GB1289542A - - Google Patents

Abstract

1289542 Tubular heat exchangers; central heating systems B HAWKLEY and A J PAVELEY 26 Sept 1969 [18 Feb 1969 25 Feb 1969] 8852/69 and 9880/60 Addition to 1237197 Headings F4A F4S and F4U In a heat exchanger 40 according to Parent Specifications comprising a housing 46 and a finned tube 42 which is coiled around a core 44 so that the fins contact the core, the wire is a hollow sleeve through which passes part of the tube 42. The exchanger may be mounted in an accumulator tank 55 containing an electric or gas heater 56 so that primary water pumped into the tank by pump 62 is heated and passes into the exchanger through a gap 72, along waterway 47 outside the core 44, returns along waterway 45 inside the core and is returned to the tank via socket 48b. The part of the tube 42 inside the core is connected to the mains by pipe 64 and the other end to a tap via constant volume device 68 and pipe 67. When secondary water is drawn off, the flow is sensed by a pressure sensitive device 63 which operates the pump 62. Alternatively, Fig. 2 (not shown) the heat exchanger 40 may be mounted in a tank (75) supplied with hot primary water from a separate boiler, in which case the primary and secondary water flows through the exchanger in directions opposite to those in the embodiment of Fig. 1. Or the exchanger may be mounted on an existing hot water accumulator (140), Fig. 9 (not shown). In a domestic heating system, Fig. 6, hot primary water from a boiler 123 passes via pipe 120c to a storage tank 121, whence it is returned via pipe 120a by means of pump 122. Water for domestic consumption can be drawn off from a heat exchanger (not shown) in the storage tank, and water for radiators 125 drawn off from the pipe 120c, passed round a subsidiary circuit and returned via a thermostatically controlled circulation inducer valve 101 which may be of the type described in copending Application No. 5427/70. When the temperature of the water returning along pipe 120a rises above a predetermined level the valve is opened by fluid-filled bellows (114), Fig. 5 (not shown), expanding to move valve plate (108) off its seating so that primary water is drawn through the subsidiary circuit. In a system for supplying water to a number of dwellings (130), Fig. 8 (not shown), cold water is supplied from a mains pipe (131) and hot water from the mains by way of the tubes 42 of heat exchangers 40 which are supplied with hot primary water via pipe (136) from a common boiler.