Waste gas scrubbing tower

Waste gas scrubbing towerThe principle is mainly based on the composition of the odor, using strong acids (sulfuric acid), strong bases (sodium hydroxide), and strong oxidants (sodium hypochlorite) as washing spray solutions to come into contact with odor molecules in the gas, transferring the odor components from the gas phase to the liquid phase, and using chemical agents to neutralize and oxidize the odor components to remove the odor substances.

commonly usedWaste gas scrubbing towerThe equipment is a packed tower, and the chemical absorption liquid is sprayed downwards from the top of the tower. The exhaust gas flows upwards, and the odor fully contacts and reacts with the absorption liquid to be removed. The ratio of absorption liquid to exhaust gas flow rate (liquid/gas ratio) is generally 1-3 L/m3, the packing height is generally 2-5 meters, and the gas flow rate in the empty tower is generally 0.5-1 meters/second. A well operated filling tower can achieve a deodorization effect of over 90%.

Common chemical absorbents include the following:

(1) Alkaline solution

Alkaline absorbent solutions commonly contain 1% to 10% sodium hydroxide solution, which is effective in eliminating hydrogen sulfide waste gas * and other substances that often cause odors in wastewater treatment plants, such as methyl mercaptan, methyl sulfide, methyl disulfide, and lower fatty acids.

(2) Acidic solution

Acid washing is mainly used to eliminate odors caused by alkaline gases such as ammonia, and sulfuric acid (0.5% -5% solution) is generally used as the washing solution.

(3) Sodium hypochlorite solution

Sodium hypochlorite is generally used together with acidic and alkaline absorbent solutions. For sulfurization that is difficult to eliminate by other methods, the use of sodium hypochlorite absorption solution has a very good control effect. When dealing with high concentration odors, the concentration of sodium hypochlorite solution (effective chlorine concentration) is about 500-2000 ppm; When dealing with low concentration odors, sodium hypochlorite solution with a concentration of about 50-500 ppm is used. In terms of the performance of various oxidants, sodium hypochlorite is cheap and has good treatment effects, so it is widely used.