Vocs-containing acid mist absorption system and method

Abstract

The invention provides a Vocs-containing acid mist absorption system and method. The system comprises an absorption tower, an acid mist adsorption device communicated with the absorption tower, a fan communicated with the acid mist adsorption device, and an alkali tank communicated with the absorption tower through an alkali supplementing pump, a circulating pump and a sewage pump which are communicated with the absorption tower are respectively arranged on the side part of the absorption tower, a liquid level meter, a second pressure monitoring meter and a pH meter are arranged in the absorption tower, the circulating pump is respectively connected with a dynamic wave regulating valve and a spraying regulating valve, a first pressure monitoring meter is arranged on a pipeline between the dynamic wave regulating valve and the absorption tower, and a second pressure monitoring meter is arranged on a pipeline between the spraying regulating valve and the absorption tower. And an acid mist pipeline is arranged at an inlet of the absorption tower. Through primary dynamic wave absorption, primary filler absorption and primary activated carbon absorption, the acid mist containing Vocs in the extraction system is absorbed and discharged after reaching the standard, and it is guaranteed that the working environment in the extraction production system is clean.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrometallurgy and relates to an acid mist absorption system and method containing VOCs. Background Art

[0002] In the existing extraction production system, the problems of sulfuric acid mist and organic solvent volatilization have become the bottleneck restricting the clean production of the process. Specifically, during the operation of key equipment such as extraction tanks and stripping tanks, the sulfuric acid mist continuously generated at the gas-liquid contact interface will form a composite acid mist containing volatile organic compounds (VOCs) with the solvent oil volatilized from the organic phase, such as sulfonated kerosene. Most of the existing technologies use a dynamic wave scrubber for treatment, but the absorption effect is not good when treating acid mist containing VOCs, resulting in the concentration of VOCs in the working environment exceeding the standard. Therefore, there is an urgent need for an acid mist absorption system for treating acid mist containing VOCs to solve the above problems. Summary of the Invention

[0003] The purpose of the present invention is to provide an acid mist absorption system and method containing VOCs to solve the problem that the existing extraction production system cannot effectively absorb and treat acid mist containing VOCs.

[0004] To this end, the present invention adopts the following technical solutions: An acid mist absorption system containing VOCs includes an absorption tower, on the side of which there are respectively a circulation pump and a sewage pump communicated therewith. A liquid level gauge, a second pressure monitor and a pH meter are arranged inside the absorption tower. The circulation pump is respectively connected with a dynamic wave regulating valve and a spray regulating valve. A first pressure monitor is arranged on the pipeline between the dynamic wave regulating valve and the absorption tower. An acid mist pipeline is arranged at the entrance of the absorption tower. An acid mist adsorption device, which is communicated with the absorption tower, and a third pressure monitor is arranged on the pipeline therebetween. A fan, which is communicated with the acid mist adsorption device, and a fourth pressure monitor is arranged on the pipeline therebetween. An alkali tank, which is communicated with the absorption tower through a make-up alkali pump. A make-up alkali pump inlet valve is arranged on the pipeline between the alkali tank and the make-up alkali pump. An automatic make-up alkali valve is arranged on the pipeline between the make-up alkali pump and the absorption tower. An alkali liquid return valve is arranged on the pipeline between the alkali tank and the absorption tower, and the alkali liquid return valve is arranged in parallel with the make-up alkali pump.

[0005] The absorption tower includes a tower body, inside which there are successively arranged a demisting wire mesh, a spray liquid distribution pipe, packing and absorption liquid from top to bottom. A dynamic wave feed pipe is arranged on the side of the tower body, and the two are communicated through a dynamic wave transition section. A dynamic wave spray head is arranged inside the dynamic wave feed pipe.

[0006] The acid mist adsorption device comprises an acid mist adsorption device shell, wherein skid-mounted activated carbon is arranged in the acid mist adsorption device shell and an activated carbon adding port is arranged on the outer wall.

[0007] A plurality of spiral spray heads arranged in parallel are provided at the bottom of the spray liquid distribution pipe.

[0008] The blower is interlocked with the second pressure monitor.

[0009] The sewage pump and the liquid level meter are interlocked.

[0010] The automatic alkali replenishing valve is interlocked with the pH meter and the liquid level meter respectively.

[0011] A method for absorbing acid mist containing VOCs, using the above-mentioned acid mist absorption system containing VOCs, the method comprises the following steps: First, the acid mist containing VOCs enters the absorption tower from top to bottom through the power wave feed pipe. The circulating pump transports the liquid in the absorption tower to the power wave feed pipe, and is discharged through the power wave nozzle. The liquid flows from bottom to top, forming a gas-liquid two-phase zone. At this time, the liquid and gas collide with each other, and the acid mist dissolves in the absorption liquid. Secondly, the gas enters the absorption tower body, and the absorption liquid is evenly distributed on the filler through the spiral nozzle inside the tower body. When the gas passes through the absorption tower filler, the acid mist is further absorbed; Finally, the acid mist containing VOCs is further absorbed by the skid-mounted activated carbon at the outlet of the absorption tower, thus completing the acid mist absorption operation.

[0012] The beneficial effects of the present invention are: 1. The present invention adopts dynamic wave absorption as the first-level absorption, that is, it utilizes the high-speed collision of the gas-liquid two-phase region to make most of the volatile organic compounds (VOCs) in the exhaust gas enter the absorption liquid through physical dissolution. The gas-liquid contact efficiency is high and high-concentration VOCs can be quickly removed; 2. The present invention adopts spray absorption as a secondary absorption method. The absorption liquid is atomized by the spray device and contacts the exhaust gas in reverse to further absorb the residual VOCs. This serves as a supplement to the primary absorption method to ensure that the VOCs removal rate meets the standard. Specific absorption liquid can be selected according to the exhaust gas composition to improve the specificity. 3. The present invention uses activated carbon adsorption as a security measure. As a terminal treatment link, it adsorbs trace VOCs that are not completely removed in the first two stages, ensuring that the exhaust gas meets environmental protection standards. Activated carbon has a high specific surface area and adsorption capacity, and has a significant effect on removing low-concentration VOCs. Activated carbon should be replaced or regenerated regularly to avoid secondary pollution after adsorption saturation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of the structure of the system of the present invention; Figure 2 It is a schematic structural diagram of the acid mist adsorption device in the system of the present invention; Figure 3 It is a schematic structural diagram of the absorption tower in the system of the present invention.

[0014] In the figure, 1 - circulation pump, 2 - sewage pump, 3 - liquid level gauge, 4 - power wave regulating valve, 5 - spray regulating valve, 6 - absorption tower, 6-1 - absorption liquid, 6-2 - tower body, 6-3 - power wave transition section, 6-4 - power wave spray head, 6-5 - power wave feed pipe, 6-6 - demisting wire mesh, 6-7 - spray liquid distribution pipe, 6-8 - spiral spray head, 6-9 - packing, 7 - first pressure monitor, 8 - acid mist pipeline, 9 - second pressure monitor, 10 - third pressure monitor, 11 - acid mist adsorption device, 11-1 - acid mist adsorption device housing, 11-2 - activated carbon addition port, 11-3 - skid-mounted activated carbon, 12 - fourth pressure monitor, 13 - fan, 14 - alkali tank, 15 - make-up alkali pump inlet valve, 16 - alkali liquid reflux valve, 17 - make-up alkali pump, 18 - automatic make-up alkali valve, 19 - pH meter. Specific embodiments

[0015] The technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

[0016] As Figure 1 shown, an acid mist absorption system containing Vocs includes: An absorption tower 6, on the side of which there are respectively a circulation pump 1 and a sewage pump 2 communicated therewith. Inside the absorption tower 6, there are a liquid level gauge 3, a second pressure monitor 9 and a pH meter 19. The circulation pump 1 is respectively connected to a power wave regulating valve 4 and a spray regulating valve 5. A first pressure monitor 7 is provided on the pipeline between the power wave regulating valve 4 and the absorption tower 6. An acid mist pipeline 8 is provided at the inlet of the absorption tower 6; An alkali tank 14, which is communicated with the absorption tower 6 through a make-up alkali pump 17. A make-up alkali pump inlet valve 15 is provided on the pipeline between the alkali tank 14 and the make-up alkali pump 17. An automatic make-up alkali valve 18 is provided on the pipeline between the make-up alkali pump 17 and the absorption tower 6. An alkali liquid reflux valve 16 is provided on the pipeline between the alkali tank 14 and the absorption tower 6, and the alkali liquid reflux valve 16 is arranged in parallel with the make-up alkali pump 17.

[0017] As Figure 2As shown, the acid mist adsorption device 11 includes an acid mist adsorption device housing 11-1. Inside the acid mist adsorption device housing 11-1, there is a skid-mounted activated carbon 11-3, and an activated carbon addition port 11-2 is provided on the outer wall. The acid mist adsorption device 11 is connected to the absorption tower 6, and a third pressure monitor 10 is provided on the pipeline between the two. A fan 13 is connected to the acid mist adsorption device 11, and a fourth pressure monitor 12 is provided on the pipeline between the two. Specifically, the skid-mounted activated carbon 11-3 is added into the acid mist adsorption device housing 11-1 through the activated carbon addition port 11-2. Third pressure monitor 10 and fourth pressure monitor 12 are respectively provided on the front and rear connecting pipelines of the acid mist adsorption device 11. By comparing the pressure differences between the two, it is judged whether the skid-mounted activated carbon 11-3 needs to be replaced.

[0018] As Figure 3 shown, the absorption tower 6 includes a tower body 6-2. Inside the tower body 6-2, a demisting wire mesh 6-6, a spray liquid distribution pipe 6-7, a packing 6-9, and an absorption liquid 6-1 are successively arranged from top to bottom. A power wave feed pipe 6-5 is provided on the side of the tower body 6-2, and the two are connected through a power wave transition section 6-3. A power wave spray head 6-4 is provided inside the power wave feed pipe 6-5. At the bottom of the spray liquid distribution pipe 6-7, a number of spiral spray heads 6-8 arranged in parallel are provided. Among them, the demisting wire mesh 6-6 is used to eliminate the floating foam carried by the gas, and the moisture carried by the acid mist is further reduced, which is convenient for reducing the external discharge amount of the absorption liquid in the absorption tower 6.

[0019] The working principle of the absorption tower 6 is as follows: The outlet of the circulation pump 1 is divided into two paths. One path transports the absorption liquid in the absorption tower 6 to the power wave spray head 6-4. The flow rate of the power wave spray head 6-4 is adjusted by the valve opening, and the absorption liquid is transported to the spray liquid distribution pipe 6-7. The absorption liquid is evenly distributed onto the packing 6-9 through a number of spiral spray heads 6-8. In addition, the spray regulating valve adjusts the spray amount of the absorption liquid on the packing 6-9 through the opening of the spray regulating valve 5. The first pressure monitor 7 judges the flow rate by judging the pressure in the power wave feed pipe 6-5.

[0020] The fan 13 and the second pressure monitor 9 are interlocked. The second pressure monitor 9 judges whether the inside of the absorption tower 6 is in negative pressure. When it is lower than the set value, the frequency of the fan 13 slowly decreases. When it is higher than this value, the frequency of the fan 13 gradually increases.

[0021] The sewage pump 2 and the liquid level gauge 3 are interlocked. When the liquid level in the absorption tower 6 is higher than the set pressure, the sewage pump 2 starts to transport the liquid in the tower to the next process.

[0022] The alkali liquid in the alkali tank 14 is used as the absorption liquid and is transported to the absorption tower 6 through the alkali replenishment pump 17. The alkali replenishment pump inlet valve 15 is normally open. When the external temperature is above zero, the alkali liquid reflux valve 16 is normally closed. The automatic alkali replenishment valve 18 is interlocked with the pH meter 19 and the liquid level meter 3. When the pH value of the absorption liquid 6-1 is lower than the set value, alkali replenishment is automatically carried out. When the liquid level of the absorption liquid 6-1 is lower than the lower limit of the set value, alkali replenishment is automatically carried out.

[0023] A method for absorbing acid mist containing VOCs, using the above-mentioned acid mist absorption system containing VOCs, comprises the following steps: First, the acid mist containing VOCs enters the absorption tower 6 from top to bottom through the power wave feed pipe 6-5. The circulating pump 1 transports the liquid in the absorption tower 6 to the power wave feed pipe 6-5 and discharges it through the power wave nozzle 6-4. The liquid flows from bottom to top, forming a gas-liquid two-phase region. At this time, the liquid and gas collide with each other, and the acid mist dissolves in the absorption liquid. Secondly, the gas enters the tower body 6-2 of the absorption tower 6, and the internal spray of the tower body 6-2 evenly distributes the absorption liquid 6-1 on the filler 6-9 through the spiral nozzle 6-8. When the gas passes through the absorption tower filler 6-9, the acid mist is further absorbed; Finally, an acid mist adsorption device 11 is installed between the outlet of the absorption tower 6 and the inlet of the fan 13. As a safety measure, the acid mist containing VOCs is further absorbed by the skid-mounted activated carbon 11-3. At this point, one round of acid mist absorption operation is completed.

Claims

1. An acid mist absorption system containing VOCs, characterized in that, Comprising: An absorption tower (6), on the side parts of which there are respectively a circulation pump (1) and a sewage pump (2) communicated therewith. Inside the absorption tower (6), there are a liquid level gauge (3), a second pressure monitor (9) and a pH meter (19). The circulation pump (1) is respectively connected to a power wave regulating valve (4) and a spray regulating valve (5). On the pipeline between the power wave regulating valve (4) and the absorption tower (6), there is a first pressure monitor (7). At the entrance of the absorption tower (6), there is an acid mist pipeline (8); An acid mist adsorption device (11), which is communicated with the absorption tower (6), and on the pipeline between the two, there is a third pressure monitor (10); A fan (13), which is communicated with the acid mist adsorption device (11), and on the pipeline between the two, there is a fourth pressure monitor (12); An alkali tank (14), which is communicated with the absorption tower (6) through a make-up alkali pump (17). On the pipeline between the alkali tank (14) and the make-up alkali pump (17), there is a make-up alkali pump inlet valve (15). On the pipeline between the make-up alkali pump (17) and the absorption tower (6), there is an automatic make-up alkali valve (18). On the pipeline between the alkali tank (14) and the absorption tower (6), there is an alkali liquid reflux valve (16), and the alkali liquid reflux valve (16) is arranged in parallel with the make-up alkali pump (17).

2. The acid mist absorption system containing VOCs according to claim 1, wherein The absorption tower (6) includes a tower body (6-2). Inside the tower body (6-2), there are successively from top to bottom a demisting wire mesh (6-6), a spray liquid distribution pipe (6-7), a packing (6-9) and an absorption liquid (6-1). On the side part of the tower body (6-2), there is a power wave feed pipe (6-5), and the two are communicated through a power wave transition section (6-3). Inside the power wave feed pipe (6-5), there is a power wave spray head (6-4).

3. The acid mist absorption system containing VOCs according to claim 1, wherein The acid mist adsorption device (11) includes an acid mist adsorption device housing (11-1). Inside the acid mist adsorption device housing (11-1), there is a skid-mounted activated carbon (11-3), and on the outer wall, there is an activated carbon addition port (11-2).

4. The acid mist absorption system containing VOCs according to claim 2, characterized in that, At the bottom of the spray liquid distribution pipe (6-7), there are a number of spiral spray heads (6-8) arranged in parallel.

5. The acid mist absorption system containing VOCs according to claim 1, characterized in that, The fan (13) is interlocked with the second pressure monitor (9).

6. The acid mist absorption system containing VOCs according to claim 1, wherein, The sewage pump (2) and the liquid level gauge (3) are interlocked.

7. An acid mist absorption system containing VOCs according to claim 1, characterized in that, The automatic make-up alkali valve (18) is respectively interlocked with the pH meter (19) and the liquid level gauge (3).

8. An acid mist absorption method containing VOCs, characterized in that, Applying the acid mist absorption system containing Vocs according to any one of claims 1-7, the method comprises the following steps: First, the acid mist containing Vocs enters the absorption tower (6) from top to bottom through the power wave feed pipe (6-5). The circulation pump (1) transports the liquid in the absorption tower (6) to the power wave feed pipe (6-5) and discharges it through the power wave spray head (6-4). The liquid flows from bottom to top, forming a gas-liquid two-phase zone. At this time, the liquid and the gas impact each other, and the acid mist dissolves in the absorption liquid; Secondly, the gas enters the tower body (6-2) of the absorption tower (6). Inside the tower body (6-2), the absorption liquid (6-1) is evenly distributed on the packing (6-9) through the spiral spray head (6-8) for internal spraying. When the gas passes through the absorption tower packing (6-9), the acid mist is further absorbed; Finally, the acid mist containing Vocs is continuously absorbed by the skid-mounted activated carbon (11-3) at the outlet of the absorption tower (6). Thus, the acid mist absorption operation is completed.

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