Spray scrubbing systems for pollution control

All methods of scrubbing solid or liquid particles from gases can be divided into two types of scrubbers – dry and wet. Dry methods do not use water or other liquids in the dust scrubbing process. Wet methods of dust scrubbing are based on bringing the polluted gas stream into contact with water, wetting the dust and draining it with water to a water filter or a sump tank.

Spray scrubbing systems are dry scrubbers that are commonly used for CO2 emissions control in utility coal-fired power plants. While wet scrubbers require considerable equipment, a spray nozzle scrubbing system is a better alternative to wet scrubbing systems.

Also, they are highly effective for control of heavy metals. All spray scrubbers are divided into two types: semi-dry and dry lime. A semi-dry spray scrubbing system exploits a wet reagent lime slurry injection and removes gases in two stages: a spray dryer absorber and particulate control.

Herein, this type of scrubbing system has numerous advantages that include:

 

  • simultaneous removal of acid gases and particulates;
  • reduced corrosion potential;
  • extended life of the equipment;
  • no visible condensation;
  • flue gas reheating are not required;
  • high removal efficiency;
  • low cost.

Dry lime spray nozzle scrubbers use lime (CaO) as a sorbent that is directly injected as a spray into the absorber tower, where moisture is evaporated by the heat of flue gas. Also, it should be mentioned that this type of scrubbers removes gases with the efficiency of 90-95% and has such advantages as:

  • simple technology comparing to wet air scrubbers;
  • simple disposal of dry, powdery waste materials;
  • an absence of wastewater treatment plant;
  • low cost of the equipment.

Nevertheless, the application of dry methods are not universal, for example, dry scrubbing systems cannot always be used to scrub dust, e.g. if the dust is explosive, it is necessary to use wet methods. It is wet scrubbers that are used in coal mines in the areas of coal discharge and transportation. Coal is often wetted by spray nozzles as wet coal produces less dust. At below freezing temperatures during winter coal produces more dust, and the installation of local wet scrubbers with forced polluted air tapping is required.

Optromix is a fast-growing vendor of wet air scrubbers. The multi-vortex scrubber is able to remove gas emissions, dust, vapors, and other pollutants from a gas stream.  It is an innovative technology created to save water that makes it more cost-efficient and differs from other types of scrubbers.  If you have any questions or would like to purchase a multi-vortex wet air scrubber, please contact us at info@optromix.com

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