US1459980A - Stoking grate - Google Patents

Description

W. B. M BURNEY June 26. 1923.

STOKING GRATE s sheets-sheet 1 Filed June 6. 1921 v fiL erzZz' {m June 26, 1923. 1,459,980

W. B. M BURNEY STOKING GRATE 1,459,980 W. B. MCBURNEY STOKING GRATE June 26, 1923.

Filed June 1921' 3 Sheets-Sheet 5 Patented June 26, F923.

WILLARD B. MGBUIRNEY,

OF ATLANTA, GEORGIA.

STOKING GBATE.

Application filed June 6,

T 0 all whom it may concern:

Be it known that I, WILLARD B. MGBUR- NEY, a citizen of the United States, residing at Atlanta, Georgia, have invented certain new and useful Improvements in Stoking Grates; and I do hereby declare the following to be a full, clear and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. 7

Thisinvention relates to stoking grates comprising one or more units, each unit consisting of a pair of parallel inclined grate bar supporting beams, said grate bars being of particular construction and provided with trunnions eccentrically positioned at the ends thereof for pivotally mounting said grate bars in proper position between their respective supporting beams, so that the grate bars swinging about said pivots will have their front portions raised and lowered to cause a feeding of the fuel along the grate during the etching operation.

The grate is preferably of the hand stoker type but it is of course to be understood that the same is also capable of mechanical operation. Heretofore one of the principal de fects in grates of this character resided in the fact that no means had been provided for properly supporting the stoking grate bars after the same had been returned to their normal position, the means for operating the said stoker bars being generally relied upon to maintain said bars in this position.

The principal object of the present invention is to provide the grate bar supporting beams with a series of projections or stops, arranged in proper position to be engaged by the ends of the grate bars when in their lower or normal position. making it impo sible for any grate or stoker bar to go beyond its original fixed position and thus keeping these bars in proper alignment, From a practical standpoint this has been found to be a very important feature resulting in the production of a stoking grate construction capable of use. without-deterioration or the necessity for repairs, for a much longer period of time than heretofore possible with previous types where no such stops were employed.

The present grate construction also contemplates a simple and novel means of anchoring the lower ends of the grate bar supporting beams and maintaining them in 1921. Serial No. 475,345.

proper position on the bridge wall of the furnace, said anchoring means preferably comprising-a perforated plate or the like to be hereinafter more fully referred to, the lower bottom ends of the grate supporting beams being provided with projections cooperating with the perforations in the anchoring plate.

Another important feature to be noted is the particular construction of dump plate associated with each grate section, which dump plate is provided with a portion extending rearwardly from its supporting trunnions, and projecting downwardly therefrom is a curved skirt or apron similar to that employed on the grate bars. to prevent any clinkers from getting backof the dump plate and interfering with its return to normal position. This rearward extension is adapted to cooperate with an inverted substantially L-shaped casting or spacing bar disposed between the lowor ends of the gate bar supportingbeams of that section, so that when the frontend. of the dump plate is dropped the back extension will be raised and break loose any clinkers collected at this point adjacent the bridge wall. This spacing bar is of such shape and so placed that one of the downwardly extending flanges thereof forms substantially an apron over-hanging the anchoring plate or bar, whereby said anchoring; plate will be protected and the greater portion of the heat will be directed down below the surface to protect the spacing bar, the particular construction of the spacing bar to be hereinafter more fully described.

Means are also provided for operating this dump plate, similar to the means for shaking; the grate bars, all of said operating means comprising substantially rods ex tending through the front wall of the furnace in a convenient position to be operated.

In the accompanying drawingsillustrating the invention,

Fig. l is a view in perspective of the grate sections properly positioned within the furnace walls.

Fig. 2 is a sectional view thereof, several of the shaking arms being omitted for the purpose of clearness in illustration.

.Fig. 3 is an enlarged detailed view of the grate bar, showing the shaking arm attached.

Fig. 4 is a sectional view thereof.

Fig. 5 is an enlarged detailed view of the dump plate.

' Fig. 6 is a sectional view thereof, and

Fig. 7 is a fragmentary detailed View illustrating the interlocking construction for the upper and lower ends of one of the main supporting beams with the spacing member and the additional cooperating anchoring plate for the lower ends only.

Referring to the drawings in detail, with particular reference to Fig. 1, the invention is illustrated in connection with a conven tional type of furnace structure 1, having 5 the usual bridge wall 2, ash pit 3, and a front Wall 4. The improved grate construction issupported within the furnace upon a transversely disposed upper shelf or dead plate 5 and a lower shelf 6, which latter shelf is formed by the brickwork of the rear part of the furnace.

Supported upon these shelves and in an inwardly declined position are the grate sections or units, each comprising a pair of parallel grate bar supporting beams 7 provided with upper end extensions 8 and lower end extensions 9, which are adapted to'rest in their supported position upon the upper andlower shelves 5 and 6 respectively. A small vertical space is left between the upper ends 8 and the dead plate 5to allow for the endwise expansion of the supporting beams 7 and prevent them from pushing out the boiler front. The top edges of these supporting beams 7 are provided with a series of recesses 9 for receiving the trunnions 10 of the rocking grate bars 11, and each trunnion is provided with an an nular shoulder 10 to prevent the ends of the grate bars from engaging the inside face of the supporting beams 7 The major part of the supporting beams 7 is inclined, which part supports the grate bars 11 but a portion of the lower end of each of said grate bar supporting beams is substantially horizontal, and between said horizontally disposed lower ends is pivotally mounted a dump plate 12, said dump plate being provided with trunnions 13 similar to the trunnions 10 of the grate bars 11.

The bottom edges of the lower ends 9 of the grate bar supporting beams 7 are provided with downwardly extending projections 14, adaptedto be seated in corresponding openings or perforations 15 in an anchoring plate or bar 16, said anchoring plate 16 being disposed between the lower ends 9 of the supporting beams 7 and the shelf 6 of the brickwork of the furnace, whereby a solid support will be provided for the lower ends of these beams 7 and at the same time the proper spacing and anchoring of said beams 7 will be assured.

Formed on each of the inner side faces of the upper ends 8 and lower ends v9 of web 19 of the inverted L-shaped casting 18 is considerably wider than the opposite flange, and when said casting is in position the flange 19, which forms substantially an apron, projects downwardly past the inner edge of the anchoring plate or bar 16 to the adjacent brickwork shelf. 6, covering all joints at this point and atthe same time protecting the anchoring plate and the main portion of the spacing member itself, by directing to a great extent the heat down below the surface thereof. The deep web of the spacing bar will also prevent warping of th spacing bar.

The dump plate 12 has a rearward extension 20, and projecting downwardly therefrom is a curved skirt or apron 20, quite similar to that employed on the grate bars. This skirt will prevent any clinkers from getting under the back edge of the dump plate and interfering with its return tonormal position. This rearward exten sion is arranged so that when the forward end of the dump plate is dropped the rear end will be raised and break loose and dislodge any clinkers that might be formed on the spacing member and adjacent portion of bridge wall.

As hereinbefore stated, the upper edges of the inclined portion of the supporting beams 7 are provided with a series of de pressions or recesses 9 for receiving the trunnions 10 of the grate bars 11. The trunnions 10 are eccentrically positioned on the ends of the grate bars, that is, the axis of the trunnions of each bar extends in close proximity with the rear longitudinal edge of the bar. lVith the "gratebars so mounted they can be rocked on their trunnions to raise and lower their front portions from and to their normal positions to effect a stoking of the fuel and to feed the same along the grate from the front to the rear thereof, the movement of the fuel being facilitated by the inward declination of the grate.

Each of the grate bars 11 comprises a substantially flat grate portion, having a depending curved skirt or apron 21 along-one longitudinal side thereof. as shown iirFig. 1. The ends of the apron 21 are joined to the ends of the grating by end plates 22 of substantially triangular shape, thereby forming practically a hollow grate bar construction. The end trunnions 10 are located approximately opposite the rear upper edge of each grate bar 11, and are therefore eccentric to the longitudinal axis of the bar,

so that, when the bar is rotated on its trunnions, it will swing in an arc of a circle, as will be understood by reference to the drawings. It is to be understood that said grate bar is cast in one piece in the form indicated.

It will be noted that these grate bars are arranged side by side and are adapted to be connected in series to the means for performing the stoking operation, causingthe rocking of said grate bars on their trunnions, as clearly shown in Fig. 1. As the front of the grate bars are elevated the curved aprons 21 will provide a means of maintaining the same relative distance between the respective grate bars during the rocking movements of said bars, thus preventing an undesirable loss of unburned or live coals through the grate during the stoking operation.

For connecting in seriesthe desired num" ber of grate bars, each grate baris provided With a downwardly projecting interchangeable shaking arm 23. This shaking arm 23 is so designed and constructed that the same may be secured to either endot any one of the grate bars. To further this object. each end of each grate bar is provided with a socket in which the end of the shaking arm can be seated. The socket is formed by the vertical longitudinal ribs of the grate bar. the ad acent end wall 22 and the apron 21, as shown in Flg. l. The end ot the arm is shaped to fit this socket and when seated therein the arm is prevented from upsetting by a bolt passing through the opening 24 in the end wall and a corresponding hole in the arm. By removing the bolt the arm can be readily unseated and detached from the grate bar; the formation of the arm and socket is such that the same arm can be fitted to the socket at either end of the grate bar. The particular advantage of this resides in the fact that in the preferred construction the grate bars of each section are divided in two series, one series operated, we will say. from. the lefthand end of the grate bars, and the other seriesoperated from the right-hand end, so that a more equal distri bution of the etching means may be provided.

The stoking means referred to consists ot a series of rods or the like 25 having their inner ends connected to a pair of parallel bars or strips 26 disposed each, side of the lower ends of the shaking and pivotally connected thereto as shown at 27,

so that uponthe operation of the stolring rod 25 all oi the grate bars so connected will be moved in unison, which operation will be clearly understood upon referring to Fig. 2 of the drawings. The outer ends of the stoking rod 25 extend through the front 4 of the furnace and are there secured to the operating means 28 pivotally mounted in a bracket 29 secured to the taco of the furnace.

their various elevated positions by the shaking arms 23, it is of course to be understood that said grate bars are swung about their eccentric trunnions 10. As said gratebars, however, are returned to their normal position, it has been found, upon a practical demonstration and use of grates of: this type, that the shaking arms 23 and connected opera tin mechanism are not suidicient to maintain the grate bars in correct alignment when lowered to their normal position, which oftentimes results in the straining or warping of the individual grate bars. allowing the edges or" the bars to stand up and be burnt out. To prevent this and to provide a solid and substantial support for these grate bars when in their normal position. and to insure correct alignment and equal distribution of weights and strains, each of the supporting beams 7 is provided with a series of inwardly extending projections or bosses 32, properly positioned to be engaged by the lower edge 01 the end pieces 22 of each grate bar 11, as clearly shown in Fig. 2. l Vhen these grate bars are dropped to their normal position, each end thereof will come to rest in proper position upon these supports or projections 32, not only forming stops for the grate bars when they reach their normal correct position, but also providing substantial supports tor these grate bars.

This is a decided improvement over previous grate constructions ot this type, the advantages of which have been practically demonstrated, resulting in the production of the present grate, capable of extensive and constant use with very slight deterioration. i

As hereinbefore stated, any number of grate sections, comprising a pair of support ing beams 7 and assocated grate bars and dump plate, may be used, according to the size of the furnace. as each grate section or unit is a complete grate in itself. The only alteration necessary would be to lengthen or shorten the anchoring plate 16 according to the number of grate sections or units to be connected thereby.

With the use of the above described stoker it is possible to carry a heavy bank of green coal just inside the doors-at the front end of the stoker, so that the gases and volatile matter willbe forced out of the coal, and these gases passover the hot fire on the rest of the Stoker they will ignite and greatly Ill) reduce the smoke. The operation of the stoker will also separatethe ash from the good coal and always maintain a clear fire. This, obviously will make cleaning fires unnecessary and by operating the stoker bars, all clinkers will be broken up and carried to the dump plates where they will be ultimately discharged into the ash pit.

Vi hat I claim is: V i

1. In astoking grate, the combination with grate bar supporting beams, of a series of pivoted grate bars mounted on said beams,

means for swinging said grate bars about their pivots, a perforated anchoringplate for securing and supporting the lower ends of said beams, said lower ends of the supporting beams having downwardly extending projections seated in the perforations in said anchoring plate, inwardly extending lugs also carried by the lower ends of said supporting beams, an inverted substantially L-shaped spacing member positioned between the lower ends of said supporting beams and supported on said lugs, and a dum plate interposed between said spacing member and the lowermost grate bar 2. In a stoking grate, the combination with inclined grate bar supporting beams, of a series of pivoted grate bars mounted on said beams, means for swinging said grate the other, and overlying'the inner edge of the anchoring plate, and a dump plate interposed between said spacing member and the extreme lowermost grate bar.

3. A stoking grate, comprising aseries of unitary sections, each section consisting of a pair of parallel, inclined supporting beams, a succession of transversely disposed grate bars each eccentrically pivoted on said beams, operative means for swinging the grate bars about their pivots to raise and lower the front portions of said bars for feeding the fuel along said grate, a removable shaking arm secured to one end of each grate bar and connected with said operative means, stops on the supporting beams to hold the grate bars when returned to their normal positions, a common anchoring bar interlocking with the lower ends of all the supporting beams of the series of unitary sections, and spacing bars between and in terlocking with the upper and lower ends respectively of the supporting beams of each unitary section. 7

4, In a stoking grate, a grate bar comprising a grate portion, ribs extending longitudinally of the bar, plates on the opposite ends of the ribs and grate portion, an apron extending from the lower edge of one of the ribs, anda shaking arm displaceably seated at one end between the ends of said apron and ribs and against the adjacent end plate.

5. In a stoking grate, a unitary section comprising opposite supporting beams having bearings in their upper edges and provided on their inner faces with short lugs forming stops adjacent to said bearings, a succession of grate bars mounted between said beams and having end trunnions approximately opposite the rear upper edge of each bar journaled in said bearings, vertical plates on the ends of said grate bars operative to engage said stops to limit the turning movement of the grate bars in one direction with their grate surfaces in the same plane, a shaking arm on an end of each grate bar inside of the vertical plate at said end and movable past the adjacent stop, and means connected with the several shaking arms to rock the grate bars.

6. In a stoking grate, a unitary section comprising opposite supporting beams having bearings intheir upper edges and provided on their inner faces with short lugs forming stops adjacent to said bearings, a succession of grate bars mounted between said beams and having end trunnions ap proximately opposite the rear upper edge of each bar journaled in said bearings, vertical plates on the ends of said grate bars operative to engage said stops to limitthe turning movement of the grate bars in one direction with their grate surfaces in the same plane, a shaking arm displaceably mounted in a socket in an end of each grate bar inside of the vertical plate at said end and movable past the adjacent stop, and means connected with the several shaking arms to rock the grate bars. I

t. In stoking grate, a unitary section comprising opposite supporting beams rearwardly declined and having bearings in their upper edges, a succession of grate bars mounted between said beams and having end trunnions j ournaled in said bearings, the axial line of the trunnions of each grate bar extending in close proximity to the rear edge ofthe grate thereof to provide an eccentric mounting for the grate bar, vertical plates on the opposite ends of each gratebar, aseries of short lugs forming stops on the inner faces of each supporting beam adjacent to the trunnion bearings to engage said vertical plates to limit the downward turning movement of the front parts of the grate bars to position the grates in the same declined plane, a shaking arm mounted on one end of each grate bar inside of the vertical plates and movable past the adjacent stop, and means connected with the several arms on one side of the unitary section to rock the grate bars to raise and lower the front parts of the grates to feed the fuel toward the lower end of the unitary section.

8. In a stoking grate, a unitary section comprising opposite supporting beams rearwardly declined and having bearings in their upper edges, spacing members between and interlocking with the upper and lower ends respectively of the opposite supporting beams, a succession of grate bars mounted between said beams and having end trunnions journaled in said bearings, an anchoring plate supporting the lower end of the grate section, said anchoring plate having openings therein and projections on the lower ends of the supporting beams seated in said openings.

9. In a stoking grate, a series of unitary grate sections in lateral extension, with each section comprising opposite rearwardly declined supporting beams having bearings in their upper edges, a succession of grate bars mounted between said beams and having end trunnions journaled in said bearings, spacing members between and interlocking with the upper and lower ends respectively of the opposite supporting beams, a succession of grate bars mounted between said beams and having end trunnions journaled in said bearings, means supporting the upper ends of adjacent grate sections, an anchoring plate common to and supporting the lower ends of the adjacent grate sections, said anchoring plate having openings therein, and projections on the lower ends of the supporting beams of adjacent grate sections seated in said openings.

In testimony whereof I atlix my signature.

WILLARD B. MQBURNEY.

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