Patent GB-427927-A (GB)
Title: Improvements in and relating to methods of and apparatus for operating explosion chambers
IPC: F02C5/12
Filed: 1934-04-24
Abstract: 427,927. Gas turbines. HOLZWARTH, H., 7, Goethestrasse, D³sseldorf, Germany. April 24, 1934, Nos. 12376, 12377, and 12378. Convention dates, April 24, 1933, May 2, 1933, and June 8, 1933. [Class 110 (iii)] Explosion chambers are provided with externally controlled igniters which are brought into action at an instant at which the explosive mixture has reached or just exceeded the self-ignition limit so that a mixed ignition is effected. This result is achieved by determining the time at which self-ignition takes place as by varying one or more of the following : (1) the discharge of residual gases from the combustion chamber ; (2) the scavenging period ; (3) the temperature of the charge air or of the scavenging air ; (4) the moisture content of the charge air or of the scavenging air ; (5) the temperature or quantity of cooling medium used in the cooling jacket. The invention is described as applied to a Holzwarth turbine having a combustion chamber A provided, as usual, with a scavenging air valve B, a fuel valve C, a charge air valve D, a products discharge valve H, and a residual products discharge valve J delivering to an intermediate stage. The valves are actuated periodically by oil supplied by a pump S and controlled by a rotary distributer O<1> driven by an electric motor R. One form of controller S<1> for varying the instant of self-ignition is shown in Fig. 11. It comprises a member 18<1> driven at constant speed by the motor R, and a double piston 6<1> working in a cylinder 7<1> to which the pressure of the explosion chamber is communicated by a pipe 12<1>. Pressure oil is supplied at 91 ond normally holds down the piston 6<1>. On the occurrence of an explosion the piston is forced up and oil passes to gaps in the periphery of the rotating member 18<1>. The gaps are so arranged that oil pressure is set up in one or both of the control pipes 25, 26, or in neither, according to the phase difference between the explosion and the constant speed member. A modified form of controller 5<1> is described. Figs. 19 and 20 show the application of the control to the discharge of the residual gases as at (1) above. These gases, passed by the valve J, are led to interstage nozzles 79 and one or both of the valves 80, 81 may be opened by impulses through pipes 25, 26 to bring additional nozzles 82, 83 into use. In this way the condition of the gases remaining in the chamber may be changed in order to alter the instant of ignition of the next charge. The unit 5<1> may be combined with the housing of the valves 80, 81. When control is to be affected by modifying the scavenging period as at (2) above, the controller 5<1> acts through the pipes 25, 26 on the section of the distributer O<1> which actuates the valve J. When, as at (3) above the temperature of the air is modified, the controller 5<1> actuates two valves which cause part of the charge air to pass through a preheater. If the moisture content is to be modified as at (4) above, the controller 5<1> actuates two jet nozzles which spray water or steam into the scavenging air. The controller 5<1> may vary the path of flow of the jacket cooling medium through its cooler, or may vary the speed of the circulating pump as at (5) above.