GB645906A - Improvements in and relating to gas turbine plant - Google Patents

Abstract

645,906. Gas turbine plant. ENGLISH ELECTRIC CO., Ltd. April 29, 1948, No. 11738. Divided out of 642,215. [Class 110(iii)] [Also in Group II] In a combustion product gas turbine plant a substance likely to condense and deposit in a turbine stage is separated out before that stage in a centrifugal or other settling chamber in which the working- fluid is brought to, or below, the dew point of that substance. Preferably, the working fluid enters the chamber at a temperature 10‹C above the dew point and is cooled in the chamber to 10‹C below the dew point. Substances with different dew points may be separated out in two or more chambers arranged in series. The cooling may be effected by a spray of sea-water and admixture with cooler air. Fig. 2 shows a plant in which the turbine 6 works over a temperature range above the dew point of the deleterious substance and exhausts at a temperature only a little above that dew point. The working fluid passes to a separating chamber 5 where it is cooled to below the dew point by admixture with air bled from the compressor 1 by line 7 and by a spray of sea-water introduced at 19. The necessary quantity of cooling air increases with decreasing load and serves also to maintain the mass flow through the turbine 9. In a modification, some cooling in the chamber 5 is effected by air from the compressor delivery which is passed through a coil in the chamber in fluid parallel with the exhaust heat exchanger. The temperatures in the chamber 5 are controlled by a valve 7a, Fig. 2, and, in the modification, additionally by valves in the parallel lines to the cooling coil and the exhaust gas heat-exchanger. A cyclone type separating chamber 15, Fig. 3, has a tangential entry 13 for the hot gases, an entry 17 for the admixture of cooling air, a spray nozzle 19 for sea-water and an exit 18 for the purified gases. The chamber has a removable lining 16 and is closed by a pressure-resisting lid 11.