GB382676A - Improvements in and relating to turbines - Google Patents

Abstract

382,676. Turbines. METZLER, F., Balgach, Switzerland. July 16, 1931, No. 20440. Convention date, June 18. [Class 110 (iii).] A combined reversible gas turbine and steam turbine of an axial type is contained within one casing which has a cooling jacket through which incoming compressed air passes to the combustion chambers. The turbine 1 drives a compressor 2, which delivers air to a regulator actuated by a governor 4, and compressed cooling air passes through a pipe 6 into the interior of the turbine casing, by way of slots 111 in a hollow annulus around the shaft 25. The compressor 2 may be separate from the turbine shaft 25. The air enters through slide valves, or other valves, to combustion chambers 6a, Fig. 3, and after mixing with fuel oil supplied by a nozzle 7 at a pressure of 150 atmospheres per square inch, the mixture is ignited by a sparking plug 41 or other means and led through nozzles 11 to the middle portions of blades 19 in the wheel 10. Steam is generated in a boiler 20 and led to the tip and root portions of blades 19 in wheel 10, which are cooled ; and afterwards the steam passes through reheaters 42, 43, and through the nozzles 8 to the blades of the second wheel 9 and then to a condenser. Exhaust gases from the wheel 10 sweep around and heat the re-heaters 42, 43, and pass through an exhaust pipe 12, below the boiler 20, then through an exhaust pipe 21 to feedwater heaters 16, and can afterwards be utilized for any heating purpose. Fresh steam may be added to the L.P. steam before it enters the second wheel 9. Self-ignition of the combustible mixture in the chambers 6a may be produced by a heated cylinder 27 which is insulated from the walls of the combustion chamber. Ignition of charges in successive chambers may be effected by sparks from preceding chambers. For starting purposes a light oil such as petrol is fed to a fuel pump through a filter, but when normal running of the turbine is secured, a heavier fuel oil is used. Steam may pass through hollow blades 19 in the wheel 10 to cool them. The air from the turbine jacket may be led to a turbine wheel before passing to the combustion chambers. The turbine is started up on steam only. The inlet and outlet valves of each combustion chamber are controlled by toothed gearing driven off the main shaft 25. Fig. 5 shows a means to secure a turbine drive in either direction. For forward running, low-pressure steam is led to nozzles 8, and for reverse drive superheated steam passes through nozzles 18 on to the upper portions of blades 19, which have reverse curvature. When the turbine is running in the reverse direction, the supply of fuel and air is cut off. Change-over valves 14, 15 allow steam to be directed to nozzles 18 for reverse drive, and prevent the flow of steam. to the high-pressure stage.