GB1328771A - Fuel nozzles - Google Patents

Abstract

1328771 Fuel spray nozzles PARKERHANNIFIN CORP 13 Jan 1972 [25 Feb 1971] 1709/72 Heading F4T A dual orifice fuel nozzle comprises a nozzle body 2 having primary and secondary fuel inlet passages 3, 4 communicating with respective primary and secondary spin chambers 12, 8 and discharge orifices 14, 9 for discharge of fuel as generally conical sprays and a pressure responsive flow modulating member 18 movable in the primary fuel passage to decrease the flow through the primary discharge orifice 14 in response to an increase in fuel pressure in the primary inlet passage 3 above a predetermined value, this also increasing the angle of fuel spray from the orifice 14. The member 18 is biased by a spring 26 to the position shown in Fig. 3 and in this position fuel is fed to a pair of diametrically opposed spin passages 15 (only one shown), which lead tangentially into the spin chamber 12, by way of passage 20,groove 19, radial passages 21, and passages 15<SP>1</SP>. Fuel is also fed to a pair of similar tangential spin passages 16 (only one shown) by way of passages 24, groove 23, radial passages 25 and passages 16<SP>1</SP>. As fuel pressure increases the member 18 moves so that the groove 19 cuts off the fuel supply through the radial passages 21 to the spin passages 15, the groove 23, however, allowing fuel to pass to the spin passages 16. The secondary fuel inlet passage communicates with the spin chamber 8 by way of helical spin passages 10 (Fig. 1). When the nozzle is mounted in an engine under starting conditions the member 18 is in the position shown and fuel passes to both spin passages 15 and 16. Under rated engine power, the fuel flow to the passages 15 is cut off and this reduced primary fuel flow rate avoids an over-rich concentration of fuel in the primary combustion zone and so minimizes the production of smoke and/or unburned hydrocarbons.