GB1129568A - Method of operating regenerative furnaces and apparatus therefor - Google Patents

Abstract

1,129,568. Regenerative chemical furnaces. UNION CARBIDE CORP. 26 Aug., 1966 [31 Aug., 1965], No. 38492/66. Heading F4B. [Also in Division C5] In a method, for the production of acetylene and/or ethylene by cracking propane in a regenerative furnace, comprising three regenerative masses 13, 14, 15 each having a plurality of longitudinal passages 19 therethrough, combustion chambers 16 and 17 and plenum chambers 20 and 21, which includes alternating heat and make steps through the furnace, the make step deposits foreign materials on the walls of the passages of the mass through which the gas flows after cracking, and the foreign materials are removed by burn out steps which precede or are combined with the heat step. In a left-hand (L.H.) make step feed stock mixed with steam in a mixer 51, is fed through a manifold 36 to plenum chamber 21 and then through L.H. mass 15, central mass 14 in which most of the cracking takes place, and R.H. mass 13 in which quenching and deposition of tar takes place, the off-gas flowing through plenum chamber 20, manifold 34 and conduit 45 to storage. In a L.H. burn out fuel gas and air are supplied to manifold 34 via conduits 33 and 37 respectively and the mixture is ignited by an electrical impulse from cable 61, and the burning mixture passes through the plenum chamber 20, to the passages 19 of mass 13 from which it burns tar, the exhaust passing through the masses 14 and 15, the plenum 21, manifold 36 and conduit 44 to an exhaust stack. In a L.H. heat step air is supplied via conduit 37, manifold 34, plenum 20 and passages 19 to combustion chamber 17 and fuel is supplied via conduits 23, 25, 28 to burners 29, the combustion re-heating the mass 14 and the combustion products being exhausted as in a L.H. burn out. The burn out step may be combined with the beginning of a heat step by setting three-way valve 26 to supply half the fuel to burner 29 and half to plenum 34. Solenoid-type valves automatically controlled by electric timers are used throughout. It is not always necessary to have a burn out at the beginning of (or before) each heat step. A differential pressure switch which responds to the pressure drop across the furnace to bring the burn out into operation when the drop reaches a preselected value, may be provided.