US2136594A - Stoker - Google Patents

Description

Nov. 15, 1938. F". T. NlcH-LSON STOKER Filed April 3. 1937 2 Sheets-Sheet 1 Nov. l5, 1938. Fr. NlcHoLsoN 2,136,594

` sToKER Filed April s, 1937 2 sheets-snaai z Jfys` Patented Nov. 15, Y e

omeosm'rss PATENTomos ,h t gppiiosti: s, 134,895

"Ihe, present invention lrelates to stokers ;for the expanding` passage of the throator connecmechanically feeding coal into` furnaces, and tion. l l j` e more particularlyuto the means for;` supplying Other features` of the `invention Will `appeal e the coal to the Stoker. t o ,1, inthe appendedrawingsand the followingjde- Asi commonly constructed, these stokers are scription'wherein are shown and describeda pre-` 5 arranged with a plurality or series of coal feedferred `form ofthe present invention as applied ing units to `which the 4coal is supplied `from a to an underfeed mechanical ,Stoker of a well single common sourceysuch as atbinor hopper, known type# i i Y i c'onnectionsibeing` providedirom the bottom fof; .,Intheaeempyin drawings Fig. 1 1S 8i Vel'- the hopper to eachistoker unit. Commonly `these tical side sectional "view taken on line I-e-I of 10 i binscr hoppers` are provided with downwardly F1352 of onlythose portions o; such a` stoker i convergingside and bottom malls, and theconf `1,115,tlJlfttiOnlaster@ dm'edneSSay 101" @n1111- nections or throatst also have converging walls derstanding of the Present" irivfntQIl, FIEQQZ iS e which formscontraoting passage ionthe cosi; a front view 'of the `same.partly in elevation 11n such` constructions difhcuity isl oftenr ext and partly in Seotioa:` F1a:-` ie a topview, partly 15 perienced in n securingw anunlnterrupted movee iniseetiompenlne 31--3` 0f Fig.` ZLEE- 4 1S ali/'ere ment or now ofthe coal through such acon; l tioalaide Seotionaiview, onanenlarsed seale.of trsoting throat, `due tothetemitmcyof` the cosi the upper ,portion ofthe onneetion lor throat, to pack and arch over under the weight` of the showing` the i agitatorifor ,i the coal; Elgs. 5, 6

zo coeiandthe wedging action offithe'taperingside yand '7, are atop plan, a front, and a s1de'e1e 2o wallswwhllestoppageof thecoal supply occurs vatiori, respeotivelvtof the -new and improved evenowhen the coal is dry, itis much more likethroat member separate and"detachedefro1n the 1y where the coal is wetor damp;` and since it is Dtliernparti Fig. 8 is a side `elevatioiri of a modii a 'common practiceito construct these coal suped 10mi Qf the Saillie Dart; aIidFg? 91Sa UMIS- ply bins or hoppers in theopen with no roof verse sectionalview, on an enlarged scale, of one 25 or other sheitenthe cociis exposed toiirsin and of; the eross-iiemiqers of thexeoal agitator; snow. I i .f l ,e The stoker,"which isishown only inpart inthe l iti isv the object` ofthe present invention to drawings; comprises bfiyi Series 0f Stoker e provide: a construction in which such stopping units extending across the front of the furnace,

3o 'in the movement .of the -ooai from `the hopper each unithavias a cylinder with a ram therein 3o to the stoker will be avoided andra continuous, and a common aetuatine'shaftfoi reciprocating uninterrupted supplyvoi` coal to each Stoker unit thE Tam t0 feed the al 111mm@ furnaces! An willbe insuredp 1 i l i ,z elevated binor hopper extending across thefront To the above Vends thepresent invention con- 0f the fill'llaf With` Si Connection 0f ,thlat from 35 templates the provision of a connection `or throat the bottom 0f the hOPPeI t0 B ah ram Wunder 35 `betiiveen the hopper or `other source of supplyand Supplies the C031 'thereto' e e i e the Stoker units inwhich an expanding passage .Refrriing stt9, thQse 9011510115 0f the On' forthe coalis provided so thatl the compacting structmll trei drawntgl `Whim mi: ,01d of the coalby the wedging' action' of the walls -a'ndfve @ma ,n hg Bfr dse lclqmpr e a' "40 `ofthe throat will be prevented" and"all danger plural ty m" sie .e-S of @In cy m ers mounted 40 i A e i y e each opposite an opening I3 in the furnace wall i ofarchingflminated N {5,1 Eachgcylinderis formed with an opening @other milie oiflth? invention 1S ith? W0' i1 in Aits top won odjocentthe furnace, Vthe side vision of a connection 0r threat membefof the nousitheineextenties` upwardly on@ overging e PbQVe WDG which is adapted t9 be posmod as shown in Fig.` 2f. The coalis supplied tothe 45 or inserted `in the converging throats oi' installacylinder through he Opening |V1-and then fed tions` already Constructed and thereby eliminate by the reciprooatious for the `rain (notshownp, liability of interference in theifuturewith the through the passageylgintq the furnace; Aram regular supply of coal tothe stoken shaft I9 mounted across the `front ofthe-cylinl i Still another featureof; the present invention ders is `rotated slowly from `a `suitable source of 50 e is theprovision of Ya `stirring ,device or agitator power to impaiftthe Ieedingand return strokes i `adjacenttheupper or entrance end ci the coal fto the rants of the severalunitsmf suitable con- `passage in the connection or throat, with sit- Anections ffamiliar tofythose `sllllled l in the `art, *able actuating mechanism fto facilitate and` lnwhichit is not necessaryhere to describe. e

sure the passage of e. coal from thesupplyinto i: 'IA'heoal `for the yseveral units of"`the`stcker is `cui supplied from a hopper or bin 2| having the downwardly converging front and rear walls Il and Il and extending across the face of the furnace above the stoker units. In these prior constructions the connections or throats and the openingsintheramcylinderswereprovidedwith asubstantially verticalbackwall Il and down-y wardly inclined and converging front and side walls Il and Il, respectively. all four walls nttingintotheopeningil in the topofthe ram cylinder.asshowninliga 1and2. l

'llo provide access to the interior of the conn tionorthroattoloosenthecoalincaseitsdownward movement should be prevented by arching orforanyotherreason, an opening Il wasformed near the bottom of the front wail Il for a slide or closure 8l removably held in place rbythe lipsv or ears I1 on the wall. When the coal became packed or arched over and ceased to flow. the slide would be removed and a poker or suitable implement used to free and loosen the coal.

l Inorder to eliminate this contracting passage orthroat with its liability to cause packing and arching of the. coal, the connection member described above has been provided. in accordance with the present invention, with an expanding throat or passage so that all compacting and wedging of the coal at this point is prevented;

This is accomplished. in the embodiment illus# trated in the drawing. by theprovision of an additional or supplementary throat' member adapted to be positioned ln the old converging throat. and provided with an expanding passage for the coal. None of the old parts'already installed have to bedisturbed, the new'throat member being of such a. size and shape asl to fit within' the old throat andbe retained in positionvby its own weight and the weight of the coal above without requiring the use of bolts or lother fastening devices. 1

The preferred e form of throat member constructed in accordance with the present invention is shown detached in Figs. 5, 6 and '7, and installed in position in Figs.) to 4. It comprises a rectangular flat top 4l of a slze'tojflt within the entrance opening of the oldthroat, with marginal portions of the top resting uponthe curved connecting tops 4I ofthe old side walls of adjacent throats, (see Fig. 2) 'Ihe top of the new throat member is provided with an opening or recess Il of rectangular connguratlon extending inwardly from the rear edge ofthe top. 4Extending downwardly from the bottom face of the top at the edges of the opening. are the front wall I1 and the side walls 0, each of which diverges outwardly from the vertical center line of the opening. so that a three-sided expanding passage is formed having a greater cross-sectional area at its bottom than st ,the top. Triangular supports or webs Il mutually reinforce and strengthen the top and side walls.

The bottom margins ofthe side walls are bevelled slightly, as shown at vI3, to avoid contact with the lowerends ofthe 'side walls of the old throat and with the upper portions of the expanding side walls of the cylinder, which might interfere withthe proper seating of the top Il on the tops of the old throat walls; vThe front wall of the supplementary throat is vprovided at its bottom with the opening or recess Il, the inner lower corners. of thewall being bevelled, as at I'L'to avoid contact with the ram when the latter is reciprocated in ithej cylinder. Oneach sideoi' the recess Il are positioned lips or ears Il which are undercut on their inner faces adiacent the wall to receive a closure or gate Il to close the opening 55. This gate or closure comes opposite the old closure 35 on the original throat construction so thatif for any reason it is desired to gain access to the interior of the ram cylinder or to the ram therein, this can be done by removing first the outer closure in the old throat and then the inner closure on the supplementary throat.

Preferably the new and improved supplementary throat or connection willbe cast in one piece. While all the intermediate throat members will be identical, separate and slightly different castings would be required for the end sections where one side wall of the old throat was straight, as shown in Fig. 2.y For such locations the margin at the top would be of reduced width on one side or the other, as required.

`While the three-wall construction shown in Figs. 5 to 'I has been found most satisfactory in actual use, the fourth or back wall qi the coal passage being formed by the straight back wall of the old throat, it may be preferred in some locations to use a throat member having four walls completely enclosing the coal passage, with all of the walls divergi'ng. Such construction is shownin Fig. 8.

To insure the continuous flow of coal from the hopper into the upper end of the coal passage in the new throat construction, there has been provided a stirrer or agitator for the coal immediately above the entrance opening, the agitator being actuated from some convenient source of power.' preferably the ram shaft. A convenient form of agitator is illustrated in Figs. l to 4 of the drawings, and comprises an elongated grid or ladder-like Vconstruction which rests upon the aligned tops of the throat members and is slowly reciprocated longitudinally during the operation of the stolzer.

' As shown in Fig. 3, the agitator-comprises the elongated side members 05 and 61 extending the width of the hopper and connected by the spaced transverse or cross-members 69. A convenient form of assembly is by welding the cross-members to the side members which are arranged as best shown in Fig. 4, with the front member positioned flatwise and the rear member edgewise. Shorter intermediate transverse members 1| which extend only part way across from the front side member toward the rear member are welded to the front member only. Preferable the transverse members are of segmental form in cross section, as shown on an enlarged scale in Fig. 9, the bottom face being fiat and the top face arcuately convex. f

The agitator is reciprocated in the illustrated embodiment ofthe invention from the continuously rotating ram shaft I9 by the crank 13 mounted on the end thereof, as shown in Fig. 3. The rotary movement of the crank is transferred into reciprocatory motion of the agitator by means of a vertical shaft 18 mounted to oscillate in suitable bearing support 11. Fixed to its lower end is the arm 19 connected by the link or pitman 8| to the crank 13, while at its upper end ls secured the arm 83 connected by link 8B to the agitator. 'I'hus as the ram shaft rotates, the agitator is reclprocated back and forth over the top surfaces of the throat members', stirring and loosening the adjacent coal so that a continuous movement oi' the loose coal into the entrance end of the passage in the throat members is insured.

The convex upper surface of the transverse members tends to maintain the agitator in posiaisasai tionfupon the top surface of the throat members, irrespectiveof `the direction of movement, but to` avoid any possibilityV of therear memberof the agitator rising, thehold-down guides l! have `been provided, `(see Figs; 2 and 4),`which are welded in position `to the back wail atthe top of the oldthroats orconnections.

The extent of movement oil the agitator is preferably such that the cross-members'` l! will traverse substantially the entire distance between adjacent throat openingabut not pass over any part of the openings themselves, while the shorter intermediate members 1i will traverse substantially that portion of the top surface of the throat members lying to the front of the opening. Thus,

on each cycle-of operation or double stroke of the agitator, substantially the entire fiat iop surface of eachv throat member will be traversed,` but at no time will the entrance to the passage in the throat member be obstructed or covered by any part of the agitator.

In the operation of the stoker illustrated in the drawings, the coal feeds downwardly in a continuous, slowly moving stream from the hopper or bin through the expanding passages of the throat members into the ram cylinders. As the ram shaft rotates slowly, increments of coal are fed successively from the cylinders into the fm'- nace by the reciprocations of the rams. At the same time, the agitator is moved back and forth adjacent the entrances to the passages of the throat members, maintaining the coal in loose and free condition irrespective of whether it is wet or dry, or what the height or weight of the coal may be in the hopper.

While the present invention has been shown and described as embodied in a construction wherein a separate and detached throat member is first formed and then positioned within the old connection or throat of an installation, the invention in its broader aspects is not to be limitedthereto, as it contemplates the provision in the coal supplying means `for a stoker of connections having expanding passages for delivering coal to the stoker whereby packing and arching over ofthe coal with resultant interruption in its movement will be avoided. A i

Nor is the present invention limited to the specific form and arrangement of the `various parts as herein illustrated and described, as these may be varied as the occasion `and conditions require within the scope of the language of the appended claims.

\ Having thus described the invention, what is claimed is: i

1. The combination with a hopper for supplying coal to a stoker or the like, connections between the hopper and the stoker having convergv ing, downwardly extending passages, and supplementary devices positioned in said passages, said devicesfeach having a downwardly expanding coal conveying-passage to facilitate the movement of coal from `the hopper to the Stoker.

2*. A throat member adapted to be positioned in the downwardly converging throat of a stoker coal supply, said member comprising a top with an opening therethrough and a plurality of diverging, downwardly extending walls forming an expending passage for the coal with a discharge opening not materially less in cross-sectional area than said throat.

3. A throat member adapted to be positioned in the downwardly converging throat of fuel supply means of a stoker, said member having a lpassage therethrough for delivering coal from said means` `fitting within the discharge end of said throat.

i 4. A throat" member adapted to be positioned within the downwardly converging walls of the fuel supply means of a Stoker,` said member comprising a substantially fiat top with an opening therethrough, walls extending downwardlyfrom the top at `the opening and diverging to form an expanding passage for the coal, said diverging walls of the throat member terminating adjacent the termination of the walls of the fuelA supply means.

5. A throat member adapted to be positioned within the downwardly converging walls of the fuel supply means of a stoker, said member comprising a substantially flat top with an opening therethrough at one edge, walls extending downwardly from the top at the edges of the opening and diverging to form with one oi' the walls of the fuel Isupply means an expanding passage for the coal.

6. A throat member adapted to be positioned `in the fuel supplying means for a Stoker, said member comprising a fiat top having a rectangular opening therein of substantially less area than the top, side walls extending downwardly from the top adjacent the opening to form an ex-` panding downward passage, one of said walls being provided with an opening in the lower portion thereof, and a removable closure therefor. 7. A hopper for supplying coal to a plurality of stoker units or the like, said hopper having a substantially flat bottom with a plurality of spaced openings therethrough, connections from the openings having downwardly expanding passages for the delivery of coal from the hopper to the stoker units, an agitator in the hopper comprising a plurality of longitudinal members, coal agitating cross-members adjacent the flat `bottom of the hopper and spacedfrom one another between the openings, and means adapted to be driven from the Stoker for actuating the agitator to cause the cross-members to reciprofree and unobstructed at all times.

8. A hopper for supplying coal to a plurality of stoker units or the like, said hopper having a substantially fiat bottom with a plurality of spaced openings therethrough, connections from the openings having downwardly expanding passages for the delivery of coal from the hopper to the stoker units, an agitator in the hopper comprising longitudinal members on opposite sides of the hopper and adjacent the bottom thereof, coal agitating cross-members connected at their ends to said longitudinal members and spaced from one another between the openings, shorter agitating members intermediate the cross-members connected to one of said longitudinal members and terminating short of the openings, and means for actuating the agitator to move the cross-members between the openings.

. 9. The combination with a stoker for feeding coal to a furnace comprising a ram cylinder with a coal receiving opening in the upper wall thereof and diverging side walls extending upwardly from said opening, of a hopper having downwardly converging side walls connecting with said cylinder walls, and a throat member positioned between said hopper walls with a top extending across the hopper and with an opening through the top, and side walls surrounding the downwardly to form a discharge throat, of a supplementary throat member positioned in the throat of the hopper, said member having a top extending across the throat oi' the hopper, an inlet opening through the top, and downwardly diverging side walls terminating in a, discharge opening positioned within and approximately of the same cross-sectional area as the throat oi the hopper.

' FRANK T. NICHOLSON.

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