Oil burner nozzle

April 22, 1952

2,593,884

R. J. IFIELD

OIL BURNER NOZZLE

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1948

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Patented Apr. 22, 1952

2,593,884

UNITED STATES PATENT OFFICE

2,593,884

OIL BURNER NOZZLE

Richard Joseph Ifield, Dural, New South Wales, Australia, assignor to Joseph Lucas, Limited, Birmingham, England

Application July 30, 1948, Serial No. 41,495 In Great Britain August 1,1947

Claims. (Cl. 299—120)

This invention relates to oil burners, and more particularly to oil burners for use with gas turbine engines, oil furnaces and the like.

The invention is particularly applicable to oil burners of the kind in which the forward part of the burner comprises an atomiser or like device for converting the supply of fuel into a fine spray. In oil burners of this character it is desirable to be able to increase the quantity of fuel passing through the atomiser as the pressure of the fuel supply increases and for this purpose it is known to provide the atomisei- with two feed systems one of which is in open connection with the main fuel supply, while the other is normally separated from such supply by a valve so arranged as to be automatically opened on the fuel supply reaching a predetermined pressure so as to permit fuel to be supplied to both feed systems.

The present invention has for its main object to provide an improved form of valve mechanism for effecting this automatic control, and the invention accordingly consists in a valve controlling the admission of fuel to a second feed system from a chamber through which fuel is supplied to a first feed system, the valve being normally held closed by a tension spring and so arranged that upon the pressure within said chamber rising to a predetermined value said valve is automatically opened so as to permit fuel to be supplied direct from the main fuel inlet to the second feed system of the burner.

In the accompanying drawings:

Figure 1 is a longitudinal sectional elevation of an oil burner having an atomiser at its forward end, constructed in accordance with the invention;

Figures 2, 3 and 4 are end views of the plates constituting the swirl chamber of the atomiser.

In carrying the invention into effect according to one convenient mode as applied by way of example to an oil burner for use in a gas turbine engine, the burner body ί has secured to its forward end a sleeve 2 having an inwardly turned forward flange 3 and the sleeve is secured in position by a shroud member 4. The forward end of the body I, which is hollow, forms a support for a member 5 upon which rest three apertured plates 6, 7 and 8 which together with the conical recess in the orifice plate 9 constitutes the swirl chamber, these elements being held in position within the sleeve 2 by the forward flange 3 thereof. The member 5 is formed with two sets of inlet passages 10 and II, one set II of which is aligned with holes (3 in the usual swirl chamber plate 6 and the other set 10 is aligned with holes

12. A pair of plain holes 13 in the plate 6 are aligned with similar holes 14 in the intermediate plate 7 and these are aligned with further holes 15 in the outer swirl plate 8. The plates 6, 7 5 and 8 are held in their proper alignment positions by dowel pins in holes IS. The set of inlet passages 10 in the member 5 are connected by holes 17 in the end of the body part I with the interior of said body part. The set of inlet 10 passages 11 lead to a recess 18 formed in the member 5, said recess communicating with an opening 19 in the end of the body part I controlled by a one way valve member 20 . This valve member conveniently consists of a conical or la partly spherical member secured to the forward end of a stem 21 which projects into the hollow interior of the body part and is attached to the end of a helical spring 22 connected to a threaded stem 23 adjustably supported by means of a nut 20 24 upon a hollow support 25 seated upon a shoulder in the interior of the body part. Apertures 26 are formed in the side of the said hollow support and are covered by a perforated screen 27, so that fuel entering the main inlet part 28 can 25 flow into the hollow interior forward part of the body I by way of the said screen and apertures. The arrangement is such that fuel flows from the main inlet through the primary passages 10 into the atomiser constituted by the swirl plates and 30 is sprayed from the central orifice. When the pressure of the fuel in the hollow body part rises to a predetermined value, determined by the adjusted tension of the spring 22, the valve member 20 will be forced open and fuel will be sup35 plied to the atomiser through the secondary feed passages 11.

It will thus be seen that by means of this invention a two stage burner is provided in which the second stage is brought into use automatical40 ly upon the fuel pressure reaching a predetermined value and in which both stages are fed from a common fuel inlet or manifold.

It is to be understood however, that the invention is not to be regarded as being limited to the ⁴⁵ particular construction hereinbefore described which is given by way of example only, and that while the invention is particularly applicable to oil burners of the kind employing atomisers, it 50 may be equally well applied to other types of burner in which a two stage fuel supply is required, particularly where it is desirable to be able to deliver the supply from a common fuel inlet or manifold.