Patent GB-679168-A (GB)
Title: Improvements in and relating to rotary regenerative heat exchangers
Inventor: WDEN ANDREW THOMPSON BO
IPC: F28D19/04
Filed: 1947-12-12
Abstract: 679,168. Rotary regenerators. BOWDEN, A. T., MINISTER OF SUPPLY, and PARSONS & CO-. Ltd., C. A. Jan. 12, 1949 [Dec. 12, 1947], No. 32768/47. Class 64(i) In a rotary regenerative heatexchanger, a method of reducing wear on a sealing shoe slidable against the rotor to seal the high pressure gas side from the low' pressure gas side comprises the application of a varying force to the shoe to keep it in sliding contact with the rotor, using a fluid pressure for this force and varying the said fluid pressure in accordance with the fluctuating gas pressure on the sealing shoe due to movement of the rotor. The preferred arrangement for carrying out the method comprises a thin metal tube in contact with the sealing shoe and filled with a substantially incompressible fluid (e.g. oil) supplied by means of a fluid pressure regulating device, the fluid pressure transmitting a force through the thin metal tube to the shoe. Fig. 2, shows a rotary regenrator in which the gases between which heat is exchanged, e.g. high pressure cold air and low pressure hot gas, flow radially through the drum e which is divided by radially extending webs i into compartments containing the heat transfer matrix material j, e.g. wire gauze. Leakage between the air and gas sides of the drum is prevented by sealing shoes b, g slidable on the inner and outer annular surfaces of the drum. Pressure pads k, l, are carried in the casing structure and are maintained in contact with the shoes b, g by fluid pressure in the thin metal tubes m, n which pressure is varied in accordance with variations in the pressure on each shoe as each compartment of the rotor passes through the seal from the high pressure side to the low pressure side or vice versa of the apparatus. In the control system shown in Fig. 7, oil is supplied by a pump u at a pressure which is maintained constant by a relief valve v. The oil flows through non-return valves w to the tubes m, n when the'pressure on the shoes b, g is at a minimum, thereby filling the tubes m, n and bringing the shoes into contact with the drum e. As soon as the gas pressure on the shoes increases the tubes m, n tend to be compressed and to displace oil back into the supply system causing the oil pressure to rise. When the oil pressure rises to above that set according to the relief valve v the non-return valves close and the oil pressure in the tubes m, n then increases according to the applied pressure on the shoe. Orifice valves t are provided for the purpose of draining a small quantity of oil out of the system to allow for changes in volume of the tubes due to changes in the dimensions of the casing and the drum under operating temperatures. When a non-return valve w is closed there is a bleed through the corresponding orifice valve t to the supply side of the non-return valve thus allowing the shoes to lift from the drum. The bleed is adjusted so that the amount of lift is small so that the sealing effect is not materially influenced. Specifications 641,377, [Group XXVI], and 655,313 are referred to in the Provisional Specification.