US842878A - Automatic stoker. - Google Patents

Description

No'. 342,878. PATBNTED PEB. 5, 1907.v

- J.s.s.PULToN.

APPLwA'TloN FILED mo. '1. 19o-1.

a slums-SHEET 1.

110.842,873. j f PATENTEDFB.5,1907.

' J. s.s. FULTON.

` AUTOMATIC STOKER. APPLIOATION FILED DEO. 7, 1904.

No. 842,878. y PATBNTEDTEB. 5. 1907.

' J.S.S.PULT0N.

-AUT0MAT1G-ST0KER- APPLIGATION FILED DE01?. 1904.

v l a SHEETS-SHEET a.

D0 Inj UNITED STATES PATENT OFFICE, l

JOHN s.l s. FULTON, oir-NEW YORK, N. Y., As'siGNoR To FULTON .FURNAoEf OOMPANIC OF NEW, YORK, N. Y., A CORPORATION OF NEW YORK.

Au'roMATlc sToKE'R.

are. 842,878.

Application filed December' 7 1904. Serial No. 235,820.

To l/,ZZ whom it may concern:

` ,Be it known that I, JOHN S. S. FULTON, a citizen of the .United States, and a resident of New -Yfork, in the county of New York and i5, State of New York, have invented certain -znewand useful Im rovements in AutomaticV Stokers, of which t 1e following is a specification.

The principal object of my invention. is to xo produce a stoking apparatus for steam-boilers and the likewhich will make possible the successful and' economical employment of peat as a fuel;

` Much trouble has been experienced hereto- 5-v f re in using peat as a fue-l, the diiliculties zo especially w z 5 peat while. burningalso settle or pack closely together to.' such an extent as to prevent air from passing in between and amo-ng them in suflicient quantities to produce combustion. In these respects peat is the exact'opposite of 3o fuelslike bituminous coal, the particles of which amalgamate while burning and do not flow freely or pack together in such a way as .to prevent the iiow of air between them.

Furthermore, peat-ashes tend to pack solidly into the air-spaces and other openings ofan 4o ous or do not pack sufficiently to exclude air.

ordinari grate, and thus to obstruct the flowof air t rough the grate and arrest combustion, and in this respect also peat is the opposite of coal, the ashes of which remain por- Other characteristics of lpeat are that it ignites slowly, relatively speaking, and normall y contains a high percentage of moisture and also a large proportion of hydrocarbon gases o r gas-producing compounds, which gases are driven out of the peat upon ignition of the latter and burn as a flame, requiring not only a large amount of oxygen, but also on account of the large percentage of moisturein the peat the maintenance of a high 'temperature in order to support it and eiect completf` combustion. the solid part or fixed carbon of the peat merely glows during combustion, burning Specicaton of Letters Patent.

This pow- On the other hand,

Patented Feb. 5, 1907.

"practically without flame, and requires that practically the entire surface of each particle vbe freely exposed to the action of the oxygen in the air. Furthermore, peat being a very light and feathery fuel and the suction or partial vacuum above the grate developed by the d'raft being equally effective over the entire top'surface of the Grate it is arequisite that the peat be fed wifl'i great precision and supplied in equal quantities and to an equal depth over all portionsl of the grate, since otherwise the draft through the grate will concentrate itself at the point of least resistance or where the peat has the least depth,` with the result that consider-able portions of the peat will be blown olf the grate and wasted,

-' According to my invention I overcome Athe it is divided into small separate ortions, which are kept constantly agitate in such manner as to provide'for the ready access of difiiculties above referred to by so handling the peat that at all times during'combustion air in sufficient quantities to support combustion, the peat being also gradually fed 'from one end of the grate to the other and provision being made for air-spaces through the grate, whichare always kept open and prevented from clogging Without permitting the burning peat to sift through them. To this end I provide a step-grate comprising a number of horizontalvplates or bars forming an inclined series, a portion of the bars being movable with respect to the remaining bars and being operated to effect the positive feeding of the peat from the Vupper to the lower end of the grate, as hereinafter described. ,In connection with this grate when used yfor burning peat I employ a combustion-chamber, which provides for the admission above the grate of sufiicient air to insure the complete combustion of the inflammable gases driven ofli' from the peat, which combustionchamber is preferably constructed and 'arranged in a manner similar to that shown and described in my prior United States Patent, No. 71 1,044, dated October 14, 1902, although in combination with my grate this chamber operates to secure new and useful results in.

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effecting the proper combustion of peat fuel,

Lgcertain special mechanisms and details, the nature of which will appear from the ensuing description. l

An a p aratus embodying the various'features o my invention in theiry preferred form is illustrated in the accompanying drawings, in which- Figure 1 shows the complete a paratus and also a portionof a return tubufar boiler arranged in the usual manner to be heated thereby, certain parts of the apparatusbeing represented in side elevation and the remainder in vertical longitudinal section.Y

be` of any usual construction and forms noY pant. of my resent invention, being shown merely to i lustrate the relative arrangement of my improvements when used in connection therewith. The end 3 of the boilercasing ismade double, thus providing an airspace 4, which has an open inlet 5 at its nper end and is provided with outlets 6 at its ower end. 7 represents the ash-pit, the front end of which is covered from side to side by a transverse arch 8 or other suitable division-wall extending rearwardly from a verticalwall 9, and above thisarch is another transverse arch or wall 10. A third arch or wall. 11 extendsfrom the rear end of the arch 10 toand beneath the adjacent end.

3 of the boiler-casing and-closes the bottom of the space 12, 'which separates. the latter from the tubes, the upper end of which space 12 leads into the smoke-stack in the usual manner. These arches spring from and are supported by side walls (not shown) of any suitable or ordinary construction, vand the arch 11 is preferably inclined somewhat, as shown, for reasons which will hereinafter appear. A passage for the burning and burnt gases is thus provided between the arches 8 and 10, and it will be understood that these gases passbeneath the boiler to its farther end and thence back through the tubes 13 into the space 12 in the usual manner. The arch 11 is provided with a number of air tubes or passages 14, extending longitudinally through it and affording communication between the outlets 6 and the space above the arch 8, the construction and arrangement of these arches and tubesbeing similar to that shown and described in my prior patent above referred to.

The grate proper is located beneath the or outer end to its front or inner end. This' grate comprises a number of flat horizontal plates or bars 15 and 16, which the bars 15 are rigidly secured to a st a ionary supportingframework and arranged like a flight of steps, while the bars 16 are secured to a movable framework and are also arranged like a iiight of steps, being interleaved between the stationary bars 15 and alternating therewith in the direction of the incline. The grate is preferably composed of two similar portions, arranged side by side, as shown in Fig. 2, for a reason which will hereinafter appear; but as the construction of these two portions is the same it-will be necessary to describe the details of but one of them. These details are c illustrated in Figs. 2, 3, and 4, in which the numerals 17 represent three stationary side bars connectedv by transversely extending top and bottom plates 18 and 19, thus forming a rigid framework which is supported --in any suitable manner at the sides of the ashpit. These side bars 17 are provided with alined slots, in which the ends of the horizontal grate-bars 15 are located and held immovable` Two movable sidel bars 2() are located between each pair of stationary side bars 17 and carry the grate-bars 16, which are rigidly secured thereto at their rear edges, said side bars 2() being cut away, as at 21, Fig. 4, to

provide spaces for the reception ofthe stationary 'grate-bars when the parts are in the position illustrated in said figure.

Means are provided for imparting to each of the two sets of giate-bars 16 a series of movements such that, starting from the position shown in Fig. 4, each bar 16 moves successively upward and rearward with re- -spect to the fixed bar 15 next above it and tated by suitable means, such as a ratchetwheel 26, secured thereto and operated by a pair of arms 27 and 28, independently journaled on one end ofthe shaft 23 and each provided with a spring-pawl 29, adapted to engage the ratchet-wheel when the arm which carries it is oscillated. The oscillating means for said arms are represented as an eccentric 30, secured to a driving-shaft 31 and having its connecting-rod 32 adjustablypiv- ITS oted tothe arm'27, said eccentric 30 being l'also provided with a crank-'pin 33 and a connecting-rod 34, adjustably pivoted to the arm 28. The shaft 31 journaled in iixedl uprights 35 and carries a driving-pulley 36, and the arrangement of the parts just described ispreferably such that when the arm 27 is operating't-he ratchet-wheel 36 the arm 28 is performing.- its backward or inoperative movement, and vice versa, the shaft 2,3 being thus given a practically continuous' rota- Above the rear or upper end ofthe grate is located a, hopper 37, the discharge-opening of which is ocated over the top plate 18.

This hopper is shown as supported by brackets' 38, rising from the side bars 17, and by plates 39, Fig. 1, connecting the ends ofthe.

hopper and the sides of the boiler, and between the lower edge of the mouth of the ,hopper and the grate is located a vertical 'j plate 40, extending transversely across the grate and having-arib ,41 projecting over the plate 18, the object being to prevent fuel froml falling over the rear edge of saidplate 18. The elivery of fuel from the hopper may be regulated by means of a verticallyadjustable plate 42, adapted to slide in front of the mouth of the hopper and operated by a handle 43. o

At the lower end of the grate is provided an -arrangement for `dumping ashes, preferablyconsisting of a plate 44, extending the entire width of the grate and normally closing the bottom of al space provided between the adjacent front wall of the ash-pit and a vertical plate' 45, carried by the .side bars 17, said plate 44 being pivoted at 'its front edge to saidwall and provided with an operating# handle 46,'pivoi ally ati ached to its rear edge,

which handle passes over and rests upon a pin 47 ixed to the stationary framework of` the grate near the pivotfed-end of the handle.

Vlhen said handle l is lifted and slid forward over the pin47 into the positionshown in dotted lines in Figrl, the ashes received on the plate 44 are dumped into the ash-pit, and

when said plate is drawn bachl into 'its ncrinal csition it is held thereby the weight of the andle 46 acting through the leverage duetot "aidpin47l-v 'te the operation. is as folffpeat having been placed in the hopper 37, it Hows lthrough the open llower end'of the latter in a stream the thickness of which is determined by the position ofthe regulator 42. accumulated on the top of the fixed plate 18 as will remain on the same it begins to fiow over the front edge of said plate onto the front portion of the movable grate-bar 16 next below and'thence down the upper portion of the grate until its flow is stopped by y the clogging of the mouth of the hopper due to the accumulation of peat beneath it.

No further iiow of peat will take place so long as the movable parts of the grate remain sta- .tionaryg .but as soon as thebars 16 are operated in the manner hereinbefoie referred to After as much peat has the peat is thereafter fed positively down the grate, and at the same time. afresh supply of peat is continuously delivered upon the upper end of the grate, so that Aultimately each grate-bar of oneseiies or the other will be carrying at any given instant asniall pile of peat extending along its exposed front' edge. The positive feeding ofthe peat down thein'- cline results from' the succession of the'upward, reaiward, downward, and forward movements of the grate-bars 16, whereby the peat resting on any one of said movable bars 16 is first carriedl up in front of the edge of .the stationary bar next above it, so that upon the rearward movement of the movable bar the peat is engaged by the front edge of saidstaiionaiy bar and pushed over the edge of said movable bar, falling upon the stationary bar next below. l. Thereupon said movable bar moves downward until it is located just above the last-mentioned stationary bar and also moves forward over said bar, whereupenhthe front edge of the-movable bar engages the pile of peat just delivered to the stationary bar andfpushes it over the front edge of the latter onto the movable bar next below, whereupon the cycle of movements is repeated. These movements are caused to take place at suoli a speed that the peat is cascaded in'a'pi'actically-continuous thin stream from one gratebar to another and is thus lcontinually agitated, so that vthe entire'surfaces of all they particles are exposed to the air flowing through the grate. The peat is ignitedat the upper portion of the gratefas hereinafter described, and is gradually consumed duringv its travel down the same. Thegreater part of the combustion occurs while the peat is falling from one grate-bar to another, and

'the rate of feed is so determined .that the- 'combustion is completed-by the tin-ie the peat ieachesthe lower end of thegrate, so

. that nothing but the ashes will fall over upon the plate 44. 'The feeding of the peat is readily governed by suitably adjusting .the

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coiinecticns between the arms 27,and 28 and the connecting-rods 32 ando34, respectively, by which adjustment-the speed of rotation of .the shaft 23 is varied in an obvious manner,

and if a very slow feedis desired one of said arms may be disconnected from its operating means or 'omitted entirely. i

It will be evident that inasmuch as the combustion of the peat progresses continuo'usly during its travel down the grate the quantities of fuel carried bythe respective grate-bars will tend to diminish as the lower end of the grate is approached, and for this reason I prefer to cause the feeding action of the grate-bars to diminish progressively.

f nounced than at the upper Vend of the grate.

By the construction and mode of operation above described provision is made for keeping the peat constantly in motion'while burning, thus shifting the position of the ignited particles and exposing them to contact with the air necessary for their combustion, and it will also be noted that inasmuch as the peat always falls from one horizontal grate- -ar upon another there will be no tendency for it to sift through the open spaces between the bars. My arrangement also provides air-spaces between the grate-bars, which are constantly kept open by the relative movements described, so that an ample supply of air is provided for and the ashes are kept from ,accumulating by being carried along as fast -as formed and deposited in the space above the plate 44 at the lower end of thel ate.

The combustion-chamber Y described performs important functions in the burning of peat in my apparatus in that the arch 8 deilects the radiant heat and hot gases rising 'upper end of the grate, thus driving the moisture out of the peat practically as soon as it leaves the hopper and ienitin it at a shortdistance therefrom. lT e arc llassists in thisl operation, as it reflects the heat downward upon the upper end of the grate, and I have found-that rpeat containing as high a percentage of moisture as lifty per cent. will readily burn in my apparatus without being-subjected to any preliininarydrying operation. In fact, it is desirable that the peat should contain as much as forty per cent. of moisture, since otherwise it will be so light as to give more or less trouble during tense heat of the lire itself.

combustion for reasons previously stated. The combustion-chamber also provides' an ample space for the complete burning of the inilammable gases driven off from' the ignited peat, and-air in sufficient quantities for supporting `the combustion of these gases is drawn in through the tubes 14 b the draft induced'by the fire, which air is st heated to some extent`- as it passes throu h the airspace 4 by the hot waste gases w ich come in contact with the inner wall of saidairspace on their way up into the stack and is t en heated to approximately the igniting temperature of the unconsumed peat-gases during its passage through the tubes 14, which are continuously exposed to the in- Thussaid gases are completely'burned without danger of reducing their temperature below the point of ignition.

While I have described my improvements as particularly adapted and intended for the burning of peat, it is to be understood that they are not limited to such use, since they are also effective for the burning of other substances, especially sawdust, and also fuelssuch as bituminous coal, for example-audit will be evident that the described detailsof construction of my apparatus may be widely varied without departing from my invention.

I claim as my invention- 1. In an automatic stoker, a step-grate comprising two inclined series of substantially horizontal grate-bars, the bars of one series being interleaved betweenthose of the other series, and means for producing' relative upward, backward, downward and forward movements between alternate bars and the bars next above and below them.

2. In an automatic Stoker, a step-grate comprising two inclined series of substantially horizontal grate-bars, the bars of one series being interleaved between those of the other series, and means for producing relative upward, backward, downward and forward movements between alternate bars and the bars next above and below them, said movements diminishing in extent froml the upper to thelower end of the grate. e

3. In an automatic Stoker, a step-grate cpmprising an inclined series of stationary grate-bars and an inclined 'series of movable grate-bars interleaved between the stationary bars, and means for imparting tov the movable series of bars sequential upward, backward, downward and forward movements.

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4. In an automatic stoker, a step-grate v path while the lower end moves in an arc of a circle less than the circuinfeencepf the latter, substantially as set forth.

5. In an automatic Stoker, a step-grate comprising an inclined series of stationary clined series of rate-bars, the bars of one se.

ries being inter eaved between and movable with respect to. those of the other series, and meansfor moving one series of movable bars upward and. backward and for simultaneously A moving the other series of` movable bars downward and forward, and vice versa.

`7. In amautomatm stoker, a stepgrate comprising an inclined series of stationary grate-bars,an`1ncl1ned movable framework tating said shaft.

pivotally supported on links at its lower end and carried by eccentrics at its upper end,l a shaft to which said eccentrics are secured, a series of grate-bars carried by said movable framework and interleaved between the stationary grate-bars, and means for rotating` said shaft.

8.111' an automatic stoker, a step-grate` composed of two similar portions located side by side and each comprising Aan inclined 4series of stationary grate bars, an mclined framework movably supported at its lower end and carried byeccentrics at its upper end, and a series of grate-bars carried by the movable framework and interleaved between the corresponding stationary grate-bars, a shaft to whlch said eccentrics are secured, the eccentrics for one movable framework being disposed on said shaft in diametrically opposite relation to the eccentrics which carry the other movable framework, and means forro- 9. In an automatic Stoker, a step-grate comprising two inclined series of substantially horizontal grate-bars supported for relative movement at their lower ends, the bars of one series being interleaved between those-of the other series, and means for producing relative upward, backward, downward and forward movements between the 'upper ends of said series of bars.

10. In an automatic Stoker, a step-grate comprising two inclined series of substantially horizontal grate-bars supported forrelative movement'at their ends, the bars of one serles bemg lnterleaved between those of the other series, and means for producing a relative circular movement between the upclmed series of substantially` fliori'zontal grate-bars, the bars of one seriesbeing'interleaved between those of the otherfseries, and n meanscommon to the two portions of' the grate for producing relative u ward, backward, downward and forwar -movements between the interleavedbara the relative movements of the bars inthe two portions of the grate being opposite in phase.v Y

12. 'In an automatic stoker,ft he combination of a step-grate comprising an inclined series ofstationary grate-bars, an inclined series of movable grate-bars interleaved loetween-the stationary grate-bars, ashaft, and operating connections between the same and said movable series of grate-bars', and means for rotating said shaft comprising a' ratchetwheel secured thereto, two arms independy ently journaled concentrically with said shaft and provided respectively with pawls adapt'- ed to engage and rotate said ratchet-wheel,

and means for oscillating said arms-simultasaid movable series of grate-bars, and means for rotating said shaft comprising 'a ratchetwheel secured thereto, two arms independently journaled concentrically with' said shaft and provided respectively with pawls adapted to engage and rotate said ratchetwheel, and means for oscillating said arms simultaneously in opposite directions, said means comprising adriving-shaft and means for rotating the same, an eccentric carried thereby and having its connecting-rod adjustably secured to one of said arms', anda crank-pin carried by said eccentric and provided with a connecting-rod which is adjustably secured to the other of said arms,

14. In an automatic Stoker, the combination of a step-grate comprising a stationary framework having` a horizontal top plate and an inclined series of grate-bars extending IOO downward therefrom, a movable framework carrying an inclined series of grate-bars which are interleaved between the stationary grate-bars, means for imparting to the moiv able series of bars sequential upward, backward, downward and forward movements, a hopper having its discharge-opening located above the top plate of the stationary framework in position to deliver fuel upon said top plate and upon the movable bar next below it. and means for regulating the delivery of v fuel from said hopper.

15. In an automatic stoker, the combination of a step-grate comprising two inclined series'of grate-bars, the bars of one series being interleaved between those of the other series, means for operating said bars in such manner that each bar of one of the series moves successively upward, backward, downward and forward with respect to the bars above and below it, and transverse division walls'8 and 11 located above said grate and providing a .combustion-chamber, substantially as described.

.16. In an automatic. stoker, the combination of a step-grate comprising two inclined series ofgrate-bars, .the bars of one series being interleaved. between those of the other series, means for operating said bars in such manner that each bar of one of the series moves successively upward, backward, downward and forward with respect tothe bars above and below it, and transverse division` walls 8 and 11 located above said grate and roviding a combustion-chamber, the wall ll eing provided with air-passages opening into the space at the front end of said wall, substantially as described. 4

17. In an automatic stoker, the combination with a step-grate located between side walls and comprising two inclined series of substantially horizontal. grate-bars, the bars of one series being interleaved between those of the other series, and means for producing relative upward, backward, downward and forward movements between alternatebars and the bars next abovevand below them, of transverse division-.walls overhanging the upper and lower' portions of said grate and' providing a combustion-chamber above the grate and an outlet-passage between the ends thereof, substantiallyas described.

18. In an automatic stoker, the combination with a step-grate located between sidewalls and comprising two inclined series of substantially horizontal grate-bars, the bars of one series being interleaved between those of the other series, and means for producing relative upward, backward, downward and forward movements between alternate bars and the bars next above and below them, of transverse division-walls overhanging the upper andlower portions of said grate and providing a combustion-chamber above the forward movements between alternate bars andl the bars next above and below them, of transverse division-walls overhanging theupper and lower portions of said grate and providing a combustion chamber above the grate and an outlet-passage between the ends thereof, and means for deliveringheated air into said outlet-passage.

20. In an automatic stoker, the combination with a step-grate located between side walls and comprising two inclined series of substantially horizontal grate-bars, the bars of one series being interleaved between those of the other series, and means for producing relative` upward, backward, downward and forward movements between alternate bars and the bars next above and below them, of transverse division-walls overhanging the upperand lower portions of said grate and providing a combustion chamber above the grate and an outlet-passage between the ends thereof, the transverse wall over the upper portion of the grate being provided with air-passages opening into the space at its front end, and a hollow casing exposed to the heat of the waste products of combustion and forming an air-space communicating with said air-passages and with the external air.

In testimony'lwhereof I have hereunto subscribed my name this 20th day of'October, 1904.

JNO. S. S. FULTON.

Witnesses:

VVEsLEY W. BLAIR, E. D. CHADWICK.

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