GB829921A - Improvements in or relating to gas turbine plants and methods of operating them - Google Patents

Abstract

829,921. Gas-turbine plant; rotary pumps. SHELL RESEARCH Ltd. Dec. 20, 1957 [Feb. 27, 1957], No. 6606/57. Classes 110 (2) and 110 (3). [Also in Group XII] The invention relates to a method of operating an open-cycle gasturbine plant in which an abrasive granular vegetable material is introduced either alone or entrained in a gaseous medium at one or more points into the gaseous stream or streams passing through the plant the material being introduced at such a point or points that it is carried by the gaseous stream passing through the point to those places where deposits tend to accumulate. The material may be introduced intermittently or continuously and may be in the form of crushed walnut or other nut shells, a flour mill by-product known as ground screenings, bran or middlings, or sawdust. The method is effective in removing fuel ash deposits on turbine blades and in removing salt deposits on compressor blades where the plant is used on board ship. The apparatus for introduction of the material shown in Fig. 2 comprises two pressure vessels 10, 11 which are filled with the vegetable material, the vessels being supplied with air under pressure through line 13, the material entrained in air under pressure passing through lines 15 containing transparent sections 16 to the appropriate points in the turbine plant. Valve-controlled ducts 17 by-passing the vessels 10, 11 are provided. The apparatus shown in Fig. 2 is for periodic injection of the material, which may be introduced either into the downstream ends of the combustion chambers or into the ducts leading from the combustion chambers to the high pressure turbine. The material may also be introduced into the intake of the air compressor. In a second embodiment for continuous introduction of the material, the material is contained in reservoir 28 and is fed to the upper chamber of a metering box 21, the material being fed to the lower chamber by means of two slowly-rotating, rubber-covered rollers 22, 22a. Air under pressure is supplied through a water separator 32 to the lower chamber, the material entrained in the air passing through outlet 33 to a point in the turbine flow path, for example the inlet duct of the high-pressure turbine. The side 23 of the box 21 is of transparent material.