Jet scrubbers

This type of technology is a part of the group of air pollution controls collectively referred to as "wet scrubbers." Venturi scrubbers are also known as venturi jet scrubbers, gas-atomizing spray scrubbers, and ejector-venturi scrubbers. The technology is based on the removal of air pollutants by inertial and diffusional interception. 

FIG. 14-128 Superheated high-pressure hot-water requirements for 99 percent collection as a function of particle size in a two-phase eductor jet scrubber. To convert gallons per 1000 cubic feet to cubic meters per 1000 cubic meters, multiply by 0.134. [Gardenier, J. Air Pollut. Control Assoc., 24, 954 (1974).]... 

Enviro-chem (2005) Dynawave Reverse Jet Scrubber. www.enviro-chem.com/airpol/common/rjs.html... 

Laurent, A., Fonteix, C., and Charpentier, J. C., Simulation of a pilot scale, liquid motivated, venturi jet scrubber by a laboratory scale model. AIChE J. 26, 282 (1980). 

In both contact processes the sulfur trioxide is, after the final passage through the final tray and cooling to 180 to 200°(3, absorbed in 98.5 to 99% sulfuric acid. This occurs either in a countercurrent absorber tower or in a jet scrubber in which acid is sprayed from the top in co-current with the reaction gas and is accompanied by conversion of sulfur trioxide into sulfuric acid. 

The flue gas is then treated with sodium hydroxide solution in a jet scrubber (n) to remove sulfur dioxide. The purified flue gas passes through a demister (o) and an induced draft fan (p), and into the stack (q). 

The pre-cleaned airstream containing carbon disulfide vapors passes through two or three parallel adsorbers, in which the CS2 is absorbed on a bed of Supersorbon activated carbon. As soon as the adsorbent is saturated it is regenerated by desorbing the solvent with a countercurrent flow of steam. The resulting mixture of water and CSj vapors is condensed and separated in gravity settlers. The recovered CSj is returned to the viscose production without further treatment. The condensed steam is stripped of residual CSj in the centrifugal scrubber and used as dilution water for operation of the jet scrubbers. 

Goosens, P. B., and Kint, W. (1995). Incineration flue gas scrubbing using reverse jet scrubbers, Presented at the 14th International Incineration Conference, Belleuve, WA. 

Cocurrent absorption is usually carried out in spray or jet scrubbers and film absorbers. Cocurrent absorption is mainly used for the absorption of chemically acting wash liquids and only small residence times are needed to obtain the required absorption yield also at a large throughput. 

Pressurized wash liquid is sprayed in a jet scrubber, and dispersed into the slow flowing gas phase. The driving force is induced by the washing liquid the gas phase is entrained by the liquid jet or the droplet swarm (Fig. 3-23 a). 

The exhaust air, saturated with water vapor, is first treated in an absorption unit for removal of H2S by routing it through two successive jet scrubbers working with dilute caustic soda solution. Downstream of these, a centrifugal scrubber is installed as an entrainment separator. The sulphide-containing solution rejected from the scrubbers is used to precipitate zinc in the waste water treatment system of the production plant. By products adsorbed on the activated carbon, such as sulphiuic acid and elemental sulphur, are removed periodically by water and alkaline extraction. 

Nasr MRJ, Abedinzadegan M (1995) Performance of a venturi jet scrubber for H2S removal by iron-complex solution. Chem Eng Technol 18 166-170... 

Packed Beds, 419 Wet Cyclones, 420 Countercunent Sptsqr Columns, 420 Venturi Scrubbers, 422 Jet Scrubbers, 422... 

Jet scrubber units are not very efficient as gas compressors or as gas absorbers, but they are simple to operate and almost maintenance ftee. They are particularly applicable to relatively small volumes of gas containing corrosive impurities. If necessary, two or more can be... 

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