Chemistry of inorganic compounds – Modifying or removing component of normally gaseous mixture – Organic component
Patent
1994-06-06
1995-10-17
Warden, Robert J.
Chemistry of inorganic compounds
Modifying or removing component of normally gaseous mixture
Organic component
422169, 422170, 422173, 422177, 422198, 422199, 422174, 431 7, 431 11, 431207, 110214, 110215, 110216, B01D 5336
Patent
active
054588626
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a process for purifying exhaust gases, especially from vacuum pyrolysis installations, by means of the extraction of the exhaust gases and their combustion with a supply of air.
To date such exhaust gases have been extracted and subsequently subjected to their own combustion, whereupon the gaseous combustion products were released into the atmosphere. Depending on the exhauster, there exists the possibility on a larger or smaller scale that the exhaust gases with their possibly harmful components will have a negative impact on the exhauster, especially an operating medium used in the exhauster, e.g. water or oil. The negative effect on the operating medium goes so far that the operating medium has to be disposed as special waste, and thus legal provisions for disposal of special waste, which have to be initiated, as a rule, with an approval process, are applied. In any case this represents a significant complication of the prior art process.
The invention is based on the problem of designing the purification of the exhaust gases in such a manner that neither the exhauster nor any operating medium in the exhauster can be negatively effected. This problem is solved by application's invention.
Preferably the exhaust gases are exhaust gases from vacuum pyrolysis installations, preferably toluene and/or benzene, and exhaust gases from extrusion processes, preferably monomers, such as caprolactam, and/or oligomers, preferably the short-chained, more complex compounds of monomers are from polymer melts.
By means of the combustion of the exhaust gases safe combustion products, preferably CO.sub.2 and/or H.sub.2 O are produced both for the exhauster and an operating medium used therein. So that at this stage the high temperatures of the combustion products resulting from the combustion of the exhaust gases cannot damage the exhauster, which is designed here as a vacuum pump, immediately following the formation of the combustion products (gaseous reaction products) there is a cooling step that provides that the gaseous reaction products are cooled so far, viz. to 10.degree. to 25.degree. C., that they can no longer damage a vacuum pump that follows. The vacuum pump is preferably a liquid ring vacuum pump. In a preferred embodiment a slide vane rotary pump is used. For purposes of a slide vane rotary pump the range of cooling is expanded to 10.degree. to 200.degree. C., preferably 100.degree. to 200.degree. C. Following the combustion of the exhaust gases to innocuous, gaseous reaction products, whereby the combustion takes places at an underpressure of 0.5 to 0.95 bar (500 to 50 mbar absolute) that is generated by the vacuum pump, and the subsequent cooling of the gaseous reaction products, then the gaseous reaction products can no longer cause any damage to the vacuum pump, so that the cooled gaseous reaction products and the cooling water from the spray condenser can be extracted with the vacuum pump and can be released into the open air. For purposes of a slide vane rotary pump, the range of underpressure, which is generated by the vacuum pump, expands to 0.5 to 0.99 bar (500 to 10 mbar absolute).
The aforementioned liquid ring vacuum pumps belong in general to the group of displacement pumps. The gas to be extracted is conveyed in these pumps with the aid of circulating liquid, the liquid ring. This type of vacuum pump is suitable for conveying gases and steams of virtually any kind, provided a suitable liquid (i.e. operating medium)--water in the normal case--is chosen to form the liquid ring. In the present invention water is preferred.
An impeller is arranged eccentrically in a cylindrical housing filled in part with liquid. Owing to the rotation of the impeller, the liquid forms a ring rotating concentrically to the axis of the housing. It is achieved with this arrangement that the operating liquid leaves piston-like from the wheel cells and re-enters. As a consequence of the rotating impeller, these gases and steams are conveyed in the direction of rotation, whereby the cells decrea
REFERENCES:
patent: 3768982 (1973-10-01), Kitzner
patent: 4564174 (1986-01-01), Sikander
patent: 4625661 (1986-12-01), Melchior
patent: 4930997 (1990-06-01), Bennett
patent: 4958578 (1990-09-01), Houser
patent: 5000098 (1991-03-01), Ikeda et al.
patent: 5213492 (1993-05-01), Ho
patent: 5333558 (1994-08-01), Lees, Jr.
Rieter Automatik GmbH
Tran Hien
Warden Robert J.
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