GB749241A - Improvements in circuits for central heating plants - Google Patents

Abstract

749,241. Heating buildings and hot water supply systems. CIALENTE, I. Aug. 16, 1950 [Aug. 16, 1949 ; May 16, 1950], No. 20342/50. Classes 64(1) and 64(2). In a central-heating plant, which may heat several buildings from one source, heat exchangers such as radiators or convectors 6 are mounted in series along a rising pipe 4 from a liquid boiler 1 to an open or closed expansion vessel 9 from which a downcomer pipe 12 returns to the boiler so that the hydrostatic head establishes in the rising pipe, at least at its lower portion, pressures greater than atmospheric so that some or all of the exchangers are operated with the liquid, e.g. water, at a temperature above its normal boiling point. A forced-feed device such as a pump 13 is included and the heat exchangers may be finned-tube or pipe-coil convectors in which the air flow, and thus the heat ouput, is controlled by a throttle, or they heat air which is passed over them by a speed-controlled fan. The heating may also be controlled by a byepass on each exchanger. Owing to the decrease in temperature progressively up the circuit with the decrease in pressure, the transmitting surface of the heat exchangers is reduced for those lower and nearer the boiler. Thermally or manually controlled throttling valves are included and to give more heat to the lower exchangers, e.g. on lower floors of a building to compensate for wind cooling, the water circulation is throttled. Where the rising pipe is inclined downwardly to avoid an obstacle an air blow-off pipe is provided to pass over the obstacle. Secondary heat exchangers 11, e.g. for heating water for washing &c., may be included in the downcomer pipe 12. Extra rising pipes 5 including heat exchangers 61 may be provided.