US1933701A - Burner for pulverized fuel - Google Patents

Description

Nov. 7, 1933. G. E. K. BLYTHE BURNER FOR PULVERIZED FUEL Filed June 6. 1930 3 Sheets-Sheet l Georgi Edwarzi Kevnn Bh he.

NOV. 7, 1933. G. BLYTHE 1,933,701

BURNER FOR PULVERIZED FUEL Filed June 6, 1930 3 Sheets-Sheet 2 George E ard KQ M BI Th b/ezf /C 72/, (Q CK L Nov. 7, 1933. G. E. K. BLYTHE 1 ,933,701

BURNER FOR PULVERIZED FUEL Filed June 6, 1930 5 Sheets-Sheet 3 George Edward Kevlfi Bw'the,

Patented Nov. 7, 1933 BURNER FOR PULVERIZED FUEL George Edward Kevin Blythe, Addiscombe, England, assignor to Buell Combustion (Foreign) Limited, London, England, a British company Application June 6, 1930, Serial No. 459,440, and in Great Britain June 25, 1929 2 Claims.

This invention relates to improvements in burners for pulverized fuel and has for its object the provision of means whereby a very short flame of substantially rectangular transverse section can be obtained with great facility by a simpler, more robust and less expensive device than has been possible heretofore.

Another object of the invention is the provision of means whereby a complete mixture of the primary air and pulverized fuel and diffusion of the said fuel in the said air is obtained in a thin flat substantially rectangular stream of primary air and pulverized fuel said stream travelling at a velocity sufiiciently high for the primary .15 air to act as a carrying medium for the fuel.

This invention consists in the arrangement of a burner for air borne pulverized fuel comprising a casing having a substantially rectangular flame nozzle, a conduit of substantially rectangular cross section and substantially constant cross sectional area adapted to deliver a fan shaped stream of air borne pulverized fuel of substantially rectangular cross section, a disperser in the path of said stream and means in the casing for admitting secondary air, the delivery from the conduit and the secondary air being intermingled by the disperser immediately prior to discharge from the substantially rectangular flame nozzle.

In order that the invention may be the better understood I will now proceed to describe the same in relation to the accompanying drawings reference being had to the letters and figures marked thereon in which Figure l is a longitudinal section through a burner constructed in accordance with this invention.

Figure 2 is a longitudinal section of the burner illustrated in Figure 1 taken on the line 2--2 of Figure 1.

Figure 3 is an end elevation of the burner illustrated in Figures 1 and 2 taken on the line 33 of Figure 2.

Figure 4 is a face view of the disperser illustrated in Figure 2 looking in the direction of the 4.5 arrow :1: and

Figure 5 is a perspective view of the conduit for the air borne pulverized fuel.

In Figures 1 and 2 of the drawings, the primary air and fuel constituting theair borne fuel is supplied to a horizontal conduit 11 of substantially constant cross sectional area which changes from a transverse section of circular configuration into a substantially rectangular configuration and then changes to a substantially rectangular formation at right angles to the first named recthat the expressions height and breadth erely refer to measurements at right angles to one another, and are without reference to verticality or otherwise. 1

The end of the nozzle b is disposed within a casing c to which secondary air is admitted said casing c supporting a dispersing device (1 comprising vanes e webs and vanes g and terminating in the nozzle h which is the fuel emission orifice proper of the burner. The dispersing device d is located in front of the substantially rectangular nozzle b delivering primary air and fuel, said device 01 including two long vanes e -e, a series of short webs f J connecting said long vanes e e and disposed at right angles thereto and a series of short vanes 91 g on the external surfaces of each of said long vanes e e.

The long vanes e e are stream lined to reduce disturbance but the webs f f and short vanes y g are so formed as to produce considerable rarefaction behind them the short vanes g g being arranged to produce jets intermediate of the jets produced by the webs f ,f.

The casing c is supplied with air through the branches 0 0' and/or through the apertures c the flow being controlled by manipulating the dampers, valves or shutters 7'. This air functions as secondary air and may be supplied by induction or under pressure and may be heated or not as required.

When the disperser d is in the proper position the spaces between the short webs f f are substantially charged with mixture from the nozzle 1) and the spaces between theshort vanes g g are substantially charged with secondary air so that in operation streams of secondary air are delivered to the zones of rarefaction between the streams of primary air and. fuel and streams of primary air and fuel are delivered to the zones of rarefaction between the streams of secondary air, the operation being, facilitated and the result enhanced by the converging walls h h of the nozzle h which tend to force the various streams together thus producing turbulence at the point of combustion and very intimate intermingling of the fuel and 110 air owing to the intense scrubbing action incidental to the impact of the streams.

The long vanes e e are arranged transversely of the streams issuing from the discharge nozle 19 for the primary air and fuel (as illustrated in Figures 1 and 2) the flattened nozzle b in conjunction with the casing c directing the flow of secondary air to the spaces between the short vanes g g.

In some cases the position of the dispersing device d may be variable so as to vary the result obtained. in which case the short vanes g g and webs f f are arranged to defiect the various streams angularly.

In operation the air borne fuel (heated or not) is supplied to the conduit a which has sloping side walls or side walls which are curved; the stream of air borne fuel travelling through the conduit a must of necessity impinge upon these side walls and owing to the continually changing angle of said side walls considerable turbulence is introduced into the stream so that the stream delivered from the nozzle 1) contains well diffused fuel and primary air and is somewhat fan shaped in contour. V

This stream is divided by the webs f scrubbed and admixed with. secondary air in manner already explained so that the stream delivered from the nozzle 71. produces a very efficient flame of the required shape.

The burner can be adjusted to suit existing conditions by altering the position of the disperser, d by means of the rods d which are provided for that purpose.

I clain 1. A burner for air borne pulverized fuel comprising a casing having a substantially rectangular fan-shaped nozzle, a conduit of substantially rectangular cross-section and substantially constant cross sectional area within said casing, a fan-shaped nozzle on said conduit terminating within said casing rearwardly of the nozzle of said casing and delivering a fan-shaped stream of air borne pulverized fuel of substantially rectangular cross section, a disperser positioned within the casing intermediate of the said two nozzles comprising two long vanes, a plurality of webs connecting the internal surfaces of said long vanes and a plurality of short vanes upon the external surfaces of the long vanes, said short vanes being located in position intermediate of the webs and adapted to cause the streams of secondary air to be delivered through the spaces between the short vanes and to eliminate the rarefaction produced in the streams of air borne fuel passing through the spaces between the webs, and means in the casing adapted to admit the secondary air at the rear of the conduit nozzle.

. 2. A burner for air borne pulverized fuel comprising a casing having a substantially rectangular fan-shaped nozzle, a conduit of substantially rectangular cross section and substantially constant cross sectional area which changes from a transverse section of circular configuration into a substantially rectangular configuration and then changes to a substantially rectangularformation at right angles to the first named rectangular configuration within said casing, a fanshaped nozzle on said conduit terminating within said casing rearwardly of the nozzleof said casing and delivering a substantially rectangular fan-shaped stream of air borne fuel, a disperser positioned within the casing intermediate of the said two nozzles comprising two long vanes, a plurality of webs connecting the internal surfaces of said long vanes and a plurality of short vanes upon the external surfaces of the long vanes, said short vanes being located in position intermediate of the webs and adapted to cause the streams of secondary air delivered through the spaces between the short vanesto eliminate the rarefaction produced in the streams of air borne fuel passing through the spaces between the webs, means in the casing for admitting secondary air at the rear of the conduit nozzle and means by which the disperser can be displaced longitudinally along the axis of the nozzle of the substantially rectangular conduit.

GEORGE E. K. BLYTHE.

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