Patent GB-759841-A (GB)
Title: Explosion gas turbine plant and method for operating the same
IPC: F02C5/12
Filed: 1952-12-19
Abstract: 759,841. Gas turbine plant. SCHILLING ESTATE CO. Dec. 19, 1952 [Dec. 24, 1951], No. 32270/52. Class 110(3) A gas turbine which may be used as a generator of combustion products for use in a power turbine or for other purposes, comprising a plurality of explosion chambers feeding a multi-stage turbine has the exhaust gases of a stage fed to a constant volume collector chamber in which the counter pressure at the rear of the stage is lowered during the period of expansion of the gases in the stage. In the arrangement shown, Fig. 1, a number of explosion chambers of which two 3, 4 are shown supply combustion gases to a two stage turbine Ia, 9, IIa, 14. Each explosion chamber has a nozzle valve 7 through which combustion gases at the highest pressure generated in the chamber are led through the turbine nozzles I on to the blading Ia. Catch nozzles 11 receive the expanded gases and lead them to the collector chamber 12. The chamber 12 discharges through further nozzles 13 on to the blading IIa. A further nozzle valve 18 is provided on each explosion chamber to discharge a portion of combustion gas at a lower pressure into the second stage of the turbine. Outlet valves 21 are also provided through which the remainder of the combustion gas displaced by the incoming charging air is led into the exhaust hous- 'ing 22. Fig. 3 shows an arrangement where the nozzle valves 7 of four explosion chambers, indicated by subscript numerals, are connected to separate nozzles I. In this arrangement two catch nozzles 11(1, 2) and 11(3, 4) are provided which lead to a single collector chamber 12 which discharges through a single nozzle 13 on to the second stage. The chamber 12 is connected by a conduit 20 with spaces 19 (1, 2) and and 19 (3, 4) to which gases are led from the valves 18. The exhaust gases of the second stage are led through a single catch nozzle 27 to the exhaust housing 22. Modifications of this arrangement are described In one of these Fig. 4 (not shown). The gases from the valves 18 are led through separate conduits to individual nozzles which discharge directly on to the second stage turbine blading. This arangement may be combined with the arrangement shown in Fig. 3 so that part of the gases discharged from the valves 18 is led to individual nozzles and 'the remainder to the collector chamber 12. In another modification, Fig. 5 (not shown), the discharge from the nozzle valves 7 and 18 are grouped and led to common nozzles discharging on to the turbine blading. In this arrangement the nozzle 13 is sub-divided into two nozzles. For satisfactory results, the volume of the collector chamber- 12 as measured between the throats of the catch nozzle and the outlet nozzle should be less than 10 per cent and preferably in the range of 1 to 5 per cent of the total explosion chamber volume. For optimum efficiency, the ratio of the throat area of the nozzle II to that of the nozzle I in the arrangement shown in Fig. 3 must be within the limits of 2.5 to 3.5. In the arrangement shown in Fig, 4, this ratio should be within the limits of 1.5 to 2.5. To reduce the windage loss screens 45 may be provided up to the nozzle openings. Specifications 288,321, 288,322, 315,366 [all in Class 51(i)], 410,040, 759,840, 759,844, 759,845 and 759,846 are referred to.