GB195217A - Improvements in compressor unloading mechanism - Google Patents

Abstract

195,217. Marks, E. C. R., (Worthington Pump & Machinery Corporation). Feb. 1, 1922. Controlling compression.-In compressor unloading mechanism in which a relief valve on a branch forms the discharge pipe between the cylinder and a discharge check valve is controlled by fluid pressure regulated by a pilot valve, the pilot valve is controlled by a speed governor to open the relief valve at low speeds at starting and stopping, and to hold it closed at higher speeds. The horizontal compressor cylinder A is furnished with the inlet and discharge valves a, b, and with a check valve c in the discharge passage C. Between the valves b, c a by-pass connection 10 leads through a valve port 12 to an outlet 11 to atmosphere; the port is closed by a valve d depressed by a spring-pressed plunger 13 working in a casing connected by a pipe 17 with a port 3 in the casing of a pilot valve e, the stem of which is connected to a centrifugal governor f. A second port 4 in the valve casing is connected by a pipe 18 with the discharge beyond the valve c. At starting, air flows through this valve c until the pressure is high enough to lift the valve d and allow air to escape. As the speed rises afterwards, the governor raises the pilot valve e, putting the port 3 which was open to atmosphere into communication with the port 4 and thereby allowing air to pass through the pipes 18, 17 to the back of the valve d and to close it.