Cause attention from all walks of life, in recent years, the prevention and control of atmospheric pollution in the process of hot dip galvanized equipment work will produce waste acid mist, if the acid mist direct emissions in the atmosphere, can produce irreversible damage to the atmospheric environment, how should we deal with the production of acid mist in the process of waste gas? There are five methods to control acid gas emission. The following five methods are briefly introduced.

1. Electrostatic defogging method

Acid mist electrostatic precipitator is a kind of electrostatic precipitator series products. After electrostatic precipitator becomes a patented technology, the first successful practical application was to capture sulfuric acid fog in 1907.

2. Acid fog purification and filtration

The filter layer of acid mist filter mainly includes three types: plate net, screen and fiber. The filter layer of the plate net defogger is usually made of polyvinyl chloride, which is staggered and stacked in the equipment. The screen in the screen mist eliminator is generally made of polyethylene or corrosion-resistant stainless steel materials. The fiber materials of fiber defogger are polypropylene and glass fiber.

3. Mechanical acid fog purification method

The principle of such waste gas treatment is to separate the droplets from the gas by the action of gravity, inertia force or centrifugal force. The commonly used equipment is the folding flow defogger, centrifugal defogger, etc.

4. Acid fog purification liquid absorption method

Liquid absorption generally includes washing method and alkali neutralization method. The commonly used absorption agents of alkaline solution include 10% Na2CO3, 4%~6% NaOH, NH3 and other aqueous solutions. The equipment used for purifying waste gas mainly includes washing tower, foam tower, packing tower, inclined hole plate tower, turbulent sphere tower and so on. Its main purification mechanism is to make full contact with gas and liquid, and to neutralize acid and alkali, so as to improve the purification efficiency.

The advantage of liquid absorption method is that the equipment investment is low and the process is simple. The disadvantage is: a. In the winter in the north, it is also easy for the equipment to operate due to ice. B. Because nitric oxide in nitric acid fog is not easily soluble in water, the purification efficiency of nitric acid fog by liquid absorption method is relatively low; C. High energy consumption and operating costs; D. it is easy to bring secondary pollution.

5. Acid fog purification solid adsorption method

The adsorbent has been successfully applied in many industries. It can purify sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, acetic acid, phosphoric acid and other acid gases (fog). It is especially suitable for acid washing operation places with intermittent discharge concentration less than 1000mg/m3. The commonly used adsorbents are activated carbon, molecular sieve, silica gel, ammonia-containing slime, etc.

The advantages of adsorption method in purifying acid fog waste gas treatment are as follows: a. B. Dry process without secondary pollution; C. nitrogen oxides pollution caused by nitric acid fog can be removed relatively well. The disadvantage is that the adsorbent adsorption capacity is limited, resulting in large equipment and intermittent operation. Therefore, the adsorption method is only suitable for purifying the waste gas with low concentration of acid fog.