GB1517500A - Control valve assembly for a liquid fuel burner - Google Patents

Abstract

1517500 Liquid fuel burner controls ASSOCIATED BRITISH COMBUSTION Ltd 6 Jan 1974 56660/73 Heading F4T A control valve assembly for a liquid fuel burner, comprising a valve 1 between a liquid fuel inlet and an outlet to the burner, a valve 2 connected between a purging medium inlet and the outlet to the burner, a valve 3 connected from the valve 2 outlet via a non-return valve V to the outlet to the burner, a valve 4 connected between a vent and the valve 2 outlet, a valve 5 connected between the valve 3 inlet and a cooling medium inlet, and an actuator system arranged so that when valve 1 is closed valves 3 and 5 are open and valve 4 is closed and when valve 1 is open valves 3 and 5 are closed and valve 4 is open. The valve 1 is operated by a pneumatic actuator A spring- biased to close valve 1 and coupled by a parallelmotion linkage (105), (106), (107), Figs. 2, 3 (not shown), to valve 3, one link (106) carrying a projecting arm (114) which is reciprocated between first and second positions in which it engages opening mechanisms of valves 4, 5 respectively. In normal operation valves 1 and 4 are open, valves 3 and 5 are closed, and valve 2, operated by an independent pneumatic actuator B, is closed, fuel flowing to the burner via valve 1. To shut the burner down actuator A is de-energized and B. is energized whereby valves 1 and 4 are closed and valves 2, 3, 5 are open, purging medium thereby passing to the burner via valves 2, 3 V. Valve 2 is subsequently closed and cooling medium flows via valves 5, 3, V to the burner until operation is again started on energization of actuator A. The cooling and purging mediums may be steam or an inert gas, or the purging medium may be h.p. air and the cooling medium 1.p. air from a supply independent, and separated by a non- return valve, from the h.p. air supply or derived therefrom via a pressure reducer.