CN113769508A

CN113769508A - Multistage treatment system of waste gas

Info

Publication number: CN113769508A
Application number: CN202111055502.0A
Authority: CN
Inventors: 陆炯
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-09-09
Filing date: 2021-09-09
Publication date: 2021-12-10

Abstract

The invention discloses a waste gas multi-stage treatment system, which comprises a filtering device, a spraying device and a photolysis device which are sequentially connected; the filtering device comprises a waste heat recovery assembly and an interception assembly; the waste gas produced in industrial production is firstly intercepted by a filtering device, then the soluble pollutant in the waste gas is absorbed by a spraying device, then a photolysis device can treat the harmful substance in the gas by means of the decomposition effect of UV (ultraviolet), and finally the gas after photolysis treatment is led into a combustion assembly, and the residual combustible gas is oxidized by the high-temperature combustion effect, so that the aim of harmless emission of the waste gas is finally achieved; the waste gas multi-stage treatment system has the advantages that links are closely connected, the energy-saving effect is greatly improved by heat recovery at the head and the tail, the system is suitable for various waste gas components, and the market application prospect is wide.

Description

Multistage treatment system of waste gas

Technical Field

The invention relates to the field of waste gas treatment, in particular to a waste gas multistage treatment system.

Background

In industrial production, exhaust gas is one of the most common pollutants. According to the requirements of relevant laws and regulations, the waste gas is treated and then can be discharged. Most of the conventional waste gas treatment equipment is specially customized, the purchase cost is high, the waste gas treatment processes of various industries are similar, and the customized waste gas treatment equipment can meet most of requirements by slightly modifying. Therefore, it is necessary to invent a multi-stage waste gas treatment system with wide applicability and heat recovery function.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects in the prior art, the invention provides the waste gas multi-stage treatment system which is wide in applicability and has a heat recovery function.

The technical scheme is as follows: in order to achieve the aim, the multi-stage waste gas treatment system comprises a filtering device, a spraying device and a photolysis device which are sequentially connected; the filtering device comprises a waste heat recovery assembly and an interception assembly; the waste heat recovery assembly is arranged at the upstream of the intercepting assembly; the waste heat recovery assembly comprises a first gas pipe and a heat exchange cover; the heat exchange cover is buckled at the periphery of the first gas conveying pipe; the inside of the heat exchange cover is filled with movable water flow; the part of the first gas pipe, which is positioned in the heat exchange cover, is of a spiral structure; the surface of the spiral structure of the first gas pipe is connected with a radiating fin; one end of the radiating fin is wound on the outer surface of the first gas pipe, and the other end of the radiating fin is attached to the inner wall of the heat exchange cover; one end of the radiating fin, which is far away from the first gas pipe, deflects towards one end of the outlet of the heat exchange cover.

Further, the heat sink includes a heat conductor, a reinforcing rib, and a fastening bolt; the reinforcing ribs are attached to the surface of the heat conductor in a zigzag manner; one end of the heat conductor close to the first gas pipe is provided with a first positioning hole and a second positioning hole at intervals; when the corresponding end of the heat conductor bypasses the first gas pipe, the first positioning hole and the second positioning hole are superposed and superposed; the fastening bolt is arranged between the first positioning hole and the second positioning hole in a connecting mode.

Further, the intercepting component comprises a second air conveying pipe; a primary filter screen, a secondary filter screen and a supporting framework are arranged in the second gas transmission pipe; the primary filter screen is correspondingly intercepted and arranged on the air path in the second air conveying pipe; the secondary filter screen is coated on the surface of the supporting framework to form a bagged structure; the primary filter screen is connected and arranged at the opening of the bagged structure; the mesh size of the first-level filter screen is larger than that of the second-level filter screen.

Further, the support armature comprises an annular member; a plurality of the annular parts are arranged in parallel at intervals; the diameters of the plurality of annular parts are gradually reduced along the direction far away from the primary filter screen; a connecting rod extends from the edge of the annular part; a sliding groove is formed in the inner wall of the second gas transmission pipe along the length direction of the second gas transmission pipe; one end of the connecting rod, which is far away from the annular piece, is in sliding fit with the sliding groove; and adjusting the distance between the annular pieces in a reciprocating manner, and correspondingly changing the surface area of the bagged structure.

Furthermore, a maintenance window is arranged on the side surface of the second gas pipe; the maintenance window is positioned at the upstream position of the primary filter screen; a shaping frame is arranged at the edge of the primary filter screen; the shaping frame is connected with the nearest annular piece in an attaching mode; the edge of the shaping frame is in sealing fit with the inner wall of the second gas conveying pipe.

Further, the photolysis device comprises a cartridge body; a clapboard is arranged inside the bin body; the bin body is provided with an air inlet and an air outlet; the air inlet and the air outlet are positioned at two opposite sides of the bin body; the plurality of baffle plates are distributed in a staggered manner, and an S-shaped channel is formed between the air inlet and the air outlet; the top of the bin body is embedded with a UV lamp; the lower end of the UV lamp extends into the S-shaped channel; a reflector is arranged on the surface of the partition plate; a plurality of the reflectors are distributed along the length direction of the partition plate; and a plurality of reflectors are in zigzag undulation connection.

Further, the UV lamp comprises a lamp body, a scraping brush and an impeller; the impeller is rotatably connected and arranged at the bottom of the UV lamp; the impeller corresponds to the position of an airflow path in the bin body; the scraping brushes are symmetrically attached to the surface of the lamp body; the lower end of the scraping brush is connected with the impeller, and the scraping brush and the impeller rotate synchronously.

Furthermore, a combustion assembly is arranged at the downstream of the air outlet in a communicating and connecting manner; the combustion assembly includes a combustion chamber; the bottom of the combustion chamber is provided with a flame nozzle; a heating cover is arranged above the flame-throwing nozzle; a stop block is arranged at the top of the combustion chamber; a gas channel is reserved between the stop block and the warming cover; an exhaust pipe is arranged on the surface of the combustion chamber; one end of the gas channel is communicated and connected with the gas outlet, and the other end of the gas channel is communicated and connected with the exhaust pipe; the heating cover is of a net structure; the aperture of the mesh on the heating cover is gradually increased along the direction far away from the fire-spraying position of the fire-spraying nozzle; the heating cover is of an arc-shaped plate structure; the part of the temperature-rising cover corresponding to the fire-spraying position of the fire-spraying nozzle is protruded upwards.

Furthermore, the outlet end of the exhaust pipe is provided with a heat exchange pipe in a connected manner; the upper end of the baffle block extends to the outside of the combustion chamber; the heat exchange tube is spirally attached and wound on the surface of the outer part exposed at the upper end of the stop block; a heat exchange shell is arranged outside the heat exchange tube; the heat exchange shell is communicated with and arranged at the downstream of the heat exchange cover.

Has the advantages that: the invention discloses a waste gas multi-stage treatment system which comprises a filtering device, a spraying device and a photolysis device which are sequentially connected; the energy-saving effect can be greatly improved by the filtering device and the heat recovery of the combustion assembly after photolysis, the production water is preheated by the heat of the waste gas treatment link, and the energy consumption in the production link is reduced; meanwhile, the photolysis device prolongs the retention time of waste gas in the gas channel and effectively solves the problem that the irradiation effect is influenced by condensation generated on the surface of the lamp body due to temperature difference by installing a cleaning mechanism which runs by means of wind power on the UV lamp; the waste gas multi-stage treatment system has the advantages that links are closely connected, the energy-saving effect is greatly improved by heat recovery at the head and the tail, the system is suitable for various waste gas components, and the market application prospect is wide.

Drawings

FIG. 1 is a schematic view of the overall process flow of an exhaust gas treatment system;

FIG. 2 is a schematic view of a waste heat recovery device;

FIG. 3 is a schematic view of a fin layout;

FIG. 4 is a schematic view of a heat sink structure;

FIG. 5 is a schematic view of the structure of the intercepting component;

FIG. 6 is a schematic view of the photolysis apparatus;

FIG. 7 is a schematic view of a separator plate structure;

FIG. 8 is a schematic view of a UV lamp configuration;

FIG. 9 is a schematic view of a combustion assembly;

FIG. 10 is a schematic view of the overall structure of the shower chamber;

FIG. 11 is a schematic view of a louver configuration;

fig. 12 is a schematic structural view of the locking and pressing member.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

As shown in fig. 1, a multi-stage waste gas treatment system comprises a filtering device 6, a spraying device, a photolysis device 7 and a combustion assembly 8 which are connected in sequence; as shown in fig. 2 and 3, the filtering device 6 comprises a waste heat recovery assembly 61 and a interception assembly 62; the waste heat recovery assembly 61 is arranged at the upstream of the interception assembly 62; the waste heat recovery assembly 61 comprises a first gas conveying pipe 611 and a heat exchange cover 612; the heat exchange cover 612 is buckled on the periphery of the first gas conveying pipe 611; the inside of the heat exchange cover 612 is filled with active water flow; the part of the first gas pipe 611, which is positioned inside the heat exchange cover 612, is of a spiral structure; the spiral structure surface of the first gas pipe 611 is provided with a cooling fin 613 in a connecting way; one end of the heat sink 613 is wound around the outer surface of the first gas pipe 611, and the other end is attached to the inner wall of the heat exchange cover 612; the end of the heat sink 613 remote from the first air delivery conduit 611 is deflected towards the outlet end of the heat exchange shroud 612.

The waste gas produced in industrial production is firstly intercepted by the filtering device 6, then the soluble pollutant in the waste gas is absorbed by the spraying device, then the photolysis device 7 can treat the harmful substance in the gas by means of the decomposition of UV, namely ultraviolet, and finally the gas after photolysis treatment is led into the combustion assembly, and the residual combustible gas is oxidized by the high-temperature combustion action, thus finally achieving the aim of harmless emission of the waste gas;

the waste heat recovery assembly 61 is arranged in the filtering device 6, and has the function that when exhaust gas is just discharged, the temperature of the exhaust gas is much higher than room temperature due to the environment of equipment such as a previous boiler and the like, the pipe wall of the first gas pipe 611 is made of a heat-conducting material, and water flow in the heat exchange cover 612 can exchange heat with the exhaust gas in the first gas pipe 611, so that waste heat is generated for water of other equipment, and the energy-saving effect is achieved; the spiral structure of the first gas pipe 611 has the function of increasing the length of the pipeline in the heat exchange cover 612, so that the heat exchange area is increased, and the heat exchange efficiency is improved; the heat dissipation fins 613 have the effects that the heat dissipation area can be further increased, the defect that the first gas pipe 611 cannot extend to the edge corner is overcome, the tail ends of the heat dissipation fins 613 deflect towards the water outlet position, the bending moment applied to the root of the heat dissipation fins can be reduced, and the structural stability is improved; meanwhile, partial water flow close to the central part can be guided to the position close to the edge of the heat exchange cover 612 through the surface of the radiating fins 613, so that acceleration and disturbance are realized, the temperature uniformity of the water flow is improved, and the overall heat exchange effect is improved.

As shown in fig. 4, the heat sink 613 includes a heat conductor 601, a rib 602, and a fastening bolt; the reinforcing ribs 602 are attached to the surface of the heat conductor 601 in a zigzag manner; a first positioning hole 604 and a second positioning hole 605 are arranged at one end of the heat conductor 601 close to the first gas pipe 611 at intervals; when the corresponding end of the heat conductor 601 bypasses the first air delivery pipe 611, the first positioning hole 604 and the second positioning hole 605 are superposed and overlapped; the fastening bolt connection is provided between the first positioning hole 604 and the second positioning hole 605.

The heat conductor 601 can be made of copper strips and the like, and one end of the heat conductor 601 can be wound on the surface of the first gas pipe 611 through the variable capacity of the heat conductor 601, so that heat transfer extension is realized; the winding position is fastened by two positioning hole structures matched with bolts, so that the quick disassembly and the quick assembly are convenient.

As shown in FIG. 5, the intercepting assembly 62 includes a second air delivery conduit 621; a primary filter screen 622, a secondary filter screen 623 and a support framework are arranged in the second gas pipe 621; the primary filter screen 622 is correspondingly intercepted and arranged on the air path in the second air delivery pipe 621; the secondary filter screen 623 is coated on the surface of the supporting framework to form a bagged structure; the primary filter screen 622 is connected and arranged at the opening of the bagged structure; the mesh size of the primary strainer 622 is larger than the mesh size of the secondary strainer 623.

As shown by the arrows in the figure, the heat-exchanged exhaust gas firstly passes through the primary filter 622 to complete the primary filtration, and then enters the inside of the bag-shaped structure and exits through the secondary filter 622; the blocking pressure of a single filter screen can be relieved by decomposing the filter interception on the first-level filter screen and the second-level filter screen, so that the filter screen can work stably for a long time, the interval of cleaning and maintenance is prolonged, and the rhythm of actual production can be adapted.

The support skeleton comprises a ring 626; a plurality of annular members 626 are arranged in parallel and spaced apart; a plurality of said annular members 626 having a diameter that tapers away from said primary strainer 622; a connecting rod 627 extends from the edge of the ring 626; a sliding groove is arranged on the inner wall of the second air delivery pipe 621 along the length direction thereof; one end of the connecting rod 627 far away from the annular member 626 is in sliding fit with the sliding groove; the spacing between the ring-shaped members 626 is adjusted to and fro, correspondingly changing the surface area of the bagged structure.

The position of the annular piece 626 and the distance between the annular piece and the annular piece can be changed in a sliding mode, the volume of the bagged structure can be adjusted, the area of the secondary filter screen 622 participating in filtering is correspondingly changed, the secondary filter screen at the tail of the bagged structure can be used in a key mode conveniently when the filtering pressure is not large, and the workload of cleaning and maintenance is reduced in a simplified mode.

A maintenance window is arranged on the side surface of the second gas delivery pipe 621; the maintenance window is located upstream of the primary strainer 622; a shaping frame 620 is arranged at the edge of the primary filter screen 622; the shaping frame 620 is in fit connection with the nearest ring member 626; the edge of the sizing frame 620 is in sealing fit with the inner wall of the second air delivery pipe 621.

As shown in fig. 6 and 7, the photolysis device 7 includes a cartridge body 71; a partition plate 72 is arranged in the bin body 71; an air inlet 701 and an air outlet 702 are arranged on the bin body 71; the air inlet 701 and the air outlet 702 are positioned on opposite sides of the cartridge body 71; the plurality of baffles 72 are distributed in a staggered manner, and an S-shaped channel is formed between the air inlet 701 and the air outlet 702; the top of the bin body 71 is embedded with a UV lamp 73; the lower end of the UV lamp 73 extends into the S-shaped channel; the surface of the partition 72 is provided with a reflecting mirror 721; a plurality of the reflecting mirrors 721 are distributed along the length direction of the partition 72; several of the reflectors 721 are in a zigzag pattern.

The S-shaped channel formed by the partition plates 72 can prolong the retention time of the waste gas in the waste gas recycling bin body 71, and the UV lamp 73 is specifically arranged at the corner of the S-shaped channel, so that the channels in the upper and lower streams can be simultaneously illuminated, the effective extension of an illumination area is realized by means of the reflector 721, the different light source illumination areas are partially overlapped, the whole channel is effectively covered, and the photolysis reaction of the whole process of the circulation of the waste gas is realized.

As shown in fig. 8, the UV lamp 73 includes a lamp body 731, a wiper 732, and an impeller 733; the impeller 733 is rotatably connected to the bottom of the UV lamp 73; the impeller 733 corresponds to the position of an air flow path in the bin body 71; the scraping brushes 732 are symmetrically attached to the surface of the lamp body 731; the lower end of the scraping brush 732 is connected with the impeller 733, and the scraping brush 732 and the impeller 733 rotate synchronously.

The exhaust gas can drive the impeller 733 to rotate in the flowing process, so that the scraping brush 732 also synchronously rotates; the scraping brush 732 wipes the surface of the lamp body 731 in the rotating process, so that the phenomenon of condensation on the surface of the lamp body caused by high gas temperature can be effectively avoided; meanwhile, the impeller 733 may further extend a gas staying time by a blocking effect on the flowing exhaust gas, thereby enhancing a photolysis effect.

As shown in fig. 9, the downstream of the air outlet 702 is connected with a combustion assembly 8; the combustion assembly 8 comprises a combustion chamber 81; the bottom of the combustion chamber 81 is provided with a flame nozzle 82; a heating cover 83 is arranged above the flame nozzle 82; a stop block 84 is arranged at the top of the combustion chamber 81; a gas channel 85 is reserved between the stop block 84 and the warming cover 83; an exhaust pipe 801 is arranged on the surface of the combustion chamber 81; one end of the gas channel 85 is communicated and connected with the gas outlet 702, and the other end of the gas channel is communicated and connected with the exhaust pipe 801; the heating cover 83 is of a net structure; the aperture of the mesh on the heating cover 83 is gradually increased along the direction away from the fire-spraying position of the fire-spraying nozzle 82; the heating cover 83 is of an arc-shaped plate-shaped structure; the part of the temperature-rising cover 83 corresponding to the flaming position of the flaming nozzle 82 is protruded upwards.

After entering the gas channel 85, the photolyzed waste gas is oxidized at high temperature by the flame passing through the temperature-raising cover 83 and the temperature-raising cover itself; the arc-shaped structure with the convex center of the heating cover 83 can ensure that gas can flow along with the cover surface when the gas is just contacted, thereby enhancing the heating effect; meanwhile, the design that the center of the mesh is small and the periphery is large is utilized, so that the flame can be guided to extend to the periphery, and the integral temperature uniformity of the heating cover 83 is improved.

The outlet end of the exhaust pipe 801 is connected with a heat exchange pipe 802; the upper end of the block 84 extends to the outside of the combustion chamber 81; the heat exchange pipe 802 is spirally attached and wound on the surface of the upper end of the stopper 84 exposed to the outside; a heat exchange shell 86 is arranged outside the heat exchange pipe 802; the heat exchange shell 86 is disposed in communication downstream of the heat exchange shroud 612.

The temperature of the waste gas after combustion treatment rises again, and heat can be recovered again through the contact of the water flow in the heat exchange shell 86 and the heat exchange pipe 802; meanwhile, the stopper 84 is also made of a heat conducting material, and the heat transfer capacity of the stopper 84 can be adjusted by adjusting the exposed volume of the stopper 84 during the combustion treatment.

Further, as shown in fig. 10, the shower device includes a shower room 1; a spraying unit 2 and a filling unit 3 are arranged in the spraying chamber 1; the spraying unit 2 comprises a water tank 21, a third communicating pipe 22, an adapter plate 23 and an injection piece 24; the water tank 21 is communicated with a water source, the third communicating pipe 22 is used for transmitting water to the adapter plate 23, and the material-adjusting unit 3 is sprayed by a plurality of spraying pieces 24 with electromagnetic valves at the bottom of the adapter plate; the spraying unit 2 is positioned above the filling unit 3; the filling unit 3 corresponds to the spraying area of the spraying unit 2; the side wall of the spray chamber 1 is provided with a transom 4; the louver 4 is positioned below the packing unit 3; the bottom of the spray chamber 1 is provided with a water return component 5, and water flow discharged by the packing unit can be filtered by utilizing the water return component 5 and can be recycled, so that the water flow utilization efficiency is improved, and the water flow can fully absorb the dissolved gas in waste; the spray chamber 1 is externally communicated and connected with an air inlet pipe 101 and a first communication pipe 102, and the first communication pipe is used for guiding the sprayed gas out of the photolysis device; the air inlet pipe 101 is communicated with the transom 4; the air injection path of the louver 4 corresponds to the position of the filler unit 3; one end of the first communication pipe 102 is communicated with the top of the spray chamber 1, and the other end is communicated with a photolysis device. A circulating component 11 is connected and arranged outside the spray chamber 1; the circulation assembly 11 includes a blower 103; the air inlet end of the blower 103 is communicated with the space above the spraying unit 2 through a first pipeline 104; the air outlet end of the blower 103 is communicated with the air inlet pipe 101 through a second pipeline 105.

As shown in fig. 11 and 12, the louver 4 includes a frame 40, a joining component 41 and an air guide plate 42; the frame body 40 is embedded in the side wall of the spray chamber 1; the engaging component 41 comprises a supporting piece 411 and a locking piece 412; the supporting member 411 is connected to a side of the frame 40 facing the external space; a locking cavity 410 is arranged in the supporting piece 411 in a penetrating manner; the locking cavity 410 is communicated and butted with the frame body 40; the bottom of the locking cavity 410 is provided with a first groove body 413; the air inlet pipe 101 is partially embedded in the first groove body 413; the locking and pressing piece 412 is slidably arranged above the first groove body 413; the locking and pressing piece 412 is movably inserted and pulled back and forth at one end of the locking cavity 410 far away from the frame body 40; a second groove 414 is formed at the bottom of the locking and pressing piece 412; the first groove body 413 and the second groove body 414 are matched in a buckling manner; an elastic cushion block 415 is arranged on the inner wall of the second groove 414; the thickness of the elastic cushion block 415 is gradually reduced along the direction close to the frame body 40; when the locking piece 412 is inserted into the locking cavity 410, the elastic cushion 415 is matched with the first groove 413 to clamp the air inlet pipe 101.

By the compression action of the locking and pressing piece 412, the air inlet pipe 101 can be quickly fixed and detached, and the equipment is convenient to assemble and maintain; meanwhile, one end of the supporting piece 411 close to the frame body 40 is provided with a thread 416 which can be matched with a sleeve pipe which is sleeved on the air inlet pipe 101 and provided with an external thread, so that the supporting piece is matched with the locking and pressing piece 412 together, and the pipe is prevented from breaking away due to air pressure change at the moment of starting and stopping in work.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.

Claims

1. The utility model provides a multistage governing system of waste gas which characterized in that: comprises a filtering device (6), a spraying device and a photolysis device (7) which are connected in sequence; the filtering device (6) comprises a waste heat recovery assembly (61) and an interception assembly (62); the waste heat recovery assembly (61) is arranged upstream of the interception assembly (62); the waste heat recovery assembly (61) comprises a first gas conveying pipe (611) and a heat exchange cover (612); the heat exchange cover (612) is buckled on the periphery of the first gas conveying pipe (611); the inside of the heat exchange cover (612) is filled with active water flow; the part of the first gas conveying pipe (611) inside the heat exchange cover (612) is of a spiral structure; the spiral structure surface of the first gas pipe (611) is provided with a cooling fin (613) in a connecting way; one end of the radiating fin (613) is wound on the outer surface of the first gas pipe (611), and the other end of the radiating fin is attached to the inner wall of the heat exchange cover (612); the end of the cooling fin (613) far away from the first gas conveying pipe (611) deflects towards the end of the heat exchange cover (612) outlet.

2. The multi-stage exhaust gas treatment system of claim 1, wherein: the heat sink (613) comprises a heat conductor (601), a reinforcing rib (602) and a fastening bolt; the reinforcing ribs (602) are attached to the surface of the heat conductor (601) in a zigzag manner; a first positioning hole (604) and a second positioning hole (605) are arranged at an interval at one end of the heat conductor (601) close to the first gas pipe (611); when the corresponding end of the heat conductor (601) bypasses the first gas pipe (611), the first positioning hole (604) and the second positioning hole (605) are superposed and superposed; the fastening bolt connection is arranged between the first positioning hole (604) and the second positioning hole (605).

3. The multi-stage exhaust gas treatment system of claim 1, wherein: the intercepting component (62) comprises a second air conveying pipe (621); a primary filter screen (622), a secondary filter screen (623) and a supporting framework are arranged in the second air delivery pipe (621); the primary filter screen (622) is correspondingly intercepted and arranged on an air path in the second air conveying pipe (621); the secondary filter screen (623) is coated on the surface of the supporting framework to form a bagged structure; the primary filter screen (622) is connected and arranged at the opening of the bagged structure; the mesh size of the primary filter screen (622) is larger than the mesh size of the secondary filter screen (623).

4. The multi-stage exhaust gas treatment system of claim 3, wherein: the support skeleton comprises a ring (626); a plurality of annular members (626) are arranged in parallel at intervals; a plurality of said annular members (626) having a diameter that tapers away from said primary strainer (622); a connecting rod (627) extends from the edge of the annular piece (626); a sliding groove is arranged on the inner wall of the second air delivery pipe (621) along the length direction of the second air delivery pipe; one end of the connecting rod (627) far away from the annular piece (626) is in sliding fit with the sliding groove; the spacing between the ring-shaped pieces (626) is adjusted to and fro, and the surface area of the bagged structure is correspondingly changed.

5. The multi-stage exhaust gas treatment system according to claim 4, wherein: a maintenance window is arranged on the side surface of the second gas pipe (621); the maintenance window is positioned at an upstream position of the primary filter screen (622); a shaping frame (620) is arranged at the edge of the primary filter screen (622); the shaping frame (620) is in fit connection with the nearest ring piece (626); the edge of the shaping frame (620) is in sealing fit with the inner wall of the second air delivery pipe (621).

6. The multi-stage exhaust gas treatment system according to claim 4, wherein: the photolysis device (7) comprises a bin body (71); a clapboard (72) is arranged in the bin body (71); an air inlet (701) and an air outlet (702) are arranged on the bin body (71); the air inlet (701) and the air outlet (702) are positioned on opposite sides of the cartridge body (71); the plurality of clapboards (72) are distributed in a staggered way, and S-shaped channels are formed between the air inlets (701) and the air outlets (702); the top of the bin body (71) is embedded with a UV lamp (73); the lower end of the UV lamp (73) extends into the S-shaped channel; a reflector (721) is arranged on the surface of the partition plate (72); a plurality of the reflecting mirrors (721) are distributed along the length direction of the partition plate (72); a plurality of the reflectors (721) are in zigzag undulation engagement.

7. The multi-stage exhaust gas treatment system of claim 6, wherein: the UV lamp (73) comprises a lamp body (731), a scraping brush (732) and an impeller (733); the impeller (733) is rotatably connected and arranged at the bottom of the UV lamp (73); the impeller (733) corresponds to the position of an airflow path in the bin body (71); the scraping brush (732) is symmetrically attached to the surface of the lamp body (731); the lower end of the scraping brush (732) is connected with the impeller (733) and the scraping brush and the impeller rotate synchronously.

8. The multi-stage exhaust gas treatment system of claim 6, wherein: the downstream of the air outlet (702) is communicated and connected with a combustion assembly (8); the combustion assembly (8) comprises a combustion chamber (81); the bottom of the combustion chamber (81) is provided with a flame nozzle (82); a heating cover (83) is arranged above the flame nozzle (82); a stop block (84) is arranged at the top of the combustion chamber (81); a gas channel (85) is reserved between the stop block (84) and the warming cover (83); an exhaust pipe (801) is arranged on the surface of the combustion chamber (81); one end of the gas channel (85) is communicated and connected with the gas outlet (702), and the other end of the gas channel is communicated and connected with the exhaust pipe (801); the heating cover (83) is of a net structure; the aperture of the mesh on the heating cover (83) is gradually increased along the direction away from the fire spraying position of the fire spraying nozzle (82); the heating cover (83) is of an arc-shaped plate-shaped structure; the part of the temperature-rising cover (83) corresponding to the fire-spraying position of the fire-spraying nozzle (82) is protruded upwards.

9. The multi-stage exhaust gas treatment system of claim 8, wherein: the outlet end of the exhaust pipe (801) is provided with a heat exchange pipe (802) in a connected manner; the upper end of the block (84) extends to the outside of the combustion chamber (81); the heat exchange pipe (802) is spirally attached and wound on the surface of the outer part exposed at the upper end of the stop block (84); a heat exchange shell (86) is arranged outside the heat exchange tube (802); the heat exchange shell (86) is arranged at the downstream of the heat exchange cover (612) in a communication mode.