Patent GB-808210-A (GB)
Title: Improvements in or relating to oscillating column combustion apparatus
IPC: F23C15/00
Filed: 1955-10-21
Abstract: 808,210. Generating combustion products under pressure. JUNKERS & CO. G.m.b.H. Oct. 21, 1955 [Oct. 22, 1954], No. 30082/55. Class 51 (1). In an oscillating column type of combustion apparatus comprising a combustion chamber and an exhaust pipe, a device for initiating operation is provided being directly associated with the exhaust pipe, not with the combustion chamber, the device being adapted to produce a suction wave in the combustion chamber so as to induce an initial charge of combustible gas and air into the combustion chamber. In Fig. 1 the exhaust pipe 1 of an oscillating column type of combustion apparatus is surrounded by a chamber 2 into which combustible gas is fed by the pipe 9 through the injector device 7, air being drawn in through the inlet 8. The mixture is ignited by the pilot flame 6 which is opposite an opening 4 in the chamber and the gases escape into the exhaust pipe 1 through the nozzle 3 which projects into the exhaust pipe 1 in the direction of the combustion gas flow from the main combustion chamber which is not shown. The flow of gases from the nozzle 3 causes a suction in the main combustion chamber whereby combustible gas and air are drawn thereinto and then ignited to set the apparatus in operation. In a second embodiment, the chamber 2 is disposed adjacent a right-angle bend in the exhaust pipe 1, the injector 7 being disposed within the exhaust pipe 1. The combustion gases from the chamber 2 discharge into the pipe 1 through a nozzle 3 as before, the nozzle 3 and the injector 7 being separated by a deflector plate 11. The combustible gas pipe-line 9 may be branched from the pipe-line to the main combustion chamber, the tapping being made at a point where, in operation, a low pressure prevails during normal operation, so that combustible gas will flow into the auxiliary chamber 2 only when the apparatus is being started. In an oscillating column type of combustion apparatus, particularly for heatexchangers such as gas - fired water heaters, comprising a combustion chamber and associated suction means for the induction of fuel and combustion air, the suction means communicate with at least one hollow resonator terminated so as to produce or simulate a reflection wave and adapted to contain a gaseous mass which will resonate at the operation frequency of the apparatus. The operation frequency is either the fundamental frequency of the gaseous mass or a harmonic thereof. The apparatus shown in Fig. 1 comprises a combustion chamber 8 and suction pipes 7 and 15 for fuel and air respectively, the fuel and air being supplied through inlets 1 and 9. Reflector pipes 5, 13 having closed ends 6, 14 extend from the pipes 7, 15 on the opposite sides of the inlets 1 and 9. The ends of the suction pipes 7 and 15 are tapered at 4 and 12 towards the inlets 1 and 9 ; similarly the reflector pipes 5 and 13 are tapered at 3 and 11 towards the inlets 1 and 9. Venturi nozzles 3, 4 and 11, 12 are thus provided, the throats 2 and 10 of the venturis being disposed at the fuel and air inlets 1 and 9. The fuel and air suction pipes 7, 15 taper at 16, 17 towards the combustion chamber 8. An exhaust pipe 18 extends from the combustion chamber and is provided with a reflector pipe 19 having a closed end 20, an exhaust outlet 22 extending from the junction of the exhaust pipe 18 and the reflector pipe 19. In a second embodiment the reflector pipes 13 and 19 are constituted by a single pipe. A second type of reflector or resonator is shown in Fig. 3, the short pipe 3<SP>1</SP> opening into a chamber 5<SP>1</SP> which is disposed about the throat portion 2 as shown.