Alkali liquor washing device for sulfuric acid tail gas

Abstract

The invention relates to the technical field of tail gas treatment equipment, in particular to a sulfuric acid tail gas alkali liquor washing device which comprises an alkali washing tower body, a gas outlet pipeline, an alkali washing part and a recycling part which are sequentially designed on the alkali washing tower body from top to bottom, and a gas inlet pipeline is arranged between the recycling part and the alkali washing part. A circulating system communicated with the recycling part is arranged outside the alkaline washing tower body, a premixing module is arranged in the gas inlet pipeline, and the premixing module comprises a first sprayer, a second sprayer and a third sprayer which are sequentially distributed in the length direction of the gas inlet pipeline; the pre-mixing module is used for preliminarily washing the sulfuric acid tail gas in the entering process of the sulfuric acid tail gas, the neutralization efficiency of acid gas can be improved, and then the overall washing effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of tail gas treatment equipment, and in particular to a sulfuric acid tail gas alkali solution washing device. Background Art

[0002] During the wet sulfuric acid production process, tail gas treatment is a top environmental priority. After separation, the sulfuric acid tail gas is sent directly to the desulfurization and denitrification recovery unit for treatment and discharge only after meeting standards. The original design of the desulfurization and denitrification station was no longer able to meet these standards.

[0003] For example, a Chinese patent (application number 202221644879.X) discloses a sulfuric acid tail gas treatment device, which belongs to the field of sulfuric acid tail gas treatment technology. It includes a base plate, the upper surface of the base plate is fixedly connected to a reduction gear box, the upper surface of the base plate is fixedly connected to a clean water tank, the left side of the clean water tank is fixedly connected to the right side of the reduction gear box, the upper surface of the base plate is fixedly connected to a treatment box, the upper surface of the base plate is fixedly connected to a demister assembly, and the upper surface of the reduction gear box is connected to the upper surface of the treatment box through an intermediate pipe. The sulfuric acid tail gas treatment device is provided with a reduction gear box, a treatment box, a dual-axis motor, a mixing screen, a water pump assembly, a clean water tank, a nozzle and a demister assembly, and then the water inside the clean water tank is transported to the nozzle and the tail gas inside the treatment box is washed with water. Under the rotation of the mixing screen, the sulfuric acid tail gas and water inside the treatment box are evenly mixed and washed, thereby ensuring the effect of sufficient absorption of the sulfuric acid tail gas during the washing process. During the use of the equipment, as the use time increases and the equipment wears out, the tail gas treatment standard can no longer meet the emission standard. Therefore, the tail gas equipment needs to be improved to meet the emission standard of sulfuric acid tail gas. Summary of the Invention

[0004] In order to solve the above problems, an embodiment of the present invention provides a method for washing sulfuric acid tail gas multiple times, neutralizing all the acidic gases therein and then transporting it to the boiler for combustion, thereby ensuring that the tail gas emissions meet the standards while avoiding corrosion to the boiler furnace.

[0005] In order to achieve the above-mentioned purpose, the embodiment of the present invention specifically adopts the following technical scheme: a sulfuric acid tail gas alkali liquid washing device, comprising an alkali washing tower body, an air outlet pipe, an alkali washing part and a recovery part designed in sequence from top to bottom, an air intake pipe is arranged between the recovery part and the alkali washing part, a circulation system connected to the recovery part is arranged on the outside of the alkali washing tower body, a premixing module is arranged in the air intake pipe, and the premixing module includes a first sprayer, a second sprayer and a third sprayer distributed in sequence along the length direction of the air intake pipe.

[0006] As a further improvement of the above technical solution:

[0007] The first sprayer and the second sprayer are respectively installed obliquely at the upper part and the lower part of the air intake pipe, and the air intake pipe of the third sprayer is coaxially distributed.

[0008] The number of the first sprayer, the second sprayer and the third sprayer is multiple, and the spraying direction is opposite to the gas delivery direction.

[0009] A guide plate is provided at the bottom of the air inlet pipe, and the guide plate extends outward from one end close to the alkali washing tower body and its thickness gradually increases.

[0010] The circulation system comprises a reflux pipe, a delivery pump and a delivery pipe. The delivery pipe is provided with a branch pipe connected with the alkali washing part, and the branch pipe is provided with a flushing pipe.

[0011] A liquid drain pipe is provided at the bottom of the recovery part, a liquid level measuring device is provided in the recovery part, and a liquid replenishing pipe group is provided at the upper part of the recovery part.

[0012] A spray head 1 connected to a branch pipe is provided in the alkali washing part, and an alkali washing filler and a grid plate distributor are provided below the spray head 1.

[0013] There are multiple grid plate distributors which are evenly distributed along the height direction of the alkali washing part. The multiple grid plate distributors form an S-shaped gas channel in the alkali washing part.

[0014] A second spray head is provided in the air outlet pipe, a demister is provided above the second spray head, and the second spray head, the demister and the air outlet pipe are coaxially distributed.

[0015] The beneficial effects of the embodiments of the present invention are as follows: the sulfuric acid tail gas alkali liquid washing device includes an alkali washing tower body, wherein the alkali washing tower body is sequentially designed with an outlet pipe, an alkali washing part, and a recovery part from top to bottom; an air intake pipe is provided between the recovery part and the alkali washing part; a circulation system connected to the recovery part is provided on the outside of the alkali washing tower body; a pre-mixing module is provided in the air intake pipe, and the pre-mixing module includes a first sprayer, a second sprayer, and a third sprayer sequentially distributed along the length direction of the air intake pipe. The pre-mixing module is used to perform preliminary washing of the sulfuric acid tail gas during its entry, thereby improving the neutralization efficiency of the acid gas and thereby enhancing the overall washing effect;

[0016] The pre-mixing module design cooperates with the spray head 1 in the alkali washing section and the spray head 2 in the gas outlet pipe to perform multiple step-by-step washing operations on the sulfuric acid tail gas, which can completely neutralize the residual gas in the sulfuric acid tail gas and prevent the gas transported to the combustion furnace from containing residual acid gas, which may cause corrosion to the side walls of the furnace.

[0017] The design of the circulation system can recycle the alkaline washing liquid, improve the utilization rate of the alkaline washing liquid, save production costs without affecting the washing effect, and cooperate with the flushing pipe to further improve the neutralization of acidic gases, achieving the purpose of environmental protection and saving;

[0018] The sulfuric acid tail gas alkali solution washing device of the present invention has a simple overall structure and is easy to manufacture. When in use, it can be quickly connected to the existing desulfurization and deacidification equipment, and the desulfurization and deacidification equipment can be upgraded and renovated without long-term production suspension. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 Schematic diagram of the structure of the grid distributor in the present invention;

[0021] Figure 3 It is a structural schematic diagram of the air intake pipe in the present invention.

[0022] In the figure: 1. Alkali washing tower body; 2. Air outlet pipe; 3. Alkali washing section; 4. Recovery section; 5. Air inlet pipe; 6. First sprayer; 7. Second sprayer; 8. Third sprayer; 9. Reflux pipe; 10. Delivery pump; 11. Delivery pipe; 12. Branch pipe; 13. Flushing pipe; 14. Liquid level measuring device; 15. Liquid replenishment pipe group; 16. Spray head 1; 17. Alkali washing filler; 18. Grid plate distributor; 19. S-shaped gas channel; 20. Spray head 2; 21. Defoamer; 22. Drain plate; 23. Drain pipe. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0024] See also Figure 1-3The sulfuric acid tail gas alkali liquid washing device disclosed in this embodiment includes an alkali washing tower body 1, which is sequentially designed with an outlet pipe 2, an alkali washing part 3 and a recovery part 4 from top to bottom. An air intake pipe 5 is installed between the alkali washing part 3 and the recovery part 4. The air intake pipe 5 is equipped with a first sprayer 6, a second sprayer 7 and a third sprayer 8 which are sequentially installed along the air intake direction. The three constitute a premixing module to premix and neutralize the incoming sulfuric acid tail gas. The first sprayer 6, the second sprayer 7 and the third sprayer 8 are all multiple in number and their spraying directions are opposite to the flow direction of the gas. The first sprayer 6 is installed at the upper part of the air intake pipe 5, and after being installed obliquely, it is aligned with the side wall of the air intake pipe 5. The angle is 100-140 degrees. The second sprayer 7 is installed at the lower part of the air intake pipe 5, and after the inclined installation, the angle formed with the side wall of the air intake pipe 5 is 100-140 degrees. The third sprayer 8 is vertically installed on the central axis of the air intake pipe 5. Through one or more groups of pre-mixing modules, the sulfuric acid tail gas can be mixed with the sulfuric acid tail gas in advance in the air intake pipe to improve the neutralization effect of the sulfuric acid tail gas. The alkali solution spraying direction of the pre-mixing module is opposite to the gas entry direction, which can slow down the forward speed of the sulfuric acid tail gas. At the same time, the neutralization time of the sulfuric acid tail gas is increased by alkali solution spraying, thereby improving the pre-neutralization effect, and cooperating with the alkali solution spraying in the subsequent alkali washing part 3 to jointly improve the washing effect of the sulfuric acid tail gas.

[0025] After passing through the air inlet pipe 5, the sulfuric acid tail gas enters the alkali washing tower body 1, and then rises to the alkali washing part 3 for secondary washing. A spray head 16 is installed in the alkali washing part 3, and an alkali washing filler 17 is installed below the spray head 16. A grid distributor 18 is installed below the alkali washing filler 17. There are multiple grid distributors 18 and they are installed in sequence along the height direction of the alkali washing part 3. A gap is reserved between each grid distributor 18 and the side wall of the alkali washing tower body 1. The gaps between two adjacent grid distributors 18 and the alkali washing tower body 1 are in opposite directions. Multiple grid distributors 18 form a continuous S-shaped gas channel 19 in the alkali washing part 3. The sulfuric acid tail gas increases the path length when passing through the S-shaped gas channel 19, thereby increasing the washing time of the sulfuric acid tail gas and improving the neutralization effect of the sulfuric acid tail gas.

[0026] In order to improve the recovery of the alkaline washing liquid in the air intake pipe 5, a guide plate 22 is installed at the bottom of the air intake pipe 5. The guide plate 22 is distributed along the gas conveying direction and the thickness gradually decreases, forming a ramp at the bottom of the air intake pipe 5 for the recovery and reuse of the alkaline washing liquid.

[0027] The sulfuric acid tail gas is discharged from the gas outlet pipe 2 after passing through the alkali washing part 3. A spray head 20 is installed in the gas outlet pipe 2. The spray head 20 washes the sulfuric acid tail gas for the third time. A demister 21 is installed above the spray head 20. The demister 21 can effectively ensure that the neutralized alkali solution can be effectively separated, recycled and reused. Finally, the washed sulfuric acid tail gas is discharged from the gas outlet pipe 2. During installation, the spray head 16, the spray head 20 and the gas outlet pipe 2 are all coaxially distributed with the alkali washing tower body 1. During actual use, the acidic gas is completely neutralized through three alkali solution spray washings, and then the washed gas is passed into the boiler furnace for combustion.

[0028] A circulation system installed outside the alkali washing tower body 1 is also connected to the recovery part 4. The circulation system does not include a reflux pipe 9, a delivery pump 10 and a delivery pipe 11 connected in sequence to the recovery part 4. Since the sulfuric acid tail gas has been desulfurized and deacidified in sequence when entering the air inlet pipe 5, the acid gas content in the sulfuric acid tail gas does not completely consume the alkaline substances in the alkali washing liquid. Therefore, the alkali washing liquid needs to be recycled and reused to improve the utilization efficiency of the alkali washing liquid and save production costs. The delivery pump 10 serves as a power source to transport the recovered alkali washing liquid through the delivery pipe 11 to the first sprayer 6, the second sprayer 7, the third sprayer 8, the spray head 16 and the spray head 20 for washing operations, wherein a branch pipe is provided between the delivery pipe 11 and the alkali washing part 3. 12. A flushing pipe 13 is installed on the branch pipe 12 for flushing the alkali wash filler 17 and the grid distributor 18. A liquid level measuring device 14 is also installed in the recovery part 4. The liquid level measuring device 14 includes an on-site liquid level meter and a remote liquid level meter, which are respectively used for on-site liquid level detection and terminal liquid level detection. When the liquid level is detected to be lower than the set value, the liquid is replenished by the liquid replenishing pipe group 15. The liquid replenishing pipe group 15 includes an alkali washing liquid replenishing pipe and a primary water replenishing pipe, which are respectively used to replenish the alkali washing liquid and adjust the concentration of the alkali washing liquid to avoid crystallization due to excessive concentration of the alkali washing liquid. A drain pipe 23 is also installed below the recovery part 4. When the concentration of the alkali washing liquid is lower than the set value, the alkali washing liquid is recovered through the drain pipe 23.

[0029] It should be noted that in the description of the present invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. These are merely for ease of description and are not intended to indicate or imply that the device or component described must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0031] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, such that a process, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, article, or apparatus / device.

[0032] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A sulfuric acid tail gas alkali liquid washing device, comprising an alkali washing tower body (1), characterized in that: The alkali washing tower body (1) is sequentially designed with an air outlet pipe (2), an alkali washing part (3) and a recovery part (4) from top to bottom; an air inlet pipe (5) is provided between the recovery part (4) and the alkali washing part (3); and a circulation system connected to the recovery part (4) is provided outside the alkali washing tower body (1); A premixing module is provided in the air intake pipe (5), and the premixing module comprises a first sprayer (6), a second sprayer (7), and a third sprayer (8) distributed in sequence along the length direction of the air intake pipe (5).

2. The sulfuric acid tail gas alkali liquid washing device according to claim 1, characterized in that: The first sprayer (6) and the second sprayer (7) are respectively installed obliquely at the upper and lower parts of the air intake pipe (5), and the third sprayer (8) is coaxially distributed with the air intake pipe (5).

3. The sulfuric acid tail gas alkali liquid washing device according to claim 2, characterized in that: The first sprayer (6), the second sprayer (7) and the third sprayer (8) are all multiple in number, and the spraying direction is opposite to the gas delivery direction.

4. The sulfuric acid tail gas alkali liquid washing device according to claim 2, characterized in that: A guide plate (22) is provided at the bottom of the air inlet pipe (5), and the guide plate (22) extends outward from one end close to the alkali washing tower body (1) and gradually increases in thickness.

5. The sulfuric acid tail gas alkali solution washing device according to any one of claims 1 to 4, characterized in that: The circulation system comprises a reflux pipe (9), a delivery pump (10) and a delivery pipe (11); the delivery pipe (11) is provided with a branch pipe (12) communicating with the alkali washing part (3); and the branch pipe (12) is provided with a flushing pipe (13).

6. The sulfuric acid tail gas alkali liquid washing device according to claim 5, characterized in that: A liquid drain pipe (23) is provided at the bottom of the recovery part (4), a liquid level measuring device (14) is provided inside the recovery part (4), and a liquid replenishing pipe group (15) is provided at the top of the recovery part (4).

7. The sulfuric acid tail gas alkali liquid washing device according to claim 1, characterized in that: A spray head (16) connected to a branch pipe (12) is provided in the alkali washing section (3), and an alkali washing filler (17) and a grid plate distributor (18) are provided below the spray head (16).

8. The sulfuric acid tail gas alkali liquid washing device according to claim 7, characterized in that: The grid plate distributors (18) are multiple in number and are evenly distributed along the height direction of the alkali washing section (3). The multiple grid plate distributors (18) form an S-shaped gas channel (19) in the alkali washing section (3).

9. The sulfuric acid tail gas alkali liquid washing device according to claim 1, characterized in that: A second spray head (20) is provided in the air outlet pipe (2), a demister (21) is provided above the second spray head (20), and the second spray head (20), the demister (21) and the air outlet pipe (2) are all coaxially distributed.

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