GB191303194A - A New or Improved Process and Apparatus for the Manufacture of Nitrogen Oxides or Oxyacids. - Google Patents

Abstract

3194. Lymn, A. H. Feb. 7. Nitrogen oxides and oxyacids. are prepared by causing nitrogen and oxygen to combine directly with each other by contact with a bed of a refractory substance or a porous mass. of refractory substance, which is heated by the burning of a combustible gas in contact with or within the mass of the refractory substance. A convenient apparatus consists of a tube filled with pieces of refractory substance such as fire-clay, of fragmentary or special shape, the combustion taking place inside and around the bed and the parts comprising the same; or the combustible gas may be passed into the interior of a cylinder or the like of porous refractory material through which the gas passes and is ignited at or near the surface thereof. The refractory material is brought to the requisite temperature by burning around or within it a mixture of combustible gas and air, after which the nitrogen and oxygen requisite for the formation of the nitrogen oxides &c. is passed in together with a suitable proportion of combustible gas, care being taken that the flames do not strike back or the gases do not explode before the proper time or place. The supply of combustible gas may be discontinued, if the refractory material has been sufficiently heated, until the material ceases to be hot enough to continue the process. - Steam superheated to the point of dissociation or hydrogen and oxygen in any other form may be added to the gases. The gases may be passed into the apparatus intermittently to produce a series of explosions, or the gases may be passed in at a high velocity. The process may be worked at a pressure above, at, or below atmospheric pressure. The nitrogen oxides formed are at once cooled in any suitable manner to prevent dissociation.