US1772021A - Underfeed furnace - Google Patents

Description

7' Aug. 5, 1930. G E WHITNEY 1,772,921

UNDERFEED FURNACE Original Filed April 22, 1927 5 Sheets-Sheet 1 Jf/orney Aug. 5, 1930. G. E WHITNEY UNDERFEED FURNACE Original Filed April 22, 192'?- 5 sheets-sheet 2 172092? for gel? Wi/zzey by 5 I d/forney Aug. 5, 1930. 5. E. WHITNEY 1,772,021

'UNDERFEED FURNACE Original Filed April 22, 1927 5 Sheets-Shee 3 1930- G. E. WHITNEY UNDERFEED FURNACE Original Filed April 22, 1927 5 sheets-Sheet 4 SN Q F o m I flea/gel: Mai/20y 53 J/rorney Aug. 5, 1930. e. E. WHITNEY UNDERFEED FURNACE 1927 5 Sheets-Sheet 5 Original Filed April 22 J71 zmzwor Georjfelz Mil na y ("nulluummuuu lllllI lll Patented Aug. 5, 1930 u rsn STATES f rt es;

. cr ase warm, or R GE ET C YNEG IN ERF U liA Ap i n fi A ril 2 1 Serial Q 4- R w 1 1 51 93$ liver the coal by means of an endless,con-,

5 veyor. i 1 Y 1 Second,to remove the ashes automatically by the action of such conveyoron its return movement to the coal hopper.

Third, 'to remove all possibilityof dele- 2 terious action of the sulphuric acid, generated from wet coal, on the conveyor which is preferably made of iron. e Fourth,to enable the conveyor to absorb heat from the ashes as well as from the fire to the coal; U a I I The coal is fed and delivered at the'bottom of the fire pot by the action of an endless conveyor which is driven by means of sprocket wheels that engage the conveyor, and the latter iscomposed of metallic links hinged together and carrying at suitable intervals pivoted members, which are hereinr after termed pushers which latter move the mass of coal forward toward the fire pot as the coal is delivered from the hopper, and this continuous pushing of the coal causes the latter to be forced upwardly within the fire pot so as to always keep up the proper supply of coal. i

As these pushers act against the coal, and

also against theashes, the inner portions of the pushers, which extend beyondthe conveyor, are in abutmentagainst elongated metallic keeper plates so that the pushers are held rigid when they are performing their functions, and when they are leaving the bottom of the fire pot orentering the bottom of the coal hopper, pr visicns. a mad wherei pot, so that it will itself contribute heat units bythese pushers'are swung downwardly so as to be out of the way. i v

The conveyor sections have lugs that engage with the teeth of the sprocket wheels, so that the latter may operate to positively effect the travel of the conveyor.

An electric motor is provided for revolving the sprocket wheels 1 at a comparatively low speed, through intermediate gearing, and this motor also serves to operate a-blower for forcing air into a closed chamber that sur roundsthe' fire pot and communicates with the latter through the medium of small perforat'ions made'in the walls of this pot,so that the combustion of the coal in the fire pot greatly facilitated bymeans of this air ast.-'

, The fire pot is usually nearly filled with coal by the action of the feeding instrumentalities abovereferred'toand a fire started in the fire pot by charcoal, wood or'other means, and the feeding of the'coal temporarily dispontinued and the blower operated; As soon as the fire is properly started in the coal the feeding of thelatter is'continued andthe blower may or may notbe put in commission, its action being regulated by" an ordinary but-terfiyrvalve, not shown in the drawings.

Goal is frequently wet, either when delivered, ,or else by the furnace tender himself for the purpose ofv preventing dust, and when coal is wet the action of the steam or vapor generated within the fire pot will act on any sulphur Which may bein the coal and will cause distillation of sulphuric acid which gravitates and attacks the iron of the coal conveyor.

Ininstances, where the coal conveyor ofunderfeed furnaces has been stationary as to lengthwise movement, that isto say, is permanently, confined, this action of thesulphu ic aci has .co xjple ely estroy t e co evQra j r, l d In the present invention the same defect would undoubtedly be present, were it notfor the fact that the conveyor is constantly traveling, and leaves the fire pot and passes into the open air and thence down through the warm ashes, and'the action of the air,as an evaporator, coupled 'withthe dryingeffects of the ashes and their heat, completely obviates all injurious eifects of the acid.

Surrounding the fire pot and spaced therefrom is the ash pan for receiving the ashes as the latter are forced over the rim of the fire pot, and this pan has a conduit which leads downwardly immediately below the conveyor chain and extends throughout the length of the latter and delivers the ashes to any suitable receptacle such asan ash pit or can, or a suitable'elevator for getting rid of the ashes. The final disposal of the ashes. however, has nothing to do with the present invention. p

This preliminary description will aid in understanding the accompanying drawings which form a part of this. application, and will be followed by a more detailed description referring specifically to these drawings by numerals of reference.

In the drawings Figure 1 is a plan view.

Figure 2 is a side elevation, the ash pan being partly broken away.

Figure 3 is a section at the line 33 of Figure 1.

Figure 4 is a section at the line 4=-4 of Figure 1.

Figure 5 is a section at the line 55 of Figure 1.

Figures 6 and 7 are sections at the line 66 of Figure 1 looking in reverse directions.

Figure 8 is a broken longitudinal section similar to Figure 3, and showing particular- 7 ly the position of the pushers when entering the hopper and leaving the fire pot, and

Figure 9 is a fragmentary section showing one of the pushers immediately after entering the hopper.

1, 2, are the base members for sustaining the entire structure at each end thereof, 3 is the ash pan mounted on said supports, and 4, 5, are pairs of spaced brackets placed on said pan at each end of the structure, and riveted to the supports thereby firmly fixing the ash pan thereto.

6, 7, are spaced cheek plates that are riveted to said brackets and are spanned by girders 8, 9, to which the fire pot 10 and coal hopper 11 are secured.

12 is an elongated track or guideway having at its sides depending flanges 13that are riveted to the inside of the cheek plates 6 and 7 at the upper ends thereof, and 14 is a similar track or guideway having depending flanges 15 that are riveted to the inside of said cheek plates 6, 7, this conduit'being intermediate guideways 12 and 14 forming abutments against which the pushers engage soas to hold the latter firmly as will be presently ex plained. v

Extending outwardly from the cheek plates 6 and 7 are ears 16, 17 (see Figure 3) within which are journaled twinsprocket wheels 18,

19, by means of shafts 20, 21, keyed to the hubs 22, 23, of the sprocket wheels.

The coal conveyor is an endless chain, denoted generally by the numeral 24 and formed by links 25 hinged together at 26, each link having on its inner face at each side a lug 27 with which the sprocket wheels engage to drive the chain.

28 is a conduit formed by riveting a rooflike part 29 directly to the hopper and fire pot and also to the girders 8, 9, of the cheek plates6, 7 this conduit being intermediate the hopper and fire pot.

At the outer end of the fire pot and hopper, openings 30, and 31, are provided, the floor of which is the upper track 12, the height and width of these openings being just sufiicient to allow the passage of the chain, while the ends of this track at the middle portions thereof are cut away to provide notches, as

shown at 32 and 33, the end wall 34: of the notch 33 being an abutment which passively functions to properly position the pushers after they have entered at the base of the hopper, as will be presently explained in detail. The conduit 28 leads from the bottom of the hopper into the bottom of the fire pot, as is clearly shown at Figure 3, while the floor of the conduit is the track 1'2,and the bottom of the hopper has an elongated opening 35 of a width about equalto the width of the chain, the bottom 36 of the fire not being provided with a similar opening 37. v 38 are normally upstanding memberscarried by the chain and which impel the coal into the bottom of the fire pot, and these members will hereinafter be termed pushers. These pushers 38 are quadrant shaped and are pivoted around hinged portions of the chain at suitable intervals, the width of the pushers being suflicient to impel coal into the fire pot, the pivotal points of the pushers being at the rectangular portions formed by the junction of the radial "faces that form part of the quadrant shape of the pushers and when the buckets are in elevated position their bottoms rest on the stop 12, as shown at Figure 3 so that the pressure against the coal will have no effect on. them. These pushers extend through openings 39 in the links 25, and when the pushers are swung rearwardly their circular backs 10 will pass close to the rear walls of said openings and the front faces ofthe buckets will: lie flush with the links as in the instance of the pushers that are snown at Figure 8 as entering the hopper and leaving the fire pot. v

Pie-supposing the parts to be in the position shown at Figure 3 with the sprocket wheels revolving, the pusher immediately pusher can enter the hopper ince,theim ai-n understood by reference to Figure 8.

Also, as is shown at Figure 3, during the travel of the conveyor chain, the pusher that is within the bottom of the fire pot will strike the rear wall thereof, which will cause the pusher to swing rearwardly and downwardly into the notch 32 in the track 12 with its front face substantially flush with the chain, as clearly shown at Figure 8.

After the pushers leave the fire pot, as above explained, they are guided by the sprocket wheels 18 into a trough 41 which is a continuation of the ash pan 3, and immediately before entering the latter, the pushers, which, when they reach the bottom of the sprocket wheels, are in inverted position, as is shown at'Figure 3, will strike the end of the track 14, which will cause them to assume normal position with their inner portions abutting said track, and during their.

travel they will shove the ashes in the trough and cause them to be emptied atzthe end of said trough. It is understood that the push er members 38 being loosely pivoted, will assume by gravity a position whereby the same will pass beneath the lower track 14. However, in event that the pushers are held by friction in the position shown at the right of Fig. 3, same will be forced to their operative position by contacting with the forward end of track 14;. g

After the pushers have left the trough 41 they are carried around the sprocket wheels I 19, as shown at Figure 3, and will successively pass Within the hopperin the manner above set forth.

Coal placed within the hopper will be positively drivenby the conveyor through the conduit 28 into the bottom of the fire pot, and this will cause the continuously delivered coal to be crowded upward Within the pot, as is usual with underfeed furnaces. The fact that an endless chain is employed which is provided with the lugs 27'that are engaged by the sprocket wheels, renders the feeding and delivery of the coal to the fire pot by the pushers absolutely positive, and this is a decided advantage possessed by my invention, and since the means which functions to this end is automatically put in inactive position for leaving the fire pot or for entering the hopper, and automatically reestablished in operative position immediately after entering the hopper, and since such means on its return movement from the fire pot to the hopper operates'to remove the chiefly to the instrumental-flies; employed for feeding and delivering the coal from the hopper to the fire pot, and attentionwill new be called to the means utilized forrevolving the {sprocket wheels and su pplyi-ngtair to the mass ofwcoa-l in the-fire pot for combustion purposes, but, since such i'means consists, of

wellknownfdevioesthat are operated in :the

usualmanner to bring aboutresu'ltsthat are quite ordinary, these devices have not been illustrated in detail, and theywillmerely be refer-red to generally.

.'=2 is an angle plate which is fixed tozoueof'the brackets 5 and-supports an rordinary electric motor 43 whosesha-ft carries zaworm.

44: that is (in mesh withia worm wheel 45 that is secured to the shaft 21 of the sprocket L9.

This worm has a very small diameter while the worm wheel is veryxlarge, so that it will beclear that the latter will berevolved very slowly.

' The shaft of the motor alsooarries a blower fan ,(znot -shown ),-and after attire-is once started in-the fire pot, -the blower may vhe regulated to furnish verylittleqainorifiheSup-;

ply of the latter may he cutiofilentirely. it will be observed that; the sprocket fwheelsl-9 are of -a .diameter rsrrieater than that .ofthe sprocket wheels 18,,and that the upper .part i of the conveyor declinesdownwardly the aSPIIOCkBt wheels $9,; and ,also'that the abutments or-fl.-tracks '12 and latv areilikewi-ise declined, but these. declinationsnmerely i n- :tributeto thereasytravel of the malted-ashes andarein no tsense to beoonsidered asulimita- ,tigns V .Heretofore, devices, such asserews, have been emploved to feed ithe eoaland delimer it to the fire ,pot butait has frequently-chap- .penedpthat the coal will hang to'the lsriaetw and that the latter {and @also.,-the ,coal will revoLve avi-thoutpropelling the coal, mild, athQFe" fore such screw {feed is not alw y reliable. .A-lso, since the screw is. stationary, except as to rotation, that .part of the latter which, is immediately (below the i fire pot times been eatenaway by the sulphuric acid distilled from thec0a1.- Y a In the presentiinstance the feedingof the coalis positive, andocthe travel ofvztheeeonveyor into the airbeyond thegfi-re .pot, through the. (hot, ashes, and again in the air, preparat r to entering h er-Pe mp y eifzaporates the acid, and removesall traces o-it.f

Therefore, thegist of 7 this .invention broadly speaking, lies 'in a continuously traveling conveyor which carries coal impelling'men'ibers or pushers that are automatically positioned for service ,andfor entering the hopper and leaving the fire pot.

ter is desirable, since the ashes may be almovement thereby, and means to actuate the lowed to fall over the rim of the fire pot into any suitable receptacle.

What is claimed is 1. An apparatus of the character described, including a hopper and fire pot, a pair of tracks disposed beneath the hopper and fire pot and supported in spaced substantially parallel relation to eachother, an endless conveyor movable on said tracks having a series of spaced pushers pivoted thereto, said tracks having contacting surfaces to engage the pushers so as to project and retain all thereof the same distance beyond said surfaces when in engagement therewith, and means to operate the conveyor and therewith the pushers.

2. In an underfeed furnace, a hopper, a fire pot, an ash pan surrounding the fire pot and having an extension providing atrough that extends beneath the furnace, an endless conveyor having continuous travel through said hopper, fire pot and trough and having a series of pivoted pushers carried thereby conveyor.

In testimony whereof I aflix my signature hereto.

for impelling fuel or ashes, means to project a portion of said pushers at substantially the same distance beyond the outer face of the conveyor during the performance of their several functions, means to position said pushers for entrance into the hopper and exit from the fire pot and means for positioning said pushers for performing their fuel impelling functions after entering the hopper and for performing their ash removing functions after leaving the fire pot.

3. An apparatus of the character described including a hopper having a front wall'and a fire pot having a rear wall, a track disposed beneath the hopper and fire pot and having its ends spaced from said walls, an endless conveyor composed of sections hinged together and having openings formed therethrough and having a series of spaced pushers carried thereby and mounted for swinging movement through the openings, said pushers being engageable with the forward 7 end of the track for movement to their operating position, the pushers being alsoengageable with the rear wall of the fire pot for movement to their inoperative position, and means to actuate the conveyor.

4. An apparatus of the character described including a hopper and a fire pot, a track disposed beneath'the hopper and fire pot, a second track beneath the first named track disposed in spaced substantially parallel reing said tracks, and having a series of pivoted pushers carried thereby, said pushers each having a pair of angularly arranged faces, means to move one face of the pushers into engagement with the upper track so as to be supported against downward movement, said other face being engaged by the lower track to be retained against upward lation thereto, an endless conveyor surround- GEORGE E. WHITNEY.

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