Patent GB-821836-A (GB)
Title: Reactions using heating by electric arcs
IPC: F22B1/28
Filed: 1955-10-18
Abstract: <PICT:0821836/III/1> <PICT:0821836/III/2> A gas moving with vertical flow and having solid particles suspended therein is heated by one or more electric arcs in the outer zone of the vortex, especially for chemical reactions, e.g. the production of nitrogen oxides or hydrogen cyanide or boron or silicon or metal compounds such as borides, nitrides and carbides, and the particles are continuously added and are removed after repeated circulation through the arc zone.  Thus gas admitted tangentially at 8 into a chamber 9 passes into a cylindrical reaction zone 6 through slots S1 between vanes V1, V2, set as shown so that the gas forms a vortex in the zone 6 and no substantial proportion of the gas traverses the locus of the arc more than once.  Some of the vanes are replaced by flat sheet arc electrodes P1, P2.  Particles are introduced between the vanes by a pipe 10 and circulate in the gas vortex and pass repeatedly through the spaced arcs.  The gas passes finally through an axial outlet 7 into a pipe 14, where the products are cooled by water sprayed through orifices 15 therein.  Some solid particles pass centrifugally through a gap 13 above the pipe 14 and fall into liquid in a tank 18, whence they are removed through a pipe 23. The cooled gas passes to an outlet 25.  Larger particles fall through an annular orifice 26 in a transverse diaphragm 5 into a tank 28, whence they are removed by a pipe 32.  Gas is introduced into the tank 28 through a pipe 27 to maintain a slight upward pressure at the orifice 26, thereby delaying the fall of the particles.  The arc may be initiated by a grounded conductor 11, which is then withdrawn into a housing 12.  The arcs extend into the periphery of the vortex and may be D.C.  When A.C. is used, the arcs are intermittently struck, travel along the electrodes and are extinguished, the electrodes being arranged closer together at their outer ends.  In the production of nitric oxide from the air, small refractory particles are used, which carry heat from the arc into the gases.  Carbonaceous particles are used and consumed in the production of hydrocyanic acid from ammonia or from a mixture of ammonia and a paraffin hydrocarbon having less than 5 carbon atoms per molecule of gas, e.g. methane.  The spray 15 to remove the acid is either water or a solution of the acid. The particles may be reused and act as catalysts.  The heated particles may pass into gas in the vortex which has not been heated by the arcs, i.e. gas entering the vortex between vanes without an arc between them, and such gas may be decomposed by the particles and deposit by accretion thereon.  Boron may be produced with boron trichloride or tribromide, preferably with hydrogen as the gas, and is deposited on particles of boron, tungsten or inert refractory.  Silicon may be produced from silicochloroform or silicon tetrachloride and hydrogen. Borides, nitrides or carbides of metal, e.g. titanium, may be produced, using as particles the required product, and using for the gas a mixture of metallic halide with a gas containing boron, nitrogen or carbon. Mixtures of boride or carbides of one or more metals may be formed and may be intercrystalline.ALSO:<PICT:0821836/IV (a)/1> <PICT:0821836/IV (a)/2> A gas moving with vertical flow and having solid particles suspended therein is heated by one or more electric arcs in the outer zone of the vortex, especially for the production of acetylene, and the particles are continuously added and are removed after repeated circulation through the arc zone.  In producing acetylene from hydrocarbon gases, e.g. methane, the particles are carbonaceous, e.g. coke, coal or charcoal, and may be consumed in the process.  Thus gas admitted tangentially at 8 into a chamber 9 passes into a cylindrical reaction zone 6 through slots S1 between vanes V1, V2 set, as shown, so that the gas forms a vortex in the zone 6.  Some of the vanes are replaced by flat sheet arc electrodes P1, P2.  Particles are introduced between the vanes by a pipe 10 and circulate in the gas vortex and pass through or near the spaced arcs.  The gas passes finally through an axial outlet 7 into a pipe 14, where the products are cooled by water sprayed through orifices 15 therein.  Some solid particles pass centrifugally through a gap 13 above the pipe 14 and fall into liquid in a tank 18, whence they are removed through a pipe 23.  The cooled gas passes to an outlet 25.  Larger particles fall through an annular orifice 26 in a transverse diaphragm 5 into a tank 28, whence they are removed by a pipe 32.  Gas is introduced into the tank 28 through a pipe 27 to maintain a slight upward pressure at the orifice 26, thereby delaying the fall of the particles.  The arcs extend into the periphery of the vortex and may be D.C.  When A.C. is used, the arcs are intermittently struck, travel along the electrodes and one extinguished, the electrodes being arranged closer together at their outer end.