GB478438A - Improvements in liquid fuel burning apparatus - Google Patents

Abstract

478,438. Rotary pumps. SALLOT, L. E. July 27, 1936, No. 20730. Convention date, Aug. 2, 1935. [Class 110 (ii)] [Also in Group XI] In a liquid fuel burning apparatus in which fuel and air are supplied to a spray burner 1, Fig. 1, by pumps 2, 3 mounted on a shaft which may be driven at various speeds, the fuel is supplied to the pump 2 by a pump 5 having a greater output than the pump 2 and mounted on the same shaft. The pump 5 draws fuel from the reservoir 4 through a filter 10 and a loaded valve 11 operated by a diaphragm 13 subjected to the suction produced by the pump 5. A constant pressure is maintained at the inlet to the pump 2 by the excess fuel being returned to the reservoir 4 through a loaded valve 9. When the pumps stop the diaphragm 13 rises and withdraws the fuel from the burner and its supply pipe through the pumps. Fig. 2 shows a suitable arrangement of pumps 2, 3, 5 mounted in a casing 15 and driven by a shaft 16 which is fitted with different sized driving pulleys 17 according to the speed at which the shaft is to be run. The pump 3 has an eccentric rotor 23 fitted with blades sliding in recesses communicating with cutaway portions 24. A channel 25 in the casing 15 connects the delivery chamber of the air pump with the cutaway portions 24 to prevent the air pressure from impeding the movement of the blades. Fuel leaking from the pumps 2, 5, which are of the gear-wheel type, lubricates the shaft bearings and escapes through a channel 20 in the shaft to a groove 28 in the casing 15 to which any air leaking along the shaft can also pass. The groove 28 communicates with a chamber 21 through which the, air passes to the inlet channel of the pump 3. The pulley 17 is provided with flanges 29 which act as baffles to prevent dust being drawn into the pump 3.