GB415024A - Improvements in or relating to spray carburetters - Google Patents

Abstract

415,024. Spray carburetters. MATHIEU, E., 25bis, Rue du Chateau, Neuilly-sur-Seine, France. Dec. 13, 1932, No. 35324. Convention date, Dec. 15, 1931. [Class 7 (iii).] In a spray carburetter, one or more fuels are atomized in excess of the maximum requirement by pumping fuel into an atmosphere of air, gas or vapour in an atomizing chamber so as to produce therein a rotating stream of atomized fuel which splits up into zones of different fineness and combustible mixture is withdrawn from the zone of desired fineness while the excess of atomized fuel is collected from another zone. A cylindrical casing 4 closed at the top by a cover 1 is divided into two chambers 17, 27 by a bell 18. The lower chamber 27 contains a fuel supply which supports a float 42 adapted to operate through a lever 43 a pair of valves 48, 49 on a rod 45. The lower valve 49 controls the fuel supply to the carburetter, the fuel being drawn through a passage 52, opening from the space between the valves, by a rotary pump which forces it into an atomizer disposed tangentially with respect to the chamber 17. The atomizer comprises a body 36, Fig. 8, having a conical orifice 32 in which is disposed a movable member 31 formed at its outer end with oblique grooves 40. The grooves, which may co-operate with similar grooves in the body member 36, provide a permanent passage for fuel pumped into a chamber 62 surrounding the movable member and impart to the fuel a gyratory motion which, assisted by a small conical chamber 41 in front of the member 31 and having a sharp edge, projects the fuel into the chamber as a thin whirling film. At its other end, the member 31 is formed as a piston 37 and increased fuel pressure acting thereon displaces the member 31 inwardly to increase the fuel supply. In a modification the taper of the orifice 32 is reversed and the member 31 is seated therein by a spring. Air inlets 30, arranged tangentially in the chamber 17 provide, with the fuel, an emulsion or very rich combustible mixture which, whirling around in the chamber separates into zones containing in the innermost zone the mixture with the finest particles of fuel and in the outermost zones the heaviest fuel drops. The fuel supply is continuous and results in an excess of combustible mixture being present in the chamber. The heaviest particles strike the wall of the chamber and run down into the chamber 27 raising the float 42 until the fuel supply valve 49 is closed thereby and the pump supplied from the chamber 27 past the valve 48, there thus being a closed fuel cycle from the chamber past the pump and atomizer back to the chamber until the fuel level is lowered sufficiently for the float to close the valve 48 and open the valve 49. The lighter mixture is drawn from the centre of the chamber through an elbow passage 16 to an annular orifice 11 in a conduit 5 bored out of the cover 1. Air is drawn into the conduit through a threaded member 6 by which the size of the orifice 11 is adjusted, a throttle valve 8 controlling the supply of combustible mixture to the engine. For idle running, with the throttle 8 closed, rich mixture is drawn through a byepass consisting of passages 19, 20, 21, Fig. 4, and air may be drawn through a passage 24. An additional outlet 26 closed by the throttle 8 is uncovered by slight opening thereof. In a modification, the conduit 5 is vertical and chamber 17 heated. In another form, a housing 66, Fig. 13, in the cover 1 encloses a casing 65 which is rotatable and axially movable therein. Co-operating apertures 77, 78 in the housing and casing admit air to the casing and similar apertures 79 in the housing are masked by oblique slots 80 in the casing to control the supply of rich mixture. The casing is rotated by a lever 68 and displaced axially by engine suction and atmospheric pressure on a wall 72 acting against a spring 71. A remotely disposed needle valve 74 may reduce the atmospheric pressure on the wall. A number of these carburetting devices may be arranged in parallel or in series and use different fuels, a separate mixer for their products being provided if necessary.