GB933793A - Improvements in or relating to feedwater supply and heating process for steam boilers - Google Patents

Abstract

933,793. Feedwater supply and heating systems for steam boilers. R. B. REGAZZI. May 2, 1961 [May 2, 1960], No. 15918/61. Classes 64 (1) and 123 (2). In a feedwater supply and heating system for a steam boiler make up water heated by contact with the hot outer surfaces of the boiler shell, the exhaust gas duct from the boiler to the chimney and the lower part of the chimney itself, is mixed with hot condensate returning from power or heating plant supplied by the boiler and the mixture constituting the boiler feedwater is further heated to a temperature equally or exceeding the boiler water temperature by indirect heat exchange with the boiler exhaust gases. In the form shown, the boiler 1, the exhaust gas duct 2 and chimney 3 are provided with a jacket 5 into which make-up water is admitted through a float valve 4. The heated make-up water leaves the jacket through a valve 6 which is mechanically adjusted according to changes in water level in the boiler by a float 7, a pipe controlled by a non-return valve 9 allowing the water to recirculate through the jacket when the valve 6 is closed. The make-up water passes into a tank 8 in which it mixes with hot condensate admitted through a pipe 10. The mixed water flows by gravity through a pipe controlled by a non-return valve 11 into a lower tank 12. When the level in this tank reaches the highest point a float opens a valve 15 and closes a valve 16 respectively admitting steam from the boiler to the top of the tank 12 and closing a steam supply to the top of the tank 8. The steam pressure forces the mixed water from the tank 12 through a pipe controlled by a non-return valve 17 into and through a heating coil 19 disposed in the duct 2 and chimney 3 into a tank 21 disposed above the boiler. When this tank is filled a float actuates a valve 23 to admit steam from the boiler above the water level whereupon the water in the tank 21 passes by gravity into the boiler through a pipe controlled by a valve 25 and non-return valve 26. To provide for a continuous feed tanks 12A, 21A may be provided, valves being arranged so that as the tanks 12, 21 are being filled the tanks 12A, 21A are being emptied and vice versa.