GB935873A - Water heating system - Google Patents

Abstract

935,873. Central heating and hot water supply systems. P. G. TACCHI. July 31, 1962 [Aug. 15, 1961], No. 29360/61. Class 64 (1). A hot-water system comprises a positive acting steam and water-mixing device 32 in which the steam inlet is opened and controlled by the flow of water passing through the device, a hot-water storage tank 29 which receives hot water from the mixing device 32, an outlet 28 from the storage tank communicating with the inlet side of a pump 27 which delivers water to the water inlet of the mixing device 32, a cold water supply to the system, and a control device 30 for the pump 27 which is responsive to the temperature of water from the outlet 28 of the storage tank 29 and to the temperature of incoming water from the coldwater supply. As shown, the system supplies a radiator 14 and hot-water consuming devices 13, 15, 18 and 19 via a pipe 35, with a return pipe 26 to the pump inlet. A cold tank 10 supplies cold water to devices 15, 18 and 19 by a pipe 24, and to the pump inlet by a pipe 25 which may have a restriction valve 40. When only the radiator 14 is in use, water circulates by natural convection until the temperature sensed by the control device 30, in the form of a thermostat switch, falls below a predetermined level. The pump 27 is then switched on, and the resultant flow rate through the mixer 32 allows steam from a supply 33 to be injected to heat the water. This continues until the thermostat senses a second, higher, predetermined temperature and switches-off the pump 27. When hot water is drawn off from the system, the replacement cold water entering the system, and passing the thermostat 30, causes an immediate activation of the pump 27, and hence of the steam injection in the mixer 32. Any excess flow from the mixer passes to the tank 29 through a pipe 36 incorporating a pressure relief valve 37 which maintains a predetermined pressure in the hot water distribution pipes while the pump 27 is running.