US2054805A - Furnace - Google Patents

Description

Sept. 22', 1936 j w D. BURTON 2,054,805 FURNACE v v Filed Dec. 15, 1950 asheets-sheet 1 Ma 11510 715m, 57 ea-59 Sept. 22, 1936. w. D. BURTON FURNACE Filed Dec. 13, 1930 3 Sheets-Sheet 2 3001215): Z Jwmn g W Patented Sept. 22, 1936 UNETED STATES FURNACE Warren Dean Burton, Goshen, Ind., assignon by niesne assignments, to The Steel. Products Engineering Company, Springfield, Qhio, a.corporation of Ohio 7 Application December 13, 19-30., SerialNo. 502,041 10.Claims. (01. 126-182 This invention relates to furnaces for biuning solid fuel and more particularly to; those of the,

efficiency by effecting proper agitation. of the fuel 'bed.

Another object is to provide a novel meansfor actuating the grate above referred to.

A further object is to combine a power-actuated o-verfeed stoker with a movable grate construc.-. tion and an ash removing mechanism so that the stoker motor may be utilized to actuate said grate and said mechanism.

v The invention also resides in the novel character of the driving connection between the.

stoker and the ash conveyor.

Further objects and advantages ofithe invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which Figure ,1 is a fragmentary sectional view of a furnace embodying the novel features. of the present invention and. equipped with a stoker which is shown substantially in elevation.

Fig. 2 is a front elevational view looking from the left in Fig. 1. V

Fig. 3 is a fragmentary plan view of the grate construction and the supporting means therefor.

Fig. 4 is a sectional view taken along the line 4-4 of Fig. 3.

Fig. 5 is a sectional view of the grate suppor and ash conveyor as viewed along the line 5-5 of Fig. 1.

Figs. 6 and 7 are fragmentary views of the grate illustratingmodifications of the means for effecting vertical agitation of the fuel bed.

Fig. 8 is an elevational view'partially in section showing a modified form of the ash' remover drive mechanism. 7

Fig. 9 is a sectional view of the driving conmotion between the stoker and ash conveyor.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describein detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressedin 'the appended claims. Y

The furnace shown. in the drawings has the usual fire-box defined by a. circular downwardly converging wall and adapted to be supplied with solid fuel such as. coal by a power driven automatic stoker ll of. well-known construction supported infront of the furnace upon a movable truck or tripod l2. The stoker includes a hopper l3..arranged to/discharge coal into a trough l 4 along which the coal is fed through the fire-door of the furnace. by a' conveyor such as a screw t and finally discharged onto a grate later to be described and generally designated by the. numeral l6. r i 1 The. coal conveyor is driven through speed re-' duction:gearinglnotshown) by an electric'motor. ll. which,'according to common practice, may also drivea blower [8 for forcing air for combustion through conduits I'Stextending throughthe fire-door. and also the draft door 20. Manual operation of the coal conveyor maybe effected by turning a crank 2| .on a shaft 22 included in the driving connection between the motor I! and the'screw I55.

Means arranged to be actuated automatically as: an incident to the operation of the stoker is provided for removing ashes from the furnace. In the present instance, this means comprises a screw 23 (Figs. 1 and 5) disposed in a horizontalttrough 24' which extends substantially the entire length of the furnace ash-pit and projects outwardly through the draft door 20. The inner end portion of the trough 24, which is supported by legs 25, has upwardly flaring side walls 26 which define an ash receptacle which receives the ashes falling through the grate I6 and denace by the screw 23' and moving them laterally to the desired point of disposal. The outer end of the shaft 2'l'is journaled in the casing 28 and of a rugged universal coupling 30 (Figs. 1 and 9),

a squaredshaft 3| telescoping with a squared tubularsleeve 32 which in turn is joined by a coupling 33 to a shaft 34 j'ournaled in a bearing 3'5 and thereby supported by the front leg ofthe tripod l2. By providing this telescoping connection, the stoker unit may be removed conveniently and wheeled away from the furnace without withdrawing or otherwise disturbing the ash conveying mechanism.

In order that the ash remover and stoker may be operated by hand independently of each other under certain conditions, a one-way connection is preferably employed between the'stoker motor and the shaft 34.

preferred form shown in Figs. 1 and 2, comprises a link 36 pivotally connected at one end to the free end of the crank 2|. The other end projects loosely through the free end of a bifurcated crank 31 loose on the shaft. 34 andcarrying a teeth of a ratchet wheel 39 fast on the shaft 34. The free end of the crank 31 is disposed between two adjustable stops it on the link 36 so as to form a lost motion connection the slack in which may be adjusted as desired to vary the extent of rotary motion which will be imparted to the conveyor screw 23 in each revolution of the crank 2|. Thus during operation of the stoker motor, reciprocation of the link 3fi'will advance the screw 23 intermittently in a direction to carry ashes out of the furnace.

The one-way drive formed by the pawl 38 and ratchet 39 permits the ash conveyor screw to be turned independently of the stoker operation as by means of a hand crank (not shown) applied to the outer end of shaft 34, the pawl riding over the ratchet teeth. When the coal conveyor becomes obstructed, it is necessary to 'rotate the same reversely by turning the crank 2|v by hand. This will not, however, effect reverse rotation of the ash conveyor in view of the pawl and ratchet connection.

Instead of driving. the ash conveyor screw intermittently, it may be turned continuously during operation of the stoker by means of the one-way connection shown in Fig. 8. In this modification, a sprocket wheel 4| fast On the shaft 22 drives an endless chain 42 to rotate a sprocket 43 loose on the shaft 34 and having teeth 44 rigid therewith which are adapted to engage lugs 45 on theshaft 34 and rotate the latter in a direction to convey ashes out of the furnaces when the stoker is operating to feed coalinto the'furnace. A compression spring =36 urges the sprocket 43 into engaging relation with respect to the lugs 45 but permits retraction of the sprocket when the inclined surfaces Al of the teeth are engaged by the lugs 45 as will be the case when the shaft 34 or the sprocket 4! is turned in a direction reverse to its normal direction of rotation. The.

remover. i If desired, the driving connection may be enclosed by a plate 48 through which the squared ends of the shafts 22' and 44 extend for application of cranks for hand-operation.

Now referring moreiparticularly to Figs. 1, 3, 4, and 5, the grate l6 upon which the bed of fuel is supported during combustion comprises generally a perforated circular plate or disk 50 forming a shallow or flattened cone which is mounted for continuous rotation relative to the fuel bed and about an upright axis. The grate perforations are in the form of elongated radially ex: tending slots 5| which, in the rotation of the-disk, move around the under surface of the fuel bed and allow the finer ash particles to fall through This connection, in the.

7 tially fall. In the rotation of the grate, the proje'ctions 52 apply sudden impacts to the lumps of ashes wedging the lumps against the furnace wall and effectively breaking them into smaller pieces which eventually fall through the peripheral grate openings. weighted pivotal pawl 38 normally engaging the In order to render the grate adaptable universally to fire-boxes of different sizes and therefore applicable to existing furnaces, the disk 50 is made to fit a small size furnace. For a larger fire-box, it is preferred to employ a substantially fiat adapter ring 53 of the proper radial width to fill the annular space between the fire-box wall and the notched periphery of the disk 50. The ring has its outer peripheral edge notched for the purpose above described and may be supported by the disk 50 through the medium of annularly spaced lugs 54 formed integral with the ring and overlying the edge of the disk so as to rest upon the upper surface thereof. The ring 53, being only slightly larger than the plate 5! is properly held concentric with the plate.

The grate is rotatably mounted upon a rugged frame structure disposed within the ash receptacle and in the present instance including a ring 55 having a diameter slightly less than that of the disk 55 and constituting a substantially circular horizontal track upon which rest a'plurality. of spaced lugs 56 depending from the under side of the disk. One side of the ring is flattened as indicated at 5! (Fig. 3) and has radially projecting arms 58 which rest in notches formed in the curved end wall 59 of the ash receptacle. The diametrically opposite side of the ring is formed with two integral legs 55 (Fig. 5) which rest upon ledges formed by the sides of the trough 24. Radial spokes 6i terminate at the center of the ring in an upstanding stud 52 over which fits a hub flange 63 depending from the under side of the disk 58 at the center thereof. The stud 62 thus defines an upright axis about which the grate is adapted to turn while the major portion of the weight of the fuel bed is sustained by the track 55 around which the lugs 56 slide during rotation of the grate.

The rotary motion of the screw shaft 21 of the ash conveyor is utilized in the present instance to impart relatively slower unidirectional movement to the grate for the purpose of shaking down the. ashesas above described. To this end, a pinion '64 fast on'the inner end of the shaft 2'] meshes with a gear 65 which rotates on a horizontal stud 56 projecting into the ash receptacle from the flattened portion of the end wallv defined by the stud 62. To'compensate for this inclination of the two axes, the lugs 56 are formed of dilferent lengths as will be apparent from Fig. 4 so that in all angular positions of the disk, their lower ends will rest upon the track 55. It will be seen, therefore, that as theplate rotatesthrough each complete revolution relative to the:

fuel bed, each portion of the fuel bed supported on the grate will be raised and lowered once through a distance corresponding to the angular relation of the axes 68 and 69. A slow and pro-* gressive agitation of the fuel is thereby effected with this arrangement Without bodily vertical movement of the grate relative to its support.

Inasmuch as the grate is actuated by means deriving power from the stoker motor, it will be apparent that the fuel bed will be agitated and the fire thereby enlivened only when the demands on the furnace as determined by the usual controlling thermostat warrant such an increase in the rate of combustion. Thus, after the thermostat has ceased to call for heat and a slow rate of combustion. is desirable for the sake of fuel 7 economy, the fuel bed remains undisturbed.

In the modified form shown in Figs. 6 and '7, vertical agitation of the fuel bed is effected by the cam action of the lug 61 on one side of the grate disk 50. For this purpose the gear 65 is mounted so that the lug 6'! not only engages and advances a depending lug 56 of the disk but also strikes the under side of the disk and momentarily raises the latter. In the same rotary motion of the disk, a lug 56 on the opposite side of the disk will ride over a stationary cam lobe 10 formed on the track 55. The result of this arrangement is to raise and lower the grate bodily each time it is advanced by rotation of the gear 65.

I claim as my invention:

1. A grate for supporting a bed of fuel in a furnace fire-box comprising a circular perforated plate adapted to be mounted in said fire-box for rotation about a vertical axis to present the grate openings to successive sections of the fuel bed, the upper surface of said plate being shaped to form a cone the axis of which is inclined relative to the rotational axis of the grate and the peripheral edge of which is located in a plane inclined to the horizontal.

2. In a furnace having a circular combustion chamber, in combination, an annular horizontal track having a flattened portion at one side, a stationary bracket adjacent said portion, outwardly extending arms on said track resting on said bracket, depending supporting legs on said track opposite said arms, a plurality of radially con-' verging spokes rigid with said track, a vertical bearing stud supported by said spokes axially of said track, a conical circular grate disk bearing centrally on said stud and having an axis inclined to said stud, an annular series of depending projections uniformly spaced about said stud and formed on the under side of said disk for engagement with said track, said projections varying in length to compensate for the inclination of said disk, a rotary gear member pivotally mounted on said bracket and having means adapted for engagement with said projections outside of said flattened portion of said track to rotate said grate disk, and means for rotating said gearmember. 3, Ina furnace; in combination, an annular horizontal track having a flattened portion at one side, a stationary'bracket adjacent said portion; a plurality of converging spokes rigid with said track, a verticalbearing supported by said spokes axially ofsaid track, a conical circular grate disk mounted centrally on said bearing and having an axis inclined to said bearing, an annular series of depending projections uniformly spaced about said bearing and formed on the under side of said disk for sliding engagement with said track, said projectionsvarying in length to compensate for the inclination of said disk, and drive means mounted on said bracket for engaging said projections outside of said flattened portion to rotate said disk. v

4, In a furnace, in combination, an annular horizontal track, avertical coaxial bearing supported by-said track, a circular grate disk mounted centrally on said bearing, said disk being inclined to its axis of rotation, an annular series of depending projections uniformly spaced about said bearing and formed on the under side of said disk for sliding engagement with said track, said projections varying in length to compensate for the inclination of said disk, and means for engagbearing for rotation in a horizontal plane, an-

nularly arranged depending means rigid with the under side of said member and concentrically about said bearing for engagement with said track, said depending means varying in height to compensate for the inclination of said member,

and means for turning said member on said bearing.

6. In a furnace, in combination, means defining a horizontal annular track, a vertical bearing supported in coaxial relation to said track,

an overfeed grate member resting centrally on said bearing for rotation in a horizontal plane upon said track, annularly arranged depending lugs rigid with the under side of said member and concentrically about said bearing for engage- '7. An overfeed grate member adaptable to fur- V nace fire-boxes of different diameters comprising a perforated substantially circular plate arranged for rotation on a substantially vertical axis, the peripheral edge of said plate being formed with a series of closely spaced outward projections substantially throughout its circumference, an adapter ring having an internal diameter slightly greater than the diameter of said plate and removably secured concentrically to said plate, said ring having a plurality of spaced inwardly extending lugs adapted to overlie and engage said plate and having means coacting with said projections to prevent rotation relative to said plate, the outer peripheral edge of said ring being formed with a-series of closely spaced outwardly extending projections.

8. In a furnace, in combination, means defining a horizontal annular track, a vertical bearing stud supported in coaxial relation to said track,

a grate member mounted for free vertical movement centrallyvon said stud and for rotation in a horizontal plan-e, annularly arranged spaced depending means on the underside of said member and concentrically about said stud for engagement with said track, vertical lift cam means on said track, and drive means coacting withsaid depending means to rotate said member andin the course of such rotation to move-said depend ing means periodically over said cam means so a to elevate and lower said member. 7

9. In a furnace, in combination, means defining a horizontal annular track, a vertical bearing stud supported in coaxial relation to said track, a grate member mounted for free vertical movement centrally on said stud and for rotation in a horizontal plane upon said track, annularly arranged spaced depending means on the underside of said member and concentrically about said stud for engagement with said track, and drive means comprising a lug carriedby a rotating member periodically coacting with said depending means and the underside of said grate memher to simultaneously impart vertical and rotary movement to the grate member.

10. In a furnace, in combination, means defining a horizontal annular track having a flattened portion on one side, a vertical bearing stud supported in coaxial relation to said track, a grate member mounted for free verticalmovement on said stud and for rotation in a horizontal plane on said track, annularly arranged spaced depending means on the underside of said member and concentrically about said stud for engagement with said track; vertical lift cam means on said track opposite the flattened portion thereof, and drive means adjacent the flattened portion of said track comprising a lug carried by a rotating member and periodicallyicoacting with said depending means and the underside of said grate member to elevate one side of the grate member and to rotate the same over said cam means and simultaneously elevate the other side of the grate 20 member.

WARREN DEAN BURTON.

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