Patent GB-768229-A (GB)
Title: Improvements in or relating to gas combustion processes and apparatus
Inventor: SPALDING DUDLEY BRIAN
IPC: F23C99/00
Filed: 1953-03-12
Abstract: In the production of acetylene from methane or other hydrocarbon with a deficiency of oxygen, the product gases are quenched from a temperature of about 1200 DEG  C. to a temperature below 700 DEG  C. by passing the products of combustion through a heat-conducting porous or foraminous quenching plate whilst maintaining the temperature of the upstream surface of said plate at a value below the said decomposition temperature.  The reaction may take place in an apparatus comprising such a plate in association with heat exchange means which bounds the downstream end of a combustion chamber, the upstream end of which is bounded by heat-conducting flame stabilizing plate having an associated heat exchanger, preferably as described and claimed in Specification 730,290 (see Group XI) and the ratio of the reactants, the velocity of the gases passing through the apparatus and the rate of extraction of heat from the plates are arranged to establish and maintain the necessary conditions of rapid combustion and quenching.ALSO:<PICT:0768229/III/1> <PICT:0768229/III/2> <PICT:0768229/III/3> <PICT:0768229/III/4> A normally unstable compound in the products of a gaseous combustion reaction e.g. cracking, formation of nitric oxide or of acetylene, is preserved by quenching said products to below the decomposition temperature of said compound by passing them through a heat-conducting porous or foraminous plate of which the upstream surface is below said decomposition temperature.  The apparatus of the invention comprises such a plate in association with heat exchange means which bounds the downstream end of a combustion chamber, the upstream end of which is bounded by a heat conducting flame stabilizing plate having an associated heat exchanger preferably as described and claimed in Specification 730,290 [Group XI].  One embodiment is shown in Fig. 9, in which the lower half of the apparatus constitutes the burner and the upper half, which is of analogous construction constitutes the quenching section.  In the central chamber combustion occurs as a thin layer of flame between the foraminous plates 1 and 2. Reactants entering at 10 pass into chamber 11 and are distributed therein by cylindrical baffles 22, 23 cooled if desired by jackets 26, 27 supplied with water or other coolant through conduits 30. The gases then pass through the flame stabilizing foraminous plate 1, consisting of three discs of sintered metal.  After combustion the products pass through the quenching plate into corresponding chamber 111 and are thence extracted by pump 32.  A plurality of such units may if desired be coupled to the same reactant source and the same product exhaust system.  Heat exchange fluid circulates in jackets 16, 161 about the foraminous plates, heat extracted from the quench plate being if desired supplied to the flame stabilizing plate to preheat the reactants.  The ratio of the reactants, the velocity of the gases passing through the apparatus and the rate of extraction of heat from the plates are arranged to establish and maintain the necessary conditions of rapid combustion and quenching.  In the synthesis of nitric oxide from a mixture containing N2 and an excess of O2 the temperature of the flame would fall from above 2500 DEG C. to below the decomposition temperature.  In the alternative constructions shown in Figs. 5, 7 and 8, the plates are respectively designated 1 and 2, and connected in heat exchange relation to feed back heat from the quench plate to the stabilizing plate and thus increase the preheating of the reactants by the latter plate.  The foraminous plates in Fig. 5 are constructed of laminae 5 e.g. of copper interleaved with laminar conductors 6 which extend between the plates.  Cooling fluid may also be supplied through jackets 7 and 8 (which may if desired be connected) periferally surrounding the plates.  Fig. 7 shows conductors 6a in contact with the foraminous plates, protected by refractory layers 6b to allow low melting point material to be used.  In Fig. 8, parts of a heat exchange element comprising a liquid or gas circulation pipe are embedded in the plates.  If desired a porous refractory plate may be provided between the foraminous plates further to increase the amount of heat radiated back to the stabilizing plate.  This plate may be placed with a small clearance from or even in contact with the quenching plate; further preheating may be obtained by a porous layer of refractory material on the downstream surface of the stabilizing plate.