbon, so that damage and blockage to the activated carbon are reduced, the service life of the activated carbon is prolonged, and the operation cost of equipment is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste gas treatment, and more specifically relates to a VOC S Exhaust gas treatment system. Background Art

[0002] Traditional paint spraying waste gas mainly comes from the volatile waste gas generated by the organic solvents contained in the paint during the spraying volatilization of paint mist and the drying process, which is called volatile organic compounds (VOCs), and its main components are benzene, toluene, xylene, etc. The most important VOCs chemical components in the coating process are aromatic hydrocarbons, ethyl acetate, butyl acetate and other VOCs substances. This type of waste gas can cause poisoning after inhalation through the respiratory tract and is currently recognized as a strong carcinogen. Long-term inhalation of low-concentration paint spraying waste gas can cause chronic respiratory diseases such as coughing, chest tightness, and asthma. In severe cases, convulsions and coma may occur; if the inhaled concentration is greater than 1500mg / m 3 Benzene vapor can cause aplastic anemia. In addition, organic waste gas plays an important role in the formation of photochemical smog pollution and acid rain.

[0003] With the introduction of environmental protection requirements, water-based paint has become a popular environmentally friendly paint. Unlike oil-based paint, the amount of tail gas produced during the use of water-based paint is significantly reduced. However, most water-based paints on the market are composed of acrylic acid and polyurethane. These substances are easy to clog activated carbon when adsorbed and are difficult to desorb, which greatly shortens the service life of activated carbon.

[0004] After searching, the application case with Chinese patent publication number CN 111974161 A discloses a VOCs waste gas treatment intelligent activated carbon adsorption box and its use method. The application case includes a main shell, multiple activated carbon filling units are arranged in the inner cavity of the main shell, one end of the main shell is provided with a waste gas inlet gradually expanding pipe, the other end is provided with a waste gas outlet gradually contracting pipe, the outlet end of the waste gas outlet gradually contracting pipe is provided with an outlet air duct, the outlet air duct is provided with an online monitoring device, the main shell is provided with at least one temperature transmitter and a differential pressure transmitter, the waste gas inlet end of the main shell is provided with a humidity transmitter, the outside of the main shell is provided with a control box, and the main shell is also provided with a fire extinguishing device, and the temperature transmitter, differential pressure transmitter, humidity transmitter, online monitoring device and fire extinguishing device are respectively connected to the control box through lines.

[0005] For another example, the application case with Chinese patent publication number CN 214809756 U discloses a VOCs waste gas treatment system. The application case includes a spray scrubber, which is composed of a primary scrubber section, an alkali scrubber section and an oxidation section connected in series from bottom to top, the primary scrubber section is connected to the alkali scrubber section through a first ascending air pipe, the alkali scrubber section is connected to the oxidation section through a second ascending air pipe, a cyclone separator with a top outlet connected to the first ascending air pipe is provided in the primary scrubber section, a first distributor is provided in the cyclone separator, a first filler and a second distributor are provided in the alkali scrubber section from bottom to top, and a second filler, a third distributor and a demister are provided in the oxidation section from bottom to top.

[0006] The above applications all involve VOCS waste gas treatment systems, and all of them can improve the utilization rate of activated carbon to a certain extent. However, the waste gas treatment systems in the above applications do not have the regeneration function of activated carbon, so there is still room for optimization. In short, the industry has never stopped researching the technology of VOCS waste gas treatment. Utility Model Content

[0007] 1. Problems to be solved

[0008] In view of at least some of the problems existing in the above-mentioned prior art, the present invention proposes a VOCS waste gas treatment system, the purpose of which is to solve the problem that the existing VOCs waste gas treatment easily causes the activated carbon to be blocked and difficult to desorb cleanly, thereby affecting the utilization rate and service life of the activated carbon.

[0009] 2. Technical solution

[0010] In order to solve the above problems, the technical solution adopted by the utility model is as follows:

[0011] The utility model is a VOC S Exhaust gas treatment systems, including filter devices,

[0012] The air inlet of the filter device is connected to the exhaust gas source, and the air outlet is connected to the purification device;

[0013] The purification device is connected to an adsorption unit via an adsorption intake manifold;

[0014] The adsorption unit is connected to an exhaust pipe via an adsorption gas outlet main pipe;

[0015] Wherein, the purification device comprises an ion generator, an ultraviolet lamp and a catalyst layer irradiated by the ultraviolet lamp;

[0016] The adsorption unit comprises an adsorption box and an adsorbent arranged in the adsorption box, and an adsorption fan is arranged between the adsorption box and the exhaust pipe.

[0017] Furthermore, a plurality of adsorption boxes are arranged in parallel, and the adsorption air inlet of each adsorption box is connected to the adsorption air inlet main pipe through its own adsorption air inlet branch pipe, and the adsorption air outlet is connected to the adsorption air outlet main pipe through its own adsorption air outlet branch pipe.

[0018] Furthermore, the filter device is a dry filter device, and a pressure sensor is provided inside the dry filter device.

[0019] Furthermore, it also includes a desorption unit, which includes a catalytic combustion box, the air inlet of which is connected to the adsorption unit through a desorption air inlet main pipeline; its air outlet is divided into two paths, one is connected to the adsorption unit through a desorption air outlet main pipeline, and the other is connected to the exhaust pipe through an exhaust pipe.

[0020] Furthermore, a flame arrester and an electric air valve are provided on the desorption air outlet main pipeline and the desorption air inlet main pipeline, and the electric air valve is linked with the temperature measuring element in the adsorption box and the catalytic combustion box.

[0021] Furthermore, the desorption gas outlet main pipeline is connected to an air supply fan through an air supply pipeline, and an electric air valve is provided on the air supply pipeline, and the electric air valve is linked to the adsorption box and the temperature measuring element in the catalytic combustion box.

[0022] Furthermore, the adsorption unit is connected to a sprayer via a spray pipe.

[0023] Furthermore, the adsorbent is activated carbon, and the activated carbon is honeycomb activated carbon with an iodine value ≥800.

[0024] 3. Beneficial effects

[0025] Compared with the prior art, the beneficial effects of the utility model are:

[0026] (1) A VOC of the utility model S In the exhaust gas treatment system, the exhaust gas first passes through the filter device to intercept the powder particles and water mist in the exhaust gas, and then enters the purification device. The ion generator can bombard the polyurethane and acrylic acid in the water-based paint to cause defects. After passing through the ultraviolet catalytic unit composed of ultraviolet lamps and catalysts, it can be effectively decomposed by ultraviolet rays, free radicals and other active substances, thereby reducing damage and blockage to the activated carbon, extending the service life of the activated carbon, and reducing equipment operating costs.

[0027] (2) The VOCS waste gas treatment system of the utility model can desorb and regenerate the adsorbed activated carbon through the provision of a desorption unit, thereby further improving the utilization rate of the adsorbed carbon.

[0028] (3) The utility model provides a VOCS waste gas treatment system, which can timely control the temperature of each part to ensure the stability of the desorption process by linking the electric air valves on the desorption air inlet main pipeline, the desorption air outlet main pipeline and the air supply pipeline with the temperature measuring elements in the adsorption box and the catalytic combustion box. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The utility model is a schematic diagram of the connection relationship between the various components of a VOCS exhaust gas treatment system.

[0030] In the figure: 1. filter device; 2. purification device;

[0031] 3. Adsorption unit; 31. Adsorption air inlet manifold; 32. Adsorption air outlet manifold; 33. Adsorption box; 34. Adsorption fan;

[0032] 4. Desorption unit; 41. Catalytic combustion box; 42. Desorption air inlet main pipeline; 43. Desorption air outlet main pipeline; 44. Exhaust pipe; 45. Flame arrester; 46. Air supply fan; 47. Electric air valve; 48. Desorption fan; 49. Air supply pipeline;

[0033] 51. Sprinkler; 52. Sprinkler pipe; 6. Exhaust pipe. DETAILED DESCRIPTION

[0034] The utility model is further described below in conjunction with specific embodiments.

[0035] Example 1

[0036] like Figure 1 As shown, a VOCS exhaust gas treatment system of this embodiment includes a filter device 1, a purification device 2, an adsorption unit 3 and an exhaust pipe 6 which are connected in sequence.

[0037] The filter device 1 is used to intercept powder particles and water mist in the exhaust gas, and its air inlet is connected to the exhaust gas source, and its air outlet is connected to the purification device 2.

[0038] The purification device 2 is used to reduce the concentration of VOCs in the exhaust gas, and includes an ion generator, an ultraviolet lamp, and a catalyst layer irradiated by the ultraviolet lamp. The purification device 2 is connected to an adsorption unit 3 through an adsorption intake manifold 31.

[0039] The adsorption unit 3 is used to adsorb the remaining organic small molecules in the exhaust gas to achieve the final purification of the organic exhaust gas; it includes an adsorption box 33 and an adsorbent arranged in the adsorption box 33, and the adsorption unit 3 is connected to the exhaust pipe 6 through the adsorption gas outlet main pipe 32, and the adsorption gas outlet main pipe 32 is provided with an adsorption fan 34.

[0040] The exhaust pipe 6 is used to discharge the purified tail gas.

[0041] The adsorption box 33 can be provided in multiple numbers according to actual needs, and the multiple adsorption boxes 33 are arranged in parallel. The adsorption air inlet of each adsorption box 33 is connected to the adsorption air inlet main pipe 31 through its own adsorption air inlet branch pipe, and its adsorption air outlet is connected to the adsorption air outlet main pipe 32 through its own adsorption air outlet branch pipe.

[0042] Specifically in this embodiment, the filter device 1 can adopt a dry filter. The dry filter is composed of multi-stage filter cotton and bag filter to form a high-efficiency dust removal device and a pressure sensor is provided. The filter cotton and dust removal bag are replaced in time according to the pressure display.

[0043] The purification device 2 is a high-energy ion-coupled ultraviolet device consisting of an ion generator, an ultraviolet lamp and a catalyst layer irradiated by the ultraviolet lamp; wherein the ion generator serves as a high-energy ion beam unit, and the ultraviolet lamp and the catalyst layer constitute an ultraviolet catalytic unit.

[0044] There are four adsorption boxes 33. The adsorbent is honeycomb activated carbon with an iodine value of ≥800, and the activated carbon is arranged in no less than six layers on the windward side, and the gaps in each layer of activated carbon are staggered to avoid short-circuiting.

[0045] It is worth noting that, in this embodiment, the dry filter and high-energy ion-coupled ultraviolet device are both existing technologies, and their specific structures are not described in detail.

[0046] A VOCs waste gas treatment system of this embodiment has the following working principle and workflow:

[0047] The VOCS exhaust gas first enters the filter device 1 for preliminary filtration to remove powder particles and water mist in the exhaust gas;

[0048] Then, after the exhaust gas enters the purification device 2, it is bombarded by the high-energy ion beam generated by the ion generator, which will cause reactions such as bond breaking and ring opening; the generated high-energy ions reach the ultraviolet catalytic unit with the airflow, which can stimulate and optimize the catalytic performance of the catalyst to produce more free radicals; the ultraviolet light generated by the ultraviolet catalytic unit can increase the discharge quantity of the high-energy ion unit; the two units have both the synergistic degradation effect of series connection, and also the effect of mutual coupling to promote the production of active substances; the generated active substances (such as ozone) can enter the adsorption box 33 with the airflow, and then degrade the organic matter adsorbed by the activated carbon, realize the dynamic regeneration of the activated carbon, realize the efficient treatment of the exhaust gas in the system and reduce the replacement frequency of the activated carbon.

[0049] The remaining small organic molecules enter the adsorption box 33 and are adsorbed in the activated carbon with a high iodine value to purify the organic waste gas. The clean tail gas flows through the exhaust pipe 6 and is discharged at high altitude to meet the standards.

[0050] Example 2

[0051] A VOCs waste gas treatment system of this embodiment, based on the above embodiment, is further provided with a desorption unit 4 for desorption and regeneration of adsorption saturated activated carbon, thereby further improving the utilization rate of adsorbed carbon.

[0052] refer to Figure 1 As shown, the desorption unit 4 includes a catalytic combustion box 41, the air inlet of the catalytic combustion box 41 is connected to a desorption air intake main pipe 42, and the desorption air intake main pipe 42 is provided with a plurality of branch pipes, which are respectively connected to the corresponding adsorption boxes 33; its air outlet is divided into two paths, one is connected to the adsorption unit 3 through the desorption air outlet main pipe 43, and the other is connected to the exhaust pipe 6 through the exhaust pipe 44.

[0053] A VOCS waste gas treatment system of the present embodiment has the following desorption principle: the gas in the desorption unit 4 (initially the air existing in the system, which is subsequently supplemented by the air supply fan) circulates in the catalytic combustion box 41 and the adsorption box 33, the gas is heated in the catalytic combustion box 41, and the generated high-temperature gas reaches the adsorption box 33 and desorbs the organic waste gas adsorbed by the activated carbon to produce high-concentration organic waste gas, which enters the catalytic combustion box 41 with the air flow, and the organic matter in the high-concentration waste gas is catalytically oxidized on the catalyst (for example, metal platinum) under high temperature conditions, and the organic matter is mineralized to purify the waste gas, and a part of the purified gas enters the adsorption box 33 for circulation, and the other part is discharged into the exhaust pipe 6 through the exhaust pipe 44 to meet the emission standards.

[0054] A VOC in this embodiment S The exhaust gas treatment system, the desorption gas outlet main pipeline 43 is provided with a desorption fan 48, an electric air valve 47 and a flame arrester 45.

[0055] The desorption gas outlet main pipeline 43 is connected to an air supply fan 46 via an air supply pipeline 49 , and an electric air valve 47 is also provided on the air supply pipeline 49 .

[0056] The desorption air intake main pipeline 42 is provided with an electric air valve 47 and a flame arrester 45 . The electric air valve 47 is used to supply cold air into the catalytic combustion box 41 .

[0057] The adsorption unit 3 is connected to a sprayer 51 via a spray pipe 52 .

[0058] In addition, the adsorption box 33 and the catalytic combustion box 41 are both equipped with temperature measuring elements. The feedback signals of the temperature measuring elements are linked with the valves of the three regulating electric air valves 47 and the sprinkler 51 through the automatic control system to adjust the temperature in the pipeline and the equipment, and automatically trigger the sprinkler 51 when the critical value is reached, thereby ensuring the safe operation of the entire system.

[0059] A VOC in this embodiment S The exhaust gas treatment system, the desorption unit 4 can be divided into online desorption and offline desorption according to the actual production and operation conditions. Among them, online desorption is aimed at continuous working conditions and can meet the continuous operation without stopping production; offline desorption is aimed at intermittent operation conditions.

[0060] Taking online desorption as an example, the following describes its working process in detail:

[0061] Disconnect the adsorption inlet branch pipe and the adsorption outlet branch pipe of the adsorption box 33 that has been adsorbed and saturated, and convert the adsorption box 33 from the adsorption state to the desorption state;

[0062] The catalytic combustion box 41 is turned on for preheating, the exhaust pipe 44 is turned on, and when the combustion chamber reaches the catalytic combustion temperature of 280°C (feedback signal of the temperature measuring element), the desorption gas outlet main pipeline 43 and the desorption gas inlet main pipeline 42 of the adsorption box 33 to be desorbed are opened, and the desorption fan 48 and the air supply fan 46 are turned on at the same time to perform desorption, and the desorption is maintained for 4 hours;

[0063] After the desorption is completed, the heating element of the catalytic combustion box 41 is turned off, and the desorption fan 48 is turned off; the air supply fan 46, the desorption gas outlet main pipeline 43, the desorption gas inlet main pipeline 42 and the exhaust pipe 44 are kept open; after working for 0.5 hours, the air supply pipeline 49, the desorption gas outlet main pipeline 43, the desorption gas inlet main pipeline 42 and the exhaust pipe 44 are closed in order;

[0064] When the remaining adsorption boxes 33 meet the desorption requirements, the above desorption process is repeated in order, during which the other adsorption boxes 33 are in a normal working adsorption state.

[0065] In the above desorption process, when the temperature in the adsorption box 33 (desorption state) is higher than 110°C or the temperature in the desorption gas outlet main pipeline 43 is higher than 130°C, the electric air valve 47 on the desorption gas outlet main pipeline 43 is closed, and the electric air valve 47 on the air supply pipeline 49 is opened;

[0066] When the temperature in the adsorption box 33 is lower than 90°C or the temperature in the desorption gas outlet main pipeline 43 is lower than 100°C, the electric air valve 47 on the desorption gas outlet main pipeline 43 is opened, and the electric air valve 47 on the air supply pipeline 49 is closed;

[0067] When the temperature in the adsorption box 33 exceeds a preset value, the sprinkler 51 will be activated to prevent fire;

[0068] When the temperature in the combustion chamber of the catalytic combustion box 41 reaches 320°C, the electric air valve 47 on the desorption air intake main pipe 42 is opened to replenish cold air. When the temperature in the combustion chamber of the catalytic combustion box 41 drops to 270°C, the electric air valve 47 on the desorption air intake main pipe 42 is closed to stop replenishing cold air.

[0069] The above schematically describes the present invention and its implementation methods, which are not restrictive. The drawings show only one implementation method of the present invention, and the actual structure is not limited thereto. Therefore, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A VOC S The exhaust gas treatment system is characterized by: comprising a filter device (1), The air inlet of the filter device (1) is connected to the exhaust gas source, and the air outlet is connected to the purification device (2); The purification device (2) is connected to an adsorption unit (3) via an adsorption intake manifold (31); The adsorption unit (3) is connected to an exhaust pipe (6) via an adsorption gas outlet main pipe (32); Wherein, the purification device (2) comprises an ion generator, an ultraviolet lamp tube and a catalyst layer irradiated by the ultraviolet lamp; The adsorption unit (3) comprises an adsorption box (33) and an adsorbent arranged in the adsorption box (33), and an adsorption fan (34) is arranged between the adsorption box (33) and the exhaust pipe (6).

2. A VOC according to claim 1 S The exhaust gas treatment system is characterized by: A plurality of adsorption boxes (33) are arranged in parallel, and the adsorption air inlet of each adsorption box (33) is connected to the adsorption air inlet main pipe (31) through its own adsorption air inlet branch pipe, and the adsorption air outlet is connected to the adsorption air outlet main pipe (32) through its own adsorption air outlet branch pipe.

3. A VOC according to claim 2 S The exhaust gas treatment system is characterized by: The filter device (1) is a dry filter device, and a pressure sensor is arranged inside the dry filter device.

4. A VOC according to any one of claims 1 to 3 S The exhaust gas treatment system is characterized by: It also includes a desorption unit (4), wherein the desorption unit (4) includes a catalytic combustion box (41), the air inlet of the catalytic combustion box (41) is connected to the adsorption unit (3) through a desorption air inlet main pipeline (42); and the air outlet is divided into two paths, one of which is connected to the adsorption unit (3) through a desorption air outlet main pipeline (43), and the other of which is connected to the exhaust pipe (6) through an exhaust pipe (44).

5. A VOC according to claim 4 S The exhaust gas treatment system is characterized by: The desorption air outlet main pipeline (43) and the desorption air inlet main pipeline (42) are provided with a flame arrester (45) and an electric air valve (47), and the electric air valve (47) is linked with the temperature measuring element in the adsorption box (33) and the catalytic combustion box (41).

6. A VOC according to claim 5 S The exhaust gas treatment system is characterized by: The desorption gas outlet main pipeline (43) is connected to an air supply fan (46) via an air supply pipeline (49). An electric air valve (47) is provided on the air supply pipeline (49), and the electric air valve (47) is linked to the adsorption box (33) and the temperature measuring element in the catalytic combustion box (41).

7. A VOCS exhaust gas treatment system according to claim 6, characterized in that: The adsorption unit (3) is connected to a sprayer (51) via a spray pipe (52).

8. A VOCS exhaust gas treatment system according to claim 7, characterized in that: The adsorbent is activated carbon, and the activated carbon is honeycomb activated carbon with an iodine value of ≥800.

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