Wet Scrubber Engineering
Wet scrubbers are air-cleaning devices where dust-laden air comes into contact with a scrubbing liquid, usually water. Fine particulates are captured by liquid droplets and removed from the air. Dirty water exits the device, but a mist eliminator is required to remove the remaining fine droplets. Wet scrubbers can also absorb noxious gas constituents, although gas absorption design criteria differ from particulate removal.
Low-Energy Wet Scrubbers
Used to collect particles greater than 5 microns, low-energy scrubbers include spray towers, orifice scrubbers, and dynamic wet precipitators. A spray tower, for example, is a cylindrical vessel with water pipes spraying downward on rising inlet air. Low air velocity (1-4 ft/sec) and large droplets (500-1000 microns) are used to prevent droplet entrainment, resulting in larger units than high-energy scrubbers.
High-Energy Wet Scrubbers
High-energy wet scrubbers are used to collect submicron particles. Two common designs are the Venturi scrubber and packed tower, both ensuring effective contact between water droplets and dust-laden air.
Venturi Scrubber
Features a converging section, throat, and diverging section. Scrubbing liquid is injected to form very small droplets at high air velocity, capturing particles efficiently. Mist eliminators are usually cyclonic separators coupled directly to the scrubber.
Packed Tower
A single cylindrical vessel where inlet air and water flow countercurrently through a packed bed. Mist eliminators at the top remove fine droplets. Packed beds provide a large contact area for intimate gas-liquid interaction, ideal for a variety of applications.
Advantages & Applications
- Handles high-temperature gas streams
- Low initial cost
- Compact installation space
- Separates explosive solids from gas streams
- Reduces exhaust stream temperature
- Capable of high collection efficiency
Expert Consultation: BCE engineers can help determine the ideal wet scrubber configuration for your application to maximize performance, efficiency, and compliance with environmental standards.