1,016,333. Liquid fuel burners. BRISTOWES MACHINERY Ltd., and E. S. DALE. Aug. 9, 1962 [Aug. 10, 1961], No. 28879/61. Heading F4T. A liquid fuel burner comprises a plug 9 provided with air swirl grooves 12 axially adjustable within an air nozzle 4, a fuel jet 14 disposed in the plug 9 and a fuel atomizing swirler 16 fixed in the fuel jet 14. Fuel is supplied to the jet 14 by a duct 2 the end of which screw threadedly engages a thermally insulated adjusting knob 8 rotatably mounted in a sleeve 7 integral with a quadrantal portion 3 of an air duct 1, leading to the air nozzle 4. The swirl grooves 12 are in a frusto-conical valve face 10 of the plug 9 which co-operates with a taper 6 on the nozzle 4. The fuel swirler 16 comprises helical blades attached to the periphery of a cylindrical rod.