GB614608A - Improvements in steam generators - Google Patents

Abstract

614,608. Steam boilers without internal flues; feedwater supply systems. STEEN, C. A. July 18, 1946, No. 21554. [Class 123 (ii) ] In a low-pressure steam boiler 1 which is provided with electric, &c. heating elements 4 located below the normal water level in the boiler and in which the feed water supply pipe 7 thereto is in communication, by an ascending pipe 8, with an expansion vessel 9 having a vent 10 to atmosphere, the said vessel 9 serving to relieve excess pressure within the boiler and simultaneously reduce the heating effect of the elements by exposing the latter to a lesser extent, the feedwater supply is controlled by a pair of automatic valves 19, 20 disposed in series in the water main 12. The valve 20 is actuated by a float located in a chamber 11 which is in communication respectively with the supply pipe 7 and steam space of the boiler by pipes 13, 14, and the valve 19 by a rod 17 coupled to a float 15 in the vessel 9, or in an enlargement in the ascending pipe 8, the valve 20 opening when the level in the boiler falls below the normal and the valve 19 closing when a predetermined level in the vessel 9, or pipe 8, is reached.