US1243869A - Furnace construction. - Google Patents

Description

` H.A. PQPP'ENHUSEN.

FURNACE CONSTRUCTION.

APNIC/mon FILED 050.6, |916. l

Patented. Oct. 23,1917.

3 SHEETSSHEET l ,'HA. POPPENHUSEN. FUBNACE CONSTRUCTION.

Patented 1m. 23, 1917.

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APPLICATION FILED 0156.6. 1916- v @mum @an 23, mi?.

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HERMAN A. POPPENI-IUSEN, OFHAMIVIOND, INDIANA, ASSIGNOR 10 GREEN ENGINEER- ING COMPANY, OF EASTCHICAGO, INDIANA, A CORPORATION O F ILLINOIS.

FURNACE CONSTRUCTION.

To all whom t may concern.'

Be it known that I, HERMAN` A. PorrEN- HUSEN, a citizen of the United States, residing at Hammond, in the county of Lake and State of Indiana, have invented new and useful Improvements in Furnace ConA structions, of which the following is a speciiication.

This invention relates to I improvements in furnaces, and more particularly to devices for controlling and regulating the draft supplied to furnaces of the type ordinarily used in connection with steam boilers.

Among the objects of the invention is to provide a construction for furnaces wherein both a natural or forced draft mayI be employed to supply an adequate amount of air to the fuel bed, .together with devices adapted to be operated to cut off the natural draft y and permit the furnace to operate'under forced draft, and likewise to cut off the forced draft and permit the furnaceto run under natural draft.

In the operation of commercial boilers and furnaces, it is well known that the load or working condition fluctuates throughout a considerable range, such fluctuations being met by increasing or decreasing thevdraft, which in turn controls the rate of-combustion ofthe fuel. Undernormal conditions a furnace may operate properly under a natural draft, but under conditions of overload or heavy firing the natural dr'aft would l be wholly inadequate, and a forced draft would be required to give the-'desired results.

The use of forced draft involves the in stall'ation of a suitable fanor blower mechanism operated by a motor other prime mover, hence the exclusive of a forced n draftwould not tend to promote efficient operation of the furnace iuider conditions where natural draft would serve. The provision of means whereby either natural or forced draft can be utilized, and the change from one to the other readily accomplished, serves therefore to increase the eiiciency of operation of boilers and to decrease the cost of maintenance of furnaces and their auxiliary operating devices. 1

The particular type of furnaceA herein described and embodying the features of the invention is of the so-called automatic or mechanical- Stoker type, embracing the traveling chain form of grate, although, as

rammed/oet. as, fait.

Application led December 6, 1916. Serial No.' .135,466.' 1

`will be seen hereinafter, the features of the after more fully set forth, the accompanying drawings illustrating a desirable embodiment of the invention, wherein- Figure 1 is a view in longitudinal section through a furnace containing the features of the invention; n

Fig. 2 is a transverse/ section of the furnace, taken on line 2 2 of Fig. 1;

Fig. 3 is a plan section taken on line 3-3 of Fig. 1, showing the arrangement of ducts and damper operating mechanism; and

' Fig. 2u is a detail View in section, showing the sealing strips on the margins of the dampers.

Referring to the drawings, the parts of the furnace illustrated comprise, in general,' the side walls 10, 10, of the brick construction common to furnace settings; a front `wall l2; a coking breast 13, extending rearwardly and over the forward end of the lire box or combustion chamber, said' front wall fand coking breast supporting the front header and forward end of the lower bank of boiler tubes 14. Rearwardly of the front wall 12, and extending upwardly from the floorof the furnace setting, is a bridge wall 15. Within the fire box and extending forwardly from the bridge wall 15 and beyond the front wall 12, is the grate 16, thesame having the form of an endless chain, as before mentioned, formed of a multitude of connected together links, the portion of the upper horizontal grate extending rearwardly from the front wall forming the acournals of a plurality of parallel and transversely extending rollers 20, which pass bei neath the upper portion of the chain grate and support the same. At the rear ends of the side frame members 17, 17 are mounted said shaft a series of sprocket` wheels 24, 24,

carrying the chain grate.

From the forward end of the furnace extend vertical side plates Q5, Q5, in the nature of exterior coiitinuations of the side frame members 17.` Journaled iii suitable bearings in said plates 25, 25 and extendin; between the same, is ay shaft 26, likewise carrying a series of sprocket w-heels27 meshing with and carrying the forward end ofthe chain grate. Suitablev driving mechanism (not shown) serves to rotate the sprocket shaft, thus moving the chain grate to carry the fuel rearwardly upon the surface of the grate. mniediately above the foi-ward lend of the grate 16 isthe fuel hopper 28, comprising end walls, integral with the side plates 25, 25, and a downwardly inclined rear wall Q9, said hopper communicating at its bottom with the fire box, through Aan elongated opening intermediate the lower edge of the front wall 12 and the surface of the grate 16, said opening being capable of regula-4 tion, as to size, by means of a vertically movable gate 30 and suitable actuating devices (not shown). The fuelv is introduced onto the forward end of the grate, and is carried rearwardly on the moving grate unt-il it reaches the rear end, in t-he forni of ash, where it drops by gravity into the ash pit or other receptacle.

Referring now to the construction and arrangement of the interior of the furnace', the space below the upper chain or lead of the grate and inwardly from the front wall 12 of the furnace is preferably divided into a ,plurality of chambers or compartments- 31, 32, and 33, formed in the following manner: As shown in Figs. 1 and 43, the side frame members 17 consistof a plurality of sections, of equal length `and arranged in pairs, each pair forming ,the sides of the three compartments. Each section or side frame member is provided at its ends with lvertical flanges 34, 34C, arranged at right angles and extending inwardly in close proximity to'the lateral edges of the grate, there being preferably provided spaces between the flanges, ext-ending the full height of the sections.

Extending transversely of the side frame members 17, 17 are a plurality of transverse frame members 35, the same -having the form of -beam sections, that is,` a vertical central web provided with transverse webs bers extend into the spaces between the flanges 3l of the side frame members (the end portions of the webs 36 and 37 being removed through the portions between said flanges), and are secured to the side frame members by means of bolts 38 extending through the flanges 3l. Extending between the transverse frame members 35 and spaced below the upper lead of the grate 1G, are a plurality of partition walls l0, the same consisting of inverted V shaped plates, secured at their ends to the faces of the transverse frame members 35 and sloping or inclined downwardly frcin the apex, spaced a short distance below the central portion of the grate, the outer margins of said walls terminating just above the side margins of, the lower .lead of the grate. The partition walls 4c() form the bottom walls of the compartments, and, by reason of the inclination the side frame members 17 and connected thereto in the same manne1 as said transv-erse frame members. The upper margin of each plate 41 is spaced below the under surface of the grate, there being mounted in said space a series of rollers l2, which engage and support the lower portion of the grate, said rollers being provided at -their ends with journals, which are mounted within bearings 43, 43, preferably formed integral with the plates 11 and located along' the upper margins thereof and immediately below the lateral margins of the grate. The lower margins of the platesl 11 are spaced above the floor level or bottom surface of the space below the grate, said margins being preferably arched, as shown in the drawings,

lcate with each other at their lower portions and adjacent to the floor of the furnace.

Associated with each compartment are two dainpers JA, 44, located at either side of the lower lead of the grate and extending upwardly from the floor of the furnace in the plane of the side margins of the grate and spaced inwardly from the side frame members 17. The dainpers comprise two hinged together plates #l5 and -lGvextending lengthwise of the compartment, the lower plate 1G being comparatively narrow in width and rotatively supported along its lower margin by a suitable joint, preferably consisting of a downwardly facing groove formed in the lower edge of the plate 46 'and engaging a rib 47 extending upwardly from the floor of the furnace. The vupper plate 45 is connected to the lower plate 46 byl means of suitable hinges` 48,'so arranged as topermit the plates to be flexed in an outward direction. The upper plates 45, 45 Aextend upwardly a considerable distance above the outer margins. of the partition wall 40, and when in the position shown in full lines in the drawings, namely, when the plates 45 and 46 arein Vertical alineinent, the mar-` gins of the partition wall 40 are in contact withthe damper and below the upper margins thereof. The dampers associated with each compartment are adapted to be oper-A ated by suitable-operating mechanism andA in a manner to shut off the natural draft and open the forced draft ducts, and vice versa, as will hereinafter be more fully pointed out. In the full line position, shown in Fig. 2, the daiiipers are in vertical position, and form the inner side ,wall of a series of pairs of vertical passages 49, 50, and '51 asso-v ciated with each of the compartments 31, 32, and 33, respectively, and including the spaces between the dampers 44, the side frame members, and the flanges 34,. 34 of each side frame member. The vertical passages thus formed extend from the floor of the furnace and communicate at their upper ends with their respective compartments,

and, furthermore, are closed from communication with the space below the grate, which is the source of natural draft-or free air, inasmuch as the space is open throughout the length of the grate and open to the atmosphere through the lower front portion of the furnace, which is entirely open.

Before describing further the mode f peration of the dampers and the means for so doing, the construction employed for supplying the forced draft, or air under pressure, to the furnace will be described. Below the floorel'evel of the furnace is provided a space extending throughout the length and width of the orate and forwardly a short distance beyond the front wall of the furnace, said space being preferably separated from the space immediately below the grate by means of'a floor plate 52 of metal or other suitable construction, which terminates-inwardly from the side frame members 17 and adjacent to the lower margins of the dampers 44, thereby forming a plurality of floor openings 53 connecting the sub-'floor space with each ofthe vertical passages 49, 50, and 51. The space below the floor plate is divided into a series of longitudinally extending ducts or air passages, formed by means of vertical partition walls 54 extending between the bottom surface'of the space and the floor plate. rThe partition walls are arranged so as to form pairs of ducts adapted to supply air to each compartment vthrough 'n civ the vertical side passages thereof, aiid the following manner.

The outer pairs of ducts 55, 55 ext-end only throughout the length-of the first or outermost compartmentV 31, the inner end thereof being closed by providing the partition wall thereof with curved end portions, which terminate at right angles to the longitudinal portions of the wallsgand in abutting relation with the side Wall of the space below the Hoor. The ducts 55, 55 communicate 'with the lower ends of the vertical passages l50, 50 through the openings 53 at the lower ends thereof. The central or larger duct 57, formed between the inner walls 54, 54, communicates with the remaining portion of the space located below the rearmost com` partment 33, said space in turn communicating with the vertical passages 51, 51 of said compartment 33 in the same manner as do the ducts 55 and 56, heretofore described, namely, by openings similar to 53 at the lower ends of said vertical passages.

The outer or forward ends of the ducts 55, 5G, and 57 communicate with a space or cross passage 58, common to all, extending transversely of said ducts and adapted to supply air to all of said ducts from a single source of supply, preferably a single'passage 59, in which is mounted a fan or blower GO, operated by a'motor 61, both fan andmotor being preferably mounted in the. passage 59, which receives a supply of air through a suitable opening covered with a grating G2 set in the floor in front of the furnace.

From the foregoing description, it is apparent that, with the danipers in vertical or closed position, the air can be supplied to the furnace only through the ducts below the floor, inasmuchas the danipers effectively shut off the air space below the grate. If it .is desired to shut off the forced draft and operate the furnace by natural draft, this is accomplished by actuating the dampers by mechanism hereinafter to be described and in a manner to swing them outwardly toward the side frame members. as shown in dotted lines in Fig. 2, namely, with the upper plate 45 extending vertically and lying flat against the surface of the side frame member, and the lower plate inclined outwardly and upwardly over the openings' 53, 53. In this position it is seen that the dampizo ' transverse plates 41 by ers completely close the openings 53, thus shutting olf the forced draft duct and simultaneously opening the vertical passages to communication with the space below the grate, thus permitting the free air to pass upwardly through the vertical passages and into the compartments beneath the upper lead of the grate.

Referring now (Fig. 3) to the means for operating the several pairs of dampers i4', 45t, it is preferred to employ actuatii'ig mechanism capable of operating each pair of dampers associated with the several compartments, independently of each other. Referring first to members of the damper operating` mechanism, common to all of the dampers, there is pivotally connected to each damper, adjacent to the lower margins o the upper plates '-15 and intermediate their lateral edges, links (55, preferably joined to journal bearing members GG fixed to the plates. The linksl extend inwardly in a horizontal direction and are pivotally connected at their inner ends tol links G7, G7 extending transversely of the links (i5, said links 67, 67 being pivotally mounted upon the Ameans of bearing members 68, G8, fixed to said plates l1 and having connection with the ends of the links G5 by means of downwardly depending connecting members G9, 69.

rl`he links G7, 67 are, in turn, connected to each other and with an operating rod, presently to be described, by means of a transverse bar and short intermediate links 7l, 71, pivotally connected at their ends with the ends of the bar '70 and the links (S7, (37 intermediate the ends of the latter..

As a means for operating` the several bars 70 independently, and at the same time provide a compact construction, a plurality of endwise movable operating rodsl '72, 73, and 74 are used, all but one of said rods being tubular, thus permitting the same to be in- 'closed or telescoped one within the other.

The rods extend longitudinally and centrally of the furnace, below the grate, and are mounted in bearings 75, preferably secured in apertures formedy in the several plates il below the grate, and forming, as before indicated, a portion of the vertical partition walls of the several compartments.

Considering the rods more in detail, the rod 72 operates the dampers ofthe forward compartment 3l and consists of a tubular member or sleeve extending inwardly from the front of the furnace a shortl distance rearwardly of the first. compartment and supported in the bearings 75, of the `first and second plates $7. lnclosed within the rod 72 is the rod or sleeve 73, which operates the damper of the compartment 32, said rod being tubular but of less diameter than the outer rod 72 and of greater length, extending beyond the inner end of said rod 72 a short distance beyond the plate 4:7

intermediate the Icompartments 32 and 33y plate.

ln the same manner, the rod 74 is mounted within the tubular rod 73 and exte-ndsyrearwardly to' the rearmost plate 47 and mounted in the bearing 7 5 thereof, said rod 74 being of less diameter and vof greater length than the rods 72' and 73 and preferably solid rather than tubular las are the rods 72 and 73. The rods 72, 73, and 7% operate the dampers of the compartments 3l, 32, and 33 respectively, as before suggested, each rod being connected to its respective bar 70, which is provided with a centrally located collar surrounding the rod. The several rods are operated from the forward end of the furnace by a series of levers arranged in the following manner: Extending transversely of the forwardly extending frame members 25, 25, is a shaft 7G, rotatively mounted 1n bearings provided in said frame members, said shaft projecting beyond the frame members on one side of the furnace. Intermediate the ends of the said shaft is provided a fixed crank arm 77, having connection with .the end of said rod 74 by means of a link 7 S, said rod projecting forwardly a short distance beyond the end ofthe tubular rod 73. At the outer end of the shaft 7 6 is a. lever 79, adapted to be operated by hand to rot-ate the shaft 76 and, through the crank and link connection, to move the rod 7l endwise, the endwise movement of the rod transmitting the desired swinging movement to the dampers through the' intermediate arrangement of the bars 70`and links 7l, (S7, and 65.

Mounted upon the shaft 76 is a rotative tube S0, extending from the central portion of said shaft through one of the side frame members, and terminating acent the lever 79, said tube being provided at its outer end with a lever 8l and atits inner end with a crank arm 82 connected to the adjacent end of the rod 73 by means of a link 33, said rod extending a, short distance ln like manner the tube 80 is surrounded by a larger tube 84C, rotatively mounted thereon and extending through the side plate and provided at itsouter end with a. lever S5 and at its inner end with a crank arm 8G connected to the rod 72 bymeans of a link S7.' By rotating the tubular shafts 30 and 34 by means of their respective levers Sl and 35, the rods 73 and 72, respectively, are moved endwise and operate the pair of dampers connected thereto, in the same manner as hereinbefore described in connection with the shaft 76.

Inasmuch as it is desirable to make each compartment quite independent, so far as' naaaeee means are employed to confine the draft Within the passages of each compartment and to eliminate the leakage of air by the dampcrs and from one compartment to another. To accomplish this purpose, there are provided along the lateral marginsof the dampers strips '88 (Fig. 2u) of flexible material, of sheet metal or other suitable material, which extend beyond.l the Inargins of said dampers and contact with the adjacent surfaces of the transverse anges 34: of the side ivall sections 17, thus closing the clearance spaces which otherwise Would permit a considerable amount of air to leak by the dampers. provided along the top margin of the partition Walls between the compartments, vertical extensions, in the form of angle-bars 89, extending transversely of the grate and mounted on the upper Webs 36 of the transverse frame members 35, 'said angle-bars having a vertically projecting web extend-- mg in close proximity to the under surface of the grate. rIhe purpose of this extension is to close the vertical space between the upper edges of the transverse frame members and the grate.

A furnace constructed in accordance with the particular arrangement of air passages and dampers is capable of being controlled and to be accurately regulated to meet all conditions of load, by manipulating the damper controlling levers, so connected to the dampers through the intermediate operating mechanism that not only canthe draft be instantly and completely changed from,

forced to natural, but separate portions of the grate can be supplied with either form of draft, bythe provision of independently operated dampers in the several compart;

ments. Thus each compartment divides the entire grate surface into a number of units i or sections, each section being capable of regulation as to the draft supplied thereto, quite independently of the other sections.

The novel features of the invention hereinbefore described are more specifically set forth in the appended claims.

I claim as my invention:

l. In a furnace, the combination of a grate, an' air space beneath the grate communicating With a source of free air and a source of forced draft, and a damper mounted in said free air space vintermediate the sources of forced draft and of free air, and movable into position to shut o' the supply of free air to said air space and to form a passage connecting said air space with said forced draft duct.

2. In a furnace, the combination of a grate, an air space beneath said grate communicating With a source of free air, a forced, draft duet opening into said air space, and a dam-per, mounted in said air space intermediate the source of free air and Furthermore, there are the opening of said air duct, and movablel into one position to form a passage -shut ed from`the source of free air and connecting said air space and forced draft duct, and into another position to close the opening of said forced draft duct and to permit the supply of free air to/the grate.

3. In a furnace, the combination of a grate, a compartment below said grate provided With a passage'adapted to communicate with sources of natural and forced draft, and a damper mounted in said passage, intermediate said sources of natural and forced draft and movable into one position to close said passage from communication with said source of natural draft and open communication with said source of forced draft, and into another position to,

close said passage from communication with said source of forced draft Aand open communication with said source of natural draft. e

4. In a furnace, the combination of a grate, a compartment formed beneath said grate, adapted to communicate With a free air space included between opposite Walls of the furnace below the compartment, by means of an opening adjacent one of said Walls, a damper mounted in said free air space and spaced from said Wall and adapted to be moved into and out of position to form a passage shut off from said free air spacey and communicating With said opening to said compartment, and a forced draft duct, and means for supplying forced dra'ftto said passage. f

adapted to communicate With a freey air ,space below said compartment, a forced.

draft duct communicating With said lfree air space, and a damper mounted in said free air space adjacent to the furnace Wall and movable into one position to form a passage shut off from said free air space and connecting said compartment Withsaid forced draft duct, and into another position to close saidpforced draft duct.

6. In a furnace, the combination of a grate, a compartment beneath said grate, adapted to communicate With a free air space adjacent said compartment, a damper mounted in said free air space and movable into and out of position to convert a part of said free-air space into a passage communicating with said compartment and shut off from said freeair space, and a forced draft duct adapted to communicate With said compartment through said passage and to be closed by said damper When moved out of position to form said passage.

7. In a furnace, the combination of a grate, a compartmentvbeneath said grate, provided With an opening communicating With a free air space below said compartment, a forced draft duct communicating with said free air spac'e below the opening to said compartment, and a damper movably mounted in said free air space and adapted when in one position to inclose a portion of said free airspace to form a vertical passage connecting said forced draft .duct with said opening to said compartment, and in another position to close the opening of said air duct.

8. In a furnace, the combination of a grate, a compartment below said grate provided with an opening between the margins of the grate and a side wall of the furnace, said opening' communicating with a free air space below the compartment, a forced draft communicating with said free air space below said opening, and a vertically arranged damper spaced inwardly from said wall and adapted in one position to form a passage shut od from the air space and connecting said opening of the compartment with said forced draft duct, and in another position to shut off said forced draft duet and open communication between said compartment and said free air space.

9. In a furnace, the combination of side walls, a grate, a compartment formed beneath said-grate, said side walls being spaced outwardly from the edges of said grate and forming openings connecting said compartment with a free air space therebelow, forced draft ducts communicating with said free air space adjacent said side walls, and a damper mounted in said free air space in spaced relation to said walls and movable into one position to form vertical passages communicating with said compartment and with said forced draft ducts, and 'into another position tomerge said passage into the free air space and to shut off said forced draft ducts.

l0. In' a furnace,the combination of a grate, the side walls of the Afurnace below the grate being spaced outwardly from the adjacent margin of the grate, a partition wall intermediate the grate and floor of the furnace and -terminating short of the side walls and forming an air space adapted to have communication with the atmosphere through an opening adjacent a side wall, a vertically arranged partition wall spaced inwardly from a side frame member and forming an air passage therebetween, and an air duct communicating with said air passage, said partition wall being movable toward the side wall of the furnace, to permit free air to enter the compartment and to close said air duct.

11. In a furnace, the combination of a grate, vertical side frame members, supporting said grate and spaced outwardly there from to provide Vertical passages on either side of the grate, a partition wall spaced below said grate and forming with said side frame members an air compartment having communication with the atmosphere through,

said vertical passages, a damper spaced `inwardly from the side frame members and forming a wall of said passages, and an air duct communicating with the lower end of each of said vertical passages, said damper being operable to shut off communication between said compartment and either the atmosphere or said air duct.

l2, In a furnace, the combination of a grate, a horizontal partition wall intermediate the grate and floor of the furnace and forming a compartment, said partition wall terminating` short of a side wall of the furnace and providing an opening communieating with a free air space below said partition vlall, an air duct for conducting air under pressure to said free air space and communicating therewith adjacent thc side walls of the furnace, and a vertical partition wall extending downwardly from the edge o l said horizontal partition wall and spaced inwardly from the side wall of the furnace and beyond the opening of said air duct, and movable into one position to form an air passage closed from communication with said air space, and into another position to close said air duct. 4

13. In a furnace, the combination of a grate` a partition wall intermediate the grate and the floor of the furnace and forming an air eompartn'ient beneath the grate, there being provided openings in said compartment adjacent the side walls, communicating with a free air space below said compartment, an air duct for conducting` air under pressure to said air space and opening thereinto adjacent a side wall of the furnace, a damper comprising hinged together plates pivotally mounted upon the floor of the furnace and spaced inwardl)T from the side wall and adjacent the opening of said air duet, said damper plates when in vertical position forming a passage closed from communica-- tion -with said free air space, and when.v

moved toward the side wall of the furnace to close the openingI of the air duct, and means for operating said damper.

14. In a furnace, the combination of a grate, a compartment beneath said grate and communicating with a free air space below the conipartnjient, an air duct for conducting air under pressure to said free air space and communieating` therewith through an opening in thetloor of the furnace below the openingto said compartment, and a damper comprising hinged together plates, the lower plate being pivotally mounted upon the floor of the furnace adjacent the air duct opening, said damper plates when in vertical position serving to inclose a porwhen moved into y.another position to open communication between the compartment and free air space, the lower plate of the damper acting as a closure for the opening,l .of the air duct.

l5. In a furnace, the combination of al `grate mounted in the combustion, chamber of the furnace, a series of. separate compartments below said grate and adapted to have communication with the atmosphere, a series of separate air ducts for supplying air to said compartments, a damper associated with each compartment to control the supply of free-air or air under pressure to said compartment, a plurality of operatingr rods in telescoped arrangement, each operativelyv connected to one of said dampers, and levers mounted exterior of the furnace and connected to said operating rods, to actuate said dampers independently of each other.

16. In a furnace, the combination of a traveling grate, a series of compartments formed between the upper and lower p0rtions of said grate, said compartments having communication with a common free air space below the grate, a series of air ducts communicating with the free air space, adapted to supply air underpressure to said compartments, a series of dampers mounted in said air space and adapted in one position to form aV passage connecting each compartment with its correspondingv air duct,

and' in another position to close said air ducts, yand independent operating means connected witlreacli of said dampers.

In testimony that I claim the foregoing as my invention I aiiix my signature in the presence' of two witnesses, this 2nd day of December, A. D. 1916.

HERMAN A. POPPENHUSEN itnesses A CHARLES H. POOLE, CLARA L. PEoPLEs.

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