GB767800A - Means for cooling gas turbines - Google Patents

Abstract

767,800. Gas turbines. MAXWELL, D. C., and PARSONS & MARINE ENGINEERING TURBINE RESEARCH & DEVELOPMENT ASSOCIATION. May 19, 1953 [May 20, 1952], No. 12787/52. Class 110 (3). A gas turbine bladed rotor disc or drum adapted for the circulation therethrough of a liquid coolant is characterized in that the inner ends of the blades comprising a blade row or each blade row are sunk in an enclosed channel beneath the periphery of the disc or drum, so as to provide surfaces for the transference of heat from the blades to coolant circulated through the channel around the inner ends of the blades. In one arrangement, Fig. 1, a turbine disc 1 is channelled inwards to form an annular channel 1a. The disc is provided with blades such as 2 having an inverted T-root fixing 2a; a cap or collar 3 welded to the blades and the disc forms a closure for the channel 1a. Cooling liquid such as water flows through a radial passage 1b through a channel in the root to the channel 1a as shown by the arrows. The channel 1a may be divided into a number of arcuate portions, for instance four, each portion having separate coolant inlet and outlet passages. As shown in Fig. 3, the coolant may pass into the channel from inlets 2c in adjacent blade roots, and may be guided by baffles such as 5 so that it traverses each blade twice; the baffles 4 separate the two streams. The blades are preferably hollow and filled with a heat transfer medium such as water. In another arrangement, Fig. 4, four rows of blades are attached to the drum 6 by a serrated root form of fixing and each row of blades is provided with a cap or collar such as 11 sealing the annular channel 6a. Radial passages 6c are drilled in the drum to carry coolant between a longitudinal bore 6d of the drum and the channels 6a. As shown in Fig. 7, the cap or collar 17 sealing the annular channel may be provided with a groove or indentation 17a in the shape of a crescent between adjacent blades of a blade row to give tangential flexibility and to give additional strength to resist the pressure of the liquid coolant.