What is the difference between Wet Scrubbers and Dry Scrubbers and what are the major advantages of Gas Absorbers / Packed Bed Scrubbers over Dry Scrubbers?
Wet scrubber is a generic name for many different types of scrubbing technology, including particulate removal and gaseous pollutant removal. For particulate removal venturi scrubbers, vane scrubbers, multi venturi scrubbers and dynamic fan scrubbers are generally utilized.
For gaseous pollutants a gas absorber or packed bed scrubber is preferred to obtain maximum efficiency. Dry scrubber is a term generally used for gaseous pollutant removal and it is an alternative technology to gas absorbers or packed bed scrubbers.
Major advantages of Gas absorbers or packed bed scrubbers over Dry Scrubbers:
- 99.99% efficiency for gaseous pollutants such as H2S, HCl, NH3, SO2, HCN, Cl2, HF
- Minimum pressure drop, low operating cost
- Random packing, minimum maintenance
- Not dependent on temperature, pressure or moisture of incoming gas
- Very small amount of liquid need to be handled after neutralization
Dry scrubbers (completely dry or semi dry) are generally used when efficiency requirements are not high (80 to 90%) and are subject to higher maintenance and pressure drop.