Safety circuit for oil fired boiler - has oil supply pipe circuit containing switch stopping oil flow if leak occurs

摘要

Fuel oil is fed from a tank by a pump to a burner in the boiler; and the oil not entering the burner is fed by a return pipe back to the tank. In the return pipe there is a branch pipe contg. a spring-loaded piston, which normally closes an electric switch when the oil pressure is present in the return pipe. If an oil leak occurs, the pressure in the return pipe drops, thus opening the switch. The switch is connected in series which a photoelectric cell, which cuts off the oil supply to the burner if the burner flame is extinguished. The piston rod pref. ends in a threaded hole contg. a screw, so the effective length of the rod can be varied. The boiler (2) has a hearth supplied by a burner (3). A motor (4) pumps oil in a tank (6) through a pipe (7), a pump (5), and a solenoid valve (8) to the burner nozzle. The surplus oil flows back to the tank (6). A pipe (13) is screwed onto a surplus oil flow pipe (9), and has a branch (14) contg. a piston (15).