GB941107A - Combined distribution valve and pump - Google Patents

Abstract

941,107. Central heating systems. REGULATOR A.G. June 7, 1962 [June 14, 1961], No. 21985/62. Heading F4U. [Also in Division F1] A combined circulation pump and mixing valve for a central heating plant comprises a housing having an inlet and two outlets, and a pump impeller for feeding liquid coming from the inlet, simultaneously to the two outlets in a distribution between them which can be varied by axially displacing the impeller. In the centrifugal pump shown, the impeller 23 has an elongated eye 33 which extends through a sleeve-like part 35 which preferably acts as a bearing. Two volutes 15, 17 are provided, separated by a flat wall 41 transverse to the pump axis, the cross-sections of the volutes changing to a truly circular shape at their outlets, which may be displaced from each other by 90 degrees, as shown, or any other angle. In the position shown, the impeller 23 discharges simultaneously through both volutes, the distribution between the two volutes being varied by axially displacing the impeller. In the two extreme positions, the impeller 23 discharges through one only of the volutes. The axial position of the impeller and its shaft may be adjusted by varying the current through a solenoid 43 acting on a core connected to the shaft. Alternatively, the displacement may be effected by mechanical, pneumatic or hydraulic means or directly by a manual control. The impeller may be adjustable to any position between the two extremes or to a few positions only, and may be retained in the adjusted position by a locking device. The inlet 13 is connected to the return pipe from the radiators, the volute 15 is connected to the boiler and the volute 17 is shunted to the main hot water supply pipe whereby the temperature of the hot water in the latter is controllable by axial displacement of the impeller, whereby cold return water is mixed into the hot water to the extent required.