Patent GB-807448-A (GB)
Title: Heat exchange apparatus and processes for the heat treatment of gases
Inventor: ELLIOTT DOUGLAS ERNEST
IPC: C10J3/08
Filed: 1955-10-21
Abstract: 807,448. Gas - producers; pulverulent fuel furnaces. POWER JETS (RESEARCH & DEVELOPMENT) Ltd. Oct. 19, 1956 [Oct. 21, 1955], No. 30115/55. Classes 51(1) and 55 (1). [Also in Group XIII] Apparatus used in the heat treatment of gases comprises a rotary wall defining a duct through which a gas flows in heat exchange relationship with a thick layer of partly molten material retained on the wall of the duct by centrifugal force, the material being caused to move between two axially spaced points in the duct by adding material to the layer at one point and withdrawing material from the layer at the other point. Fig. 1 shows an apparatus for gasefying coal in which steam and oxygen entering an inclined rotary duct 1 at one end thereof through tubes 14, 23 respectively react in a reaction zone 4 of the duct, with fuel such as powdered coal admitted from an injector 25. The reaction gases flow to the upper zone 3 of the duct and thence to a duct 27 for ultimate consumption, e.g. as firing or town gas ; which may be enriched by volatile constituents stripped from powdered coal injected from a second injector 31. A layer 39 of slag is maintained by centrifugal force, on the inner surface of the duet 1 and is continuously supplemented by sand injected from a nozzle 30, the sand and the residues of the reaction from the injector 31 fusing and flowing down as slag towards the lower zone 2 thereby carrying heat from zone 3 to zone 2 in which the steam and oxygen are flowing towards the reaction zone 4. The continuous flow of slag down the tube results in a continuous overflow of slag into the water trough 18, the slag giving up its heat to form of steam which is withdrawn and pressurized by a fan 37, is passed through a heater in the duct 27 and is admitted under a pressure controlled by a valve 38 to the tube 14. The end wall 10 of the gas duct 1 is water cooled. The axis of the duct 1 may be horizontal (Figs. 2 and 3, not shown). Fig. 4 shows an apparatus for heating oxygen, an inclined rotary tube in which a layer of slag is maintained by centrifugal force being provided as before. The slag is supplemented continuously from a rotary combustion chamber 50 (generally similar to that described in Specification 784,745) from the mouth 70 of which the slag flows continuously to a water-cooled nozzle 71 and thence to the duct 1. Oxygen is preheated in a heat exchanger 80 by the gases from combustion chamber 50 before passing to a duct 75 leading to a chamber 74 surrounding the nozzle 71. From the chamber 74 the oxygen flows into the duct 1 where it receives heat from the slag before passing through an outlet conduit 76 at the lower end of the duct 1. Surplus slag falls continuously from the lower end of the duct 1 into a water trough 18 as before. A further form is described (Fig. 5, not shown) in which the axis of the rotary duct in which the oxygen is heated, extends vertically. At least some of the slag which falls into the water trough may be crushed and recycled. Specification 791,160 also is referred to.