Acid-alkali waste gas absorption system

Abstract

The utility model discloses an acid-base waste gas absorption system, which belongs to the field of waste gas treatment and comprises a primary absorption tower, a secondary absorption tower and a fan which are sequentially connected in series, the system further comprises a solution storage tank, a solution delivery pump, a dosing tank and a dosing pump, a spraying device is mounted in the primary absorption tower, and two ends of the solution delivery pump are respectively connected with the solution storage tank and the spraying device through pipelines; two ends of the dosing pump are respectively connected with the dosing tank and the solution storage tank through pipelines; the system further comprises a water storage tank and a water delivery pump, a spraying device is mounted in the secondary absorption tower, and two ends of the water delivery pump are respectively connected with the water storage tank and the spraying device through pipelines; the solution storage tank and the water storage tank are connected with water inlet valves; the solution storage tank and the water storage tank are both connected with a pH sensor; the system further comprises a controller electrically connected with the water inlet valve, the pH sensor, the dosing pump and the solution conveying pump. According to the utility model, the concentration of the waste gas exhaust port cannot exceed the standard, and chemicals cannot be wasted.

Description

Technical Field

[0001] The utility model relates to the technical field of waste gas treatment, in particular to an acid-base waste gas absorption system. Background Art

[0002] With the continuous development of my country's economy and the in-depth adjustment of its industrial structure, clean production has become a popular development concept. In recent years, my country has been increasing its efforts in environmental remediation, especially the remediation and investment of industrial waste gas, and has achieved remarkable results.

[0003] In the process of industrial production, especially in the chemical industry, a large amount of acidic or alkaline waste gas is discharged, such as HCl waste gas, organic acid waste gas, ammonia waste gas, methylamine waste gas, etc. Regardless of the type of waste gas, the principle of acid-base absorption is adopted when treating it. Acidic waste gas is generally absorbed by alkaline solution, and alkaline waste gas is generally absorbed by acidic solution. Acid-base absorption has high efficiency, simple equipment, and low investment and operation costs, so it is widely used in industry.

[0004] However, in actual industrial production processes, such as the fine chemical industry, different production processes will cause the emission concentration and emission rate of waste gas to fluctuate greatly, which will cause the efficiency of subsequent processing equipment to fluctuate.

[0005] Take the absorption of HCl waste gas by alkaline solution as an example. The pH of the sprayed alkaline solution is usually controlled to be a fixed value. When the emission concentration and emission rate of HCl waste gas are moderate, the treatment effect will be better. However, if the emission concentration and emission rate become higher, the sprayed alkaline solution may not be able to keep up, resulting in the discharge port (waste gas concentration) exceeding the standard; on the contrary, when the emission concentration and emission rate of the waste gas are low, the sprayed alkaline solution cannot be fully used by the waste gas, resulting in excess alkaline solution (in the form of water mist) being carried downstream, which not only causes a waste of alkaline solution, but also causes corrosion and blockage to downstream equipment. Summary of the invention

[0006] In view of the problem in the prior art that the concentration and rate fluctuations of waste gas may affect the treatment effect or cause waste and equipment damage, the purpose of the utility model is to provide an acid-base waste gas absorption system to at least partially solve the above problems.

[0007] To achieve the above purpose, the technical solution of the utility model is:

[0008] An acid-base waste gas absorption system comprises a primary absorption tower, a secondary absorption tower and a fan; the primary absorption tower and the secondary absorption tower are both provided with an air inlet at the lower end and an exhaust port at the upper end, the air inlet of the primary absorption tower is connected to an exhaust gas inlet pipe, the exhaust port of the primary absorption tower is connected to the air inlet of the secondary absorption tower through a pipeline, and the exhaust port of the secondary absorption tower is connected to the fan through a pipeline;

[0009] It also includes a solution storage tank, a solution delivery pump, a dosing tank and a dosing pump, wherein the solution storage tank is used to store a solution for neutralizing the exhaust gas, a spray device is installed in the primary absorption tower, and the liquid inlet end and the liquid discharge end of the solution delivery pump are respectively connected to the solution storage tank and the spray device through pipelines; the dosing tank is used to store the agent for configuring the solution, and the liquid inlet end and the liquid discharge end of the dosing pump are respectively connected to the dosing tank and the solution storage tank through pipelines;

[0010] It also includes a water storage tank and a water delivery pump, wherein the water storage tank is used to store water, a spray device is installed in the secondary absorption tower, and the liquid inlet end and the liquid discharge end of the water delivery pump are connected to the water storage tank and the spray device respectively through pipelines;

[0011] Wherein, the solution storage tank and the water storage tank are both connected to a water inlet pipeline, and a water inlet valve is installed on the water inlet pipeline; the solution storage tank and the water storage tank are both connected to a pH sensor;

[0012] It also includes a controller, which is electrically connected to the water inlet valve, the pH sensor, the dosing pump, and the solution delivery pump.

[0013] In some preferred embodiments, the spray device comprises a spray pipe, and the spray pipe is provided with a plurality of spray holes or is installed with a plurality of spray heads.

[0014] In some preferred embodiments, the bottoms of the primary absorption tower and the secondary absorption tower are both provided with drainage ports.

[0015] In some preferred embodiments, the drain outlet of the primary absorption tower is connected to the solution storage tank, and the drain outlet of the secondary absorption tower is connected to the water storage tank.

[0016] In some preferred embodiments, a discharge port is provided at the lower end of the solution storage tank and the lower end of the water storage tank, a discharge pipe is connected to the discharge port, and a discharge valve is installed on the discharge pipe.

[0017] In some preferred embodiments, overflow ports are provided at the upper ends of the solution storage tank and the water storage tank, and the overflow ports are connected to overflow pipes.

[0018] In some preferred embodiments, the primary absorption tower and the secondary absorption tower are both cylindrical and installed vertically; the primary absorption tower and the secondary absorption tower both have two or more of the spray devices spaced apart along their height direction.

[0019] In some preferred embodiments, there are more than two solution delivery pumps and they are arranged in parallel.

[0020] In some preferred embodiments, there are more than two water delivery pumps and they are arranged in parallel.

[0021] By adopting the above technical scheme, the beneficial effect of the utility model is that under the feedback of the pH sensor installed on the water storage tank, the controller of the utility model can flexibly and timely adjust the pH value of the solution in the solution storage tank, so that after the exhaust gas and the solution in the primary absorption tower react with each other, neither of them will have a residual amount exceeding the standard, so that the concentration of the exhaust gas outlet will neither exceed the standard nor waste the reagents. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the utility model.

[0023] In the figure: 1-primary absorption tower, 2-secondary absorption tower, 3-fan, 4-exhaust gas inlet pipe, 5-exhaust gas pipeline, 6-exhaust pipeline, 7-solution storage tank, 8-solution delivery pump, 9-dosing tank, 10-dosing pump, 11-water inlet pipeline, 12-water inlet valve, 13-spraying device, 14-spraying valve, 15-water storage tank, 16-water delivery pump, 17-discharge pipe, 18-discharge valve, 19-overflow pipe, 20-discharge main pipe, 21-pH sensor. DETAILED DESCRIPTION

[0024] The specific implementation methods of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these implementation methods is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each implementation method of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] It should be noted that, in the description of the present invention, the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back", etc. are based on the description of the structure of the present invention as shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0026] The "first" and "second" in this technical solution are only used to distinguish the names of the same or similar structures, or corresponding structures with similar functions, and are not an arrangement of the importance of these structures, nor do they have a ranking, comparison of size, or other meanings.

[0027] In addition, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection between the two structures. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood based on the overall idea of ​​the utility model and the specific context of the scheme.

[0028] Example

[0029] An acid-base waste gas absorption system, such as Figure 1 As shown, it includes a primary absorption tower 1, a secondary absorption tower 2 and a fan 3.

[0030] The lower ends of the primary absorption tower 1 and the secondary absorption tower 2 are both provided with air inlets, and the upper ends of the primary absorption tower 1 and the secondary absorption tower 2 are both provided with exhaust ports. The air inlet of the primary absorption tower 1 is connected to an exhaust gas inlet pipe 4, the exhaust port of the primary absorption tower 1 is connected to the air inlet of the secondary absorption tower 2 through an exhaust gas pipeline 5, and the exhaust port of the secondary absorption tower 2 is connected to the suction end of the fan 3 through an exhaust pipeline 6.

[0031] It also includes a solution storage tank 7, a solution delivery pump 8, a dosing tank 9 and a dosing pump 10.

[0032] The solution storage tank 7 is used to store a solution capable of neutralizing exhaust gas, the dosing tank 9 is used to store a medicine capable of configuring the solution, the liquid inlet end of the dosing pump 10 is connected to the dosing tank 9 through a pipeline, and the liquid discharge end of the dosing pump 10 is connected to the solution storage tank 7 through a pipeline. The solution storage tank 7 is also connected to a water inlet pipeline 11, and a water inlet valve 12 is installed on the water inlet pipeline 11. In this way, under the joint action of the water inlet valve 12 and the dosing pump 10, a solution capable of neutralizing exhaust gas can be configured in the solution storage tank 7.

[0033] A spray device 13 is also installed in the primary absorption tower 1. The liquid inlet end of the solution delivery pump 8 is connected to the solution storage tank 7 through a pipeline, and the liquid discharge end of the solution delivery pump 8 is connected to the spray device 13 in the primary absorption tower 1 through a pipeline. Usually, a spray valve 14 is installed on the pipeline connected between the solution delivery pump 8 and the spray device 13.

[0034] In this embodiment, the spray device 13 includes a spray pipe, which is located inside the solution storage tank 7 and is fixed to the tank wall of the solution storage tank 7 through a flange. At the same time, a plurality of spray holes are opened on the spray pipe, or a plurality of spray heads are installed on the spray pipe. There can be multiple spray pipes, which can be linear or annular, so that the spray holes or spray heads can be evenly distributed in the cross section of the solution storage tank 7.

[0035] It also includes a water storage tank 15 and a water delivery pump 16 .

[0036] The water storage tank 15 is used to store water, and a spray device 13 is also installed in the secondary absorption tower 2, and the spray device 13 is the same as the spray device 13 in the primary absorption tower 1. The liquid inlet end of the water delivery pump 16 is connected to the water storage tank 15 through a pipeline, and the liquid discharge end of the water delivery pump 16 is connected to the spray device 13 in the secondary absorption tower 2 through a pipeline. The water storage tank 15 is also connected to the water inlet pipeline 11, and the water inlet valve 12 is also installed on the water inlet pipeline 11.

[0037] The bottom of the primary absorption tower 1 and the secondary absorption tower 2 are both provided with a drainage port, the drainage port of the primary absorption tower 1 is connected to the solution storage tank 7, and the drainage port of the secondary absorption tower 2 is connected to the water storage tank 15. For example, the primary absorption tower 1 is fixedly installed on the top of the solution storage tank 7, and the bottom surface of the primary absorption tower 1 is open to form a drainage port, which is fixed to the top of the solution storage tank 7 through a flange, and the secondary absorption tower 2 is also fixedly installed on the top of the water storage tank 15 in the same way. Correspondingly, the solution delivery pump 8 is also fixedly installed on the top of the solution storage tank 7, and the water delivery pump 16 is fixedly installed on the top of the water storage tank 15.

[0038] The lower end of the solution storage tank 7 is provided with a discharge port, to which a discharge pipe 17 is connected, and a discharge valve 18 is installed on the discharge pipe 17. The lower end of the water storage tank 15 is also provided with a discharge port, to which a discharge pipe 17 is also connected, and a discharge valve 18 is also installed on the discharge pipe 17. The upper end of the solution storage tank 7 is provided with an overflow port, to which an overflow pipe 19 is connected. The upper end of the water storage tank 15 is also provided with an overflow port, to which an overflow pipe 19 is also connected. In addition, a discharge main pipe 20 is also included, to which the above-mentioned discharge pipe 17 and overflow pipe 19 are both connected.

[0039] In addition, the solution storage tank 7 and the water storage tank 15 are both connected to a pH sensor 21, and the controller is electrically connected to the water inlet valve 12 on the water inlet pipeline 11 connected to the solution storage tank 7, the pH sensor 21 provided on the solution storage tank 7, the pH sensor 21 provided on the water storage tank 15, the dosing pump 10, and the solution delivery pump 8.

[0040] In other preferred embodiments, both the primary absorption tower 1 and the secondary absorption tower 2 are cylindrical and installed vertically. Both the primary absorption tower 1 and the secondary absorption tower 2 have two or more spray devices 13 arranged at intervals along their height direction.

[0041] In other preferred embodiments, there are two or more solution delivery pumps 7 and they are arranged in parallel, and the pipelines connected to the discharge ends of the two solution delivery pumps 7 are converged together through a three-way joint (or a multi-way joint), and then connected to the spray valve 14, and then delivered to the spray device 13 in the primary absorption tower 1. There are two or more water delivery pumps 16 and they are arranged in parallel. Similarly, the pipelines connected to the discharge ends of the two (or more) water delivery pumps 16 are converged together through a three-way joint (or a multi-way joint), and then connected to the spray valve 14, and then delivered to the spray device 13 in the secondary absorption tower 2.

[0042] The working process of the acid-base waste gas absorption system provided by the utility model is as follows:

[0043] Before use, the solution is pre-configured in the solution storage tank 7. Under the control of the controller, the dosing pump 10 is started to transport the agent to the solution storage tank 7. At the same time, the water inlet valve 12 on the water inlet pipeline 11 connected to the solution storage tank 7 is opened to mix water and the agent in the solution storage tank 7 for solution configuration. During the configuration process, the pH value of the solution is regulated by the pH sensor 21 installed on the solution storage tank 7. At the same time, the water inlet valve 12 on the water inlet pipeline 11 connected to the water storage tank 15 is opened to replenish water to the water storage tank 15.

[0044] When in use, the waste gas first passes into the lower end of the primary absorption tower 1, then is discharged from the upper end of the primary absorption tower 1, and passes into the lower end of the secondary absorption tower 2 through the waste gas pipeline 5, and then is discharged from the upper end of the secondary absorption tower 2.

[0045] When the waste gas passes through the primary absorption tower 1, under the control of the controller, the spray valve 14 of the primary absorption tower 1 is opened, the solution delivery pump 8 is started, and the solution in the solution storage tank 7 is pumped to the spray device 13 in the primary absorption tower 1, so that the solution is sprayed from top to bottom, and the waste gas is absorbed by acid-base neutralization. The reactants formed by the acid-base reaction are discharged into the solution storage tank 7.

[0046] The unabsorbed waste gas in the primary absorption tower 1 is passed into the secondary absorption tower 2 through the waste gas pipeline 5. Under the control of the controller, the spray valve 14 of the secondary absorption tower 2 is opened, the water delivery pump 16 is started, and the water in the water storage tank 15 is pumped to the spray device 13 in the secondary absorption tower 2, so that the water is sprayed from top to bottom, and the waste gas in the secondary absorption tower 2 is absorbed by the water, and the water used for absorbing the waste gas is discharged into the water storage tank 15.

[0047] Taking the waste gas as HCL gas as an example, the solution in the solution storage tank 7 is an alkaline solution. If the waste gas is alkaline gas, the acidic agent can be stored in the dosing tank 9. When the pH sensor 21 installed on the water storage tank 15 detects that the pH value is too low, it means that the primary absorption tower 1 does not absorb the waste gas sufficiently. At this time, the controller starts the dosing pump 10 to increase the amount of medicine in the solution storage tank 7, so that the pH of the alkaline solution in the solution storage tank 7 increases, so that after the alkaline solution is sprayed into the primary absorption tower 1, it can more fully absorb the waste gas in the primary absorption tower 1. When the pH sensor 21 installed on the water storage tank 15 detects that the pH value is too high, it means that the waste gas in the primary absorption tower 1 does not absorb the alkaline solution sufficiently (that is, the alkaline solution is excessive). At this time, the controller opens the water inlet valve 12 on the water inlet pipeline 11 connected to the solution storage tank 7, thereby adding water to the solution storage tank 7, so that the pH of the alkaline solution in the solution storage tank 7 is reduced, so that the alkaline solution spray can be fully absorbed by the waste gas.

[0048] In this way, under the feedback of the pH sensor 21 installed on the water storage tank 15, the controller can flexibly and timely adjust the pH value of the solution in the solution storage tank 7, so that after the exhaust gas and the solution in the primary absorption tower 1 react with each other, neither of them will have a residual amount exceeding the standard, so that the concentration of the exhaust gas outlet will neither exceed the standard nor waste the reagents.

[0049] The above is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. An acid-base waste gas absorption system, characterized in that: It includes a primary absorption tower, a secondary absorption tower and a fan; the primary absorption tower and the secondary absorption tower are both provided with an air inlet at the lower end and an exhaust port at the upper end, the air inlet of the primary absorption tower is connected to an exhaust gas inlet pipe, the exhaust port of the primary absorption tower is connected to the air inlet of the secondary absorption tower through a pipeline, and the exhaust port of the secondary absorption tower is connected to the fan through a pipeline; It also includes a solution storage tank, a solution delivery pump, a dosing tank and a dosing pump, wherein the solution storage tank is used to store a solution for neutralizing the exhaust gas, a spray device is installed in the primary absorption tower, and the liquid inlet end and the liquid discharge end of the solution delivery pump are respectively connected to the solution storage tank and the spray device through pipelines; the dosing tank is used to store the agent for configuring the solution, and the liquid inlet end and the liquid discharge end of the dosing pump are respectively connected to the dosing tank and the solution storage tank through pipelines; It also includes a water storage tank and a water delivery pump, wherein the water storage tank is used to store water, a spray device is installed in the secondary absorption tower, and the liquid inlet end and the liquid discharge end of the water delivery pump are connected to the water storage tank and the spray device respectively through pipelines; Wherein, the solution storage tank and the water storage tank are both connected to a water inlet pipeline, and a water inlet valve is installed on the water inlet pipeline; the solution storage tank and the water storage tank are both connected to a pH sensor; It also includes a controller, which is electrically connected to the water inlet valve, the pH sensor, the dosing pump, and the solution delivery pump.

2. The acid-base waste gas absorption system according to claim 1, characterized in that: The spray device comprises a spray pipe, and a plurality of spray holes are opened on the spray pipe or a plurality of spray heads are installed on the spray pipe.

3. The acid-base waste gas absorption system according to claim 1, characterized in that: The bottoms of the primary absorption tower and the secondary absorption tower are both provided with drainage ports.

4. The acid-base waste gas absorption system according to claim 3, characterized in that: The drain outlet of the primary absorption tower is connected to the solution storage tank, and the drain outlet of the secondary absorption tower is connected to the water storage tank.

5. The acid-base waste gas absorption system according to claim 1, characterized in that: The lower ends of the solution storage tank and the water storage tank are both provided with discharge ports, the discharge ports are both connected with discharge pipes, and the discharge pipes are both provided with discharge valves.

6. The acid-base waste gas absorption system according to claim 1, characterized in that: The upper ends of the solution storage tank and the water storage tank are both provided with overflow ports, and the overflow ports are both connected with overflow pipes.

7. The acid-base waste gas absorption system according to claim 1, characterized in that: The first-stage absorption tower and the second-stage absorption tower are both cylindrical and vertically installed; the first-stage absorption tower and the second-stage absorption tower are both provided with two or more spray devices spaced apart along their height direction.

8. The acid-base waste gas absorption system according to claim 1, characterized in that: There are more than two solution delivery pumps which are arranged in parallel.

9. The acid-base waste gas absorption system according to claim 1, characterized in that: There are more than two water delivery pumps which are arranged in parallel.

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