GB1248948A - Improvements in or relating to hot water systems - Google Patents

Abstract

1,248,948. Domestic hot water and central heating systems; surface condensers. MEGATHERM CORP. 24 Dec., 1968, No. 61436/68. Headings F4A, F4S and F4U. A domestic hot water and central heating system comprises a heat storage tank 10 having a heater 11 e.g. an immersion heater utilising off-peak electricity, to heat a heat storage liquid in which a first pilot coil 12 is immersed for heating the water in the hot water supply system to a prescribed level without raising its temperature above its flash point whilst drawing off occurs. The coil may be used separately or jointly with a second, primary coil 14 of larger dimension to ensure sufficient exposure of the water to be heated therein to a predetermined maximum but below its flash point. The coil 12 is only operative at or above a predetermined temperature e.g. 280‹ F. and a mixing valve 46 is thermostatically controlled to allow flow of water thereto when this temperature is not reached. An equalizing chamber 20 for condensing steam formed in the coil 12 from residual water remaining during an inoperative period comprises elongated concentric chambers 24, 26, the steam passing to the outer chamber and condensing by contact with the wall of the inner chamber which is sprayed with water from an apertured tube 70, the water having first passed through the condenser, the valve 46 and a line 52. The water for the closed central heating system is heated in a further coil 90 immersed in the heat storage liquid, the amount of heat transferred to the water and the introduction of water into the coil 90 being controlled. Heated water from the coil passes through piping 110 to a condensing chamber 92 comprising a closed heat reserve chamber 94, condensing tube 96 and an apertured spray tube 98 with an inlet opening at its upper end whereby the return water from the central heating system passes from the chamber 94 into the spray tube for outward flow into the condensing tube 96 in order to cool the water and condense the steam therein. The water passes from the chamber 92 to a flow chamber 100 to be directed either to the coil 90 or into a supply line 102 of the system through a 3-way valve 104 which is thermostatically controlled.