Venturi scrubbers system use a liquid stream to remove solid particles as well as gases present in the exhaust. In the venturi scrubber system, gas laden with particulate matter passes through a short tube with flared ends and the middle is constricted. This constriction causes to speed up the gas stream when the pressure is increased. The difference in velocity and pressure resulting from the constriction causes the particles and water to mix and combine above. The reduced velocity at the expanded section of the throat allows the droplets of water containing particles to drop out of the gas stream. Venturi scrubbers are effective part in removing small particles, with removal efficiencies of up to 99%
Most important operation in the control of gaseous related pollutant emissions is the removal of one or many pollutants from a gaseous mixture by absorption. The Absorption is a process in which a gaseous pollutant is dissolved in the form of liquid. As the gas stream passes through the liquid format, the liquid absorbs the gas, it is the same way that sugar is absorbed in a glass of water when it is stirred. Absorbers are often referred to as scrubbers, and there are various types of absorption equipment. The principal types of gas absorption equipment include packed columns, spray towers, spray chambers and venturi scrubbers. In general, absorbers can achieve removal of waste efficiencies greater than 95%
When a gas or vapour is brought into contact with a solid, part of it is taken up by the solid. The molecules that disappear from the gaseous material either enter the inside of the solid or remain on the outside attached to the surface. The most common industrial adsorbents are silica gel, activated carbon, and alumina because they have enormous surface areas per unit weight. Activated carbon is the universal standard for purification and removal of trace organic contaminants from liquid and vapour streams. Carbon adsorption systems are either regenerative or non-regenerative.