GB892993A - Radial outflow catalytic pack such as for a rocket engine or gas turbine - Google Patents

Abstract

A catalytic pack assembly comprises a series of annular catalyst members disposed parallel to one another, means being provided for introducing fluid to be decomposed to the inner periphery of the annular members so that it flows radially outwardly parallel to the members, the decomposition products discharging from the members at the outer periphery thereof. The invention is shown in Fig. 1 applied to a rocket engine which comprises a double-wall outer shell 12 and an end wall 13 within which are disposed a catalytic assembly 11, a fuel and decomposition product distributer 25, a combustion space 24 and a combustion gas discharge nozzle. The catalytic assembly 11 comprises a series of annular catalytic screens 16 which are disposed radially between an inner preforated cylinder 18 and an <PICT:0892993/III/1> <PICT:0892993/III/2> outer perforated cylinder 17, and axially between annular end plates 62, 64. The assembly also comprises forward and rearward support plates 14, 15 by which the assembly is supported on an inner tubular member 41 which also constitutes a fuel supply duct and supports at its downstream end the fuel and decomposition product distributer 25. The fluid to be decomposed, for example hydrogen peroxide, is supplied through inlet 30 and flows forwardly through the space between the double walls of the shell 12, then radially inwardly through the space 33 between the end wall 13 and the forward support plate 14, then entering the space within the inner perforated cylinder 18 through inlet opening 19. A frusto-conical baffle 20 is disposed within the cylinder 18 so as to cause the fluid to flow substantially equally radially outwardly through the catalytic pack. The fluid becomes decomposed in passing therethrough and the products discharge through the outer perforated cylinder 17 into the annular space between the cylinder and a frusto-conical baffle 21. The decomposition products are then deflected by a further baffle member 22, some passing into the combustion space 24 through the annular passage 25a between the periphery of the distributer 25 and the shell 12, and the remainder passing through ducts in the distributer and issuing as sprays 45. Fuel supplied through the duct 41 is injected as sprays 46 and burns with the decomposition products in combustion space 24. The hydrogen peroxide flowing through the double-walled shell 12 provides a cooling effect and is preheated thereby. A similar catalytic assembly is utilized in the construction shown in Fig. 3, the products of decomposition in this case passing through inlet nozzles 74 and impinging on turbine rotor blades 76. The catalytic pack is supported on a fixed shaft 78 between a shoulder 79 thereon and a retaining nut 80 which bears against the end wall 85. The fluid to be decomposed is supplied through inlet 72. The catalytic assembly may comprise over two hundred screens stacked within an axial length of between five and six inches. The screens may be of mesh or may be in the form of discs, perforated or imperforate; they may be wholly of catalytic material, for example silver, or coated therewith.