Flue gas scrubbing in wastewater treatment

The control of emissions from solid waste incinerators is tightly regulated. Spray nozzles are commonly used in gas scrubbing systems to remove pollutants before exhaust gases are released to the atmosphere. There are many types and designs of gas scrubbers used. 

For wet scrubbers, the nozzles are used to generate a spray through which the flue gas passes. This spray will knock out or react with contaminants, removing them from the flow. The surface area of the spray will determine how effectively it comes into contact with the target contaminants. The more finely atomised the spray, the higher the overall surface area will be. So, in theory, very fine sprays should be deployed in gas scrubbers. However, this needs to be offset by the fact that gas flows are often moving very quickly, and fine sprays will become rapidly entrained in the flow. This means that if the spray is too fine, then it may not reach each part of the gas flow, and thus reaction rates will be suboptimal.  Wet scrubber design involves a balancing act between getting well atomised, high surface area sprays and having droplets big enough to give complete coverage of the whole gas flow. 

A more detailed explanation of nozzle selections for gas scrubbing applications can be found on our gas scrubbing application page, where there is also a video series on the topic.