CN212548968U - Exhaust gas treatment system - Google Patents

Abstract

The utility model provides a waste gas treatment system, which comprises at least two subsystems which are arranged in series and are used for the waste gas to flow through, wherein each subsystem is provided with at least one gas treatment device in series, part of the gas treatment device is filled with treatment liquid, and a treatment unit is arranged in the gas treatment device; the treatment unit can contain dust or a plurality of gaseous substances in the waste gas into the treatment liquid; the treatment liquid in the first branch system positioned at the upstream catches or dissolves dust and soluble gaseous substances in the waste gas; the neutralization reaction of the treatment liquid with the less soluble basic or acidic gaseous substance in the second sub-system located downstream of the first sub-system. Waste gas treatment system, adopt the processing of multistage process system completion to all kinds of harmful substance in the waste gas, have the advantage that reduces pollutant discharge and recovery efficiency is high.

Description

Exhaust gas treatment system

Technical Field

The utility model relates to an exhaust-gas treatment purifies technical field, in particular to exhaust-gas treatment system.

Background

As steel mill power plants and garbage power plants are important sources for generating waste gas, pollutants generated by coal-fired steel mill and power plants mainly comprise smoke dust, sulfur dioxide, oxynitride, dioxin, carbon dioxide and the like, wherein the proportion of sulfur components contained in coal is up to 1% -7%, and the discharged pollutants are main sources of sulfur dioxide in the atmosphere. For the waste gas generated by burning garbage for power generation, the pollutants comprise smoke dust, sulfur dioxide, nitrogen oxides and substances containing highly toxic dioxin and the like. In addition, tail gas discharged from factories, workshops and the like is also a main source of air pollution, and due to environmental pressure, many factories are required to limit production and stop production due to environmental protection, so that enterprises are greatly lost.

The existing desulfurization and denitrification process for treating tail gas of large coal-fired boilers in electric steel plants and the like has the following defects: because the pollutant treatment does not reach the standard, low-sulfur coal is adopted, and the cost difference of each ton of low-sulfur coal and high-sulfur coal is more than one hundred yuan; some exhaust tail gas requires white smoke elimination treatment again, so that the operation cost is high; meanwhile, the method has the advantages of more maintenance and use personnel, large occupied area, high investment cost, incomplete treatment and the like.

In the prior art, the waste incineration tail gas treatment technology usually adopts an activated carbon powder adsorption or dry deacidification process, for example, a method of directly spraying activated carbon powder or an absorbent into a flue is adopted, so that the aim of removing harmful substances in the flue gas is fulfilled. The tail gas treatment method has high cost, low treatment efficiency and poor effect. Carbon dioxide is a greenhouse gas, coal or garbage combustion power generation is one of the main sources of carbon dioxide pollution, and the cost for processing carbon dioxide by cash technology is too high. Therefore, it is necessary to develop a waste gas treatment apparatus and a waste gas treatment process with low cost, high purification efficiency and good environmental protection performance.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention is directed to an exhaust gas treatment system to prolong the life of the filter material in the exhaust gas treatment system, thereby reducing the cost of gas treatment and purification.

In order to achieve the above purpose, the technical scheme of the utility model is realized like this:

an exhaust treatment system for treating exhaust flowing therethrough, comprising:

at least two subsystems which are arranged in series and are used for the waste gas to flow through are arranged, and at least one gas treatment device is arranged in each subsystem in series;

the gas treatment device is partially filled with treatment liquid, and a treatment unit which is used for the waste gas to pass through and can form the sufficient contact between the treatment liquid and the waste gas is arranged above the liquid level of the treatment liquid; the dust or a plurality of gaseous substances in the waste gas can be contained in the treatment liquid due to the filtering interception or adsorption effect of the treatment unit;

the treatment liquid in the first sub-system located at the upstream is a solution which is used for capturing or dissolving dust and soluble gaseous substances in the waste gas;

the treatment liquid in the second sub-system positioned at the downstream of the first sub-system is acid liquid or alkali liquid, so that the neutralization reaction with the insoluble alkaline or acidic gaseous substances in the waste gas is formed.

Further, the exhaust gas treatment system further comprises a third subsystem downstream of the second subsystem having at least one of the gas treatment devices; the treatment liquid contained in the gas treatment device of the third sub-system is an alkaline solution, and the gas treatment device is provided with a filtering device and a reactor; filtering weak alkaline salt generated by the reaction of the carbon dioxide in the waste gas and the alkaline solution by the filtering device, and conveying the weak alkaline salt to the reactor; the reactor is arranged in the flow-through channel of the exhaust gases upstream of the first subsystem a.

Further, the exhaust gas discharged from the third sub-system is discharged to the outside through a catalyst disposed in the flow passage upstream of the reactor.

Furthermore, the waste gas treatment system also comprises a plurality of filtering devices and treatment liquid improving devices; the filtering device and the treatment liquid improving device are communicated in groups or individually and are arranged below the gas treatment device; the filtering device receives the inflow of the treatment liquid in the gas treatment device or the treatment liquid improvement device so as to collect and filter solid substances in the treatment liquid; the treatment liquid improving device receives the inflow of the treatment liquid in the gas treatment device or the filtering device, and the treatment liquid improving device is subjected to neutralization reaction with the inflow treatment liquid due to the feeding of the acid-base dissimilar substances and/or is used for precipitating salt substances in the treatment liquid due to the cooling of the temperature reducing unit.

Furthermore, a return pipeline is arranged between the treating fluid improving device and the gas treating device.

Further, the gas processing device in each of the first sub-system and the second sub-system is multiple; the treatment liquid in the same subsystem is supplied and conveyed from the most downstream gas treatment device to the most upstream gas treatment device in sequence against the flow direction of the exhaust gas, and a liquid replenishing port is opened in the most downstream gas treatment device, and only the most upstream gas treatment device is provided with the filtering device and/or the treatment liquid improving device.

Further, the gas processing device is provided with a cavity formed by a shell body surrounding structure, and the processing unit is driven to be rotationally separated between the gas inlet and the gas outlet at two ends of the shell body; the treatment unit is partially immersed and washed in the treatment liquid by rotation; the separation and/or removal of several substances within the exhaust gas may be constituted by interception by the treatment unit and/or by the action of the treatment liquid when the exhaust gas passes through the treatment unit wetted with the treatment liquid.

Furthermore, along the flow direction of the waste gas, a plurality of treatment units are sequentially arranged in the cavity at intervals; at least one of the processing units in the gas processing device positioned at the most upstream is a filter screen; and each treatment unit in the gas treatment device in the second subsystem is a filter disc made of activated carbon.

Compared with the prior art, the utility model discloses following advantage has:

(1) the waste gas treatment system of the utility model adopts a multistage series process system to complete the treatment of various harmful substances in the waste gas, firstly utilizes the treatment unit soaked with treatment liquid to capture dust, utilizes solution to dissolve soluble harmful gas, adopts an acid-base neutralization mode and completes the adsorption capture and reaction removal of the insoluble gas by means of the adsorption of active carbon; achieves good classification and gradual removal and purification, and has good cost advantage and higher purification performance. The third sub-system of the waste gas treatment system utilizes the weak alkali solution reaction of alkali liquor such as sodium carbonate and the like in water, completes the reaction of carbon dioxide by means of the adsorption of activated carbon to generate weak alkali salt, utilizes the waste heat of the system to realize the reverse reaction from the weak alkali salt to the alkali salt, realizes the separation and purification of the carbon dioxide in the waste gas, and can reduce the carbon emission. The system mainly uses limestone raw materials to finish the treatment of waste gas, can produce byproducts such as calcium sulfate, calcium nitrate, carbon dioxide with higher purity and the like, has low overall treatment cost and has considerable economic benefit advantage.

The system adopts a multistage series process system to complete the treatment of various harmful substances in the waste gas, firstly, a treatment unit soaked with treatment liquid is used for capturing dust, soluble harmful gas is dissolved by using solution, and the adsorption, capture and reaction removal of the insoluble gas are completed by adopting an acid-base neutralization mode and the adsorption of activated carbon; achieves good classification and gradual removal and purification, and has good cost advantage and higher purification performance.

The third sub-system of the system utilizes weak alkali solution reaction of alkali liquor such as sodium carbonate in water, completes the reaction to carbon dioxide by means of the adsorption of activated carbon to generate weak alkali salt, and utilizes the waste heat of the system to utilize and heat up to realize the reverse reaction from the weak alkali salt to the alkali salt, thereby realizing the separation and purification of carbon dioxide in waste gas and reducing the carbon emission. The system mainly uses limestone raw materials to finish the treatment of waste gas, can produce byproducts such as calcium sulfate, calcium nitrate, carbon dioxide with higher purity and the like, has low overall treatment cost and has considerable economic benefit advantage

Drawings

The accompanying drawings, which form a part of the present disclosure, are provided to provide a further understanding of the present disclosure, and the exemplary embodiments and descriptions thereof are provided to explain the present disclosure, wherein the related terms in the front, back, up, down, and the like are only used to represent relative positional relationships, and do not constitute an undue limitation of the present disclosure. In the drawings:

fig. 1 is a schematic view of an overall structure of an exhaust gas treatment system according to a first embodiment of the present invention;

fig. 2 is a schematic view of an overall structure of a first gas processing apparatus according to a first embodiment of the present invention at a viewing angle;

fig. 3 is a schematic view of an overall structure of the first gas processing apparatus at another viewing angle according to the first embodiment of the present invention;

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 2;

fig. 5 is a schematic view of an internal structure of the second gas processing apparatus according to the first embodiment of the present invention;

FIG. 6 is a schematic diagram of a processing unit;

FIG. 7 is an enlarged view of portion B of FIG. 6;

description of reference numerals:

1-shell, 100-lower shell, 101-gas inlet side plate, 102-gas outlet side plate, 103-settling tank, 104-packaging flanging, 105-first return pipeline, 106-gas inlet, 107-gas supplementing port, 108-gas outlet, 109-second return pipeline, 110-upper shell, 111-third return pipeline, 112-first conveying pipeline, 113-second conveying pipeline, 114-third recovery port, 115-third conveying pipeline, 116-waste gas inlet port, 117-feeding port, 120-liquid supplementing port, 133-discharge port, 137-filter plate, 138-liquid outlet port and 150-spray head;

2-processing unit, 200-filter body, 201-frame, 202-support rib, 203-rotating shaft, 204-motor, 206-shaft seal, 207-sealing body, 21-first processing unit, 22-second processing unit, 23-third processing unit and 24-fourth processing unit;

3-flow channel, 31-first heat exchange tube, 32-feed inlet, 33-observation port, 34-reactor, 35-first recovery port, 36-second recovery port and 37-catalyst;

a-a first sub-system, B-a second sub-system and C-a third sub-system;

4-a first gas treatment device, 40-a first treatment liquid improvement device, 41-a feeding port, 42-a stirrer, 43-a first filtering device, 44-a second heat exchange tube, 45-a fourth recovery port, 46-a fifth recovery port, 47-a second filtering device;

5-a drainage fan, 6-a second gas treatment device;

7-a third gas treatment device, 71-a second treatment liquid improving device, 72-a third heat exchange tube, 73-a sixth recovery port, and 74-a third filtering device;

8-fourth gas treatment device, 9-fifth gas treatment device, 91-fourth filtering device and 92-seventh recovery port.

Detailed Description

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, terms of left, right, up, down, and the like are used for convenience of description and are based on terms in the illustrated state, and should not be construed as limiting the structure of the present invention; references to first through seventh, etc. are also for convenience of description and are not to be construed as indicating or implying relative importance.

Example one

The embodiment relates to an exhaust gas treatment system for treating exhaust gas to reduce pollutant emission. The waste gas treatment system comprises at least two subsystems which are arranged in series and are used for waste gas to flow through, and at least one gas treatment device is arranged in each subsystem in series. The gas treatment device is partially filled with treatment liquid, a treatment unit which is used for waste gas to pass through and can form sufficient contact between the treatment liquid and the waste gas is arranged above the liquid level of the treatment liquid, and the treatment unit can filter, intercept or adsorb dust or a plurality of gaseous substances in the waste gas so as to contain the dust or the plurality of gaseous substances in the treatment liquid.

Wherein, along the flow direction of the exhaust gas, the treatment liquid in the first sub-system a located upstream is a solution that constitutes the capture or dissolution of dust and soluble gaseous substances in the exhaust gas. The treatment liquid in the second sub-system B positioned at the downstream of the first sub-system A is acid liquid or alkali liquid, so that the neutralization reaction with the insoluble alkaline or acidic gaseous substances in the waste gas is formed. The waste gas treatment system can be used for treating dust, soluble gaseous substances and insoluble alkaline or acidic gaseous substances in waste gas in a targeted manner according to different components in the waste gas, so that the pollution of waste gas discharge to the environment can be reduced, and better economic and social benefits are achieved.

The waste gas in this embodiment may be waste gas generated by coal burning (such as power plant), waste gas generated by garbage burning (garbage power plant), or other industrial waste gas. The following describes the exhaust gas treatment system in this embodiment by taking the exhaust gas generated by a garbage power plant as an example. When the waste gas is other waste gas, the working principle of the waste gas treatment system is substantially the same as the treatment mode of the waste gas of the garbage power plant, and the detailed description thereof is omitted.

Pollutants in the waste gas generated by the garbage power plant comprise smoke dust, sulfur dioxide, nitrogen oxides and substances containing highly toxic dioxin and the like. Based on the above general principles, the first sub-system a is used for treating smoke and sulfur dioxide, and the second sub-system B is used for treating nitrogen oxide.

Referring to the drawings, an exemplary structure of the exhaust gas treatment system of the present embodiment is shown in fig. 1, and the first sub-system a includes a first gas treatment device 4 and a second gas treatment device 6 connected downstream of the first gas treatment device 4. The second sub-system B comprises a third gas treatment device 7 and a fourth gas treatment device 8, which are arranged downstream of the second gas treatment device 6 in series in the flow direction of the exhaust gases. A draught fan 5 can be arranged between two adjacent gas treatment devices to drive the waste gas to flow. Here, by setting each subsystem to two, the classification treatment of pollutants in the exhaust gas can be realized, and the exhaust gas treatment efficiency is improved. Of course, the number of the gas processing devices in each subsystem in this embodiment may also be increased according to specific requirements. The treatment liquid in the first gas treatment device 4 may be clean water for converting sulfur dioxide into sulfuric acid solution. Of course, the treating fluid can be other solutions besides clear water, but the sulfuric acid solution prepared by the clear water has higher concentration and purity and lower cost.

Upstream of the first gas treatment device 4, a flow-through channel 3 is provided for conveying the exhaust gas into the first gas treatment device 4. The exhaust gas flows into the flow-through passage 3 through the exhaust gas inlet port 116. Because the temperature of untreated flue gas can reach 800-1100 ℃, and the problem of potential safety hazard and energy waste exists when untreated flue gas directly enters each subsystem, as shown in fig. 1, a first heat exchange pipe 31 is arranged in the flowing channel 3, a heat exchange medium flows in the first heat exchange pipe 31, and the heat exchange medium can exchange heat in the process of flowing of waste gas, so that the temperature of the waste gas is reduced to release energy, the temperature of the heat exchange medium is increased to realize energy storage, and the energy storage can be used for heating in winter, and is energy-saving and environment-friendly. In addition, in order to check the state in the flow path 3, the flow path 3 is further provided with an observation port 33.

In addition, when the exhaust gas flows through the channel 3, due to the obstruction of the first heat exchange tube 31 and the space of the channel 3, the smoke in the exhaust gas is pretreated, so that part of the smoke falls to the bottom of the channel 3 and is finally collected through the second recovery port 36 at the bottom of the channel. So set up, reducible smoke and dust volume of flowing through the branch system, and then do benefit to the life who prolongs branch system.

Each of the gas processing apparatuses in this embodiment has a cavity defined by the enclosure of the housing 1, and a processing unit 2 disposed in the cavity, wherein the housing 1 has an inlet port 106 and an outlet port 108 for allowing gas to enter and exit the cavity at both end portions thereof, and the processing unit 2 is rotationally driven and partitioned between the inlet port 106 and the outlet port 108. The treatment unit 2 is partially immersed and washed in the treatment liquid by rotation; the interception by the treatment unit 2 and/or the action of the treatment liquid may constitute a separation and/or removal of a substantial part of the sulphur dioxide in the exhaust gases, when the exhaust gases pass through the treatment unit 2 soaked with the treatment liquid.

Since the respective gas processing apparatuses have substantially the same configuration, the configuration of the first gas processing apparatus 4 will be described below as an example. As shown in fig. 2 and fig. 3, the above-mentioned housing 1 includes an upper housing 110 and a lower housing 100 which are connected by being buckled up and down, wherein, the edges of both sides of the upper housing 110 and the lower housing are formed with outward-turned packaging flanges 104, and the upper housing 110 and the lower housing 100 are fastened and installed by fastening bolts passing through the corresponding packaging flanges 104. The two ends of the casing 1 are respectively provided with side plates for closing the openings at the two ends of the casing 1, and the air inlet 106 and the air outlet 108 are respectively positioned on the two side plates. For the sake of convenience of distinction, in the present embodiment, the side plate having the air inlet 106 is referred to as an air inlet side plate 101, and the other side plate is referred to as an exhaust side plate 102.

In order to improve the purifying effect of the processing liquid, the air inlet 106 is located at the top of the air inlet side plate 101, and the air outlet 108 is located at the top of the air outlet side plate 102. Of course, the air inlet 106 and the air outlet 108 in this embodiment can also be disposed on the upper housing 110 at both ends.

As shown in fig. 4, the four processing units 2 are arranged at intervals along the flowing direction of the exhaust gas to perform four-stage filtration on the smoke in the flowing exhaust gas, so as to achieve a better smoke filtering effect. Of course, the number of treatment units 2 in the gas treatment device of the present embodiment may also be adapted according to the specific filtration requirements. Here, in order to achieve a better classification filtering effect, the filtering capacity of each processing unit 2 is higher and higher along with the flow direction of the exhaust gas. The cross section of the cavity corresponding to each processing unit 2 is circular, and the processing units 2 are revolved bodies coaxially arranged with the cavity, so that the processing units 2 are favorable for rotary arrangement, the cavities can be well separated by the processing units 2, and good conditions are created for purification of waste gas. For convenience of description, the processing units 2 arranged according to the flow direction of the exhaust gas are referred to as a first processing unit 21, a second processing unit 22, a third processing unit 23, and a fourth processing unit 24, respectively.

In order to improve the treatment effect of the gas treatment device on the smoke dust, the spray head 150 is arranged on the upper shell 110 at the upstream of the first treatment unit 21, and the spray head 150 can spray water into the space between the first treatment unit 21 and the gas inlet end side plate 101 in the form of water curtain or water mist, so that most of the smoke dust suspended in the cavity can be precipitated into the treatment liquid when meeting water, the attaching effect of the smoke dust on the treatment unit 2 can be increased, and the smoke dust can smoothly enter the treatment liquid.

The most basic function of each processing unit 2 is to filter the smoke dust in the exhaust gas to obtain gas with high cleanliness, and specifically includes a frame 201 and a plurality of layers of thin-walled filter bodies 200 arranged in the frame 201. Here, the predetermined filtering effect can be achieved by filtering with the filter body 200, and the rotation of the filter body 200 is facilitated. Although clogging of the filter 200 is inevitably caused during the filtering of the soot, since each processing unit 2 in this embodiment can contact the processing liquid by rotation, the filter 200 on the processing unit 2 can be self-cleaned due to the impact of the processing liquid on the soot and the centrifugal action of the soot during the rotation of the processing unit 2, which is advantageous for prolonging the service life of the processing unit 2 and reducing the maintenance cost thereof.

The filter 200 is a single layer, and as shown in fig. 6, the outer peripheral wall of the frame 201 is annular, and one side of the frame is connected to the outer peripheral wall, so as to provide a base for mounting the filter 200. The side part of the frame 201 is provided with a plurality of support ribs 202 which are matched with the curved surface of the filter body 200, and the support ribs 202 are arranged around the frame 201 at intervals in the axial direction, so as to achieve a better support effect. In this embodiment, the filter bodies 200 on the processing unit 2 may be provided with two layers, and when the two layers are provided, the filter bodies 200 on the two sides may be filled with filter materials, such as activated carbon, to achieve a better filtering effect.

The filter 200 in this embodiment may be at least one of a filter screen, an activated carbon filter block, and a ceramic filter sheet. The first treatment unit 21 to the fourth treatment unit 24 may all adopt the same filter screen, or one of the two filter screens, and the other one is an activated carbon filter screen, an activated carbon filter block, a ceramic filter sheet, or the like. Thereby realize filtering the smoke and dust impurity of different specifications through the aperture of filtering the hole on it. The filter 200 is easy to be assembled, and has the advantages of being suitable for filtering, high in durability and the like.

As can be seen from the specific selection of the above filter body 200, each filter product has a filter hole for realizing the filtering function, the filter hole can filter the smoke dust, and can also form a water film in the filter hole in the process of immersing in the treatment liquid, when the water film is in the flow path of the waste gas, the waste gas easily penetrates through the water film and breaks the water film under the driving of external force, so that the contact between sulfur dioxide and water can be increased at the moment, and the generation of the sulfuric acid solution is facilitated. Especially, when the filter 200 is a filter screen with activated carbon or a filter disc made of activated carbon, the activated carbon itself can directly transfer the absorbed sulfur dioxide to the treatment solution for more efficient conversion of sulfur dioxide due to the adsorption of sulfur dioxide. For this reason, the most downstream processing unit 2 in the first gas treatment device 4 and the second gas treatment device 6 is preferably an activated carbon filter 200.

In this embodiment, the filter body 200 may be a curved surface protruding toward the flowing direction of the solid impurities, so that the smoke impurities isolated by the corresponding processing unit 2 can be better removed on the filter body 200 by centrifugal force and flow to the periphery, thereby improving the filtering efficiency of the filter body 200. Of course, the filter 200 may have a planar shape in addition to a curved shape, but the filter 200 may have a better use effect than the curved filter 200.

In order to improve the effect of the treatment unit 2, the liquid level of the treatment liquid in the housing 1 is between one third and two thirds of the height of the treatment unit 2 in the present embodiment, for example, the liquid level of the treatment liquid is one half of the height of the treatment unit 2. In this state, the intercepted solid impurities may be washed into the treatment liquid as the treatment unit 2 rotates, and may be separated from the treatment unit 2 by centrifugal force and/or impact of the treatment liquid, thereby reducing clogging of the treatment unit 2. Based on the important function of the height of the processing liquid, in the present embodiment, the liquid replenishing port 120 is provided on the upper casing 110 near the exhaust port 108 to ensure the using effect of the processing liquid by replenishing the processing liquid.

In this embodiment, the power driving the processing units 2 in the first gas processing apparatus 4 to rotate comes from the motor 204 installed on the exhaust end side plate 102, the power output end of the motor 204 is connected with the rotating shaft 203, the two processing units 2 are installed on the rotating shaft 203 through the frames 201 thereon, the rotating shaft 203 is driven to rotate around the axis thereof by the motor 204, and the filtering and removing effects of the smoke and dust impurities on the processing units 2 are improved by the rotation, wherein, in order to ensure the sealing between the rotating shaft 203 and the exhaust end side plate 102 during the rotation, a shaft seal 206 is further installed on the rotating shaft 203.

In addition, in order to improve the use effect of the processing unit 2 during the rotation, in the present embodiment, as shown in fig. 6, a sealing body 207 is provided on the outer peripheral wall of the frame 201 to restrict the exhaust gas from flowing backward between the outer peripheral wall of the frame 201 and the inner wall surface of the cavity. In a specific structure, as shown in fig. 7, the sealing body 207 in this embodiment specifically includes an adhesive layer adhered or fixed to the outer peripheral wall surface of the frame 201 by fastening screws, and a plurality of bristles disposed on the adhesive layer and extending outward in the radial direction of the filter body 200, and the bristles are provided in multiple sets along the height direction of the adhesive layer. The adhesive layer and the bristles may be made of prior art acid-resistant rubber materials in consideration of the acidity of the treating fluid. Here, a good restraining effect can also be achieved by the bristles not affecting the rotation of the processing unit 2. Of course, the sealing body 207 in this embodiment may be a gas sealing member which is easily installed on the frame 201 and is resistant to corrosion of acid solution, besides the brush hair.

In this embodiment, the inner wall surface of the cavity is provided with annular projections disposed on the left and right sides of each processing unit 2, and a plurality of rolling members are disposed between the annular projections and the processing units 2. In a specific structure, as shown in fig. 4, a bracket is provided on a side surface of the annular protrusion facing the corresponding processing unit 2, and the rolling member is a ball positioned and mounted on the bracket. The frame 201 is provided with a slide for sliding the balls. Here, through setting up cyclic annular arch and rolling member, can increase the bearing capacity of casing 1 to processing unit 2, simultaneously, adopt rolling friction to increase the steadiness to effectively reduce the frictional force of processing unit 2 in rotatory process, and then reduce the wearing and tearing in the use.

In this embodiment, in order to facilitate the treatment of the soot impurities in the treatment liquid in the first gas treatment device 4, with continued reference to fig. 1, a settling tank 103 communicating with the cavity and declining against the flow of the gas is constructed at the bottom of the casing 1; the sediment generated by the capture or reaction of the treatment liquid is slipped into the end of the settling tank 103 through the settling tank 103, and can be discharged through a discharge port 133 provided at the end. Here, a settling tank 103 is constructed at the bottom of the casing 1, and solid substances in the treatment liquid can be accumulated and slipped out, thereby improving the clarity of the treatment liquid.

In a specific structure, the first filtering device 43 is disposed at the drain opening 133, and has a first filtering cavity communicated with the drain opening 133, a liquid outlet 138 is disposed on the first filtering cavity, and a filter plate 137 for separating the smoke from the sulfuric acid solution is disposed at the upstream of the liquid outlet 138, so that the smoke will sink at the bottom and be recovered through the third recovery opening 114 due to the obstruction of the filter plate 137. In order to convert the sulfuric acid solution with higher concentration, the first sub-system a is further provided with a first treating fluid improving device 40, which can perform a neutralization reaction with the sulfuric acid solution through the alkaline solution, thereby realizing the treatment of concentrated sulfuric acid. Specifically, the first treatment liquid improving apparatus 40 has a first treatment liquid improving chamber communicated with the liquid outlet 138, and a feed port 41 for introducing an alkaline substance is provided at the top of the treatment liquid improving chamber. The alkaline substance can be calcium carbonate powder, the procurement cost is low, the conversion investment is favorably reduced, and the mesh number is preferably more than 200. Since calcium carbonate is very insoluble in water, in order to promote the neutralization reaction, in this embodiment, a stirrer 42 is further provided in the first treatment liquid improvement chamber to stir calcium carbonate powder into a suspension. At this point, the calcium carbonate reacts with the sulfuric acid to produce calcium sulfate, water, and carbon dioxide. Because the solubility of calcium sulfate in water is low, calcium sulfate obtained by filtering calcium sulfate through a filtering device in the prior art is recovered through the fifth recovery port 46 at the bottom of the first treatment liquid improvement cavity.

The solution from which the calcium sulfate is filtered out can be conveyed to the liquid replenishing port 120 of the second gas treatment device 6 through the first return pipeline 105, and the solution is recycled, so that liquid pollutants cannot be discharged, and the environment-friendly effect is better. In addition, since the concentration and purity of carbon dioxide generated by the reaction in the first treatment liquid improvement chamber are high, the generated nitrogen dioxide can be recovered through the fourth recovery port 45, and waste can be changed into valuable.

In the present embodiment, the second to fourth gas treatment devices 6 to 8 are configured as shown in fig. 5, and since the soot in the exhaust gas has been removed in the first gas treatment device 4, the soot content in several gas treatment devices located downstream is small. Therefore, the structure of the spray head 150 and the settling tank 103 is not provided, and the drain opening 133 is provided only at the bottom of the air inlet end thereof. And because the second gas treatment device 6 is used for converting a small part of sulfur dioxide which is not treated by the first gas treatment device 4, the property of the treatment liquid is changed from clean water to dilute sulfuric acid, the dilute sulfuric acid can flow into the first gas treatment device 4 again through the first conveying pipeline 112 connected between the discharge port 133 and the exhaust port 108 of the first gas treatment device 4 to react with the sulfur dioxide again to generate sulfuric acid, the treatment route in the first gas treatment device 4 is repeated, and calcium sulfate and carbon dioxide gas are harvested on the premise of realizing pollution-free discharge of the whole first sub-system A.

As shown in fig. 1, the third gas treatment device 7 in the second sub-system B is used to treat most of the nitrogen oxides in the exhaust gas, and the nitrogen oxides generate a nitric acid solution and a nitrous acid solution by the action of the oxygen gas supplied through the gas supply port 107, so that the treatment liquid in the third gas treatment device 7 is an alkaline solution that can react with the nitric acid and the nitrous acid. Since nitrous acid is unstable and is easily converted into nitric acid, the reaction between alkali solution and nitric acid is mainly considered. The lye here can be a solution prepared from calcium carbonate, and under the action of the treatment units in the third gas treatment device 7, the lye can stir the calcium carbonate solution, so that the calcium carbonate exists in the form of a suspension, the calcium carbonate solution reacts with the nitric acid solution to generate calcium nitrate, water and carbon dioxide, wherein the water is left in the treatment solution, the carbon dioxide flows backwards under the driving of the draught fan 5, and the calcium nitrate can be precipitated. The specific structure is provided with a second treatment liquid improving device 71 for separating out calcium nitrate, the second treatment liquid improving device 71 is provided with a second treatment cavity communicated with the discharge port of the third gas treatment device 7, after the calcium nitrate solution flows into the second treatment cavity, the calcium nitrate solution can be cooled through a third heat exchange tube 72, then a calcium nitrate solid state is separated out by a third filtering device 74, the separated solid state is recovered through a sixth recovery port 73, and no pollutant is discharged in the whole reaction process.

In the reaction in which calcium carbonate can also react with carbon dioxide and water to produce calcium bicarbonate, it is preferable to use a porous filter structure or an adsorbent for the filter 200 in the third gas treatment device 7, for example, a filter disk made of activated carbon, which can play a crucial role in the treatment reaction, specifically, the carbon dioxide can be directly transferred to the treatment liquid by the adsorption action of the activated carbon filter disk itself to convert carbon dioxide more efficiently. The calcium bicarbonate solution prepared here can generate calcium carbonate precipitate and water under heating, and the product is the component of the treatment liquid in the third gas treatment device 7, so that the calcium bicarbonate solution can be conveyed to the liquid supplementing port 120 of the fourth gas treatment device 8 through the second return pipeline 109 for recycling.

The fourth gas treatment apparatus 8 absorbs a small amount of nitrogen oxides, and the treatment liquid therein is still a suspension of calcium carbonate. The treating liquid in the fourth gas treatment device 8 can be conveyed into the liquid supplementing port 120 of the third gas treatment device 7 through the drain port 133 and the second conveying pipeline 113 thereon, so that the dilute nitric acid is converted into concentrated nitric acid for reuse.

The pollutants in the exhaust gas are mainly carbon monoxide, carbon dioxide and dioxin through the treatment of the first sub-system A and the second sub-system B. Based on this, continuing to refer to fig. 1, the exhaust gas treatment system in this embodiment further includes a third subsystem C having at least one gas treatment device, located downstream of the second subsystem B. Here it has one gas treatment device, namely a fifth gas treatment device 9. Of course, it is also possible to provide a plurality of further gas treatment devices downstream of the fifth gas treatment device 9, depending on the particular requirements of use. The treating liquid contained in the gas treating device of the third sub-system C is an alkaline solution, and the weak alkaline salt generated by the reaction of the carbon dioxide in the waste gas and the alkaline solution is filtered by the filtering device and is conveyed to the reactor 34. And which gas treatment device is provided with filtering means and a reactor 34 arranged in the flow-through channel 3 of the exhaust gases upstream of the first subsystem a.

The alkaline solution in the fifth gas treatment device 9 is specifically a saturated sodium carbonate solution, and a feeding port 117 for adding a solid sodium carbonate is provided on the upper housing 110. Sodium carbonate reacts with carbon dioxide and water to produce sodium bicarbonate. The sodium bicarbonate has low solubility in water, and sodium carbonate, carbon dioxide and water are sufficient, so sodium bicarbonate is continuously generated, and sodium bicarbonate crystals can be separated out when the concentration of the sodium bicarbonate is higher than the saturated solubility. Here, the filter disk made of activated carbon in the fifth gas treatment device 9 functions to promote the reaction. Because of the adsorption effect of the active carbon filter disc on carbon dioxide, the adsorbed carbon dioxide is directly transferred into the treatment liquid, and more efficient carbon dioxide conversion is carried out.

In order to collect the sodium bicarbonate crystals, the third subsystem C in this embodiment is further provided with a fourth filtering device 91, the crystals are recovered from the seventh recovery port 92 under the action of the fourth filtering device 91, and the liquid is transported to the liquid replenishing port 120 of the fifth gas processing device 9 through the third return pipeline 111, so that no pollutant is discharged in the whole reaction process. It should be noted that, besides sodium carbonate, other alkaline solutions that can react with carbon dioxide can be used as the alkaline solution.

The reactor 34 is used for decomposing and recovering sodium bicarbonate crystals, and has a specific structure, as shown in fig. 1, the reactor 34 is positioned at the upstream of the first heat exchange pipe 31 and is provided with a decomposition cavity arranged in the flow channel 3, after the sodium bicarbonate crystals are placed into the feed inlet 32 at the top of the decomposition cavity, the sodium bicarbonate crystals are dehydrated into sodium bicarbonate due to high external temperature in the falling process, and then are decomposed into a mixture of sodium carbonate powder, water vapor and carbon dioxide. In order to recover the sodium carbonate, a baffle plate is arranged in the decomposition cavity in an inclined downward manner to prolong the retention time of the sodium carbonate in the decomposition cavity, sodium carbonate powder falls to the bottom and is recovered through the second recovery port 36 due to the baffle plate, and the recovered sodium carbonate can be added into the feeding port 117 of the fifth gas treatment device 9, so that the chemical product can be recycled. The water generated by the water vapor and carbon dioxide mixture can be transported to the second heat exchange tube 44 through the third transport line 115 and recycled through the first return line 105, and the produced carbon dioxide is recovered through the fourth recovery port 45.

The fifth gas treatment device 9 can also perform adsorption treatment on carbon monoxide and dioxin in the exhaust gas through the adsorption effect of activated carbon, wherein the activated carbon soaked with alkali liquor has better adsorption efficiency on dioxin. As shown in fig. 1, the exhaust gas discharged from the third subsystem C is discharged to the outside through the catalyst 37, and the catalyst 37 oxidizes and reduces harmful gases such as carbon monoxide, untreated carbon oxides, and dioxin to generate harmless gases, and then discharges the gases. For example, a three-way catalyst may be used, which is arranged in the flow-through channel 3 upstream of the reactor 34 for better treatment, since its use requires temperature. Although the exhaust gas treatment device in the embodiment still discharges carbon dioxide, compared with the conventional exhaust gas treatment system, the exhaust gas treatment device still has a good emission reduction effect on reducing the emission of carbon dioxide, and has a good meaning.

Obviously, in the embodiment, based on the process principle and the composition of the system, the processing process can be carried out by controlling the working conditions of temperature, pressure, liquid level, content and the like of each process link; the operation of the system can be controlled more conveniently by additionally arranging the detection device and the control execution device in each link. For example, in order to maintain the relevant reaction or change working condition of each process link of the system, oxygen content detecting instruments can be arranged in the second gas treatment device 6, the third gas treatment device 7, the fourth gas treatment device 8 and the fifth gas treatment device 9 so as to reasonably control the amount of air or oxygen in the supplementing device; a liquid level detection device can be additionally arranged in each device, and treatment liquid is supplemented or conveyed based on the liquid level condition. And differential pressure detection instruments can be additionally arranged on two sides of the processing unit 2 to monitor the blockage degree condition of the processing unit so as to facilitate timely maintenance.

In addition, in this embodiment, another first sub-system a connected in parallel with the first sub-system a may be further disposed between the second sub-system a and the flow-through channel 3, so that when one of the first sub-systems a is failed and needs to be repaired, the other first sub-system a may be used first. Similarly, a subsystem may be provided in parallel with the second subsystem B and the third subsystem C, respectively.

The waste gas treatment system described in this embodiment adopts a multistage series process system to complete the treatment of various harmful substances in the waste gas, firstly utilizes the treatment unit 2 soaked with treatment liquid to capture dust, utilizes solution to dissolve soluble harmful gas, adopts an acid-base neutralization mode, and completes the adsorption capture and reaction removal of the insoluble gas by means of the adsorption of activated carbon; achieves good classification and gradual removal and purification, and has good cost advantage and higher purification performance. The third sub-system C of the waste gas treatment system utilizes weak alkali solution reaction of alkali liquor such as sodium carbonate and the like in water, completes the reaction of carbon dioxide by means of the adsorption of activated carbon to generate weak alkali salt, utilizes the waste heat of the system to realize the reverse reaction from the weak alkali salt to the alkali salt, realizes the separation and purification of the carbon dioxide in the waste gas, and can reduce the carbon emission. The system mainly uses limestone raw materials to finish the treatment of waste gas, can produce byproducts such as calcium sulfate, calcium nitrate, carbon dioxide with higher purity and the like, has low overall treatment cost and has considerable economic benefit advantage.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. An exhaust treatment system for treating exhaust gas flowing therethrough, comprising:

at least two subsystems which are arranged in series and are used for the waste gas to flow through are arranged, and at least one gas treatment device is arranged in each subsystem in series;

the gas treatment device is partially filled with treatment liquid, and a treatment unit (2) through which the waste gas passes and which can form the treatment liquid and the waste gas to be fully contacted is arranged above the liquid level of the treatment liquid; the dust or a plurality of gaseous substances in the waste gas can be contained in the treatment liquid due to the filtering interception or adsorption effect of the treatment unit (2);

the treatment liquid in the first sub-system A positioned at the upstream is a solution which is used for capturing or dissolving dust and soluble gaseous substances in the waste gas;

the treatment liquid in the second sub-system B positioned at the downstream of the first sub-system A is acid liquid or alkali liquid, so that the neutralization reaction with the insoluble alkaline or acidic gaseous substances in the waste gas is formed.

2. The exhaust treatment system of claim 1, wherein: the exhaust gas treatment system further comprises a third subsystem C having at least one of the gas treatment devices downstream of the second subsystem B; the treatment liquid contained in the gas treatment device of the third subsystem C is an alkaline solution, and the gas treatment device is provided with a filtering device and a reactor (34); the weak alkaline salt generated by the reaction of the carbon dioxide in the waste gas and the alkaline solution is filtered out by the filtering device and is conveyed to the reactor (34); the reactor (34) is arranged in the flow-through channel (3) of the exhaust gases upstream of the first subsystem A.

3. The exhaust treatment system of claim 2, wherein: the exhaust gas discharged from the third sub-system C is discharged to the outside through a catalyst (37), and the catalyst (37) is disposed in the flow-through passage (3) upstream of the reactor (34).

4. The exhaust treatment system of claim 1, wherein: the waste gas treatment system also comprises a plurality of filtering devices and treatment liquid improving devices; the filtering device and the treatment liquid improving device are communicated in groups or individually and are arranged below the gas treatment device; the filtering device receives the inflow of the treatment liquid in the gas treatment device or the treatment liquid improvement device so as to collect and filter solid substances in the treatment liquid; the treatment liquid improving device receives the inflow of the treatment liquid in the gas treatment device or the filtering device, and the treatment liquid improving device is subjected to neutralization reaction with the inflow treatment liquid due to the feeding of the acid-base dissimilar substances and/or is used for precipitating salt substances in the treatment liquid due to the cooling of the temperature reducing unit.

5. The exhaust treatment system of claim 4, wherein: a return line is arranged between the treating fluid improving device and the gas treating device.

6. The exhaust treatment system of claim 5, wherein: the gas treatment devices in the first sub-system A and the second sub-system B are both multiple; the treatment liquid in the same subsystem is supplied and conveyed from the most downstream gas treatment device to the most upstream gas treatment device in sequence against the flow direction of the exhaust gas, and a liquid supplementing port (120) is opened on the most downstream gas treatment device, and only the most upstream gas treatment device is provided with the filtering device and/or the treatment liquid improving device.

7. The exhaust gas treatment system according to any one of claims 1 to 6, wherein: the gas processing device is provided with a cavity formed by the enclosure of a shell (1), and the processing unit (2) is rotationally driven and separated between a gas inlet (106) and a gas outlet (108) at two ends of the shell (1); the treatment unit (2) is partially immersed and washed in the treatment liquid by rotation; the separation and/or removal of several substances within the exhaust gas may be constituted by the interception by the treatment unit (2) and/or by the action of the treatment liquid when the exhaust gas passes through the treatment unit (2) wetted with the treatment liquid.

8. The exhaust treatment system of claim 7, wherein: a plurality of the treatment units (2) are sequentially arranged in the cavity at intervals along the flow direction of the waste gas; at least one of the treatment units (2) in the gas treatment device located most upstream is a sieve; each processing unit (2) in the gas processing device in the second subsystem B is a filtering disc made of activated carbon.

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