CN113457845B

CN113457845B - Device for treating oil smoke tail gas and process method thereof

Info

Publication number: CN113457845B
Application number: CN202110878187.5A
Authority: CN
Inventors: 杨少康; 王成林
Original assignee: Ruiqi Shanghai Environmental Engineering Technology Co ltd
Current assignee: Ruiqi Shanghai Environmental Engineering Technology Co ltd
Priority date: 2021-08-02
Filing date: 2021-08-02
Publication date: 2022-04-19
Anticipated expiration: 2041-08-02
Also published as: CN113457845A

Abstract

The invention discloses a device for treating oil smoke tail gas and a process method thereof, the device comprises a washing unit, an electrostatic unit and a polishing unit, the washing unit is connected with the electrostatic unit through a pipeline, the electrostatic unit is connected with the polishing unit through a filtering channel, the washing unit comprises a flue gas inlet, the flue gas inlet is connected with one side of a washing pipe through a flue gas pipeline, a waste reducing device is arranged in the washing pipe, the other side of the washing pipe is connected with a separating device, the separating device comprises a separating tower, the lower end of the separating tower is connected with a liquid return pipe of the waste reducing device, the upper end of the separating tower is connected with one side of the pipeline, the other side of the pipeline is connected with the electrostatic unit, and various problems in various treatment processes can be reasonably and effectively solved through the device for treating the oil smoke tail gas, thereby ensuring the standard emission requirements of each index in the tail gas emission process.

Description

Device for treating oil smoke tail gas and process method thereof

Technical Field

The invention relates to the technical field of waste gas treatment, in particular to a process method of a device for treating oil smoke tail gas.

Background

Aiming at the purification treatment of industrial oil fume waste gas, the common treatment processes and technologies at present comprise physical interception and filtration, electrostatic oil and dust removal, activated carbon adsorption, incineration and the like. The oil fume exhaust gas has the characteristics of high content of removed particles, high temperature, sticky particles, certain amount of gaseous pollutants (such as Volatile Organic Compounds (VOCs)) and heavy peculiar smell. For example, the physical interception and filtration are usually determined by the existence of dirty filter cotton, no high temperature resistance, no removal of gaseous pollutants and the like. The electrostatic dust and oil removal cannot resist high temperature and remove other pollutants and peculiar smell. The activated carbon adsorption has the defects of fire risk, easy filth blockage, unobvious odor removal effect and the like; the high-temperature incineration process has the problems of high investment and operation cost, easy blockage of a heat accumulator and a heat exchanger by viscous substances and the like.

Disclosure of Invention

The invention aims to provide a process method of a device for treating oil fume tail gas, which aims to solve the problems in the background technology, and can reasonably and effectively solve various problems in various treatment processes through the device for treating the oil fume tail gas, so that the standard emission requirements of various indexes in the tail gas emission process are ensured.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a device for handling oil smoke tail gas, includes washing unit, static unit and polishing unit, the washing unit pass through the pipeline with the static unit is connected, the static unit with the polishing unit passes through filtering channel and connects, the washing unit includes the flue gas import, the flue gas import pass through the flue gas pipeline with wash tub upper end is connected, it falls useless device to be provided with in the washing pipe, wash tub lower extreme and separator are connected, separator includes the knockout tower, the knockout tower lower extreme with fall useless device's liquid return pipe and be connected, the knockout tower upper end with pipeline one side is connected, the pipeline opposite side with the static unit is connected, the static unit includes static module, static module install in filtering channel, static module installs polishing unit in one side, polishing unit includes pre-filtration net, The electrostatic module comprises a filter screen and a final filter screen, wherein the pre-filter is installed on one side of the electrostatic module, the filter screen is installed on one side of the pre-filter screen, the final filter screen is installed on one side of the filter screen, and an exhaust pipeline is installed on one side of the final filter screen.

Preferably, include the one-level nozzle with useless device, the one-level nozzle is installed in the water pipe upper end, the water pipe stretches into middle part position in the washing pipe, the water pipe opposite side is connected with water pump supercharging system, water pump supercharging system includes first valve, check valve, booster pump, filter and second valve, first valve, check valve, booster pump, filter and second valve connect gradually, the second valve with return the union coupling.

Preferably, a reservoir is installed at the lower end in the separation tower, a detection device is installed on one side of the reservoir, an overflow pipe is installed on the other side of the reservoir, a water replenishing valve is installed at the upper end of the overflow pipe, a demisting filtering section is installed at the upper end of the reservoir, a liquid separating chamber is arranged between the reservoir and the demisting filtering section, and an exhaust cavity is arranged at the upper end of the demisting filtering section.

Preferably, the prefiltering net is installed on a guide groove in the filtering channel, an extrusion device is installed at the upper end of the prefiltering net and comprises an extrusion plate, the extrusion plate is installed at the upper end of the guide groove and is provided with the prefiltering net, the extrusion plate is fixedly connected with the prefiltering net, an extrusion electromagnetic valve is arranged at the upper end of the extrusion plate and is installed at the upper end of the filtering pipeline, the lower end of the prefiltering net is provided with a collecting port, and the lower end of the collecting port is provided with a collecting tank.

Preferably, the prefiltering net is an oil absorption cotton material, the prefiltering net is a folding and stretching structure, the upper end of the folding and stretching structure is connected to the lower end of the extrusion plate, and the lower end of the folding and stretching structure is connected to the upper end of the collection port.

Preferably, the filter screen sets up to dry-type chemical filter screen, dry-type chemical filter screen includes porous medium and chemical, fill chemical in the porous medium, chemical includes strong oxidant, phosphoric acid, FeS, MgO, NaOH, KOH and dibromo thymol sulfophthalein, strong oxidant is potassium permanganate or sodium permanganate.

Preferably, a plurality of blowing holes are formed in the inner wall of the guide groove, the blowing holes are connected with air compression pipes, and the blowing holes are uniformly formed in the inner wall of the guide groove.

Preferably, the upper end of the pre-filtering net is provided with a first load cell, the upper end of the filtering net is provided with a second load cell, and the upper end of the final filtering net is provided with a third load cell.

A process method of a device for treating oil fume tail gas comprises the following steps:

s1, enabling the oil smoke tail gas to enter a washing unit from a smoke inlet, enabling the oil smoke tail gas to enter a washing pipe through a pipeline, arranging an upward nozzle in the washing pipe, enabling washing liquid sprayed from the nozzle to intersect with smoke flow from top to bottom to form a washing area, and transferring particulate matters and water-soluble gaseous pollutants in the waste gas into the washing liquid by mass transfer in the washing area;

s2: when the temperature of the oil fume tail gas is higher than the temperature of liquid, the oil fume tail gas and the liquid transfer heat, so that the temperature of the oil fume tail gas is reduced, the oil fume tail gas enters a separation tower after being washed in a washing pipe, gas-water separation is carried out in the separation tower, the oil fume tail gas without particulate matters and soluble gaseous pollutants rises, washing liquid mixed with the washed pollutants flows into a liquid storage tank, the washing liquid in the liquid storage tank passes through a liquid return pipe, a water pump pressurization system mode is adopted, pressure and washing liquid are continuously provided for a nozzle, the washing liquid enters an exhaust cavity through a demisting section, and then the washing liquid enters an electrostatic unit through a pipeline;

s3: the tail gas in the electrostatic treatment unit is further purified in the electrostatic module, and the electrostatic module adopts a wide polar distance type to remove dust, so that particulate matters which are not washed and liquid drops carried out from the washing tower are removed;

s4: tail gas treated by the electrostatic unit enters a polishing unit 36 of a next-stage advanced treatment unit, the structure of the filtering unit is filtered in three stages, the first stage is that a pre-filtering net adopts a filter made of oil-absorbing cotton, the filtering oil-absorbing cotton can be folded for use, the pre-filtering net can be extruded for repeated use after being fully absorbed with oil through an extruding device arranged on the pre-filtering net, and residual oil mist particles are deeply removed through pre-filtering to protect the filtering unit from being polluted by oil mist and the like;

s5: after the oil smoke tail gas passes through the pre-filtering screen, the oil mist and other sticky particles are completely removed. Then the tail gas enters a filter screen, a dry chemical filtering treatment process is adopted in the filter screen, volatile organic compounds are removed when the tail gas passes through the section of the filter screen, a dry chemical filtering material is adopted in the filter screen and comprises a porous medium and a chemical agent, the material has the typical function that the chemical agent is subjected to adsorption reaction with harmful components in the gas and removed, the purpose of purifying peculiar smell is achieved, and then the residual particles are filtered through the final filter screen and discharged into the atmosphere after being filtered.

Compared with the prior art, the invention has the beneficial effects that:

1. in the process method, the washing tower can effectively remove the particulate matters in the waste gas, and simultaneously has the function of reducing the temperature, and particularly, the removal of the sticky particulate matters can not cause the blockage of the washing device.

2. In the gas after washing, liquid particle carrying capacity is little, compares general scrubbing tower, can effectively avoid the defroster to block up in the operation process.

3. Compared with a single electrostatic dust removal and oil removal process, the process has the advantages that the waste gas enters the electrostatic unit after the front end is washed, and after the load of particles is reduced, the safety, reliability and stability of operation are obviously improved.

4. After removing the sticky substances such as particulate matters, grease and the like in the waste gas, the waste gas is further deeply treated by adopting dry chemical filtration, and compared with adopting activated carbon, the method has the advantages of large treatment capacity and high efficiency. Meanwhile, the harsh requirement on the relative humidity of the waste gas of the activated carbon can be avoided, and the dry-type chemical filter material has the characteristic of flame retardance, so that the risk of ignition of the activated carbon can be avoided for high-temperature tail gas. If the active carbon is singly used for treating the oil smoke tail gas, the active carbon is easy to block and catch fire, and high potential safety hazard exists.

5. The whole set of treatment process, it is outside for the consumptive material to handle dry-type chemical filtration and the filtering material around it, all the other all do not consume, compare with the burning method, because the calorific value of oil smoke tail gas is very low, need supply a large amount of energy in normal operation, in order to maintain the normal thermal oxidation purification process of system, the operation energy consumption is high, simultaneously, because thermal oxidation system still need dispose heat exchanger or heat accumulator, when waste gas carries out the heat exchange in heat exchanger or heat accumulator, particulate matter and viscous substance in the oil smoke tail gas cause the jam very easily, thereby influence the normal operating of system, also there is certain potential safety hazard.

6. Through the design of a series of combined processes in the invention, various problems in various treatment processes are reasonably and effectively solved, and a safe, effective, economic and reliable treatment process and method are provided for treating oil fume tail gas, so that the emission standard requirements of various indexes, such as VOCs concentration, particulate matter concentration, peculiar smell (malodor) and the like, on tail gas emission are ensured, considerable economic benefits are brought to enterprises when the enterprises are engaged in environment protection work, and small social benefits are also obtained.

Drawings

Fig. 1 is a schematic view of the overall structure principle of the device for treating lampblack tail gas.

FIG. 2 is a schematic view of the extrusion apparatus of the present invention.

FIG. 3 is a schematic view of a collection tank according to the present invention.

FIG. 4 is a schematic view of a prefilter screen according to the present invention.

Fig. 5 is a schematic structural diagram of the porous medium of the present invention.

Reference numerals: 1. a flue gas inlet, 2, a flue gas pipeline, 3, a washing pipe, 4, a primary nozzle, 5, a water pipe, 10, a liquid return pipe, 11, a separation tower, 12, a liquid storage tank, 13, a detection device, 15, an overflow pipe, 18, a water replenishing valve, 19, a liquid separation chamber, 20, a demisting filtering section, 21, an exhaust cavity, 22, a pipeline, 23, an electrostatic module, 25, a pre-filtering screen, 26, a filtering screen, 27 a final filtering screen, 28, a first pressure measuring element, 29, a second pressure measuring element, 30, a third pressure measuring element, 32, an exhaust pipeline, 33, a separation device, 34, a washing unit, 35, an electrostatic unit, 36, a polishing unit, 37, a filtering channel, 38, a waste reduction device, 39, a guide groove, 40, an extrusion device, 41, an extrusion plate, 42, an extrusion electromagnetic valve, 43, a collection port, 44, a collection groove, 45 porous medium, 46, a chemical agent, 47, a blow hole, 48, an air compression pipe, 100. a water pump pressurization system 101, a second valve 102, a filter 103, a booster pump 104, a one-way valve 105 and a first valve.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings.

The utility model provides a device for handling oil smoke tail gas, includes washing unit 34, static unit 35 and polishing unit 36, washing unit 34 pass through pipeline 22 with static unit 35 is connected, static unit 35 with polishing unit 36 passes through filtering channel 37 and is connected, washing unit 34 includes flue gas inlet 1, flue gas inlet 1 pass through flue gas pipeline 2 with wash pipe 3 upper end is connected, be provided with in the wash pipe 3 and fall useless device 38, wash pipe 3 lower extreme is connected with separator 33, separator 33 includes knockout tower 11, knockout tower 11 lower extreme with fall useless device 38's return liquid pipe 10 and be connected, knockout tower 11 upper end with pipeline 22 one side is connected, pipeline 22 opposite side with static unit 35 is connected, static unit 35 includes static module 23, static module 23 install in filtering channel 37, polishing unit 36 is installed to static module 23 one side, polishing unit 36 includes prefiltration net 25, filter screen 26 and final filter screen 27, prefiltration net 25 installation with static module 23 one side, filter screen 26 installation with prefiltration net 25 one side, final filter screen 27 install in filter screen 26 one side, exhaust duct 32 is installed to final filter screen 27 one side.

The waste reducing device 38 comprises a primary nozzle 4, the primary nozzle 4 is installed at the upper end of a water pipe 5, the water pipe 5 extends into the middle position in the washing pipe 3, the other side of the water pipe 5 is connected with a water pump pressurization system 100, the water pump pressurization system 100 comprises a first valve 105, a one-way valve 104, a booster pump 103, a filter 102 and a second valve 101, the first valve 105, the one-way valve 104, the booster pump 103, the filter 102 and the second valve 101 are sequentially connected, and the second valve 101 is connected with the liquid return pipe 10; the gas with detergent is mixed with the oil gas through the primary nozzle 4, so that the oil gas is cleaned.

The device comprises a separation tower 11, a liquid storage tank 12 is installed at the lower end in the separation tower 11, a detection device 13 is installed on one side of the liquid storage tank 12, an overflow pipe 15 is installed on the other side of the liquid storage tank 12, a water replenishing valve 18 is installed at the upper end of the overflow pipe 15, a demisting filtering section 20 is installed at the upper end of the liquid storage tank 12, a liquid separation chamber 19 is arranged between the liquid storage tank 12 and the demisting filtering section 20, and an exhaust cavity 21 is arranged at the upper end of the demisting filtering section 20.

The pre-filtering net 25 is arranged on a guide groove 39 in the filtering channel 37, an extruding device 40 is arranged at the upper end of the pre-filtering net 25, the extruding device 40 comprises an extruding plate 41, the extruding plate 41 is arranged at the upper end of the guide groove 39, the pre-filtering net 25 is arranged in the guide groove 39, the extruding plate 41 is fixedly connected with the pre-filtering net 25, an extruding electromagnetic valve 42 is arranged at the upper end of the extruding plate 41, the extruding electromagnetic valve 42 is arranged at the upper end of the filtering channel 37, a collecting port 43 is arranged at the lower end of the pre-filtering net 25, and a collecting tank 44 is arranged at the lower end of the collecting port 43; through the extrusion device 40 that sets up in the prefilter screen 25 can be after prefilter screen 25 absorbs full load's oil gas, extrude unnecessary oil through the cotton setting of oil absorption, make it can used repeatedly, set up in the below simultaneously and collect mouthful with fluid and collect, treat the later stage and handle.

The pre-filtering net 25 is made of oil absorption cotton, the pre-filtering net 25 is of a folding and stretching structure, the upper end of the folding and stretching structure is connected to the lower end of the extrusion plate 41, and the lower end of the folding and stretching structure is connected to the upper end of the collecting port 43; set up to folding tensile structure through the oil absorption cotton, increase absorbing area simultaneously can be better filtration, be convenient for simultaneously the extrusion device 40 can be better extrude the oil absorption cotton, guarantee simultaneously that the cotton structure of oil absorption after the extrusion is not damaged.

Filter screen 26 sets up to dry-type chemical filter screen, dry-type chemical filter screen includes porous medium 45 and chemical 46, fill chemical 46 in the porous medium 45, chemical 46 includes strong oxidant, phosphoric acid, FeS, MgO, NaOH, KOH and dibromo thymol sulfophthalein, strong oxidant is potassium permanganate or sodium permanganate.

The inner wall of the guide groove 39 is provided with a plurality of blowing holes 47, the blowing holes 47 are connected with air compression tubes 48, the blowing holes 47 are uniformly formed in the inner wall of the guide groove 39, the blowing holes 47 can blow air after the oil absorption cotton is stretched after extrusion is completed, and the oil gas filtering effect is achieved continuously.

The oil fume filter is characterized in that a first load cell 28 is arranged at the upper end of the pre-filtering net 25, a second load cell 29 is arranged at the upper end of the filtering net 26, a third load cell 30 is arranged at the upper end of the final filtering net 27, the pressure difference of the two sides of the filtering net is measured through the first load cell, the second load cell and the third load cell, whether the filtering net is replaced or not is judged through the pressure difference, and the oil fume filtering efficiency is improved.

s1, enabling the oil smoke tail gas to enter a washing unit 34 from a smoke inlet 1, enabling the oil smoke tail gas to enter a washing pipe 3 through a pipeline 22, arranging an upward first-stage nozzle 4 in the washing pipe 3, enabling washing liquid sprayed from the first-stage nozzle 4 to intersect with smoke flow from top to bottom to form a washing area, and transferring particulate matters and water-soluble gaseous pollutants in the waste gas to the washing liquid by mass transfer in the washing area;

s2: when the temperature of the oil smoke tail gas is higher than the liquid temperature, the oil smoke tail gas transfers heat with the liquid, the temperature of the oil smoke tail gas is reduced, the oil smoke tail gas enters the separation tower 11 after being washed in the washing pipe 3, gas-water separation is carried out in the separation tower 11, the oil smoke tail gas without particulate matters and soluble gaseous pollutants rises, the washing liquid mixed with the washed pollutants flows into the liquid storage tank 12, the washing liquid in the liquid storage tank 12 passes through the liquid return pipe 10, a water pump pressurization system 100 mode is adopted, pressure and the washing liquid are continuously provided for the nozzle, the washing liquid enters the exhaust cavity 21 through the demisting section 20, and then the washing liquid enters the electrostatic unit 35 through the pipeline 2;

s3: the tail gas in the electrostatic treatment unit is further purified in the electrostatic module 23, and the electrostatic module 23 adopts a wide polar distance type to remove dust, and particulate matters which are not washed and liquid drops carried out from a washing tower are removed;

s4: tail gas treated by the electrostatic unit 35 enters a next-stage advanced treatment unit polishing unit 36, the polishing unit 36 is structurally filtered in three stages, the first stage is that the pre-filtering net 25 is made of oil-absorbing cotton, the filtering oil-absorbing cotton can be folded for use, the pre-filtering net 25 can be extruded for reuse after being fully filled with oil through an extruding device 40 arranged on the pre-filtering net 25, residual oil mist particles are deeply removed through the pre-filtering net 25, and the filtering net 26 is protected from being polluted by oil mist and the like;

s5: after the oil smoke tail gas passes through the pre-filter screen 25, sticky particles such as oil mist and the like are completely removed, then the oil smoke tail gas enters the filter screen 26, a dry chemical filtering treatment process is adopted in the filter screen 26, volatile organic matters are removed when the tail gas passes through the section of the filter screen, a dry chemical filtering material is adopted in the filter screen 26 and comprises a porous medium 45 and a chemical agent 46, the material has the typical functions that the chemical agent is subjected to adsorption reaction with harmful components in the gas and is removed, the purpose of purifying peculiar smell is achieved, and then the residual particles are filtered through the final filter screen 27 and are discharged into the atmosphere after being filtered.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions are considered to be within the protective scope of the present invention.

Claims

1. The device for treating the oil fume tail gas comprises a washing unit, an electrostatic unit and a polishing unit, and is characterized in that the washing unit is connected with the electrostatic unit through a pipeline, the electrostatic unit is connected with the polishing unit through a filtering channel, the washing unit comprises a flue gas inlet, the flue gas inlet is connected with the upper end of a washing pipe through a flue gas pipeline, a waste reducing device is arranged in the washing pipe, the lower end of the washing pipe is connected with a separating device, the separating device comprises a separating tower, the lower end of the separating tower is connected with a liquid return pipe of the waste reducing device, the upper end of the separating tower is connected with one side of the pipeline, the other side of the pipeline is connected with the electrostatic unit, the electrostatic unit comprises an electrostatic module, the electrostatic module is arranged in the filtering channel, and the polishing unit is arranged on one side of the electrostatic module, the polishing unit comprises a pre-filtering net, a filtering net and a final filtering net, wherein the pre-filtering net is arranged on one side of the electrostatic module, the filtering net is arranged on one side of the pre-filtering net, the final filtering net is arranged on one side of the filtering net, and an exhaust pipeline is arranged on one side of the final filtering net;

the pre-filtering net is installed on a guide groove in the filtering channel, an extrusion device is installed at the upper end of the pre-filtering net and comprises an extrusion plate, the extrusion plate is installed at the upper end of the guide groove, the pre-filtering net is arranged in the guide groove, the extrusion plate is fixedly connected with the pre-filtering net, an extrusion electromagnetic valve is arranged at the upper end of the extrusion plate and is installed at the upper end of the filtering channel, a collecting port is formed in the lower end of the pre-filtering net, and a collecting tank is arranged at the lower end of the collecting port; the pre-filtering net is made of oil absorption cotton, the pre-filtering net is of a folding and stretching structure, the upper end of the folding and stretching structure is connected to the lower end of the extrusion plate, and the lower end of the folding and stretching structure is connected to the upper end of the collection port; the guide slot inner wall is provided with a plurality of holes that blow, blow the hole and be connected with the air compression pipe, blow the hole evenly set up in on the guide slot inner wall.

2. The device for treating lampblack tail gas as claimed in claim 1, wherein the waste reducing device comprises a primary nozzle, the primary nozzle is mounted at the upper end of a water pipe, the water pipe extends into the middle position in the washing pipe, a water pump pressurizing system is connected to the other side of the water pipe and comprises a first valve, a one-way valve, a booster pump, a filter and a second valve, the first valve, the one-way valve, the booster pump, the filter and the second valve are sequentially connected, and the second valve is connected with the liquid return pipe.

3. The device of claim 1, wherein a reservoir is installed at a lower end of the separation tower, a detection device is installed at one side of the reservoir, an overflow pipe is installed at the other side of the reservoir, a water replenishing valve is installed at an upper end of the overflow pipe, a defogging filtering section is installed at an upper end of the reservoir, a liquid separation chamber is arranged between the reservoir and the defogging filtering section, and an exhaust cavity is arranged at an upper end of the defogging filtering section.

4. The device of claim 1, wherein the filter screen is a dry chemical filter screen, the dry chemical filter screen comprises a porous medium and a chemical agent, the porous medium is filled with the chemical agent, the chemical agent comprises a strong oxidant, phosphoric acid, FeS, MgO, NaOH, KOH and dibromothymolsulfonphthalein, and the strong oxidant is potassium permanganate or sodium permanganate.

5. The device for treating lampblack exhaust according to claim 1, wherein a first load cell is arranged at the upper end of the pre-filtering net, a second load cell is arranged at the upper end of the filtering net, and a third load cell is arranged at the upper end of the final filtering net.

6. A process method for an apparatus for treating oil smoke tail gas, which is characterized in that the apparatus for treating oil smoke tail gas is the apparatus for treating oil smoke tail gas as claimed in any one of claims 1 to 5, and comprises the following steps:

s1, enabling the oil smoke tail gas to enter a washing unit from a smoke inlet, enabling the oil smoke tail gas to enter a washing pipe through a pipeline, arranging an upward first-stage nozzle in the washing pipe, enabling washing liquid sprayed from the first-stage nozzle to meet with smoke flow from top to bottom to form a washing area, and transferring particulate matters and water-soluble gaseous pollutants in the waste gas to the washing liquid by mass transfer in the washing area;

s4: tail gas treated by the electrostatic unit enters a next-stage advanced treatment unit polishing unit, the polishing unit is structurally filtered in three stages, the first stage is that a pre-filtering net adopts a filter made of oil-absorbing cotton, the filtering oil-absorbing cotton can be folded for use, the pre-filtering net can be extruded for repeated use after being fully filled with oil through an extrusion device arranged on the pre-filtering net, and residual oil mist particles are deeply removed through pre-filtering to protect the filtering net from being polluted by oil mist and the like;

s5: the oil smoke tail gas is after passing through the prefilter screen, sticky particulate matters such as oil mist are completely removed, then the oil smoke tail gas enters the filter screen, in the filter screen, a dry type chemical filtering treatment process is adopted, when the tail gas is filtered through the section, volatile organic matters are removed, a dry type chemical filtering material is adopted in the filter screen, the material comprises a porous medium and a chemical agent, the typical function of the material is that the chemical agent is in adsorption reaction with harmful components in the gas and is removed, the purpose of purifying peculiar smell is achieved, then the residual particles are filtered through the final filter screen, and the filtered gas is discharged into the atmosphere.