GB681186A - Improvements in or relating to compressor systems having electrically heated blades and to blading elements therefor - Google Patents

Abstract

681,186. Electrically heated compressor blade. ROLLS-ROYCE, Ltd. Oct. 20, 1950 [Oct. 20, 1949], No. 27021/49. Class 39(iii) [Also in Group XXVI]. An anti-icing blade for a compressor is hollow and is wholly filled with conductive rubber 7, e.g. graphited rubber or similar homogenous material, e.g. graphite of low electric conductivity with one or more wire electrodes 8 embedded therein for passage of current therethrough. The stator blades 3a, 3b and the rotor blades 4a, 4b are of sheet metal or are cast and are closed at the tip and open at the base. An electrode 8 is embedded in the conductive rubber in each rotor blade, and current is fed thereto through a conductor ring 10 mounted. on but insulated from the rotating disc 5a, which carries a second conductor ring 11, so that the wall of the blade forms the other electrode. In the stator blade, two electrodes 13 are embedded in the conductive rubber 7, which is insulated from the blade by cement. The electrodes 13 are connected to terminals 16 on an insulating plug 17 in the stator casing 1. Current may be supplied from an A.C. generator having an armature winding on the compressor rotor and a fixed field portion, the output from which may be directly wired to the rotor blading. The generator may have a rotating field portion and a stationary ..armature, the latter being wired directly to the stator blades. The embedded electrodes may be positioned or shaped to give a desired heat distribution to the blade, e.g. by placing it near the leading edge of the blade. The compressor may be of the axial flow or centrifugal kind.