Waste gas treatment system and process of stainless steel annealing furnace

Abstract

A waste gas treatment system and process for a stainless steel annealing furnace, belonging to the technical field of waste gas treatment, has a waste gas collection pipe connected to the stainless steel annealing furnace, the waste gas collection pipe is connected to a desulfurization tank integration, the desulfurization tank integration is connected to a waste gas exhaust pipeline; the desulfurization tank integration has a gas inlet main pipe and an alkali liquid inlet main pipe matched therewith; it also has a controller, the controller includes valves arranged on the waste gas collection pipe, the gas inlet main pipe, the alkali liquid inlet main pipe, the waste gas exhaust pipeline and the desulfurization tank integration; the pH value in the desulfurization tank integration is adjusted by controlling the opening and closing of the valve to achieve complete desulfurization of the waste gas. Using ammonia water as a desulfurizer can not only use the waste gas selective catalytic reduction method (SCR) but also use the absorption method to treat the waste gas.

Description

Technical Field

[0001] The present application belongs to the technical field of waste gas treatment, and in particular, relates to a waste gas treatment process and a treatment system thereof. Background Art

[0002] In the document with publication number CN113058412A, sodium hydroxide aqueous solution is used to replace calcium hydroxide aqueous solution as a desulfurizing agent to solve the problem that calcium hydroxide has low solubility in water and the content of free active calcium ions in calcium hydroxide aqueous solution is low, thus affecting the desulfurization effect.

[0003] However, since the exhaust gas discharged from the stainless steel annealing furnace is above 1000℃, the NaOH aqueous solution reacts with the CO in the high-temperature exhaust gas. 2 The reaction generates Na 2 CO 3 ; Moreover, high temperature will evaporate some water, making it impossible for nitrogen oxides to undergo normal hydration reaction to generate HNO 3 . Summary of the invention

[0004] The purpose of the present invention is to solve the above technical problems and to provide a waste gas treatment system and process using ammonia water as a desulfurizing agent.

[0005] The technical solution of the first aspect adopted to solve the above technical problems is: an exhaust gas treatment system of a stainless steel annealing furnace, comprising an exhaust gas collection pipe connected to the stainless steel annealing furnace, the exhaust gas collection pipe being connected to a desulfurization tank integration, and the desulfurization tank integration being connected to an exhaust gas exhaust pipe;

[0006] The desulfurization tank is integrated with a gas inlet main pipe and an alkali solution inlet main pipe;

[0007] It also has a controller, which includes valves arranged on the waste gas collection pipe, the gas inlet main pipe, the alkali liquid inlet main pipe, the waste gas exhaust pipe and the desulfurization tank integration;

[0008] By controlling the opening and closing of the valve to adjust the pH value in the desulfurization tank, complete desulfurization of the exhaust gas can be achieved.

[0009] As an practicable manner, the desulfurization tank integration has four stages, namely, a first desulfurization tank, a second desulfurization tank, a third desulfurization tank and a fourth desulfurization tank, and the above desulfurization tanks are connected end to end in sequence.

[0010] As an practicable manner, the valve comprises a first valve arranged on the exhaust gas collecting pipe and a second valve arranged on the exhaust gas exhaust pipe;

[0011] In addition, a gas branch pipe with a third valve on the gas inlet main pipe is connected to the first desulfurization tank, a gas branch pipe with a fourth valve is connected to the second desulfurization tank, a gas branch pipe with a fifth valve is connected to the third desulfurization tank, and a gas branch pipe with a sixth valve is connected to the fourth desulfurization tank;

[0012] There is also a branch pipe with a seventh valve on the main pipe for alkali solution to enter, which is connected to the first desulfurization tank; a branch pipe with an eighth valve is connected to the second desulfurization tank; a branch pipe with a ninth valve is connected to the third desulfurization tank; and a branch pipe with a tenth valve is connected to the fourth desulfurization tank.

[0013] As an practicable manner, the first desulfurization tank, the second desulfurization tank, the third desulfurization tank and the fourth desulfurization tank all have a tank body, the tank body includes an exhaust gas inlet pipe located at the middle cavity and an exhaust gas outlet pipe located at the top cavity, the bottom cavity of the tank body contains an alkaline liquid, the exhaust gas inlet pipe extends below the liquid surface, and is bent and arranged to form an exhaust gas pipe layer, and the exhaust gas inlet pipe in the exhaust gas pipe layer is provided with a plurality of through holes for exhausting exhaust gas;

[0014] There is an adsorption layer in the top cavity, and the exhaust gas enters the exhaust gas output pipe after passing through the adsorption layer;

[0015] The waste gas inlet pipe on the first desulfurization tank is connected to the waste gas collecting pipe, and the waste gas output pipe on the fourth desulfurization tank is connected to the exhaust pipe.

[0016] As an practicable manner, a partition is provided between the middle cavity and the top cavity of the tank body, the partition has at least one set of exhaust gas channels, the exhaust gas channels have a baffle located in the middle cavity, and the baffle is fixed to the partition by at least two fixing rods.

[0017] A second aspect: A waste gas treatment process for a stainless steel annealing furnace based on a waste gas treatment system for a stainless steel annealing furnace according to any one of the first aspects, comprising the following steps:

[0018] S1: Check the parameter settings of the exhaust gas treatment system; check whether the pipeline is complete; check the opening and closing status of each valve to ensure that the first valve is closed and the second valve is open;

[0019] The third valve, the fourth valve, the fifth valve and the sixth valve are in the closed state;

[0020] The seventh valve, the eighth valve, the ninth valve and the tenth valve are in the open state;

[0021] S2: After step S1 is completed, a certain amount of alkali liquid is injected into the first desulfurization tank, the second desulfurization tank, the third desulfurization tank and the fourth desulfurization tank through the alkali liquid entering the main pipe, and then the seventh valve, the eighth valve, the ninth valve and the tenth valve are closed; the alkali liquid of the present application is ammonia water.

[0022] S3: After step S2 is completed, the pH values ​​of the first desulfurization tank, the second desulfurization tank, the third desulfurization tank and the fourth desulfurization tank are detected; when the pH value of the desulfurization tank with a large deviation from the set parameter is detected, the second valve is closed, the valve connecting the desulfurization tank and the gas inlet main pipe is opened, and alkaline gas is filled to make the pH value in the desulfurization tank meet the reaction requirements, and then the aforementioned opened valve is closed;

[0023] S4: After step S3 is completed, the first valve and the second valve are opened, and the exhaust gas enters the first desulfurization tank, the second desulfurization tank, the third desulfurization tank and the fourth desulfurization tank in sequence;

[0024] S5: The waste gas from step S4 enters the waste gas exhaust pipe for discharge.

[0025] As an practicable manner, in step S1: the third valve and the seventh valve cooperate to control the pH value of the first desulfurization tank;

[0026] The fourth valve and the eighth valve cooperate to control the pH value of the second desulfurization tank;

[0027] The fifth valve and the ninth valve cooperate to control the pH value of the third desulfurization tank;

[0028] The sixth valve and the tenth valve cooperate to control the pH value of the fourth desulfurization tank.

[0029] As an practicable manner, step S4.1: when it is detected that the pH value in the first desulfurization tank is reduced, the seventh valve is opened to inject alkaline solution into the first desulfurization tank, and the fourth valve, the fifth valve and the sixth valve are opened to respectively introduce alkaline gas into the second desulfurization tank, the third desulfurization tank and the fourth desulfurization tank;

[0030] After the pH value in the first desulfurization tank is restored and the pH values ​​in the second desulfurization tank, the third desulfurization tank and the fourth desulfurization tank are maintained, step S5 is entered.

[0031] As an practicable manner, step S4.2: when it is detected that the pH values ​​in the first desulfurization tank, the second desulfurization tank and the third desulfurization tank are reduced, the second valve is closed, the third valve, the fourth valve and the fifth valve are opened to introduce alkaline gas, and at the same time, the tenth valve is opened to inject alkaline solution into the fourth desulfurization tank, and then the second valve is opened to enter step S5;

[0032] Step S4.3: Then open the seventh valve, the eighth valve, and the ninth valve to inject alkali solution into the first desulfurization tank, the second desulfurization tank, and the third desulfurization tank. After the pH values ​​displayed by the first desulfurization tank, the second desulfurization tank, and the third desulfurization tank reach the set parameters, close the seventh valve, the eighth valve, and the ninth valve.

[0033] As an practicable method, in step S4.4, when it is detected that the pH value of the fourth desulfurization tank is reduced, the first valve and the second valve are closed, and the seventh valve, the eighth valve, the ninth valve and the tenth valve are opened to inject alkali solution, and then the seventh valve, the eighth valve, the ninth valve and the tenth valve are closed and the first valve and the second valve are opened to enter step S5.

[0034] Compared with the prior art, the present invention has the following beneficial effects: the present application uses ammonia water, which can satisfy the selective catalytic reduction (SCR) of exhaust gas. The ammonia in the desulfurization tank can be used as a reducing agent. Under the action of a special catalyst, it selectively reacts with nitrogen oxides in the exhaust gas and does not react with oxygen, so that the nitrogen oxides are reduced to nitrogen and water. In the present application, all the pipes in the desulfurization tank are made of copper pipes, which can be used as non-precious metal catalysts in the selective catalytic reduction (SCR) method. The exhaust gas can also be treated by absorption method. Nitrogen oxides react with ammonia water to generate nitric acid, and then react with ammonia to generate ammonium nitrate. In the stainless steel annealing furnace, NO 2 More gas is generated, and the two desulfurization methods improve the purification efficiency.

[0035] Air volume in exhaust gas collection pipe: 26000m 3 / h is the nitrogen oxide emission concentration of 1041.91 mg / m 3 , the emission is 27.12kg / h; after adopting this technical solution, the emission concentration of nitrogen oxides is 102.22 mg / m 3 The emission is 2.56kg / h; the purification efficiency reaches 90.2%. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] 1 Waste gas collection pipe, 2 Gas entering the main pipe, 3 Alkali liquid entering the main pipe, 4 Desulfurization tank integration, 5 Waste gas exhaust pipe, 6 Valve,

[0037] 21 the third valve, 22 the fourth valve, 23 the fifth valve, 24 the sixth valve, 31 the seventh valve, 32 the eighth valve, 33 the ninth valve, 34 the tenth valve, 41 the first desulfurization tank, 42 ​​the second desulfurization tank, 43 the third desulfurization tank, 44 the fourth desulfurization tank, 61 the first valve, 62 the second valve,

[0038] 401 tank body, 402 exhaust gas inlet pipe, 403 exhaust gas outlet pipe, 404 exhaust gas pipe layer, 405 through hole, 406 adsorption layer, 407 partition plate, 408 exhaust gas channel, 409 baffle plate, 410 fixing rod,

[0039] Figure 1 It is a cross-sectional structural schematic diagram of embodiment 1;

[0040] Figure 2This is a schematic diagram of the control valve position of Example 1;

[0041] Figure 3 This is a schematic diagram of the structure of a single desulfurization tank;

[0042] Figure 4 It is a schematic diagram of the structure of the partition and bottom cavity of a single desulfurization tank;

[0043] Figure 5 is a schematic diagram of the partition structure; DETAILED DESCRIPTION

[0044] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 The first embodiment shown is a waste gas treatment system for a stainless steel annealing furnace, which has a waste gas collecting pipe 1 connected to the stainless steel annealing furnace, the waste gas collecting pipe 1 is connected to a desulfurization tank integration 4, an induced draft fan is provided between the waste gas collecting pipe 1 and the desulfurization tank integration 4, and the desulfurization tank integration 4 is connected to a waste gas exhaust pipe 5.

[0045] The desulfurization tank assembly 4 is provided with a gas inlet main pipe 2 and an alkali solution inlet main pipe 3 matched therewith.

[0046] The whole system also has a controller, which includes valves 6 arranged on the waste gas collection pipe 1, the gas inlet main pipe 2, the alkali liquid inlet main pipe 3, the waste gas exhaust pipe 5 and the desulfurization tank integration 4;

[0047] The pH value in the desulfurization tank assembly 4 is adjusted by controlling the opening and closing of the valve 6 to achieve complete desulfurization of the exhaust gas.

[0048] In this embodiment, the desulfurization tank assembly 4 has four stages, namely, the first desulfurization tank 41, the second desulfurization tank 42, the third desulfurization tank 43 and the fourth desulfurization tank 44, which are connected end to end in sequence. The desulfurization tanks are connected by conventional exhaust gas pipes.

[0049] In this embodiment, the valve 6 is a set, which mainly includes a first valve 61 arranged on the exhaust gas collecting pipe 1 and a second valve 62 arranged on the exhaust gas exhaust pipe 5 .

[0050] There are also four valves 6 on the gas inlet main pipe 2 corresponding to the four desulfurization tanks, and the specific distribution is as follows:

[0051] The gas inlet pipe 1 with the third valve 21 on the gas inlet main pipe 2 is connected to the first desulfurization tank 41, the gas pipe 2 with the fourth valve 22 is connected to the second desulfurization tank 42, the gas pipe 3 with the fifth valve 23 is connected to the third desulfurization tank 43, and the gas pipe 4 with the sixth valve 24 is connected to the fourth desulfurization tank 44;

[0052] There are also four valves 6 on the main pipe 3 for the alkali solution to enter, corresponding to the four desulfurization tanks, and the specific distribution is as follows:

[0053] The branch pipe with the seventh valve 31 on the alkali solution inlet main pipe 3 is connected to the first desulfurization tank 41, the branch pipe with the eighth valve 32 is connected to the second desulfurization tank 42, the branch pipe with the ninth valve 33 is connected to the third desulfurization tank 43, and the branch pipe with the tenth valve 34 is connected to the fourth desulfurization tank 44.

[0054] The specific structure of the desulfurization tank in this embodiment is as follows: the first desulfurization tank 41, the second desulfurization tank 42, the third desulfurization tank 43 and the fourth desulfurization tank 44 all have a tank body 401, the tank body 401 includes a waste gas inlet pipe 402 located at the middle cavity, and a waste gas outlet pipe 403 located at the top cavity. There is an alkaline liquid in the bottom cavity of the tank body 401, and the waste gas inlet pipe 402 extends below the liquid surface and is bent and arranged to form a waste gas pipe layer 404. The waste gas inlet pipe 402 in the waste gas pipe layer 404 is provided with a plurality of through holes 405 for discharging waste gas.

[0055] The various pipes located in the tank body 401 are copper pipes.

[0056] An adsorption layer 406 is provided in the top cavity, and the exhaust gas enters the exhaust gas output pipe 403 after passing through the adsorption layer 406;

[0057] The exhaust gas inlet pipe 402 on the first desulfurization tank 41 is connected to the exhaust gas collecting pipe 1 , and the exhaust gas outlet pipe 403 on the fourth desulfurization tank 44 is connected to the exhaust pipe 5 .

[0058] A partition 407 is provided between the middle cavity and the top cavity of the tank body 401 . The partition 407 has four exhaust gas channels 408 . The exhaust gas channels 408 have a baffle 409 located in the middle cavity. The baffle 409 is fixed to the partition 407 by at least two fixing rods 410 . Example

[0059] A waste gas treatment process for a stainless steel annealing furnace, this embodiment adopts the hardware system in the first embodiment, and has the following steps:

[0060] S1: Check the exhaust gas treatment system parameter settings; check whether the pipeline is complete; check the opening and closing status of each valve to ensure that the first valve 61 is closed and the second valve 62 is open;

[0061] The first valve 61 is closed to ensure that the exhaust gas cannot enter the desulfurization tank integration 4. The second valve 62 is opened to ensure that the gas filled into the desulfurization tank integration 4 during regulation can be discharged to prevent the desulfurization tank integration 4 from having an excessively high gas pressure and causing an incomplete reaction.

[0062] The third valve 21, the fourth valve 22, the fifth valve 23 and the sixth valve 24 are in the closed state; the valve 6 through which the gas enters the main pipe 2 and enters the first desulfurization tank 41, the second desulfurization tank 42, the third desulfurization tank 43 and the fourth desulfurization tank 44 is closed during the inspection stage because the pH value in the four desulfurization tanks needs to be adjusted by introducing gas.

[0063] The seventh valve 31, the eighth valve 32, the ninth valve 33 and the tenth valve 34 are in the open state; the valve 6 for the alkali solution to enter the main pipe 3 into the first desulfurization tank 41, the second desulfurization tank 42, the third desulfurization tank 43 and the fourth desulfurization tank 44 is open during the inspection stage, because the next step is to inject alkali solution into the desulfurization tank, and there is no need for an additional step of opening the valve.

[0064] In this step, the third valve 21 and the seventh valve 31 cooperate to control the pH value of the first desulfurization tank 41; the fourth valve 22 and the eighth valve 32 cooperate to control the pH value of the second desulfurization tank 42; the fifth valve 23 and the ninth valve 33 cooperate to control the pH value of the third desulfurization tank 43; the sixth valve 24 and the tenth valve 34 cooperate to control the pH value of the fourth desulfurization tank 44.

[0065] S2: After step S1 is completed, a certain amount of alkali solution is injected into the first desulfurization tank 41, the second desulfurization tank 42, the third desulfurization tank 43 and the fourth desulfurization tank 44 through the alkali solution entering the main pipe 3, and then the seventh valve 31, the eighth valve 32, the ninth valve 33 and the tenth valve 34 are closed;

[0066] In this step, the amount of alkali solution injected is just enough to immerse the exhaust gas pipe layer 404, because if the exhaust gas pipe layer 404 is immersed too deeply in the alkali solution, it cannot be used as a non-precious metal catalyst.

[0067] S3: After step S2 is completed, the pH values ​​of the first desulfurization tank 41, the second desulfurization tank 42, the third desulfurization tank 43 and the fourth desulfurization tank 44 are detected; when the pH value of the desulfurization tank with a large deviation from the set parameter is detected, the second valve 62 is closed, the valve connecting the desulfurization tank and the gas inlet main pipe 2 is opened, and alkaline gas is charged to make the pH value in the desulfurization tank meet the reaction requirements, and then the aforementioned opened valve is closed;

[0068] S4: After step S3 is completed, the first valve 61 and the second valve 62 are opened, and the exhaust gas enters the first desulfurization tank 41, the second desulfurization tank 42, the third desulfurization tank 43 and the fourth desulfurization tank 44 in sequence.

[0069] In this step, the first situation that occurs is: when the pH value in the first desulfurization tank 41 is detected to be reduced, the seventh valve 31 is opened to inject alkaline solution into the first desulfurization tank 41, and the fourth valve 22, the fifth valve 23 and the sixth valve 24 are opened to respectively introduce alkaline gas into the second desulfurization tank 42, the third desulfurization tank 43 and the fourth desulfurization tank 44. Then, the pH value in the first desulfurization tank 41 is restored, and the pH values ​​in the second desulfurization tank 42, the third desulfurization tank 43 and the fourth desulfurization tank 44 are maintained, and the next step S5 is entered.

[0070] In this step, the second situation that occurs is: it is detected that the pH values ​​in the first desulfurization tank 41, the second desulfurization tank 42 and the third desulfurization tank 43 are reduced, the second valve 62 is closed, the third valve 21, the fourth valve 22, and the fifth valve 23 are opened to introduce alkaline gas, and at the same time, the tenth valve 34 is opened to inject alkaline solution into the fourth desulfurization tank 44, and then the second valve 62 is opened to enter step S5.

[0071] In this case, one more step is required, which is to open the seventh valve 31, the eighth valve 32, and the ninth valve 33 to inject alkaline solution into the first desulfurization tank 41, the second desulfurization tank 42, and the third desulfurization tank 43, and close the seventh valve 31, the eighth valve 32, and the ninth valve 33 after the pH values ​​displayed by the first desulfurization tank 41, the second desulfurization tank 42, and the third desulfurization tank 43 reach the set parameters.

[0072] In this step, there is also a third situation: when it is detected that the pH value of the fourth desulfurization tank 44 is reduced, the first valve 61 and the second valve 62 are closed, the seventh valve 31, the eighth valve 32, the ninth valve 33 and the tenth valve 34 are opened to inject alkali solution, and then the seventh valve 31, the eighth valve 32, the ninth valve 33 and the tenth valve 34 are closed and the first valve 61 and the second valve 62 are opened to enter step S5.

[0073] S5: The waste gas from step S4 enters the waste gas exhaust pipe 5 for discharge.

[0074] In Example 1 and Example 2, the alkali solution is ammonia water with a pH value of 11. The flow rate of the induced draft fan connected to the exhaust gas collection pipe 1 is 14000m 3 / h, the pressure drop in the entire desulfurization tank integration 4 is 850Pa. The air volume of gas entering the main pipe 2 is 14000m 3 / h, the speed of entering the desulfurization tank is 10.2m / s, and it is made of PP anti-corrosion material. The alkali solution enters the main pipe 3 connected to a corrosion-resistant and wear-resistant fluoroplastic lined centrifugal pump, with an inflow of 55 m 3 / h.

[0075] When the exhaust gas enters the first desulfurization tank 41, part of the NO in the exhaust gas 2First, the hydration reaction with the water in the ammonia water generates nitric acid, and then the nitric acid reacts with ammonia to generate ammonium nitrate. The waste gas has a high temperature. After passing into the first desulfurization tank 41 for a period of time, a large amount of ammonia water will be evaporated, and part of the waste gas pipe layer 404 will be exposed as a catalyst to reduce the nitrogen oxides in the waste gas to nitrogen and water. The waste gas entering the second desulfurization tank 42 contains waste gas, ammonia, nitrogen, water vapor, nitric acid, and ammonium nitrate. At this time, the first situation occurs in step S4.

[0076] If the exhaust gas contains NO 2 If the content is too high, the second situation in step S4 will occur. 2 The third situation is unlikely to occur when the content is too high. If the third situation occurs, after taking the solution in step S4, step S2 needs to be repeated to restart the entire system.

[0077] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A waste gas treatment system for a stainless steel annealing furnace, comprising a waste gas collecting pipe (1) connected to the stainless steel annealing furnace, characterized in that: The exhaust gas collection pipe (1) is connected to a desulfurization tank assembly (4), and the desulfurization tank assembly (4) is connected to an exhaust gas exhaust pipe (5); The desulfurization tank assembly (4) is provided with a gas inlet main pipe (2) and an alkali solution inlet main pipe (3) matched therewith; It also has a controller, which includes valves (6) arranged on the waste gas collection pipe (1), the gas inlet main pipe (2), the alkali liquid inlet main pipe (3), the waste gas exhaust pipe (5) and the desulfurization tank assembly (4); By controlling the opening and closing of the valve (6), the pH value in the desulfurization tank assembly (4) is adjusted to achieve complete desulfurization of the exhaust gas; The desulfurization tank assembly (4) has four stages, namely a first desulfurization tank (41), a second desulfurization tank (42), a third desulfurization tank (43) and a fourth desulfurization tank (44), and the desulfurization tanks are connected end to end in sequence; The valve (6) comprises a first valve (61) arranged on the exhaust gas collecting pipe (1), and a second valve (62) arranged on the exhaust gas exhaust pipe (5); A first gas pipe with a third valve (21) on the gas inlet main pipe (2) is connected to the first desulfurization tank (41), a second gas pipe with a fourth valve (22) is connected to the second desulfurization tank (42), a third gas pipe with a fifth valve (23) is connected to the third desulfurization tank (43), and a fourth gas pipe with a sixth valve (24) is connected to the fourth desulfurization tank (44); A branch pipe with a seventh valve (31) on the alkali solution inlet main pipe (3) is connected to the first desulfurization tank (41), a branch pipe with an eighth valve (32) is connected to the second desulfurization tank (42), a branch pipe with a ninth valve (33) is connected to the third desulfurization tank (43), and a branch pipe with a tenth valve (34) is connected to the fourth desulfurization tank (44); The first desulfurization tank (41), the second desulfurization tank (42), the third desulfurization tank (43) and the fourth desulfurization tank (44) all have a tank body (401), the tank body (401) comprises a waste gas inlet pipe (402) located at a middle cavity and a waste gas outlet pipe (403) located at a top cavity, an alkaline liquid is contained in the bottom cavity of the tank body (401), the waste gas inlet pipe (402) extends below the liquid surface and is bent and arranged to form a waste gas pipe layer (404), and a plurality of through holes (405) for discharging waste gas are provided on the waste gas inlet pipe (402) in the waste gas pipe layer (404); An adsorption layer (406) is provided in the top cavity, and the exhaust gas enters the exhaust gas output pipe (403) after passing through the adsorption layer (406); The exhaust gas inlet pipe (402) on the first desulfurization tank (41) is connected to the exhaust gas collecting pipe (1), and the exhaust gas outlet pipe (403) on the fourth desulfurization tank (44) is connected to the exhaust pipe (5); A partition (407) is provided between the middle cavity and the top cavity of the tank body (401), the partition (407) has at least one set of exhaust gas channels (408), the exhaust gas channels (408) have a baffle (409) located in the middle cavity, and the baffle (409) is fixed to the partition (407) by at least two fixing rods (410).

2. A waste gas treatment process for a stainless steel annealing furnace based on a waste gas treatment system for a stainless steel annealing furnace according to claim 1, characterized in that: The following steps are involved: S1: Check the exhaust gas treatment system parameter settings; check whether the pipeline is complete; check the opening and closing status of each valve to ensure that the first valve (61) is in a closed state and the second valve (62) is in an open state; The third valve (21), the fourth valve (22), the fifth valve (23) and the sixth valve (24) are in a closed state; The seventh valve (31), the eighth valve (32), the ninth valve (33) and the tenth valve (34) are in an open state; S2: After step S1 is completed, a certain amount of alkali solution is injected into the first desulfurization tank (41), the second desulfurization tank (42), the third desulfurization tank (43) and the fourth desulfurization tank (44) through the alkali solution entering the main pipe (3), and then the seventh valve (31), the eighth valve (32), the ninth valve (33) and the tenth valve (34) are closed; S3: After step S2 is completed, the pH values ​​of the first desulfurization tank (41), the second desulfurization tank (42), the third desulfurization tank (43) and the fourth desulfurization tank (44) are detected; for the desulfurization tank whose pH value deviates greatly from the set parameter, the second valve (62) is closed, the valve connecting the desulfurization tank and the gas inlet main pipe (2) is opened, and alkaline gas is injected to make the pH value in the desulfurization tank meet the reaction requirements, and then the aforementioned opened valve is closed; S4: after step S3 is completed, the first valve (61) and the second valve (62) are opened, and the exhaust gas enters the first desulfurization tank (41), the second desulfurization tank (42), the third desulfurization tank (43) and the fourth desulfurization tank (44) in sequence; S5: The waste gas from step S4 enters the waste gas exhaust pipe (5) for discharge.

3. The waste gas treatment process of a stainless steel annealing furnace according to claim 2, characterized in that: In step S1: the third valve (21) and the seventh valve (31) cooperate to control the pH value of the first desulfurization tank (41); The fourth valve (22) and the eighth valve (32) cooperate to control the pH value of the second desulfurization tank (42); The fifth valve (23) and the ninth valve (33) cooperate to control the pH value of the third desulfurization tank (43); The sixth valve (24) and the tenth valve (34) cooperate to control the pH value of the fourth desulfurization tank (44).

4. The waste gas treatment process of a stainless steel annealing furnace according to claim 3, characterized in that: Step S4.1: when it is detected that the pH value in the first desulfurization tank (41) is reduced, the seventh valve (31) is opened to inject alkaline solution into the first desulfurization tank (41), and the fourth valve (22), the fifth valve (23) and the sixth valve (24) are opened to respectively introduce alkaline gas into the second desulfurization tank (42), the third desulfurization tank (43) and the fourth desulfurization tank (44); After the pH value in the first desulfurization tank (41) is restored and the pH values ​​in the second desulfurization tank (42), the third desulfurization tank (43) and the fourth desulfurization tank (44) are maintained, step S5 is entered.

5. The waste gas treatment process of a stainless steel annealing furnace according to claim 4, characterized in that: Step S4.2: When it is detected that the pH values ​​in the first desulfurization tank (41), the second desulfurization tank (42) and the third desulfurization tank (43) are reduced, the second valve (62) is closed, the third valve (21), the fourth valve (22) and the fifth valve (23) are opened to introduce alkaline gas, and at the same time, the tenth valve (34) is opened to inject alkaline solution into the fourth desulfurization tank (44), and then the second valve (62) is opened to enter step S5; Step S4.3: Then, the seventh valve (31), the eighth valve (32), and the ninth valve (33) are opened to inject alkaline solution into the first desulfurization tank (41), the second desulfurization tank (42), and the third desulfurization tank (43). After the pH values ​​displayed by the first desulfurization tank (41), the second desulfurization tank (42), and the third desulfurization tank (43) reach the set parameters, the seventh valve (31), the eighth valve (32), and the ninth valve (33) are closed.

6. The waste gas treatment process of a stainless steel annealing furnace according to claim 5, characterized in that: Step S4.4, when it is detected that the pH value of the fourth desulfurization tank (44) is reduced, the first valve (61) and the second valve (62) are closed, the seventh valve (31), the eighth valve (32), the ninth valve (33) and the tenth valve (34) are opened to inject alkali solution, and then the seventh valve (31), the eighth valve (32), the ninth valve (33) and the tenth valve (34) are closed and the first valve (61) and the second valve (62) are opened to enter step S5.

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