US1885067A - Fuel burner - Google Patents

Description

Oct. 25, 1932. w. A. WOODESON FUEL BURNER Filed Sept. 4, 1928 2 Sheets-Sheet l Oct. 25, 1932. w. A. WOODESON FUEL BURNER Filed Sept. 4, 1928 2 Sheets-Sheet 2 in liquid,

Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE WILLIAM ARMSTRONG WOODESQN, OF GATESHEAD-ON-TYNE, ENGLAND, ASSIGNOR TO CLARKE CHAPMAN 86 COMPANY, LIMITED, 013 GATESHEAD-ON-TYNE, ENGLAND,

AND TO SAID WILLIAM ARMSTRONG; WQODESON FUEL BURN-ER,

Application filed September 4, 1928, Serial No. 303,859, and in Great Britain January 19, 1928.

This invention relates more particularly to burners of the kind in which a casing constitutin g a mixing chamber surrounds the delivery end of a fuel supply pipe and airenters between such pipe and easing prior to encountering means employed to produce an intimate mixing of the fuel and air as well as retardation of velocity. The invention is particularly applicable to burners of this kind suitable for the firing of furnaces with pulverized fuel, although also intended to apply to burners for dealing with fuels in general gaseous or colloidal conditions.

7 In some burners additional air is supplied to the mixture of air and fuel whichhas already been established from the sources referred to, as for example, from a space between the mixing chamber which surrounds the fuel pipe end and an outer casing having an inwardly tapering mouth piece whereby the air emerging. from the passage, is caused to take an inward or converging line of travel in order to reduce the velocity of themixture.

The object of the invention is to eflect improvements and ensure that the combustion of the fuel may be better achieved as early as possible after leaving the burner, to which end the invention includes novel provisions for the admixture ofsecondary air with the air and fuel mixture pr marily formed in the mixing chamber. The invention also contemplates the provision of means for adding tertiary air to the mixture of fuel, primary air and secondary air issuing from'the burner the tertiary air being so directed into the stream of mixture as to reduce the velocity thereof. 7 V

But in order that the invention may be more readily understood and easily carried into effect it will be further described with the aid of the accompanying drawings which illustrate two constructional forms of burner embodying the improvements. Of these drawings :Fig. 1 is a longitudinal section of one construction, Figs. 2 and 3 being respectively front and rear elevations thereof, certainsv parts in Fig. 3 being in section. Fig.

4 is a view, partly in section, of a detail of deflector 1'0 and the fueldischarge or supply Fig. 1. Fig. 5 is a view similar to Fig. 1 showing a simplified construction.

In the invention the burner comprises a member 1 formed with a series of air inlet holes 2 or ducts at or near the extreme end where the mixture of fuel and air leaves the burner. inclined to the axis of the burner, their axes, for example, being on elements 3 of an imaginary cone having its apex beyond the discharge orifice of the burner. The said holes or ducts may be of elongated cross section and so arranged in the burner mouth as to impart a whirling motion to the issuing air, th s being the preferred form and that illustrated. The holes or ducts 2 may communicats with an air belt constituted by a space 4 between the major part 1 of the burner and an outer casing 5. The eifect of the holes or. ducts 2 according to the invention is to disrupt the form of the stream which without them naturally issues from the burner whereby it is spread immediately in front of the bu rner.

The mixing chamber is shown as equipped with a. deflector 10 comprising inclined vanes EEO 1arranged to give a whirling motion to the ue In addition to the disruptingholes 2 referredto, the deflector 10 of the burner is so constructed that air, for example, can be admitted thereto, as by making one or more of These holes or ducts 2 are suitably the vanes 10 hollow and providing the same 7 .with air discharge apertures 13, Figs. 2 and space.4 forward- 7 4, to discharge 'air from the ly of the burner. g

, The burner shown in Figs. lto 4 is a compact and easily regulated constructional form in which the space 4 constituting the secondary air chamber has a duct 14 leading to a hood 15 with lateral air branch 16 arranged to enclose a hit and miss or other suitable regulating device 17 controlling admission of air to the inner casing before the deflector is encountered, the said duct 14 being provided with means, such as a'slide'18, so that the proportionof air which passes through V the di'sruptingholes 2 and deflector 10 via the hit and miss regulator 17 can be varied.

.At a convenient .position,-:say between the pipe 19,, one or more upwardly directed holes 20 may be formed in the inner casing 1 at the bottom thereof so that air may blow in and somewhat lift the stream of primary coal and air and so prevent or minimize the tendency for part of the fuel to spill instead of being carried through the burner, which tendency frequently exists when the coal and air mixture is delivered through the supply pipe 19 at a low velocity.

In Fig. 5 there is shown a modification in which when the burner is to be fitted to, say, a boiler casing, the outer casing 5 may be formed with a suitable flange 6 adapted to be bolted to the boiler casing, 7 being lateral air inlet openings located to the rear of the flange 6, considering the discharge end to be the front. The burner proper may then be fixed to the outer casing 5 so that it can be separately disconnected therefrom with facility as by bolting together the flanges 8, 9. In this modification further the deflector 10 has a central chamber or hollow hub 11 between which and the space 4 connection is established through passages 10 in the vanes 10 holes 12 being formed between the vanes through which holes air from the chamber 11 is directed.

As will be obvious the pipe 19 may be adapted to be fed with powdered fuel either alone or in conjunction with liquid fuel, or with powdered fuel after starting with liquid fuel and if so desired the secondary air admitted through the disrupting holes 2, the deflector 10, or both, might be enriched with a combustible.

What I claim is 1. A burner of the kind herein referred to, comprising a mixing chamber, means for introducing fuel into such mixing chamber, means for admitting air to said chamber in the vicinity of said fuel inlet means and a vaned deflector disposed within said chamber directly in the path of the combining streams of fuel and air through the chamber so as to constrain said combining streams to pass wholly between the vanes, said deflector eing externally shaped to promote intermixture of said streams and including hollow vanes connecting a source of secondary air supply with secondary air discharge orifices opening directly into the mixing cham- 2. A burner of the kind herein referred to, comprising a mixing chamber, means for introducing fuel into such mixing chamber, means for admitting air to said chamber in the vicinity of said fuel inlet means, a vaned deflector disposed within said chamber directly in the path of the combining streams of fuel and air through the chamber so as to constrain said combining streams to pass wholly between the vanes, said deflector being externally shaped to promote intermixture of said streams and including hollow vanes connecting a source of secondary air 'mary mixture of air and fuel emerging besupply with secondary air discharge orifices opening directly into the mixing chamber and means for adding tertiary air to the mixture emergent from the vaned deflector through the mouth of the burner.

3. A burner of the kind herein referred to, comprising a mixing chamber, means for introducing fuel into such mixing chamber, means for admitting air to said. chamber in the vicinity of said fuel inlet means, a vaned deflector disposed within said chamber directly in the path of the combining streams of fuel and air through the chamber so as to constrain said combining streams to pass wholly between the vanes, said deflector being externally shaped'to promote intermixture of said streams and including hollow vanes connecting a source of secondary a1r supply with secondary a1r discharge orifices opening directly into the mixing cham- 1 ber and, at the mouth of the burner, means for projecting air with a whirling motion into the stream of mixture emergent from the burner.

4:. A burner according to claim 1 characterized by the hollow vanes of the deflector having frontal air discharge openings arranged to discharge the secondary air substantially in the direction taken by the pritween the vanes and passing to the mouth of the burner.

5. A burner according to claim 1 characterized by the hollow vanes of the deflector communicating with air outlet openings arranged in the rear part of the deflector so as to discharge the secondary air into the mixing chamber in a direction transverse to the direction of flow of the mixture through said chamber to the deflector vanes.

6. In a burner of the kind herein referred to, a mixing chamber, an air chamber to the rear of said mixing chamber, means for introducing fuel into the rear end of said mixing chamber so that it flows therealong,

means for admitting air to said mixing chamber in the vicinity of the fuel inlet thereto and an auxiliary connection from said air chamber to said mixing chamber, said auxiliary connection comprising means for jetting air upwardly intothe current through the mixing chamber so as'to lift the fuel particles in such current.

Signed at Newcastle-on-Tyne, this third day of August, 1928.

WILLIAM ARMSTRONG WOODESON.

England,

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