CN113975961A

CN113975961A - Comprehensive treatment system for waste gas in coating industry

Info

Publication number: CN113975961A
Application number: CN202111205807.5A
Authority: CN
Inventors: 徐文星; 黄万平; 黄德浪
Original assignee: Guangdong Siji Environmental Protection Development Co ltd
Current assignee: Guangdong Siji Environmental Protection Development Co ltd
Priority date: 2021-10-15
Filing date: 2021-10-15
Publication date: 2022-01-28

Abstract

The invention relates to the technical field of waste gas treatment, in particular to a comprehensive waste gas treatment system in the coating industry. The utility model provides a coating trade waste gas integrated processing system, is including the collection wind device, one-level wet-type spray column, static defroster, second grade wet-type spray column and the biological filter bed that connect gradually. The invention skillfully adds a high-voltage electrostatic demister in the whole treatment system as a front-end processor of the biological filter bed, and simultaneously adds a wet spray tower behind the high-voltage electrostatic demister. Therefore, the efficient paint mist removing performance of the high-voltage electrostatic demister can be utilized, the damage of ozone generated by the high-voltage electrostatic demister to a biological bacterial film of the biological filter bed can be avoided, and the biological filter bed can stably run for a long time; the discharged gas after treatment is ensured to meet the environmental protection standard, and the waste gas treatment efficiency is improved.

Description

Comprehensive treatment system for waste gas in coating industry

Technical Field

The invention relates to the technical field of waste gas treatment, in particular to a comprehensive waste gas treatment system in the coating industry.

Background

The biological filter bed is very suitable for treating organic waste gas in various air volume low-concentration coating industries due to the characteristics of low running resistance, low running cost, stable running and the like. In the waste gas treatment process in the coating industry, a biological filter bed is also commonly used for filtering the waste gas, organic waste gas is pretreated by a multi-stage wet spray tower and then enters the biological filter bed for treatment, and the smoke is discharged after the treatment of the biological filter bed. However, the coating waste gas has high paint mist content, so that the paint mist is not easy to eliminate by a conventional method, the operation of a biological filter bed is influenced, and the paint mist cannot be discharged up to the standard due to the fact that the paint mist is discharged from a chimney. The main problem that exists among the present technical means is that the efficiency of multistage wet spray tower preliminary treatment coating cloud is not high, contains more coating cloud in the flue gas that gets into biological filter bed, and the coating cloud can block up biological filler, influences the long-term steady operation of system. The paint mist can also affect a biological bacteria film, so that the operation of the biological filter bed is unstable, the state of the biological bacteria is unstable, and the discharged smoke can not stably reach the standard.

Disclosure of Invention

The invention aims to overcome the defects existing in the prior technical means in the background technology that the pretreatment efficiency of paint mist of the multi-stage wet spray tower is not high, the smoke entering the biological filter bed contains more paint mist, and the paint mist can block biological fillers to influence the long-term stable operation of the system. The paint mist can also influence a biological bacteria film, so that the operation of the biological filter bed is unstable, the state of the biological bacteria is unstable, and the discharged flue gas can not stably reach the standard. The invention can efficiently remove paint mist in the smoke, so that the biological filter bed can stably operate for a long time.

In order to solve the technical problems, the invention adopts the technical scheme that: the utility model provides a coating trade waste gas integrated processing system, includes collection wind device, one-level wet-type spray tower, static defroster, second grade wet-type spray tower and biological filter bed, the first air intake connection that is equipped with on the one-level wet-type spray tower collect wind device, the first air exit that is equipped with on the one-level wet-type spray tower with connect through first tuber pipe between the second air intake that is equipped with on the static defroster, the second air exit that is equipped with on the static defroster pass through the second tuber pipe with the third air intake connection that is equipped with on the second grade wet-type spray tower, the third air exit that is equipped with on the second grade wet-type spray tower pass through the third tuber pipe with fourth air intake connection that is equipped with on the biological filter bed.

Further, one-level wet spray tower includes the tower body, is located the pond of tower body bottom, spray the layer group and first defogging layer, first exhaust port is located the top of tower body, first defogging level in the inside being close to of tower body the position in first exhaust port, spray the layer group and be located first defogging layer with between the pond, spray the layer group with there is the interval between the pond, first air intake with the interval air current switches on, it includes a plurality of range upon range of layers of layer that spray that sets up to spray the layer group.

Further, the layer of spraying is including spraying the basic unit and being located spray the first shower of basic unit top, be equipped with a plurality of on the shower just to spray the first nozzle of basic unit, first shower with it sprays the clearance to exist between the basic unit to spray.

Furthermore, the spraying base layer is a packing layer or a rotational flow plate layer.

Further, the static defroster includes the equipment casing, installs power on the equipment casing and be located the inside electrostatic field of equipment casing, be equipped with the ionization subassembly in the electrostatic field, the ionization subassembly with the power is connected, the second air intake is located one side of equipment casing bottom, the equipment casing is inside to be close to the position of second air intake still is equipped with even wind layer, the electrostatic field is located the top on even wind layer, the second air exit is located the top of equipment casing, the inside of equipment casing is close to the position of second air exit still is equipped with the second shower, be equipped with a plurality of second nozzles on the second shower.

Further, the ionization subassembly is including being located the support and the equal negative pole line of quantity and the positive pole pipe at electric field top, negative pole line and positive pole pipe respectively with the power electricity is connected, the negative pole line hangs on the support, the positive pole pipe is installed the equipment casing with on the inner wall that the electric field position corresponds.

Further, the secondary wet spray tower and the primary wet spray tower have the same structure.

Preferably, the number of the spraying layers is 2-4.

Furthermore, a fan is also arranged on the third air pipe.

Furthermore, the biofilter comprises a filter box body and a biological filler layer positioned in the middle of the filter box body, the fourth air inlet is formed in the top of the filter box body, a third spray pipe is arranged in the position, close to the fourth air inlet, of the filter box body, a plurality of third nozzles facing the biological filler layer are arranged on the third spray pipe, a spray interval exists between the third spray pipe and the biological filler layer, an exhaust interval is reserved between the bottom surface of the biological filler layer and the inner wall of the bottom of the filter box body, the filter box body is further provided with an exhaust channel communicated with the exhaust interval, and a second demisting layer is arranged in the exhaust channel; the bottom of the filtering box body is also connected with a water tank, and the water tank is connected with the third spraying pipe through a spraying pump.

Compared with the prior art, the beneficial effects are:

the invention skillfully adds a high-voltage electrostatic demister in the whole treatment system as a front-end processor of the biological filter bed, and simultaneously adds a wet spray tower behind the high-voltage electrostatic demister. Therefore, the efficient paint mist removing performance of the high-voltage electrostatic demister can be utilized, the damage of ozone generated by the high-voltage electrostatic demister to a biological bacterial film of the biological filter bed can be avoided, and the biological filter bed can stably run for a long time; the discharged gas after treatment is ensured to meet the environmental protection standard, and the waste gas treatment efficiency is improved. Can be used for treating coating waste gas with large paint mist content, so that the biofilter process can be widely applied to the treatment of the spraying waste gas with medium-low concentration organic waste gas content.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic structural view of a primary wet spray tower according to the present invention.

FIG. 3 is a schematic view of the electrostatic demister of the present invention.

FIG. 4 is a schematic view of the structure of the biofilter bed of the present invention.

Detailed Description

The drawings are for illustrative purposes only and are not to be construed as limiting the patent; for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted. The positional relationships depicted in the drawings are for illustrative purposes only and are not to be construed as limiting the present patent.

As shown in fig. 1, the comprehensive treatment system for waste gas in coating industry comprises a wind collecting device 5, a first-stage wet spray tower 1 or a multi-stage wet spray tower, the electrostatic demister 2, the second-stage wet spray tower 3 and the biological filter bed 4, the first air inlet 11 arranged on the first-stage wet spray tower 1 is connected with the air collecting device 5, the first air outlet 12 arranged on the first-stage wet spray tower 1 is connected with the second air inlet 21 arranged on the electrostatic demister 2 through a first air pipe (not drawn in the figure, refer to the arrow direction), the second air outlet 22 arranged on the electrostatic demister 2 is connected with the third air inlet 31 arranged on the second-stage wet spray tower 3 through a second air pipe (not drawn in the figure, refer to the arrow direction), and the third air outlet 32 arranged on the second-stage wet spray tower 3 is connected with the fourth air inlet 41 arranged on the biological filter bed 4 through a third air pipe (not drawn in the figure, refer to the arrow direction).

As shown in fig. 2, the primary wet spray tower 1 includes a tower body 13, a water tank 14 located at the bottom of the tower body 13, a spray layer 16 group and a first demisting layer 15, the first exhaust port 12 is located at the top of the tower body 13, the first demisting layer 15 is located inside the tower body 13 and close to the first exhaust port 12, the spray layer 16 group is located between the first demisting layer 15 and the water tank 14, a gap exists between the spray layer 16 group and the water tank 14, the first air inlet 11 is communicated with the gap air flow, and the spray layer 16 group includes a plurality of spray layers 16 arranged in a stacked manner; the spraying layer 16 comprises a spraying base layer 164 and a first spraying pipe 161 positioned above the spraying base layer 164, a plurality of first nozzles 162 facing the spraying base layer 164 are arranged on the spraying pipe, and a spraying gap 163 is formed between the first spraying pipe 161 and the spraying base layer 164; wherein the spray base layer 164 is a filler layer or a swirl plate layer. The second stage wet spray tower 3 is substantially identical in structure to the first stage wet spray tower 1, wherein the spray base layer 164 is generally designed as a packing layer. In this embodiment, the number of the spraying layers 16 is 3, and in other embodiments, the number of the spraying layers 16 can be adjusted according to actual conditions, and is generally 2 to 4.

As shown in fig. 3, the electrostatic mist eliminator 2 in this embodiment is a high-voltage electrostatic mist eliminator 2, and the high-voltage electrostatic mist eliminator 2 can effectively treat paint mist, and the treatment efficiency is more than 90%. The electrostatic demister 2 comprises an equipment shell 23, a power supply 251 arranged on the equipment shell 23 and a high-voltage electrostatic field 26 positioned in the equipment shell 23, wherein an ionization assembly 25 is arranged in the high-voltage electrostatic field 26, the ionization assembly 25 is connected with the power supply 251, a second air inlet 21 is positioned on one side of the bottom of the equipment shell 23, an air homogenizing layer 24 is further arranged in the equipment shell 23 at a position close to the second air inlet 21, the electrostatic field 26 is positioned above the air homogenizing layer 24, a second air outlet 22 is positioned at the top of the equipment shell 23, a second spray pipe 27 is further arranged in the equipment shell 23 at a position close to the second air outlet 22, and a plurality of second nozzles are arranged on the second spray pipe 27; the ionization assembly 25 comprises a bracket 254 positioned at the top of the electric field, and equal numbers of cathode wires 252 and anode tubes 253, wherein the cathode wires 252 and the anode tubes 253 are respectively electrically connected with the power supply 251, the cathode wires 252 are suspended on the bracket 254, and the anode tubes 253 are installed on the inner wall of the equipment shell 23 corresponding to the position of the electric field.

In this embodiment, a fan 6 is further installed on the third air duct, the fan 6 can ensure that the gas can smoothly enter a fourth air inlet 41 at the top of the biofiltration bed 4, wherein, as shown in fig. 4, the biofiltration bed 4 comprises a filtration box 42 and a biofiltration layer 43 located in the middle of the filtration box 42, the fourth air inlet 41 is located at the top of the filtration box 42, a third spraying pipe 44 is arranged in the filtration box 42 near the fourth air inlet 41, a plurality of third nozzles 45 facing the biofiltration layer 43 are arranged on the third spraying pipe 44, a spraying space 46 exists between the third spraying pipe 44 and the biofiltration layer 43, an exhaust space 47 is left between the bottom surface of the biofiltration layer 43 and the inner wall of the bottom of the filtration box 42, the filtration box 42 is further provided with an exhaust passage 48 communicated with the exhaust space 47, and a second defogging layer 49 is arranged in the exhaust passage 48; the bottom of the filtering box 42 is also connected with a water tank 50, and the water tank 50 is connected with the third spraying pipe 44 through a spraying pump 51.

The working principle of the embodiment is as follows: referring to fig. 1, arrows indicate the flowing direction of the organic waste gas, the organic waste gas firstly enters the first stage wet spray tower 1 through the wind collecting device 5, and the wind collecting device 5 is generally a wind collecting cover. One or more layers of spraying layers 16 are arranged in the primary wet type spraying tower 1, a first spraying pipe 161 is arranged in each spraying layer 16, and spraying liquid is conveyed to the first spraying pipe 161 through a pump 17 and is sprayed out from a nozzle in a mist shape under the action of pressure. The lower end part of each spraying layer 16 is provided with a packing layer or a rotational flow plate layer. When waste gas passes through the spraying gap 163 and the packing layer or the rotational flow plate layer, the waste gas fully contacts with 16 fog drops on the spraying layer, most particles in the waste gas and gas components dissolved in water, partial paint mist and the like can be collected by spraying liquid and enter the spraying liquid, then most water mist is removed when the smoke carrying more water mist passes through the first demisting layer 15, and the rest clean gas is discharged into the high-voltage electrostatic demister 2.

After being treated by the first-stage wet spray tower 1, the organic waste gas enters the high-voltage electrostatic demister 2 through the first air pipe, is subjected to air homogenizing treatment by the first air inlet pipe and the air homogenizing layer 24, passes through a high-voltage electric field in the box body 42, and is discharged. The high-voltage electric field is provided with a cathode line 252 and an anode tube 253, and the cathode line 252 and the anode tube 253 are insulated from each other. The cathode line 252 and the anode tube 253 are connected to two poles of the high voltage power supply 251, respectively, and a high voltage electric field is entirely provided between the anode tube 253 and the cathode line 252. When the smoke passes through the high-voltage electric field, air molecules in the smoke are ionized into positive ions and negative electrons under the action of the high-voltage electric field, the negative electrons are adsorbed to paint mist particles, aerosol and smoke dust particles in the smoke to enable the paint mist particles, the aerosol and the smoke dust particles to carry negative charges, and the negatively charged particles and the aerosol move to the anode plate under the action of the electric field force and are finally attached to the anode plate. Thus, the gas passing through the electric field is a purge gas from which most of the particles and aerosols have been removed. The electric field top is equipped with spray set (being equipped with a plurality of second nozzles on second shower 27 and the second shower 27 promptly), regularly sprays when the electric field is out of work, washes attached to particulate matter and the aerosol on the anode plate and gets off the anode plate along with the rivers and fall to the defroster bottom, discharges to waste water treatment device through the row mouth and handles back water cycle and use.

After passing through the high-voltage electrostatic demister 2, the organic waste gas enters the secondary wet spray tower 3 through a second air pipe from a second air outlet 22 on the high-voltage electrostatic demister 2. In the second-stage wet spray tower 3, ozone generated by the high-voltage electrostatic demister 2 is dissolved in water and decomposed into oxygen in the water, particulate matters and paint mist in the flue gas are continuously absorbed by the spray liquid, and purified gas continuously enters the main fan 6 and enters the biological filter bed 4 through the main fan 6.

After being treated by the second-stage wet spray tower 3, the organic waste gas enters the box 42 of the biological filter bed 4 from the fourth air inlet 41 on the biological filter bed 4 through the third air inlet pipe, passes through the biological filler layer 43 in the box 42 from top to bottom, enters the exhaust passage 48, is subjected to demisting treatment through the second demisting layer 49, and is then discharged. Wherein, the bio-filler layer 43 is provided with a plurality of biological bacteria, and the biological bacteria can absorb and decompose a plurality of organic matters to generate CO2 and H2O. When the smoke passes through the biological filler layer 43 in the box body 42, the organic gas components contained in the smoke are absorbed and decomposed by biological bacteria, and the purified gas reaches the standard and enters the exhaust port to be discharged. The top of the biological filler layer 43 is provided with a plurality of third nozzles 45, and the third nozzles 45 can regularly spray water to keep the filler layer in a wet state so as to ensure that the biological bacteria are in an optimal living environment. A water tank 50 and a spray pump 51 are arranged beside the biological filter bed 4, and spray water is recycled.

The key point of the embodiment is that the high-voltage electrostatic demister 2 is skillfully added in the whole system to serve as a front-end processor of the biological filter bed 4, and a wet spray tower is added behind the high-voltage electrostatic demister 2. Therefore, the high-efficiency paint mist removing performance of the high-voltage electrostatic demister 2 can be utilized, the damage of ozone generated by the high-voltage electrostatic demister 2 to a biological bacterial film of the biological filter bed 4 can be avoided, and the biological filter bed 4 can stably run for a long time; the discharged gas after treatment is ensured to meet the environmental protection standard, and the waste gas treatment efficiency is improved. Can be used for treating the coating waste gas with large paint mist content, so that the technology of the biological filter bed 4 can be widely applied to the treatment of the spraying waste gas with medium and low concentration organic waste gas content.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A comprehensive treatment system for waste gas in coating industry is characterized by comprising a wind collecting device (5), a primary wet spray tower (1), an electrostatic demister (2), a secondary wet spray tower (3) and a biological filter bed (4), a first air inlet (11) arranged on the primary wet spray tower (1) is connected with the air collecting device (5), a first exhaust port (12) arranged on the primary wet spray tower (1) is connected with a second air inlet (21) arranged on the electrostatic demister (2) through a first air pipe, a second air outlet (22) arranged on the electrostatic demister (2) is connected with a third air inlet (31) arranged on the second-stage wet spray tower (3) through a second air pipe, and a third air outlet (32) arranged on the second-stage wet spray tower (3) is connected with a fourth air inlet (41) arranged on the biological filter bed (4) through a third air pipe.

2. The coating industry waste gas comprehensive treatment system according to claim 1, wherein the primary wet spray tower (1) comprises a tower body (13), a water tank (14) located at the bottom of the tower body (13), a spray layer (16) group and a first defogging layer (15), the first exhaust port (12) is arranged at the top of the tower body (13), the first defogging layer (15) is located at a position inside the tower body (13) close to the first exhaust port (12), the spray layer (16) group is located between the first defogging layer (15) and the water tank (14), a space exists between the spray layer (16) group and the water tank (14), the first air inlet (11) is communicated with the space air flow, and the spray layer (16) group comprises a plurality of spray layers (16) which are arranged in a stacked mode.

3. The comprehensive treatment system for the exhaust gas in the coating industry according to claim 2, wherein the spray layer (16) comprises a spray base layer (164) and a first spray pipe (161) positioned above the spray base layer (164), a plurality of first spray nozzles (162) facing the spray base layer (164) are arranged on the spray pipe, and a spray gap (163) is formed between the first spray pipe (161) and the spray base layer (164).

4. The painting industry exhaust gas integrated processing system of claim 1, wherein the spray base layer (164) is a filler layer or a swirl plate layer.

5. The comprehensive treatment system for the exhaust gas in the coating industry according to claim 1, wherein the electrostatic demister (2) comprises an equipment housing (23), a power supply (251) installed on the equipment housing (23), and an electrostatic field (26) located inside the equipment housing (23), an ionization assembly (25) is arranged in the electrostatic field (26), the ionization assembly (25) is connected with the power supply (251), the second air inlet (21) is located at one side of the bottom of the equipment housing (23), a wind-homogenizing layer (24) is further arranged inside the equipment housing (23) at a position close to the second air inlet (21), the electrostatic field (26) is located above the wind-homogenizing layer (24), the second air outlet (22) is located at the top of the equipment housing (23), and a second air exhaust pipe (27) is further arranged inside the equipment housing (23) at a position close to the second air outlet (22), and a plurality of second nozzles are arranged on the second spray pipe (27).

6. The coating industry exhaust gas comprehensive treatment system according to claim 5, wherein the ionization assembly (25) comprises a bracket (254) positioned at the top of the electric field and equal numbers of cathode wires (252) and anode tubes (253), the cathode wires (252) and the anode tubes (253) are respectively and electrically connected with the power supply (251), the cathode wires (252) are hung on the bracket (254), and the anode tubes (253) are installed on the inner wall of the equipment shell (23) corresponding to the position of the electric field.

7. The painting industry exhaust gas integrated treatment system according to any one of claims 1 to 4, characterized in that the secondary wet spray tower (3) and the primary wet spray tower (1) are identical in structure.

8. The coating industry exhaust gas comprehensive treatment system according to claim 2 or 3, wherein the number of the spraying layers (16) is 2-4.

9. The coating industry exhaust gas comprehensive treatment system according to claim 1, wherein a fan (6) is further installed on the third air pipe.

10. The comprehensive treatment system for waste gas in the coating industry according to claim 1, wherein the biofilter bed (4) comprises a filter box body (42) and a biofilter layer (43) positioned in the middle of the filter box body (42), the fourth air inlet (41) is arranged at the top of the filter box body (42), a third spray pipe (44) is arranged in the filter box body (42) and close to the fourth air inlet (41), a plurality of third nozzles (45) facing the biofilter layer (43) are arranged on the third spray pipe (44), a spray space (46) exists between the third spray pipe (44) and the biofilter layer (43), an exhaust space (47) is reserved between the bottom surface of the biofilter layer (43) and the inner wall of the bottom of the filter box body (42), and an exhaust channel (48) communicated with the exhaust space (47) is further arranged on the filter box body (42), a second demisting layer (49) is arranged in the exhaust channel (48); the bottom of the filtering box body (42) is also connected with a water tank (50), and the water tank (50) is connected with the third spraying pipe (44) through a spraying pump (51).