Patent GB-825841-A (GB)
Title: Method of carrying out endothermic chemical gas reactions
IPC: C10G9/36
Filed: 1956-01-02
Abstract: <PICT:0825841/III/1> <PICT:0825841/III/2> An endothermic chemical gas reaction is performed in a reactor having a shape of circular cross-section such that a stream of reaction material introduced tangentially assumes a spiral movement changing at a determined turning point into an axial counter-movement, and a stream of reaction material, if desired preheated below reaction temperature, is passed in a spiral path along the curved surface of the reactor in countercurrent to a substantially axially-proceeding turbulent stream of a suitable heat-providing gas by which reaction material is thus preheated and if necessary vaporized, the two streams being intermixed at or in the vicinity of that part of the path of said first stream at which the general direction of flow is reversed by the limits of the reactor, the desired endothermic reaction thus initiated then proceeding until it is terminated due to the exhaustion of the heat available, the equilibrium then existing being maintained if necessary and the reaction products continuing to move in the direction of the heat providing gas.  The heat providing gas may be superheated steam of a mixture of gaseous combustion products. As shown in Figs. 1 and 2, a liquid, vaporized or gaseous reaction material enters the reaction chamber at A in a spiral path, forming a stream along the internal wall of the chamber.  This stream moves with constantly increasing angular velocity until it reaches the vertex of the cyclone, at which point it reverses its general direction of movement and after proceeding in turbulent flow about the axis of the cyclone, finally leaves the reaction chamber at C.  A stream of the gaseous or vaporized heat-providing medium is introduced at B.  In the neighbourhood of the exit C the temperature is so far reduced that undesired further reactions can no longer take place and the equilibrium is stabilized.  At high temperatures, short reaction times and low partial pressures, heavy hydrocarbons may be cracked to give high yields of gaseous hydrocarbons such as acetylene, ethylene, propylene and butylene; at lower temperatures, longer reaction times and higher partial pressures, less gaseous and more liquid products, including high-aromatic benzines with good octane value are produced.  The cracking gas produced may be used to atomize the liquid reaction material for introduction into the reactor. Should the reaction material contain constituents, or should such constituents be formed, as are not vaporized at the desired reaction temperature (for example carbon in the cracking of heavy oils or petroleum residues) these constituents can be withdrawn in a simple manner at the point B at the vertex of the cyclone.  In this case the heat-providing gas must be introduced into the reaction chamber through a separate central tube projecting thereinto at B. The non-vaporized fraction separated off may be used as fuel, for example for the production of the heat-providing gas.  A catalyst can be provided in the form of a net or upon a porous substratum located in the vicinity of the mixing point in the reaction path BC, or in the form of dust into the stream of heat-providing gas or through a separate inlet D to allow it to remain, during the period of reaction, in contact with the reaction material and to remove it again in an attached separator, for example a cyclone separator.ALSO:<PICT:0825841/IV (b)/1> <PICT:0825841/IV (b)/2> An endothermic chemical gas reaction is performed in a reactor having a shape of circular cross-section such that a stream of reaction material introduced tangentially assumes a spiral movement changing at a determined turning point into an axial counter-movement, and a stream of reaction material, if desired preheated below reaction temperature, is passed in a spiral path along the curved surface of the reactor in countercurrent to a substantially axially-proceeding turbulent stream of a suitable heat-providing gas by which reaction material is thus preheated and, if necessary, vaporized, the two streams being intermixed at or near the vicinity of that part of the path of said first stream at which the general direction of flow is reversed by the limits of the reactor, the desired endothermic reaction thus initiated then proceeding until it is terminated due to the exhaustion of the heat available, the equilibrium then existing being maintained if necessary and the reaction products continuing to move in the direction of the heat-providing gas.  The heat providing gas may be superheated steam of a mixture of gaseous combustion products.  As shown in Figs. 1 and 2, a liquid, vaporized or gaseous reaction material enters the reaction chamber at A in a spiral path, forming a stream along the internal wall of the chamber.  This stream moves with constantly increasing angular velocity until it reaches the vertex of the cyclone, at which point it reverses its general direction of movement and after proceeding in turbulent flow about the axis of the cyclone, finally leaves the reaction chamber at C.  A stream of the gaseous or vaporized heat-providing medium is introduced at B.  In the neighbourhood of the exit C the temperature is so far reduced that undesired further reactions can no longer take place and the equilibrium is stabilized.  At high temperatures, short reaction times and low partial pressures, heavy hydrocarbons may be cracked to give high yields of gaseous hydrocarbons such as acetylene, ethylene, propylene and butylene; at lower temperatures, longer reaction times and higher partial pressures, less gaseous and more liquid products, including high-aromatic benzines with good octane value are produced.  The cracking gas produced may be used to atomize the liquid reaction material for introduction into the reactor. Should the reaction material contain constituents, or should such constituents be formed, as are not vaporized at the desired reaction temperature (for example carbon in the cracking of heavy oils or petroleum residues) these constituents can be withdrawn in p a simple manner at the point B at the vertex of the cyclone.  In this case the heat-providing gas must be introduced into the reaction chamber through a separate central tube projecting thereinto at B. The non-vaporized fraction separated off may be used as fuel, for example for the production of the heat-providing gas.