GB442366A - Improvements in pneumatically operated fans and the like - Google Patents

Abstract

442,366. Compressed-air engines; centrifugal fans. JERRARD, E. P., 22, Pretoria Street, Hillbrow, Johannesburg, South Africa. June 29, 1934, No. 19212. [Classes 110 (i) and 122 (iii)] Apparatus for propelling fluids comprises a compressed-air or other fluid-pressure reciprocating engine or turbine, a pump element and a heat interchanger adapted to effect heat interchange between the motor working fluid and the fluid impelled. The propeller blades are made hollow and form conduits for the working fluid. In the construction shown, a compound engine with radial high and low-pressure cylinders 5, 6 has the exterior of the cylinders formed as blades for propelling ventilating air in mines, &c. Arranged within the circular casing A<1> is the interchanger C through which the compressed air and ventilating air pass. The cylinders revolve on the shaft which is rigidly secured to the frame or housing. Or the fan may be connected to the shaft and be driven by a rotary and /or radial cylinder engine. The fluid passes from the supply 1 to the port 8 and then to cylinder 5 where it expands. The fluid is exhausted through the exchanger parts 18B and 8B to the L.P. cylinder 6 without cut-off where it further expands and is finally exhausted into the impelled stream or other places. Fluid condensate is led away from the casing at D. The guide vanes C1 are attached to the housing A1 and comprise hollow strips of piping connecting the conduits 18B, 8B through which the H.P. exhaust passes. A double-acting motor may be used. The fan blades form the heads of the power cylinders, and the cylinder passages are shaped to pass therethrough. A casing is provided to ease the flow of impelled fluid over the motor. Two oppositely rotating engines may be used in combination. When using radial and /or rotary motors, the fluid is passed through the fan between the stages of the motor. The heat interchange results in isothermal expansion. The temperature is determined by adjusting the H.P. cut-off, and the temperature of the H.P. and L.P. exhaust is maintained above the freezing point of water. Specifications 5135/10, 16340/12, and 4293/13, [all in Class 7 (i)], are referred to.