GB1355647A - Liquid-fuel injection system - Google Patents

Abstract

1355647 Fuel injection system with ultrasonic atomizer PLESSEY CO Ltd 14 June 1971 [14 May 1970] 23355/70 Heading F4T A liquid fuel injection system for a burner or gas turbine engine comprises a swirl chamber 1 which receives liquid fuel through tangential ports 5 and terminates in a reduced diameter outlet orifice 4, and a stepped diameter ultrasonic vibrator element 7, 18 in the chamber whose stem 18 co-operates with the orifice 4 to form an annular outlet, such that the ultrasonic vibrator assists atomization of the fuel when the rate of fuel supply is insufficient for adequate swirl atomization and when the rate of fuel supply is sufficient for adequate swirl atomization the hollow core of the vortical fuel flow clears the tip of the transformer stem 18. In the embodiment shown a pressure sensitive switch 16 controls a switch over valve 21 to supply fuel to the ports 5 when the fuel supply pressure is sufficiently high for effective swirl atomization and to supply fuel to a bore 19 in the vibrator element and to simultaneously activate the vibrator when the fuel pressure is low. In an alternative embodiment the valve 21 and bore 19 are omitted and the fuel is continuously supplied through the ports 5, the vibrator element being activated when the fuel pressure falls below a certain level. The vibrator element is driven by a piezoelectric element 10 energized by an ultrasonic oscillator 12.