US939526A - Furnace. - Google Patents

Description

W. B. MERKEL.

FURNACE.

APPLICATION FILED DEG.14, 1907.

Patented Nov. 9. 1909.

2 SHEETS-SHEBT 1.

attoznug W. B. MERKEL.

FURNACE.

APPLIOATION FILED D3014, 1907.

L w e m n e a a .1] M e2 t M WW I. e a m M W Wihwooeo WILLIAM B. MERKEL, OF

NEW YORK, N. Y., A SSIGNOR T0 JOHN S. S. FULTON, 0F FULLERTON, PENNSYLVANIA.

. FURNACE.

specification of Letters Patent.

Patented Nov. 9, 1909.

Application filed December 14, 1907. Serial No. 406,530.

To all whom it may concern:

Be it known that 1, WILLIAM B. MERKEL,

of New York, in the county of New Yorkintense heat to which they are subjected.

This is especially true of the grate bars and the risers on which they are mounted when inclined or shaking grates are employed, while the movableparts entering into the means by which the grates and ashes recep tacle are operated are liable to become ineffective and necessitate frequent repairs or substitution of parts. The heat is transmitted through the back'wallof the fuel hopper with the frequent result that the coal therein fuses and adheres to the walls of the hopper and prevents its proper and uniform discharge therefrom. When this fusing occurs the attendant is required to dislodge it by poking or barring or the fused fuel, soon becomes a burning mass and-the hopper back is destroyed. A similar difficulty is encounteredat the lower or back end of the furnace walls and the sides thereof extending for several inches above the grate surface. At the former point the ashes and clinker-s tend to adhere to the walls, not only preventing the proper operation "of the dumping and moving grates, but whenever these clinker-s are removed by the use of a hammer or sledge, as is necessary every few weeks, the amalgamation of the clinker-s to the walls is so intense that the fire brickwalls, being the weaker, a portion thereof is always destroyed in removing the clinkers, requiring frequent-renewing of the walls. This is not only troublesome, but exceedingly expensive. But the greatest source of annoyance and expense is the constant destruction of the grate bars which support, and are at all times in direct contact with, theburning'fuel. Without efficient protection, or as at present constructed and in practical operation, mechanical stokers of the inclined grate type require a renewal of grate bars approximately four or five times a year, due to their being destroyed by the fire.

The primary object of my present invention is to overcome these difliculties and provide effective means for preserving the integrity of the parts as against the action of the heat by a system of water circulation which will include supplying cooling water to both the movable and stationary fuel grates, the adjacent walls of the furnace and the wall of the fuel hopper.

. A further object is to connect one grate to another and lead cooling water to and from the different parts in multiple, so that should any unforeseen contingency arise where it would be desirable to cut out the wateror cooling supply to any of the different portions protected, it may be done without affecting the others or impairing their efficiency. This is effectually accomplished v by having a separate supply and outlet leadin to and from the different parts with shut-0% valves fore and aft. For instance, the moving grates are fed with an independent supply of water, a shut-0E valve being. providedin the pipes leading to and from them, so that in case of a defect developing or a pipe bursting in the moving grates, or in the zone between the entrance and shutoff valves, this portion of the water cooling system can be cut out by closing these valves .without affecting the 'other water cooled portions. Another system with independent shut-off valves leads to the fixed or stationary grate; another to the side risers which extend above the grates and act as a protection to the side walls of the furnace; another extends to the lower, or back furnace wall, and still another to the back wall of the fuel supply hopper.

A further object of the invention is to incorporate the cooling water system with the boiler feed and to provide means whereby the cooling system may be continuously supplied whether or not water is being fed to the boiler. v

In the accompanying drawing Figure l is a View partly in section and partly in side elevation showing av furnace equipped with a grate and stoker mechanism embodying my invention, a water tube boiler being shown mounted above the fire box in the usual or any preferred manner; Fig. 2 is, a front elevation. Fig. 3 is adetail view showing no the grate.

the pipe connections between the respective bars of the moving series as well as those of grate bars of the two series thereof, and Fig. the stationary series are in communication '42 is a detail view showing the construction with each other so that the water entering of one of the gratebars. the lowermost movable grate bar 21 will Referring to the drawings 1 designates a pass through it and successively into and furnace having an inclined grate2, a dumpthrough each of the moving bars to the uping grate 3 at the lower end thereof conpermost one 24 and thence through pipes 25 trolled'by a handle 3, and a coal hopper 4 and 26 into the boiler. Thus with valve 10 at a point in its front wall near the top of closed, as it always will be, the feed water must pass down to the furnace beforeit can The grate proper comprises two separate enter the boiler. Pipe 19 hangs freely from series of bars, one series being fixed, that 1s, its point of connection topipe 13 and thus mounted upon stationary side risers, and the it may swing sufiiciently to .compensate for other series having its grate bars interleaved the movement of the grate bars.

with those of the fixed series and mounted The grate bars of the stationary series 27 upon movable risers, all of the bars of both are supplied with water by branch 28 of series collectively forming the fuel supportpipe 13, the connections between the respecing surface. The series of fixed bars is intive grate bars of this seriesbeing, as shown dicated by 27, Fig. 1, and one of the stain Fig. 3,'substantially the same as those of 2 tionary side risers on which these fixed bars the moving grates. From the top fixed are mounted is indicatedby 38. The series grate bar 29 a pipe 30 leads to pipe 31, the of movable bars is designated by 23 and one latter terminating in pipe 26 leading to the of the risers for supporting this series is boiler. shown at R. ,The risers R are mounted at 28 designates the'inlet valve and 30 the 35 their upper and lower ends upon pivoted outlet valve by which the circulation through t.

gear segments R, R The stoker actu- 'the fixed rates is controlled.

ating devices impart a rocking action to the I provide an extremely simple, cheap and upper gear segment R and this action is durable method of connecting the water suptransmitted by the riser R to the lower gear ply from one grate to the other in both the so segment R with the result that the grate moving and stationary series of grate bars bars 23 are bodily moved back and forth as well as a simple, and thoroughly reliable intermediate the fixed bars 27. The means method of providing means for the water to for actuating the moving grate bars forms flow through the front portions of the grate no part of this invention and need not ,be debars themselves. It must be understood that 35 scribed. The only essential of the actuating it is only the front orir mgr portion A (Figs.

mechanism so far as concerns the risers R '1 and 4) which comes indirect contact with is that it shall oscillate the gearsegment R the burning fuel and is the only portion of to slowly move the bars 23 relatively to the the grate bar that requires protection. As

fixed bars 27 and thus advance the fuel down long as this front portion rema ns intact the an the inclined grate. A water tube boiler 6 is remainder of the grate barv is practically inshown-mounted above the grate 2. Througha destructible from the action of the furnace Y pipe 7 and branch 8 water is supplied to the heat: To accomplish this I bend an iron boller, the pipe 7 being designed to constitute pipe in the manner shown in Fig. 1 by the the supply for a battery of boilers. From dotted lines and indicated at B. To one end branch 8 apipe 9 leads to the boiler, a valve of this pipe I attach an elbow G. The pipe 10. being shown in pipe 9. Apipe 12 connects is made sufficiently long to extend the full branch 8 with the cooling system supply 13, r length of the grate and the grate is prefera valve 14 inpipe 1'2 havingits stem 15 exably constructed to extend the full width of tending downwardly and equipped with a the furnace. The pipe is laid in the mold 50 hand wheel 16 in reach of the furnace atin place of a sand core and the grate cast tendant. From the top of pipe 13 is shown around it. While it is possible to construct a pipe 17 extending rearwardly beside the these grate bars of all. cast iron, using a sand boiler and entering the latter at its rear end core to provide the hole for the passage of where the water, is coolest. This pipe is the water, yet this construction is extremely t3 provided with a check valve 18. unreliable, as cast iron is of very low tensile 12a The water supply pipe 13 is shown exstrength, brittle and not suited for withtendlngi down to a point approximately in standing the boiler pressures to which these llne with the lower end of grate 2. Argrates are at all times subjected. In proranged parallel therewith is a pipe 19 in viding a set fora furnace, every other one 50 communication with pipe 13 and controlled iscast with the elbow C at the opposite end by inlet valve 20, and having an outlet valve from the preceding one. The reason for 20?. This pipe 19 is shown incommunicathis will be apparent by reference to-Fig. 3 tion with the lowermost grate bar-21 of the which shows in detail the method in which series 23 of movable'grates. As will be seen the water supply is connected from one grate 35 by reference to Fig. 3 the respective grate bar to the other.

The holes D at the ends of the grate as shown in Fig. 4 are provided for bolting to the side risers. The spaces E are. slots through the grates for the admission of air in addition to that which entersbetween the grates. i

I have shown the rear wall 32 of the coal hopper 4 of hollow formation to constitute a water jacket supplied by pipes 13 and 0:), 3+ designating the outlet from the water jacket to'pipe 31, and 33 and '34, respectively, the inlet and outlet valves.

Practice has demonstrated that in the use of an inclined grate having a dumping grate at its lower end, the clinkers and ashes, as they collect near the bottom of the inclined grate, fuse on the hot walls above the dump- .ing grate, seriously interfering with its acthereto. Provision has also been made for protecting the side walls from clinkers fusing to them, whichseriously interferes with the operation of the moving grates and causes the rapid deterioration of the walls.

This is accomplished. by constructing the fixed or stationary side risers so that they extend several inches (suflicient to cover the zone in which clinkers adhere to the walls) I above the level of the gratearea and include the portion exposed to the action of the fuel in the water cooling system. To this end the fixed or stationary grate supports or side risers 38 are shown in communication with supply pipe 13*through pipe 13", the latter having a branch pipe 13 extending to the lower end of the side-riser; the right side-riser having its outlet 40 at its upper end extending across the top of the fuel hopper 4 and discharging into pipe 26. The

left side-riser also has an'outlet 39 at its upper end, which discharges into the pipe 40. Both the right and left side-risers are provided. with means for cutting out the water supply in case of accident; right sideriser by the inlet valve 13 and outlet valve 4-0 and left side-riser by the-inlet valve 13f and outlet valve 39. By this construction the side-risers perform a dual functiomthat of supporting the stationary or fixed grates, and acting -.as a protection for the side walls of the furnace.

Assuming that water is being. fed to the boiler from supply pipe 7, and that yalve 10 is closed, and valve 14 open, the course the water before reaching the boiler is down By this means there is.

, gate movement through pipes 13 and 19 to the two series of grates, the side-risers, furnace back and back wall of the coal hopper, and then through pipe 26 to the boiler. If, however, feed to the boiler is cut off and valve 14: is closed by 'manipulation of hand Wheel 16, then under "as any preferred means may be employed have not shown or described this feature.

Practice has demonstrated that a furnace equipped with my improvements will effect thorough combustion while maintaining the integrity of the mechanical elements entering into the construction and operation of the grate.

A feature of my invention is that it pro' vides for supplying cooling water to the grate bars of both series of grates, that is the series of moving grates as well as the series of stationary grates; Water cooled stationary grates are, ofcourse, well known;

there is no difliculty in forming them with passage-ways through which cooling water may flow. Likewise a moving grate, the individual rocking members of which form an inclined automatic stoker, is well known in art, the Roney stoker being the most extensively used. But I am not aware of any practical automatic stoker in which the moving grate, as well as the alternate stationary grates, are supplied with cooling water,;al-

though many efforts have been made to accomplish that purpose. In automatic stokers of the Honey type the moving grate bars are mounted upon pivots to p ermit the barsto turn axially. This is known as the Now it is obvious that any means for supplying coolingwater to moving grates must fulfil certain requirements. The tubes through which the water flows must permit of the movements of the grate bars, either by their own flexibility or that .of their connections to the moving grates, and When the water is intended to be conducted to the boiler from the grate,

these tubes and their'joints must be capable of withstanding boiler pressure. The impossibility of satisfying these requirements in pivoted grate bars is-fully realized in the art. Their. oscillating motion would neces sitate using a flexible hose for conducting the water to and from the grates or provid ,ing flexible joints or couplings at their points of connection. That neither of these devices would withstand the furnace heat pivotally mounted leaving the lower end free to swing form part of the and the boiler pressure is apparent. I overcome these difficulties by dispensing with the grate bars and employing bars which arerigid upon their supporting risers and so mounting and reciprocating the risers that the series of grate bars move bodily back and forth, the individual bars always 'co-acting with the alternate stationary bars to form the fuel'supportin'g surface. To these moving bars cooling water is conducted through iron pipes. The vertically disposed pipe'19 from which the water entersy the grates is secured at its top only,

' sufficiently to compensate for the reciprocation of the series of moving grate bars. The pipe 25 (Fig. 2) which is similarly connected, furnishes the outlet for the water fr 'om the grates to the boiler. I thus provide effective means for cooling vby water circulation both series of grates in an automatic stoker, and I am enabled to supply the cooling water at boiler, pressure, there being no loose joints to permit of leakage. I am aware that grates of the class to which mine relates have heretofore been used in which the movable members arranged-alternately with the fixed bars do not oscillate upon pivots but reciprocate or move bodily. T hose movable elements, however, do not .ment of the grate movement to insure the.

proper relative reciprocations. Furthermore this construction necessitates a great deal of mechanical work without any corresponding advantage as compared to the type to which my invention relates and in which one series of grate bars is stationary.

NVhile I have pointed out the fact that the absence of loose joints in the cooling system enables'me to supply Water thereto at boiler pressure, yet it will be understood that my invention is not limited to, nor is the success of the stoker dependent upon, the use of coolin water at boiler pressure, since the water may be supplied to the cooling system at city main pressure and after leaving the system be pumped into the boiler at boiler 1 pressure.

I claim as my invention v 1. In a furnace, a grate having fixed and movable bars, means for bodily moving said movable bars as a unit relatively to said fixed bars, said movable bars'having water tight passages therein, andconnections' between said movable bars;

2. Ina furnace having a grate com rising alternately arranged fixed and movab e grate bars, means for bodily moving said movable bars back and forth in the spaces intermedifuel supporting surfaces, but are merely pushers to advance the fuel..

a 7. A furnace movable bars,

a cooling water circulating system in which both movable and fixed bars are included, and means for conducting the feed water to and through said circulating system before its entrance to the boiler.

4. In a furnace having a boiler and a grate comprising alternately arranged fixed and movable grate bars, means for bodily moving said movable bars, a cooling water circulating system in which the fixed and movable bars are included, means for conducting cooling water from the boiler through said circulating system, and means for returning the cooling water to the boiler from the circulating system.

5. In a furnace having a boiler and feed water supply, and a grate comprising alter.- nately arranged fixed and movable grate bars, means for bodily moving said movable bars, a cooling water circulating system in which both the-fixed and the movable bars are included, means for conducting the feed water to and through said circulating system before its entrance to the boiler, and means automatically actuated on the out off of said feed water supply for conducting water from the boiler through said circulating system. 1

6. In a furnace equipped with a boiler, an inclined grate comprising two series of step grate bars having water tight passages extending therethrough, one series being fixed and the other movable, their respective bars being alternately arranged, risers supporting said movable grate bars and forming therewith one rigid unit, means for reciprocating said risers, side risers supporting said fixed grate bars and forming therewith a second rigid unit, therbars of the two units of fixed and movablegrate bars being interleaved, each grate bar of the moving series being in water tight communication with the other rate bars-of its series, and each grate bar 0 the fixed series being in water tight communication .with the other grate bars of the fixed series, and means for Suppl ing cooling water to said two series of grate arshaving a boiler and feed water supply and stoking mechanism having a coal hopper provided with-a water jacket, in combination prising alternate fixed and movable bars, a cooling water circulatin the water jacket of sai hopper and said grate bars are included, and means for conucting the feed water and grate boiler.

8. A furnace equipped with a boiler and to said water jacket bars before its entrance to the with an inclined grate comsystem in which E said water jacket and sald grate bars are included, means for conductlng the feed water to said water jacket and grate bars before its entrance to the boiler, and means automatically actuated on the cutoff of said feed water supply for col'iducting water from the boiler to said water jacket and grate bars.

10. In a furnace equipped with a'boiler the combination of an inclined grate comprising alternate fixed and movable bars, means for conducting'cool-ing water to both sets of bars, a. dumping grate at the lower end of said ate, and a water back in the rear wall of t ie fire box adjacent said dumping grate, a feed water supply for said boiler, a cooling water circulating system in which said water back and grate bars are included, and means for conducting the feed water to said water back and grate bars before its entrance to the boiler.

11. In a furnace equipped with a boiler the combination of-an inclined grate comprising alternate fixed and movable bars, means for conducting cooling water to both sets of bars, a dumping grate at the lower end of said grate, and a water back in the rear Wall of the fire box adjagent said dumping gate, a cooling water circulating system in which said water back and grate bars are included, and means for conducting water from the boiler to said water back and grate bars. a

12. In a furnace equipped with a boiler, an inclined grate, a dumping grate at the lower end thereof, and a Water back in the rear wall of the fire box adjacent said dumping grateya feed water supplyv for said mg a coal hopper provided with a water boiler, a cooling water circulating system in which said water back is included, and means automatically actuated on the cut-off of said feed water supply for conducting water from the boiler to said water back.

13. In a furnace, an inclined grate comprising a series of hollow fixed grate bars, and a series of hollow movable grate bars alternating with the fixed bars, side-risers on which said fixed bars are mounted, said bars terminating at their fuel supporting edges within the width of ,said side-risers, means for conducting cooling water through both series of bars, and means for conducting cooling water through said risers.

l4. In a furnace, a series of fixed grate bars, and side-risers on which said bars are mounted, said bars terminating at their fuel supporting edges within the width of said side-risers, means for conducting cooling water through said risers, and independent means for conducting cooling water through. said bars.

15. In a furnace, two series of grate bars, alternately arranged, one series being fixed and the other movable, a pipe extending through each of said series and entering its respective-bars successively at opposite ends and lying adjacent their fuel supporting edges, and means for conducting cooling water through said pipes.

16. In a furnace having an inclined grate comprising two series of grate bars, one series being fixed and the other bodily movable, and having the bars of one series alt-ernatin with those of the other, and means for bodi y reciprocating the movable bars in horizontal planes, each of said series having its respective bars hollow adjacent their fuel supporting edges to form water tight passages and connected at opposite ends with the next'bar of the series, and means for conducting cooling water to each of said series.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

WILLIAM B. M ERKEL.

Witnesses:

GRAFTON L. MCGILL, ALICE LIND.

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