US1675548A - Burner for solid fuel - Google Patents

Description

July 3, 1928. 7 1,675,548

c. H. HALL ET AL BURNER FOR SOLID FUEL Filed July 1925 2 Sheets-Sheet l A TTORNEY C. H. HALL El AL July 3, 1928.

BURNER FOR SOLID FUEL 2 Sheets-Sheet Filed July 9, 1925 A TTORNEY Patented July 3, 1928.

UNITED STATES PATENT OFFICE.

CORTICE H. HALL, OF IE'A'IERSON, NEW JERSEY, AND WILLIAM LLOYD, OF HAZLETQIT, PENNSYLVANIA, ASSIGNORS TO DOMESTIC STOKER COMPANY, OF NEW YORK, 11'. Y.,

A CORPORATION OF DELAWARE.

BURNER non SOLID FUEL.

-App1icatioiffi1ed July 9, 1925. Serial No. 42,347.

This invention relates generally to the construction of burners for domestic furnaces and more particularly to burners of the under-feed, mechanically-stoked type for use with solid fuel.

In the operation of domestic or household furnaces of the under-feed burner type in which solid fuel is fed to the lower extremity of the burner through the action of a screw conveyor, considerable difliculty is found in practice in causing the upper extremity of the column of fuel rising through the burner to distribute itself in a uniformly even layer on the grate structure.

Difliculties in manufacture have also been encountered in casting a grate or burner plate of an annular and frusto-conical for-.

mation most suitable for use with underfeed burners of thetype referred to.

.A general object of this invention is to eliminate the objections and difficulties referred to, and to provide a burner structure in which the fuel will be automatically dis-- tributed in a uniform layer for correspondingly uniform combustion on the burner plate. Another object of the invention is to provide a burner plate or grate structure which can be inexpensively manufactured, and, in general, to provide a burner characterized by simplicity of structure, adaptability to function infurnaces of various sizes, and to operate effectively and efficiently with a minimum degree of attention.

The invention includes a fuel distributing member forming part of the. burner structure. The fuel distributing member is arranged to receive fuel from the delivery terminal of a screw conveyor and to direct the- 0 received fuel upwardly to resent a uniformly level combustion sur ace at the upper end of the burner. In order to provide the desired uniformity of surfacelevel, the

fuel distributing member is provided. with baflle or directing surfaces arranged to counteract a tendencyof the screwv conveyor to bank the material atone side of the burner and thereby interfere with a desired uniformityof combustion.

Another feature of the invention resides in a perforated burner plateor grate having an annular frusto-conical formation and formed in sections to facilitate the operation of casting. i

Still another feature of the invention resides in the provision of means for adapting the burner to furnace structures having firepot chambers of different heights and Widths.

Other features of the invention will be hereinafter referred to. I

In the drawings, in which a preferred embodiment of the invention has been selected for illustration,

Figure 1 is a view partly in plan and partly in horizontal section of a solid-fuel burner embodying the invention and taken on the line 11 of Figure 2.

Figure 2 is a View in vertical longitudinal section of the burner shown in Figure 1.

Figure 3 is a view in vertical section taken on the line 33 of Figure 2.

Figure 4 is a detail sectional view taken on the line 44 of Figure 2.

Referring to the drawings for a more detailed description of the invention, a burner of the under-feed solid-fuel type is shown in which a hollow framework or casing 10.

opens upwardly and isprovided, at one side and in a lower portion thereof with a fuel inlet port or opening 11 through which is passed a pipe or con uit 12- in which a fuel feeding device of the screw conveyor type 13 is mounted for operation.

The fuel or feed pipe 12 delivers into an elbow-shaped conduit member 14 which opens upwardly into an annular fuel conducting member 15.

The fuel conducting member 15 in turn delivers fuel upwardly into an annular burner plate or grate member 16 having expanding or flaring walls terminating in the orizontal plane of a horizontal flange mem,

ber 17 :formed on an annular burner plate supporting member 18.

The lower or tapering end of the burner plate, member 16 is received in a seat or recess 19 formed for the purpose in the up-' 7 conduit 25 through which a draft of air may be forced by a blower of any suitable form to assist in the combustion of fuel in the burner. It will be seen that air passing through the conduit 25 takes the form of an annular stream in surrounding or enclosing relation to the feed pipe 12 and that the air stream passes into the chamber 26 formed by the casing 10 from whence it passes through openings or ports 27 provided in the fuel conducting member 15 and corre sponding ports or orifices 28 in the burner plate 16, into the mass of fuel contained within these portions of the burner. The combustion of the fuel which takes place at and adjacent the upper surface of the bed of fuel resting in the hollow burner plate 16 and on the flange 17 of the burner plate support, is, as will be seen, facilitated or enhanced by the draft of air forced into and through the fuel bed from beneath. The conducting member 15 and the burner plate 16 combine to form the grate of the burner. The term grate is used in the appended claims to include both of these members.

Al feature of the invention herein described resides in the provision of means for insuring that the fuel rising through the conducting member 15 and the burner plate 16 will distribute itself in a uniform and level layer at the area in which combustion takes place. The means adopted for performing this important function takes the form of baflie or directing surfaces 29 and 30 formed on the inner surface of the fuel conducting member 15 in the lateral surface thereof against which fuel emerging from the elbow-shaped member 14 is forced by the lateralthrow of the terminal portion of the helical feed screw 13. The baflling or directing action of the specially formed portions 29 and 30 is such that the tendency of the fuel to rise to a higher level at that side of the burner plate construction is counteracted with the result that when the fuel mass arrives at the upper portion of the flaring burner plate it distributes itself in a uniformly level layer which results in a correspondingly uniform zone of combustion at the top of the burner structure. The fuel directing portions 29 and 30 of the fuel conducting member 15 constitute simple, upward extensions of the substan-- portions thus provided restrict the movement of fuel against the adjacent flaring wall surfaces 52. This action prevents the building up of an abnormal level of fuel at one side of the burner through the action of the screw conveyor, the substantially vertical deflecting areas being so located as to offset the lateral drift of the material due to the conveyor action.

Fig. 4 of the drawings shows the height of the upstanding lip at the point 30 (Fig. 2), the dotted line marked A in Fig. 4 being a reproduction of the section at A in Fig. 2 for purposes of comparison.

Another feature of the invention resides in the construction of the burner plate .16. In order to facilitate the production of burner plates of the formation and type shown the burner plate structure is cast in a plurality of sections, for example, six,

as is indicated in Figure 1 of the drawing. This feature contributes materially. to theproduction of the burner plate members at a low cost since the converging air passages 28 provided in the burner plate can be formed in a casting operation thereby eliminating the expense of drilling or other cutting operations performed subsequent to and in addition to the casting operation in which the plate is itself formed. The direction of the orifices 28 which is substantially perpendicular to the tangent to the arc of curvature of the plate 16 rendersit impossible to cast the burner plate structure in the form of a one-piece annular member as will be seen. The sectional structure accordingly enables the burner plate device to be produced by a relatively inexpensive casting operation.

In order to provide for the removal of accumulations of dust or fine ashes from the chamber 26 withinthe casing 10 as required. a series of clean out ports or openings 31 are provided in the floor member 32 of the casing 10. The openings 31 are normally covered by a closure plate 33 pivoted on a central downwardly projecting boss 34 formed on the floor plate 32., The closure plate 33 is provided with. openings 35 which through the operation of a link 36 and manually operable handle member 37 can be moved into or out of register with the cor responding ports 31 in the floor member 32; A stop member50 is provided to limit the movement of the closure plate 33 in one direction. When the openings are brought: into register it will be seen that the air draft passing into the chamber 26 through the conduit 25 will blow the accumulated (lust through the openings 31 from the chamber 26 and thereby accomplish the desired cleaning out operation.

In order to adjust the burner structure to different elevations required in different furnaces, the rearmost portion of the main frame member or casing 10 is provided with a flange or bracket member 38 having a stepped formation 39 along its vertical rearward edge. A hook-shaped support-engaging member 40 is also provided with a stepped formation 41 arranged to engage the stepped edge 39 of the flange 38 at different steps of the length of the flange 38. It will be seen that by this structure the flange 38 can be placed at different elevations along the vertical forward edge of the member 40 and locked or attached securely thereto by means of a screw 42 passing through the member 40 into -'.the flange 38.

The member 40 is provided at its upper end with a hook or bill 43 and at its lower extremity with a concave seat 44 so that the hook can be applied to a horizontal bar 45 of a supporting bracket or standard 46 either at the upper hook extremity 43 or the lower recessed portion 44 to thereby provide a considerable difference in the elevation of the burner structure as a whole.

To further adapt the burner structure to furnace chambers of different sizes, provision is made fon varying the lateral or diametrical area of the upper surface of the burner structure. This is accomplished by the provision of removable ring members 4-7 which are provided with lugs 48 adapted to fit into corresponding recesses 49 formed in the enclosed ring or flange 17 of the burner structure. It will be seen that one or more rings may thus be provided to in crease the area of the fire pot top to the desired size, it being necessary merely to provide an annular passage which may be of relatively small width, between the outer edge of the outermost ring and the inner wall of the furnabe structure through which ashes and clinkers remaining when combustion of the fuel hasbeen completed may fall from the outer edge of the flange 17 or outermost ring.

What We claim is 1. In a solid fuel burner of the underfeed type, an upwardly flaring annular grate, a feed conduit having a horizontal portion and an upwardly directed portion communicating'with the lower end of the grate, a screw in said conduit for forcing fuel through said conduit and over the ,in-

'terior of thegrate, the lower portion of said grate being provided on the interior thereof, at the side at which the conveyer tends to convey fuel most rapidly, with-an;

upstanding lip adapted to retard the passage of fuel over the grate on that side and thus produce a level combustion surface at the top of said grate.

2. In a solid fuel burner of the underfeed type, an upwardly flaring annular grate, a feed conduit having a horizontal portion and an upwardly directed portion communicating With the lower end of the grate, a screw in said conduit for forcing fuel through said conduit and over the interior of the grate, the interior of the lower portion of said grate at the side at which the conveyer tends to convey fuel most rapidly being provided with a fuel retarding surface whereby a level combustion surface at the top of the grate is attained.

Signed at New York, in the county and State of New York, this 1st day of July,

CORTICE H. HALL. WILLIAM LLOYD.

Images