GB191018475A - Improvements relating to the Fixation of Nitrogen and Oxygen at High Temperatures. - Google Patents

Abstract

18,475. Soc. l'Air Liquide (Soc. Anon. pour l'Etude et l'Exploitation des ProcÚdÚs G. Claude). Aug. 9, 1909, [Convention date]. Void. [Published under Section 91 of the Act.] Nitrogen oxides.-To prevent decomposition of the nitrogen oxides produced by the combination of nitrogen and oxygen at a high temperature, the process is effected under pressure, and this pressure is utilized for expanding the gases to produce an instantaneous fall of temperature. The process is conveniently carried out in a cylinder C, combination of the gases being effected in a tube T and the gases passing out through a nozzle, from which they expand. This nozzle may form part of an injector arranged so that cold air is drawn in and produces a further cooling of the gases; the admixture gases may be such as have already been treated and cooled. To maintain the temperature of the gases until the precise instant at which they expand, the nozzle is made of difficultly-fusible metal, and is maintained at the highest possible temperature. The tube T is loosely mounted in pockets A, A<1> in the cylinderwalls, which may be water-cooled, and is packed in magnesia or other infusible non-conductor of heat. Heating of the gases is effected by metal spiral enclosed in the tube C and electrically heated; or arcs may be struck in the tube, and the tube itself may be used as a conductor of the Nernst type. Or heating of the gases may be effected by combustion, combustible gases such as acetylene, hydrogen, being forced in through the pipes R, r, together with nitrogen and superoxygenated air.