Wet desulfurization tower

General introduction: A wet desulfurization tower is specialized equipment for removing sulfides from industrial waste gas. Solvent contacts flue gas in counter-current to absorb harmful substances, and the regenerated solvent can be recycled.

Working Principle

Limestone-gypsum desulfurization process: Limestone is used as absorbent to chemically react with sulfur dioxide. The reaction includes absorption, neutralization, oxidation and crystallization, eventually forming recyclable gypsum.

Absorption stage: Sulfur dioxide dissolves in water to form sulfurous acid.

Neutralization stage: Calcium carbonate reacts with hydrogen ions to generate calcium sulfite.

Oxidation stage: Oxidation air converts calcium sulfite into calcium sulfate.

Crystallization stage: Saturated calcium sulfate combines with water molecules to form gypsum crystals.

Basic Structure

Oxidation and crystallization zone: Located at the bottom slurry tank. Equipped with agitators and oxidation air pipes to prevent sedimentation and accelerate oxidation reaction. Emergency spraying devices reduce excessive flue gas temperature.

Absorption zone: The core area for sulfur dioxide removal. Circulating slurry is atomized by nozzles and makes counter-current contact with flue gas. Trays and turbulators optimize gas distribution and improve absorption efficiency.

Mist elimination zone: Installed at the top of the tower. Flat, ridge or tube-type demisters remove moisture and gypsum droplets. Regular flushing is required to avoid blockage.

Performance Characteristics

Advantages: Fast reaction speed and high desulfurization efficiency above 95%. Suitable for large flue gas volume and high sulfide concentration.

Disadvantages: High initial investment for towers and auxiliary equipment. High operating cost of reagents and power consumption. By-products may cause secondary pollution.

Application Fields

Application scope: Widely applied in thermal power, steel and chemical industries. As the most mature desulfurization technology, it is highly reliable for ultra-low emission requirements.