GB438132A - Improvements in or relating to raising liquids by gas pressure - Google Patents

Abstract

438,132. Raising liquids by gas pressure. COOMBS, J. A., 12, Princes Park Avenue, Golders Green, London. May 11, 1934, Nos. 14224 and 37111. [Class 102 (ii)] In liquid-raising apparatus in which the liquid, e.g. sewage, is drawn into a chamber 10 and subsequently discharged therefrom by compressed air, the air 31 and/or liquid 17, 21 valves are controlled by a pressure sensitive device 33 operating in accordance with the air pressure and liquid level in the chamber. The device 33 comprises two chambers 42, 43, closed by diaphragms or pistons carried by a frame 46, and connected respectively to an air pocket 36 at the bottom of the chamber 10 and to the air suction and supply pipe 29. The pressure in the air pocket and chamber 42 varies with the rise and fall of liquid in chamber 10 ; rise of pressure in chamber 42 corresponding with fall of pressure in chamber 43 and vice versa. Such variations in pressure raise or lower the frame 46 thereby actuating a pilot valve 34 controlling movement of a valve 35, which may be of the kind described in Specification 6804/10, [Class 102 (ii)], and which regulates admission and exhaust of air to and from cylinders 57, 60 operating the air and liquid valves 31, 32, 17, 21. When two pumping chambers 10, 11 are used, the exhaust air from one being recompressed for emptying the other, the second chamber is also provided with a pressure sensitive device 33 and pilot valve 34 to assist in controlling the valve 35. If a single chamber 10 is employed, two pressure sensitive devices may be employed to operate pilot valves at top and bottom liquid level respectively. Air losses in the system may be compensated by a snifting valve 63 acting automatically on drop in pressure or actuated periodically by air pressure under control of the valve 35. The latter may also control the cyclic operation of a liquid byepass valve on the top of the chamber 10 to prevent liquid flowing into the air system. An air vessel 78 supplied with air at reduced pressure may be inserted in the liquid discharge pipe 23. The compressor motors 24 are started and stopped by a liquid level sensitive device in the suction sump to which the chambers 10, 11 are connected.