Patent GB-206497-A (GB)
Title: A method of and apparatus for regulating the working condition of centrifugal compressors
IPC: F04D27/02
Filed: 1923-10-26
Abstract: 206,497. Graemiger, B. Nov. 2, 1922, [Convention date.]. Regulating.-The regulation of a compressor depends jointly on the suction volume and the delivery pressure, the difference between the delivery pressure and the pressure produced! by the flow of fluid on a resistance member in the pipe, being maintained constant over part of the working range of the compressor. The pipe 1, Fig. 1, of a compressor contains a plate 2 set transversely to the flow of fluid and which acts by levers and rods on a disc valve 7, placed between chambers 8, 9. The chamber 9 communicates with the pressure pipe. 1, and the opening 10 in the chamber 8 communicates to the atmosphere or a place of low pressure. A disc 64 on the rod 6 of the valve 7 hangs in an oil chamber 62 and this constitutes an oil brake. A pipe 11 connects the chamber 9 to a chamber 12 below the diaphragm 13 and the chamber 8 is connected to the chamber 14 above the diaphragm. The spindle 16 is attached to the diaphragm and also to a link 19 on the lever 20 and is normallv held down by a weighted lever 22. The lever 20 is connected at one end to a regulating slide valve 26 and at the other end to the piston 29 of a servomotor with a cylinder 28. The servo-motor operates the valve 31 controlling the admission of fluid to the turbine driving the compressor. If the consumption of the fluid delivered by the compressor decreases the load is reduced and the diaphragm 13, and the slide 26 fall. Pressure fluid flows to the upper side of the servo-motor piston 29; the servo-motor then operates the valve 31 to reduce the supply to the turbine to diminish the speed of the compressor. The same apparatus may be used to operate a " blow-off " valve. In a modification the diaphragm 13 is replaced by a suspended bell in a chamber, the bell being responsive to the difference of pressures in the chambers 8, 9 and being arranged to operate a speed-governor gear for the driving turbine. In the modification shown in Fig. 3, the plate 101 in the suction pipe. controls r,he position of the valve 104 between a chamber 106 connected to the pressure pipe of the compressor, and a chamber 107 connected by a pipe 108 to a chamber 109 and the suction pipe. The stem of a slide valve 115 carries a bell 113 the end of which dips into liquid so that the casing containing it is divided into two chambers 112, 114 the former 112 of which is connected by a pipe 111 to the chamber 107 while the latter 114 is open to the atmosphere. The valve 115 controls the admission of fluid to an oil motor which operates a speed regulating device of the compressor. The leverage between the plate 101 and the valve 101 is rendered adjustable bv the arrangement shown in Fig. 6. Screw threaded hollow rods 121, 122 are mounted on the arms 116, 119 respectively and nuts 123, 124 connected by a link 125 engage the threads. By rotation of the threaded rods 121, 122 the position of the link may be altered thereby altering the ratio of transmission. The apparatus may be used to adjust the regulating resistance of an electric motor driving the compressor, or to operate a throttle valve in the suction pipe, or to adjust diffusing blades.