GB1206253A - Gas burner - Google Patents

Abstract

1,206,253. Burners. KONINKLIJKE NEDERLANDSCHE HOOGOVENS EN STAALFABRIEKEN N.V. 11 Feb., 1969 [13 Feb., 1968], No. 7406/69. Heading F4T. In a non-atmospheric gas burner, particularly for natural gas and for use over a wide range of heat output, a nozzle 7, screwed on to a gas supply conduit and from which gas is allowed to flow into an air duct mounted in the wall of a furnace, Fig. 1 (not shown), comprises a duct 8 having a main orifice 10 in its end face 9, an annular part 13 of L-cross-section welded to the duct 8 to define therewith an expansion chamber for gas issuing from a number of smaller orifices 11 in the duct wall a short distance from the face 9, and a collar 14 on the duct extending outwardly beyond the part 13 and defining therewith a slit 16 from which the small quantity of gas issues and, under the action of the air flow round the collar, gives a flame which prevents the main flame from lifting off. In a second embodiment, Fig. 3 (not shown), the orifices 11 discharge into the chamber 12 upstream of the collar, which is secured to the part 13 and forms an annular passage with the duct 8. A ring or the duct downstream of the collar defines with the collar the outlet slit 16. The cross-section area of each orifice 11 is preferably less than one fifth of the cross-section area of the chamber 12 taken in any plane containing the longitudinal central axis of duct 8. Suitable dimensions of the nozzle parts are described. A burner giving full output when the gas pressure is one atmosphere above atmospheric may operate at less than 1 cm of mercury excess pressure e.g. for drying the bricks of a furnace.