US1127824A - Furnace. - Google Patents

Description

` vAPPLICATION FILED 1350.22, 1906. 1,127,824. Petentea Feb. 9, 1915.

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APPLICATION FILED 1350.22, 1906,

- Patented Feb. 9, 1915.

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. y LELAND L sUMntns, or CHICAGO, ILLINOIS.

FURNACE.

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Specification of Letters Patent.

Patented Feb. 9, 1915.

Application led December 22, 1906. Serial No. 349,087.

To all whom t may concern.'

Be it known that I, LELAND L. Soutiens, a citizen of the United States, residing at Chicago, Cook county, Illinois, have invent'- ed certain new 'and useful Improvements in Furnaces, of which the following is a speci.

' sure in the ash pit' is maintained, at practi cally atmospheric pressure, and in providing means whereby the supply of air may be varied at will for different portions of the fuel bedaccordin'g to the depth thereof or amount of resistance offered by the particular character of the fuel used, or to meet other conditions that may require such variations in air supply, with the result that the proper amount of air is suppliedy to insure complete combustion overthe Whole grate area and the ash and refuse is per-` mitted to be discharged into the ash pit without causing any inrush of air therefrom to the furnace chamber which would interfere withor disturb the processes of combustion therein. As a further result, a continuous process of combustion is maintain,- ab'le in a' furnace of any construction and mode of operation, unaffected by the clean'- ing of the fire or the addition of fresh` fuel in the manually fed type of boiler, as any lopening of the -ire doors for the addition of fuel will not cause any inrush of air as the layer of fresh coal and semi-consumed coal is maintained between the source of air pres sure and the furnace and the atmosphere.

The various features of advantage and utility in my form and construction of furnace will be apparent from the description hereinafter given.

In the drawings Figure 1 is a sectional elevation of my improved form of furnace as sht Wn applied to a Well-known type of steamy boiler, the particular furnace illustrated being of the automatic feed or stoker type; Fig. 2 is an end elevation partly in section of 'the grate bars and associated parts, this view being on an enlarged scale as compared with Fig. 1; Fig. 3 a section on the line 3-3'of Fig. 2 illustrating the construction of one of the grate bars and the airl boxes at the ends thereof; Fig. 4 a cross-section on the lined-f4 of Fig. 3; Fig. 5 an elevation of the plate 14 and an end of a grate bar; Fig. 6 a sectional elevation of a modified construction of my furnace shown applied to the same vtype ofsteam boiler as 1n Fig. l; Fi 7 a cross-section on an enlarged scale 'o' the grate bars of said modified form of construction; and Fig. 8 a plan view of the grate bars illustrated in Fig. 7 but on a smaller scale and showing the setting of the boiler in section.

My invention is applicable to different forms or types of furnaces, for instance the same may be applied to the automatic feed or Stoker type of boiler furnace illustrated in Fig. l of the drawings or to the ordinary manually fed furnace illustrated in Fig. 6.

Moreover, as is obvious, my furnace may be used in connection with any type or character of steam boiler or may be put to other 'ruses than the mere generation of steam, but

for convenience I have shown the same applied to a steam boiler which is of such wellknown construction that it need not be further referred to, especially as my invention is not concerned with the type or character thereof. A A

Referring first to the type of furnace illustrated in Figs. 1, 2 and 3 in which the fuel is fed in an automatic manner, I provide a furnace chamber Il of suitable dimenr sions and arrange therein a series of trans- 'Verse grate bars having the peculiar construction and mode of operation aboutto be described. Below the grate bars is formed an ash pit 2 into which the ash and refuse may be discharged.

Any suitable number of the grate bars may be employed but in the present instance I have illustrated six ofthe same which,

with the exception of the innermost one, are

arranged at an angle so as to provide for the proper feed of the fuel from a fuel vhopper 3 to the furnace chamber. Inasmuch as all of these grate bars are similar in construction a description of one of them will suiice for all.

Each grate bar consists of a tubular portion 4 which constitutes the grate surface proper and while l have shown these grate bars as cylindrical in form and will herein- "uta Aat

after refer to them as of that fo'rm, yet it will be understood-that my invention is not limited thereto but that other forms such as an oval orv cam form may be adopted, especially for the purpose of slicing or breaking up the bed of such fuel as tends to form a hard or impervious clinker. Each grate bar proper is provided with a central longitudinal sleeve 5 which fits upon and is suitably secured to a central shaft 6. The cylindrical grate bar 4 is connected with its sleeve by means of a series of radial partitions 7 which are, in the present instance, eight in number and extend from end to end of the grate bar thereby dividing the interior of the grate bar into a series of eight compartments s'gnental in cross-section, such compartments communicating with the walls of thel grate bar through air spaces or openings such as the series of openings 4B. It will be understood that di'erent characters or designs of air spacing may be adopted and also that if desired the grate bars may be provided with projections or teeth to better convey the coal forward and to assist the slicing or breaking up of the bed of coal if occasion should require. The grate bars, by reason of their hollow con' struction, are arranged todeliver a supply of air which is admitted thereto at either or both ends, the latter arrangement being the one herein illustrated and moreover the arrangement is such, resulting from' the proand therefore having the general inclinationv Fig.-2.

of the series of grate bars as illustrated in A These air boxes are separated from each other by partitions 10, there being as many of them as there are grate bars so that each grate baris supplied with air from its own air box, or air boxes in case that air boxes are provided at both ends of the grate bars. The air boxes are independently supplied with air through an air supply pipe 11 by means of a series of pipe connections 12 leading from the supply pipe llrtothe air boxes.

In order to attain one' of the objects of my invention provision is made for supplying variable quantities of air to different portions of the fuel bed and in the present instance this result lis obtained by providing means for regulating the supply of the air into-the different air boxes. According to the present construction illustrated in Figs. 2 and 3 I provide: independent valves 13 in the pipe connections 1.2 so that the amount of air admitted to the different boxes may be independently regulated at the will of the operator to suit the depth of fire or fuel bed carried .on the grate bars. By this means the supply of air may be proportioned to the depth of the fuel bed. For instance over that portion of the grate where the-fuel is in excess, a certain ,suilicient amount of air is required and is supplied in the proper quantity as determined by the operator while over that portion where the fuel is partially consumed a smaller quantity of air is suppliedand over that portion where the ash is in excess the supply is restricted, thus preventing an excess of air from entering the furnace or fire chamber which would diminish the efficiency by lowering the temperature of the furnace and also causing an increased amount of heat to be carried away as waste heat in the stack, due to increased quantity of the gases di luted with the air.

In order to provide for the delivery ofthe air upwardly only from the grate bars into the furnace chamber and prevent deliver of the air ldownwardly into the ash pit provide the air boxes with means whereby the air is delivered therefrom to the upper portion only of the grate bars, and in fact only to one or more of the particular compartments' thereof which are presented 11pwardly at the time. Under the present construction as herein shown such means consists of plates 14.- arranged one in/each air box and adapted to be held with a yielding pressure against the end of its grate b ar, to which end each plate is strung upon its shaft 6 and held in working position by means of the coiled lspring '15, encircling said shaft toward its outer end. Each plate is solid or imperforate except as to a segioo mental opening 1-1 formed in its upper half above the line of the shaft and arranged to register with the particular compartment or compartments which are presented thereto when the same are in position to deliver their air upwardly into the furnace chamber. The air supplied from the air boxes thus finds exitonly through the segmental openings 14 in these plates inasmuch as the latter are held against the ends of the grate bars as well as against the inturned flanges 9a forming a part of the air boxes.

The plurality of compartments in each grate bar is provided for the purpose of compelling the air supply to be directed upwardly only and preventing the admis.-

sion of the air into t e ash pit.

As shown and by preference I provide eightof these compartments and each segmental opening' of the air to the ash pit.

memset 14a is made of a size corresponding to the i cross-sectional area of two of the comparti YVof hand valves 29 which control thesupply ments so that the full area of two of thev compartments is always effective and so that also a compartment is always fully shut olf from the yair supply before it has `been rotated sufficiently to communicate with the ash pit. Consequently the full effective' area necessary for the adequate supply of air to the bed of fuel remains practically constant without any possibility of delivery The grate bars may be actuated in any suitable manner, a driving mechanism suliicient for the purpose being illustrated herein. Such driving mechanism consists ofa driving pulley 16 arranged to drive the inclined shaft 17 through the mediumof the worm 18, wormgear 19 and shaft 20, which latter is connected with the shaft 17 by means of the universal joint 21. The shaft 17 is provided at intervals along its length with worms 22 adapted to mesh with worm-gears 23 secured to the outer ends of the shafts 6. By these means the grate bars are all rotated inunis'on so as to feed the fuel from' the hopper 3 inwardly into the furnace and to discharge the ash through a suitable open- 'ing 24 formed'adjacent the bridge wall of the furnace and emptying into the ash pit below. If desired the innermost grate bar adjacent the bridge wall may be unprovided with the air-supplying arrangement and be formed'merely as an ash bar for discharging theash and refuse into the ash pit. As hereinbefore stated my invention may also be applied as well to the shaking grate type of furnace as to the conveying grate type,

to illustrate'which other adaptation l have shown in Figs. 6, 7 and 8 of; the drawings. a modified form of construction in which a series of shaking grates 25 are employed in copration with a series of transverse air pipes 26. Each grate is provided with a suitable number and 4design of air spaces for the" purposes of delivering to the fuel bed the air which is supplied from they air .pipes through openings in the upper; portions thereof immediately adjacent the grate bars proper. These air tubes, in the present instance, extend through the brick Work or setting 27 of the boiler and are arranged to communicate with an air-supply pipe 28. If desired, asindicated inFig. 8 these air pipes may be connected at both. ends with supply pipes so as to assure va more even distribution of air over the entire width of the grate surface. Each airpipe 26 is formed continuous at thosevportlons passing through the setting and is open only at that intermediateV portion which is exposed to the grate surface as illustrated clearly in Fig. 8. The different air pipes are independently governed as to their air supply for the purposes hereinbefore mentioned and in the present instance such control is had through the medium of a series of air from the supply pipesY 28 to the ends of the air pipes through the short connections 30.

The grate bars which form 4the grate sur-y face are of any desired numberv but in the present instance I have illustrated a series of nine thereof which are connected by means of a connecting bar 31 which is in turn' connected to and operated by the usual shaking bar 32 extending to the front of the furnace and arranged to be operated by the hand 'lever 33. Each grate bar is so cqustructed as toV oscillate around the centrall axis of its airl pipe and the adjacent grate bars are arranged to coperate with each other for thel purpose of slicing or breaking up the bed of fuel, especially in cases of certain kinds of fuel tending to Yform a is provided with an inwardly directed and substantially radial langeor web 25"v whose inner edge corresponds to the curvature of its air tube and bears against and slides upon the same in the oscillation of the grate bars. One of the radial flanges 25h of each vgrate bar is connected by a depending extension 25c with the connecting bar31 here-- inbefore described. According to this construction, the air which is supplied to the air pipes 26, in the manner hereinbefore ex plained, is delivered upwardly and passes through the grate bars and through the fuel bed in amounts proportionate to the depth of the fue]il or fire carried in the furnace chamber, as may be determined by the operator. who its the series of valves 29 in the proper adjusted yposition to supply the *necessary amount ofair. scribed construction, the air which is supplied through the air pipes 26 is compelled to pass upwardly through the grates inasmuch as the grates proper.V are cut oli' from the ash pit below by the closed portion of the air pipes and by. the radial webs 25h which are always in contact with the air tubes as clearly indicated iny Fig. 7, so that a pressure .will be maintained beneath the fuel bed and between such fuel bed and the bar, thereby providing a cooling influence on the grate bar and at the same time preventing the air pressure from equalizing so that the effect will` be to maintain a series of varying air supplies in the fuelfbed while the ash pit pressure and the furnace 'pressure above the fuel bed will be approxi- Also, according to the demately 9 'equal' to '1 th "f atmospheric pressure.- Under thisconstruction and arrangement,

. it is possible to have a series of ordinary grate bars such asthe two bars 34 (Fig. 6), which may be `termed ash removing bars, also connected to the shaking device described and arranged in the rear of the furnace so as to permit theash and refuse to be emptied --intothe ash pit through wide and unobstructed'openings, for owing to the described adjustment of the air pressures there will be no inrush of air from the ash pit into the furnace, but if the furnace pressure should be' slightly in excess there will behal slightl discharge of the gases into the ash -pit with. th eshesand refuse tending to assist in'cleaning the fires. The process of combustion can thus be maintained continuously, unaffected by the cleaning of the and is graduallyworked toward the rear of the furnace as combustion proceeds, the

. light 'ash and some elinkers being removed bythe shaking grates without allowingan inrush of air owing to the design of the grate bar and the? heavy clinker and refuse being removed through the ordinary grate bars 34 through which a free discharge is permitted either bly means of a wider range of movement or by a wider spacing of the grate bar fingers. It will be understood that the character of the fuel consumed will letermine the detail ofthe's'e ash removing iars.V

It will be evident that in the application of my invention toeither the shaking grate type or the conveying grate type of furnace, it is not necessary that the entire air supply should be admitted through the grates, for. inthe combustion of certain fuels haying a considerable proportion of volatile combus-- tible it is an advantage to arrange the furnace as a semi-gas-producing furnace in which case only sufficient air, or a mixture of air and steam, will be admitted through the grate as will consume the fixed combustible and drixe off the volatile combustible, the principal supply of air being admitted over the fire or through the bridge lwall and being preferably previously heated -by the waste heat of the fuel gases or by other means.

lt will be understood that the resistance to the passageof air through the grates and through the fuel bed is overcome by the application of the pressure through the grates while a negative air-induced pressure may he applied beyond the furnace by means of a stack or fan (not shown), this induced pressure overcoming the frictional losses through the boiler or other apparatus utilzing the heat Beyond the' furnace, the' same not ybeing of sufficient amount to maintain a negative-pressure or suction in the furnace Where the pressure is preferably maintained at atmospheric pressure or slightly in excess thereof. B 'y"so' proportioning the pressure and volume of the air suppliedthrough sistance to the passageof the air may have the pressure .correspondingly reduced,' the air furnished through the hollow grate bars thus supplying the furnace as the products of combustion are removed by the chimney and preventing the draft from the chimney lowering the furnace pressure.

I claim:

1. In lcombinationwith a furnace, a series of hollow grate bars therein arranged transversely -ofthe direction of supply of the fuel and'communi'cating with a supply of air underv pressure, and' a series of independently operated valves for governing the air supplied to the grate bars and ar'' ranged toavary the pressure or'volume ofthe air supplied tothe different grate barsl from the front to the rear of the furnace.'

2. In combination with a furnace, a series of rotatable grate bars, each divided intoseparate longitudinal compartments adapted to communicate with a source of air under pressure, and means for supplying such air toa' compartment only when presented toward the fuel bed so as to deliverwits air thereto.V 'f f e 3. ln combination with a furnace, a series l of rotatable grate bars, leach divided Vinto separatelongitudinal compartments adapted to communicate with-a'sourceof air under pressure, and means for interrupting said communication with a' compartment except when presented toward the fuel bed# 4. in combination with a furnace, a series of rotatable grate bars, each divided into separate longitudinal compartments adapted to communicate with a source of air under pressure and means for admitting theair successively to those compartments which are exposed to the fuel bed. 5. in combination with a furnace, a series of rotatable grate bars, each divided into separate longitudinal compartments adapted to communicate with a source of air under pressure and means for successively cutting off the supply of air to thosecompartments exposed to the ash pit. I

6. In combination with a furnace, a seriesof rotatable grate bars, each divided into separate longitudinal compartments segsol l municate with a source of air under pressure,

and means for admitting the air successively to the compartments.

7. In combination with a furnace, a series of rotatable` grate bars, each divided into' separate longitudinal compartments segmental in cross section and adapted to communicate with a source of air under pressure, and plates. each provided with an opening through which the air passes into the compartments as the latter are successively presented to such opening.

8. In combination with a furnace, a series and means for admitting the air to the compartlnents successively through an opening substantially segmental in form and corresponding in area substantially with the cross sectional areaof two .compartments of the grate bar.

10. In combination with a furnace, a series of rotatable grate bars, each divided into separate longitudinal compartments segmental in cr'oss section and adapted to communicate with a source of air under pressure, a series of separate air boxes 10- cated at the end of the grate bars and communicating with said source of air supply, each of said air boxes having on its inner side adjacent its grate bar an opening for admitting the air to the compartments successively.

11. In combination with alfurnace, a

series f rotatable grate bars, each divided y into separate longitudinal compartments segmental in cross section and adapted to communicate with a source of air under pressure, a series of separate air boxes located at the end of the grate bars and communicating with said source of air supply, each of said air boxes having on its inner side adjacent its grate bar and in the upper portion thereof a segmental opening for ad-4 mitting the air to the compartments successively as they are exposed to the fuel bed.

12. In combination with a furnace, a series of rotatable grate bars, each divided into separate longitudinal compartments Y successively as the grate bar rotates to expose the compartments to the fuel bed.

, 13. In combination with a furnace, a series of rotatable grate bars, each divided into separate longitudinal compartments segmental in cross section and adapted to communicate with a' source of air under pressure, a series of separate air boxes located at the end of the grate bars and communicating `with said source of air supply, a plate 14 located in each air box and spring pressed against the end of its grate bar, each plate having an opening for admitting the airto the compartments successively as the grate bar rotates to expose the compartments tothe fuel bed. y

` 14. In combination with a furnace, a series of rotatable grate bars, each divided into separate longitudinal compartments segmental in cross section and adapted to communicate with a source of air under pressure, a series of separate air boxes located at the end of the grate bars andl communicating with said source of air` supply, each of said air boxes having on its inner side adjacent its grate box and in the upper portion thereof a segmental opening for admitting the air to the compartments successively as they are exposed to the fuel bed, a main supply pipe 11, individual connecting pipes 12 therefrom to the air boxes, and independently operated valves 13 in the connecting pipes, whereby the supply of air to the different grate bars may be varied at` will.

15. In combination with a furnace, a series of rotatable grate bars, each comprising a tubular grate surface 4, a longitudinal sleeve 5, a series of radial partitions dividing the grate bar into a series of sepaate compartments which are segmental in cross-section, a shaft or spindle 6 which passes through the sleeve 5 and on which the grate bar is mounted to rotate, and means for introducing a supply of air into said compartments successively.

LELAND L. SUMMERS.

Witnesses:

S. E. HIBBEN, y LOUIS B. ERwIN. Y Y.

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