wet scrubber, process, operation and applications

wet scrubber, process, operation and applications

1. Particulate Scrubber

2. Many industries like   chemical  and Building Materials industries may be required to reduce the amount of particulate they release into the environment . Scrubbers are devices to control  air pollution  and used to remove some particulates and gases from industrial exhaust streams.  Particulate Scrubber

3. The two main types of scrubbers are wet scrubbers and dry scrubbers . 1. Wet Scrubbers These can be used to control particulate matter less than 10 micrometers as well as inorganic gases such as SO 2 , H 2 S, NH 3 , and various chlorides and fluorides. Wet scrubbers may also be useful to control volatile organic compounds i.e. VOCs. Particulate Scrubber - Types

4. Wet Scrubbers are air pollution control devices for removing particles and gases from industrial exhaust stream . It is operated by introducing the dirty gas stream with a scrubbing liquid as water or wet limestone slurry which traps sulfur particles . Then particles are collected in the scrubbing liquid . The liquid droplets are removed for treatment and is recycled. Wet Scrubber

5. 2. Dry Scrubbers: The system sprays a collection of dry reagents into an exhaust stream. These chemicals can react differently depending on which material they are specifically targeting for removal. Some of these materials neutralize harmful  pollutants in the stream through a  chemical  reaction, while others cause a material to react and turn into a different substance.  Particulate Scrubber - Types

6. What is the nature of the particulate/dust to be removed? What is the particulate size distribution? What is the initial pollutant loading/ concentration in the waste stream?  Is it flammable or combustible? What is the required removal efficiency? What is the temperature and flow rate of the waste stream?  Where will the scrubber be located, indoors or outside?   The scrubber’s design will be impacted by a wide range of variables such as:

7. 1. Packed Tower Wet Scrubbers 2. Impingement Wet Scrubbers 3. Venturi Wet Scrubbers Wet Scrubber - Types

8. Pollutant laden gases enter at the bottom of the packed tower and rise upward, making contact with the scrubbing liquid draining down through the packed column. Packed Tower Wet Scrubbers

9. Since the pollutant concentration decreases as the gas rises, there is constantly fresher solvent available for contact, resulting in an efficient removal of contaminants.   Packed Tower Wet Scrubbers

10. Finally, the fine moisture droplets, still suspended in the cleaned gas stream, are removed by a mist eliminator . Scrub liquid from the eliminator is collected in an integral reservoir and recycled to the tower . Packed Tower Wet Scrubbers

11. This is a low energy device that offers an advantage of particulate collection, cooling, condensing and gas absorption all in a single unit . Gases enter the unit from the bottom and flow upward through a series of trays, each containing perforations designed to achieve the highest efficiency with minimum pressure drop. Impingement Wet Scrubbers

12. Scrubbing liquid is introduced above the top tray and cascades downward to the lower trays . As the gases accelerate through the perforations, a fluidized zone of liquid and gas is created. Impingement Wet Scrubbers

13. The turbulent mixing in each of these zones provides intimate contact where gas scrubbing and cooling occurs. Units are furnished with a final demister section to minimize liquid carry over problems before the cleaned gases are exhausted via the top outlet. Impingement Wet Scrubbers

14. The type and number of trays is selected to meet the process requirements . The CGS Impingement Wet Scrubber is particularly useful where particulate matter would foul a packed bed type scrubber, and on applications where gas absorption and/or sub-cooling is required. Impingement Wet Scrubbers

15. Impingement Wet Scrubbers