Patent GB-747561-A (GB)
Title: Apparatus for generating and utilising combustion products under pressure
IPC: F23R7/00
Filed: 1953-03-30
Abstract: 747,561. Generating combustion products under pressure; gas producers. SCHMIDT, P. March 30, 1953, No. 8666/53. Classes 51(1) and 55(1). [Also in Groups XXVI, XXVIII and XXIX] Apparatus for generating combustion products under pressure comprises an elongated intermittently operating combustion chamber, in which a combustible mixture is ignited by means of a shock wave, having a controlled inlet and an open outlet which discharges into an accelerating chamber arranged to conduct a large flow of gaseous medium in the direction of flow of the combustion products through the outlet during the intervals between the consecutive discharges at so high a velocity that the sucking back of gases into the combustion chamber outlet is prevented. The apparatus, Fig. 1, comprises a combustion chamber 1 and an acceleration chamber 2. Valves 3 control the airflow into the chamber 1 and valves 4 the flow of gaseous medium into the chamber 2. Combustible is introduced into the combustion chamber through nozzle head 5. A nozzle 7 fed with air from high pressure supply pipe 8 and fuel pipe 9 is provided for starting. The air-fuel mixture from the pipe 7 is ignited by a spark plug 10. After the initial ignition, the combustion gases leave through the open end of the combustion chamber and cause fresh air to be drawn into the chamber through valves 3. To this air fuel is added through nozzles 5. After the inlet end of the combustion chamber has been filled with ignitable mixture it is ignited by a shock wave formed by the preceding efflux of combustion gases at the outlet end of the combustion chamber. The efflux of these gases also causes the formation of a pressure front which accelerates the gaseous medium in the chamber 2 supplied through conduit 11. The flow of gaseous medium through the chamber 2 aids the formation of a vacuum at the combustion chamber outlet and hinders the return of gaseous medium into the combustion chamber outlet and so causes a vigorous shock wave to travel back into the combustion chamber. The distance between the outlets of chambers 1 and 2 is so selected that a self pulsation of the gaseous medium within the chamber 2, in the rhythm of the pulsating gas column in the chamber 1, occurs. In order to reduce the pressure losses through the valves 3, the inlet end of the combustion chamber 1 may be enlarged to form a larger area for the valves 3 and the main part of the combustion given a divergent form with a divergence of less than 5 degrees. In a jet propulsion engine, Fig. 3, the combustion chamber 17 discharges into the accelerating chamber 23. Air under ram pressure is supplied to the inlet valves 18, 22 by the casing 24. In a further modification, two combustion chambers operating out of phase discharge into a common accelerating chamber, In this arrangement an outlet duct together with a control valve is provided to supply pressurised gaseous medium to an external user. In another modification, Fig, 5. two sets of combustion chambers and accelerating chambers are arranged in series. The first combustion chamber 42 discharges into an accelerating chamber 36. Part of the gaseous medium from the chamber 36 passes through a control valve 37 and conduit 47 to the second combustion chamber 39. The remainder of the gaseous medium passes through the valves 49 to the accelerating chamber 50. In the arrangement shown in Fig. 7, two combustion chambers 86 feed, through accelerating chambers 85, gas to the stator blades 64 of a gas turbine. This turbine drives a two stage centrifugal air compressor supplying air to the chamber 57. The combustion chamber 95, Fig. 8, burns powdered fuel which is supplied through conduit 94. Oxygen containing medium is supplied through conduit 93 and valves 92. The chamber has double walls 96, 97 between which cooling medium flows from an inlet 98 to an outlet 99 and is lined with fireproof material 100. The gases have a helical motion through the chamber so that the ash particles are thrown to the walls. The slag layer is withdrawn at 106. It is stated that by limiting the supply of oxygen containing medium, this combustion chamber can be used as a gas producer. The combustion chamber may be rotated to accentuate the effect of the rotating gases. In another modification, Fig. 10, four sets of combustion chambers and accelerating chambers 107, 108, 109 and 110 are arranged in a series. The compressor 111 supplies air to the combustion chamber of set 107, the accelerating chamber of which is supplied with exhaust gases from the turbine. The combustion chambers of the other sets are supplied with air from the various stages of the compressor. The accelerating chambers of the other sets are fed with the gases discharged from the previous set. A jacket 115 and tube 114 may be provided through which air or water flows. This air or water may be used in an engine or for heating purposes. A centrifugal separator 116 may be provided to clean the gases entering the turbine 119. The turbine exhaust gases may be used elsewhere. In a further modification, the combustion chamber discharges tangentially into a circular accelerating chamber which feeds a gas turbine driving an air compressor, a water pump and an electric generator. The air compressor feeds the combustion chamber, and the pump a jacket around the combustion chamber where steam is generated and fed to a steam turbine driving another electric generator. The jet propulsion engine shown in Fig. 3 may have the casing lined with sound deadening material and the propelling nozzle divided into sections by plates also lined with this material. A number of forms of inlet valves for the combustion and accelerating chambers are also described. An arrangement for starting the apparatus consisting of an auxiliary combustion chamber the air supply to which is excited into vibrating motion by a reed is also referred to.