GB816507A - Apparatus for extracting energy from an elastic fluid such as gas - Google Patents

Abstract

816,507. Lubricating. AIR PRODUCTS Inc. Nov. 18, 1955, No. 33010/55. Class 12 (3). Apparatus for extracting energy from an elastic fluid such as a gas comprises a turbine 1, or other elastic fluid expansion engine, operable to remove energy from the fluid upon expansion of the latter, and a pump 6 coupled thereto and having an inlet 10 and an outlet 8 for an hydraulic fluid, e.g. a lubricant, which is circulated in a closed system including a cooler &c. 9. In the construction shown, a gas turbine having a gas inlet 2 and a gas outlet 3 has its rotor 25 carried on a vertical shaft 27 which passes through a radial bearing 4 and rests upon a thrust bearing 5. The lower end of the shaft is connected to a pump rotor carrying impeller blades 53. The pump is adapted to discharge lubricant under pressure through the outlet 8 and the cooler 9 and back through the pump inlet 10. Part of the lubricant from the outlet 8 is supplied to a connection 11 leading to the bearing 4 and part is supplied to a connection 12 leading to the thrust bearing 5. Lubricant supplied to these bearings is drawn off through a connection 13 into a reservoir 14 which is provided at the top with a receptacle 16 provided with a small leak 17. The outlet 8 of the pump is connected to the receptacle through a valve 18 whereby, during the operation of the apparatus, the receptacle 16 may be supplied with lubricant in quantity greater than that which can leak through the opening 17. The gas turbine is enclosed by a cover-plate 19 and a seal is provided between the housing and the rotor 25, comprising a carbon ring 28 carried on a flexible metallic bellows 29. The shaft 27 below the rotor passes through a sleeve 31 which fits close to, but not in tight frictional engagement with, the shaft 27, and is carried on a plate 32 closing an opening in the turbine housing 1. Below the plate 32 is a block 34 of thermal insulating material surrounded by a sleeve 36. Thermal insulating material 40 surrounds the entire turbine housing. Leakage of gas down the outside of the shaft 27 is prevented by the lubricant passed to the bearings 4 and 5. In order that the inlet pressure required by the pump may be high enough, lubricant is supplied to the pump through a connection 58 with a tip 59 located within the entrance to a restriction 57 from the pipe 10. When the apparatus is in use lubricant entering the top of the reservoir 14 will gradually fill the receptacle 16, the level in the lower part of the reservoir falling to the line 62, so that the space 44 below the radial bearing 4 will be kept drained of lubricant which would otherwise be beaten into froth.