Acid mist absorption system

Abstract

The utility model belongs to the field of acid mist treatment, and particularly relates to an acid mist absorption system which is characterized in that an air outlet of a fan connected with an acid mist collecting pipeline is connected with an air inlet pipe of an absorption tower, an air outlet pipe of the absorption tower extends below the liquid level in a water seal device, and an exhaust pipe at the top of the water seal device is communicated with outside air; and a liquid discharge pipe of the water seal device is connected to the neutralization tank. According to the scheme, the alkali liquor is used for neutralizing the acid mist, most acidic substances in the acid mist are intercepted, a small part of the acid mist enters the water seal device along with the air flow, water in the water seal device can be alkaline or neutral, a small amount of the acid mist in the air flow is absorbed by the water, and the acid mist in the air flow is recycled. Water absorbing a small amount of acid mist in the water seal device is discharged after reaching the standard after being neutralized and can also be recycled in the water seal device after being neutralized, and outlet gas of the water seal device can be directly discharged into the atmosphere, so that the acid mist is thoroughly solved.

Description

Technical Field

[0001] The utility model belongs to the field of acid mist treatment, and specifically relates to an acid mist absorption system. Background Art

[0002] In the acid-using process in the chemical, electronics, metallurgy, electroplating, textile, machinery manufacturing and other industries, the acid mist volatilized from the acid liquid is highly corrosive and cannot be directly discharged into the air. Therefore, acid mist is also a common waste gas.

[0003] The methods for treating acid mist in the prior art are generally water washing and neutralization. For example, sulfuric acid, hydrochloric acid and nitric acid are all soluble in water, and can be directly diluted and purified with water, and then the waste liquid is neutralized. However, the water washing method is only suitable for treating acid mist with low concentration. When the concentration is high, the water washing effect is not ideal; for acid mist with high concentration, a low concentration of alkaline solution can be used for neutralization. However, in actual application, whether it is the water washing method or the neutralization method, after the acid mist gas flow is treated, due to the high humidity, water vapor will carry a small amount of escaping acid mist into the atmosphere, that is, the method for treating acid mist in the prior art cannot guarantee that the pH value of the tail gas after the acid mist treatment is neutral, causing certain pollution to the air.

[0004] For example, the invention patent named "Acid Mist Absorption Tower" (patent number CN 200910025986.7) includes a cylindrical tower body, an exhaust pipe connected to the upper end of the tower body, a water tank connected to the lower part of the tower body, an air inlet connected to the side wall of the tower body, a steam-water separator, a packing layer, a guide tube, and a three-stage spray pipe are arranged inside the tower body from top to bottom; the water tank is connected to the three-stage spray pipe through a connecting pipe and a circulating water pump, the guide tube is located between the upper spray pipe and the middle spray pipe, and a water receiving tray is fixedly connected between the guide tube and the tower body. The guide tube and the water receiving tray of the acid mist absorption tower of this scheme cooperate to make the spray liquid and the rising harmful gas mix and rotate at high speed in the tower, increase the gas-liquid contact area and time, and improve the removal effect of harmful gases. However, in fact, although this scheme increases the contact area between the acid mist and the spray liquid, allowing the spray liquid to bring the acid mist into the liquid phase for treatment, it also greatly increases the vaporization phenomenon of the spray liquid. When the vaporized spray liquid is discharged from the exhaust pipe, the probability of the acid mist being discharged along with the vaporized spray liquid is also increased.

[0005] It can be seen that how to more effectively treat acid mist to prevent it from being discharged into the air and polluting the environment is a topic that technicians in this field need to continue to study. Utility Model Content

[0006] The utility model aims to provide an acid mist absorption system, which can absorb the acid mist 100% and prevent the acid mist from being discharged into the atmosphere and affecting the environment.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: an acid mist absorption system, characterized in that: the air outlet of the fan connected to the acid mist collection pipeline is connected to the air inlet pipe of the absorption tower, the air outlet pipe of the absorption tower penetrates below the liquid level inside the water seal device, the exhaust pipe on the top of the water seal device is connected to the outside air, and the drain pipe of the water seal device is connected to the neutralization tank.

[0008] In the above scheme, the acid mist is first neutralized with alkaline solution to intercept most of the acidic substances in the acid mist, and a small part of the acid mist enters the water seal device with the air flow. The water in the water seal device can be alkaline or neutral. The water is used to absorb a small amount of acid mist in the air flow. The water in the water seal device that absorbs a small amount of acid mist is neutralized and then discharged in compliance with the standards, or it can be recycled in the water seal device after neutralization. The outlet gas of the water seal device can be directly discharged into the atmosphere, thereby achieving a complete solution to the acid mist. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a flow chart of the acid mist absorption system of the utility model, wherein the hollow arrows represent the gas flow direction, and the solid line and the solid arrows represent the liquid flow direction;

[0010] Figure 2 Schematic diagram of the water seal device. DETAILED DESCRIPTION

[0011] The technical solution of the utility model is further described in detail below in conjunction with the accompanying drawings.

[0012] An acid mist absorption system is characterized in that: the air outlet of the fan 10 connected to the acid mist collection pipeline is connected to the air inlet pipe of the absorption tower 20, the air outlet pipe 22 of the absorption tower 20 penetrates below the liquid level inside the water seal device 30, the exhaust pipe 31 at the top of the water seal device 30 is connected to the outside air, and the drain pipe 33 of the water seal device 30 is connected to the neutralization tank 40.

[0013] Specifically, the absorption tower 20 forms an alkali liquid circulation loop with the alkali liquid tank 50 and the circulation pump 60 arranged beside it, and the alkali liquid tank 50 is provided with an alkali liquid dosing device 51. That is, after the acid mist enters the absorption tower 20 through the fan 10, the acid mist is neutralized by the alkali liquid to absorb most of the acid in the acid mist, and the dosing device 51 adds 30% of all the sodium hydroxide solution into the alkali liquid tank 50, and the absorption capacity of the absorption tower 20 for the acid mist is guaranteed by the circulation of the alkali liquid circulation loop.

[0014] The outlet pipe 22 of the absorption tower 20 is provided with a through hole 221 on the side wall of the pipe section below the liquid level of the water seal device 30. The airflow coming out of the absorption tower 20 carries a small amount of escaped acid mist, and the airflow enters the water seal device 30 and reaches directly below the liquid level. A small amount of acid mist (hydrochloric acid) is absorbed by the water in the water seal device 30, which further improves the acid mist treatment effect. The setting of the through hole 221 can divide the airflow entering the water into small-volume bubbles, thereby increasing the speed at which the acid mist in the airflow dissolves into the water, thereby ensuring the acid mist treatment effect.

[0015] A drain pipe 33 is connected to the side wall of the water seal device 30, and a water inlet 32 ​​is provided on the top of the water seal device 30, and the water inlet 32 ​​is connected to a water source. Water is added to the water seal device 30 from the water inlet 32 ​​to dilute the absorption liquid therein, so that the absorption liquid always remains neutral or close to neutral; more preferably, water is continuously and in small amounts added to the water seal device 30 from the water inlet 32 ​​to always keep a small amount of absorption liquid overflowing from the drain pipe 33, thereby saving the trouble of operators adding water in batches.

[0016] The air inlet end of the exhaust pipe 31 of the water seal device 30 is provided with a demister 70. If there is too much escaping acid mist in the air flow, the outlet air of the exhaust pipe 31 may be weakly acidic. The demister 70 is provided to dehumidify the outlet air in the water seal device, that is, to liquefy and retain the water vapor in the outlet air, so as to avoid the water vapor carrying acidic substances when being discharged, and further ensure the acid mist absorption effect. According to the test, the outlet pH value of the exhaust pipe 31 of the water seal device 30 is neutral for a long time.

[0017] The effluent of the neutralization tank 40 meets the standards and is discharged or returned to the water seal device 30. The liquid discharged from the water seal device 30 is an absorption liquid that absorbs a small amount of acid mist, and is neutralized in the neutralization tank 40.

Claims

1. An acid mist absorption system, characterized in that: The air outlet of the fan (10) connected to the acid mist collection pipeline is connected to the air inlet pipe of the absorption tower (20), the air outlet pipe (22) of the absorption tower (20) penetrates below the liquid level inside the water seal device (30), the exhaust pipe (31) at the top of the water seal device (30) is communicated with the outside air, and the drain pipe (33) of the water seal device (30) is connected to the neutralization tank (40).

2. The acid mist absorption system according to claim 1, characterized in that: A through hole (221) is provided on the side wall of the pipe section of the gas outlet pipe (22) of the absorption tower (20) that penetrates below the liquid level of the water seal device (30).

3. The acid mist absorption system according to claim 1, characterized in that: The absorption tower (20) forms an alkali liquid circulation loop with an alkali liquid tank (50) and a circulation pump (60) arranged beside the absorption tower (20). The alkali liquid tank (50) is provided with an alkali liquid dosing device (51).

4. The acid mist absorption system according to claim 1, characterized in that: A liquid discharge pipe (33) is connected to the side wall of the water seal device (30), and a water inlet (32) is provided on the top of the water seal device (30), and the water inlet (32) is connected to a water source.

5. The acid mist absorption system according to claim 1, characterized in that: A demister (70) is provided at the air inlet end of the exhaust pipe (31) of the water seal device (30).

6. The acid mist absorption system according to claim 1, characterized in that: The effluent from the neutralization tank (40) meets the standards and is discharged or returned to the water sealing device (30).

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