GB1459097A - Gas-atomizing nozzle - Google Patents

Abstract

1459097 Injection nozzles S TAMAI 8 Nov 1973 51993/73 Heading FIB [Also in Divisions B2 and F4] Fuel is atomized in internal combustion engines by a nozzle comprising a longitudinally extending liquid passageway 1 terminating in a liquid orifice in an end-wall of said nozzle and converging gas passages delimited by grooves 4 in a tapered solid of rotation (formed by rotation of a line about the liquid passageway axis) and a cover 5 fitting over the grooves, which terminate in orifices spaced radially from and arranged symmetrically about the liquid orifice, the gas passages being each (a) less than one turn of a helix, the helices, if notionally extended, converging to a focal point 7 lying on the liquid passageway axis beyond the liquid orifice, the focal point 7 coinciding with the imaginary apex of the solid of rotation, and (b) of such a shape that, when projected on to a plane perpendicular to the liquid passageway axis, the projections of the edges of each groove correspond to the shapes of a selected pair of stream lines, Fig. 5 (not shown) directed towards a sink (b), (Fig.5), of a hydrodynamic dipole, said sink (b) coinciding with said axis at said focal point 7. Determining first the radii of the base and the upper face of the solid of rotation of the nozzle body 3, the shape of a groove is determined by selecting the radius of the inner stream line of the pair to be in tangential relationship with the circle defining the base. The groove shape is enclosed by a line joining the intersections of the two stream lines with the circles. The number and area of the grooves determines the power of the stream. Gas supplied under pressure, via an annular chamber 2, to the passages is focused at 7 and atomizes the liquid droplets which then follow orbits (8), Fig. 3 (not shown) in a state conical zone (9). The solid of rotation may be a truncated cone, as shown, or a hemisphere truncated by a plane perpendicular to the axis of the liquid passageway.