What is a three acid waste gas treatment system?

The three acid waste gas treatment system mainly adopts the combination process of "spray tower+wet electrostatic precipitator" to efficiently remove acidic gases and acid mist such as hydrochloric acid, sulfuric acid, nitric acid, etc., achieving ultra-low emissions.

Composition and hazards of three acid waste gas

Main components: hydrogen chloride (HCl), sulfuric acid mist (H ₂ SO ₄), nitric acid mist (NOx), and mixed acid mist, often accompanied by organic waste gas and high temperature and high humidity gases.

Typical features:

Strong corrosiveness: causing severe corrosion to equipment, pipelines, and building structures;

Stimulating odor: strongly irritating to the respiratory tract and eyes, long-term exposure can cause chronic diseases;

Difficult to handle: Especially for NOx (nitrogen oxides), the conventional spray removal rate is only 50-70%, which can easily form "yellow smoke" pollution.

Mainstream processing technology flow

Acid mist generation source → collection by gas hood → neutralization by spray tower → deep purification by wet electrostatic precipitator → discharge by induced draft fan

1. Absorption and neutralization of spray tower

Working principle: The exhaust gas enters the PP material spray tower from bottom to top, and comes into countercurrent contact with the alkaline solution (such as NaOH) sprayed at the top, removing most of the acidic gases through neutralization reaction.

Applicable scenarios: Suitable for easily neutralizing acid mist such as HCl and H ₂ SO ₄, with a removal efficiency of over 90%.

Optimization design: Adopting multi-stage packing layers to enhance gas-liquid contact area and improve mass transfer efficiency.

2. Wet electrostatic precipitator (WESP) deep treatment

Core function: It provides ultimate purification for residual micron level acid mist, PM2.5, NOx, and "white smoke" after spraying, with a defogging rate of over 99%.

Technical advantages:

Using a high-voltage electric field to charge acid mist and adsorb it to the dust collection electrode;

Continuous flushing with water film to avoid secondary dust and achieve "smokeless to the naked eye" emissions;

Corrosion resistant design (made of fiberglass/PP material), with a service life of over 10 years.

3. Response plan for special working conditions

Nitric acid containing yellow smoke (NOx) exhaust gas: Conventional spraying has poor effectiveness and requires the addition of a yellow smoke removal agent (such as Kunshan Weak Water Wuji Environmental Protection R&D agent), which can increase the NOx removal rate to 99%.

High concentration mixed acid mist: Pre treated with "dual alkali method+multi-stage spraying" to reduce the load before entering the wet electricity system.

Waste liquid treatment: After neutralization, the waste liquid contains high salt content (such as NaCl, Na ₂ SO ₄), and it is recommended to use an evaporation crystallization system to achieve resource recycling.