Air Pollution Control System
February 3rd, 2009 | by Ramaswami |Air pollution control system refers to the system which controls the pollutants in the air. This helps the humans to breathe the unpolluted air. Some of the methods for removing air pollutants are patented in USPTO.
In Patent no: 4,344,920 titled ‘Air pollution control system’ with the abstract: The disclosure is of gas-cleaning apparatus comprising a chamber having a downwardly vertical gas and fluid flow path, with the gas and fluid moving at high velocity. One or more layers of solids is disposed across the path of gas and fluid flow, and these solids and the spaces between them act as multiple venturi scrubbers and impingement surfaces so that the gas is cleaned by agglomeration and absorption. A vibrator is coupled to the layers of solids for vibrating them to prevent matter removed from the gas from adhering thereto and blocking the passages therebeween. Also disclosed is a centrifugal cyclone separator, adapted to be coupled to the output of the above-described gas scrubber, comprising an upright chamber containing a rotatable cylinder carrying blades on its outer surface, the free edges of the blades being positioned close to the inner wall of the chamber. The blade configuration and high rotational velocity and long distance travel of the gases provide improved separating action. The above apparatus is utilized in a system for converting sulfur dioxide in the clean gas to sulfuric acid.
Patent no: 3,984,312 titled ‘Process for insolubilizing potentially water pollutable wastes from sodium or ammonium type sulfur dioxide air pollution control systems’ with the abstract : Process for insolubilizing water soluble wastes from alkaline sodium or ammonium type sulfur dioxide control systems used in conjunction with industrial or power plants. The sodium or ammonium sulfite or sulfate wastes are reacted in solution with ferric ions and sulfuric acid to produce an insoluble basic, hydrous or anhydrous, sodium and/or ammonium hydroxy ferric sulfate or sulfite compounds of the generic type M.sub.v (Na, NH.sub.4).sub.w Fe.sub.x (SO.sub.u).sub.y (OH.sub.z)nH.sub.2 O, wherein M is selected from an alkali metal other than sodium, or an authigenic metal or other cation present in industrial or power plant wastes, v is selected from zero to six, w is selected from zero to five, x is selected from zero to six, y is selected from one to five, u is 3 and/or 4, z is selected from zero to 12, and n is selected from zero to 20. Principal end product compounds include Natrojarosite, Ammoniojarosite, Metasideronatrite, Sideronatrite, Depegite, Rosarite, Iriite, and mixtures thereof. The reaction takes place at an acid pH in a temperature ranging from about 50.degree.-300.degree. F. and may occur in single or multi-stage reactors. Air and/or bacterial activation at a pH of less than about 5.5 may be employed. The end product basic, sodium and/or ammonium hydroxy ferric sulfate and sulfite compounds are water insoluble as compared to the standard in the industry, CaSO.sub.4, and may be disposed of by simple landfill without the water pollution hazards inherent with landfilling of wet or dry sodium or ammonium sulfite and/or sulfate baghouse or wet scrubber wastes. The process also uses, and conversely can dispose of, other pollutants as reactants, such as hot waste water from power plant ash tanks, waste sulfuric acid, pickle liquior, acid mine water (blackwater), iron slag or scrap, or gob or pyrite leachate as part of an integrated, multiple-pollutant disposal process
