US670781A - Furnace-front. - Google Patents

Description

Patented rm. 26, 190|.

No. 670,7al.

J. B. HousToN. FunNAcl-z FRoNT.

[Application led Apr. 2B, 1900.)

2 Sheetsf-Sheet l.

(No Model.)

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2 Sheets-Sheet 2.

(No Model.)

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UNiTnD STATES PATENT OFFICE.

JOHN BROADFOOT HOUSTON, OF VANCOUVER, CANADA.

FU RNACE-FRONT.

SPECIFICATION forming partof Letters Patent No. 670,781, dated March 26, 1901.

Application iiled April 28, 1900. Serial No. 14.731. (No model.)

To @ZZ wtontvt may concern:

Beit known that I, JOHN BRoADr-oo'r Hous- TON, a citizen of the Dominion of Canada, residing at Vancouver,in the Province of British Columbia, Canada, have invented a new and useful Furnace-Front, of which the following is a speciiication.

My invention relates to improvements in furnace-fronts especially designed for the application of mechanical draft, and it is particularly constructed to convey the air for combustion to the furnace and admit it to above and below the furnace-bars in any desired proportion or shut it off from either one or both; and my objects are, first, to simplify the construction of furnace fronts of this class and make them comparatively easy to put together or remove one or more of the parts for repairs or renewal or for any other purpose without disturbing the remainder of the parts by constructing the same in sections, as will be fully pointed out in this speciiication; second, by conveying the air for combustion through the passage formed by the outer and inner walls of the lining the passing air abstracts the heat, which would other-l wise have a destructive effect on the liner and the elevated temperature which the air thus attains to insure a more perfect combustion when combined with the fuel-gases in the furnace, and, third, to construct the furnace-doorway lining particularly strong with an outer and inner wall cast with a suiiiciency of webs between, so as to resist the warping and straining tendency caused by unequal expansion.

I simplify construction and reduce first cost, facilitate repairs, and lengthen the life of the liner by diverting the heat, which tends to destroy it, back to the furnace, insuring economy of fuel, and in securing these points the construction of the liner is one which is strong and durable.

I attain these objects by the mechanical arrangement of my furnace-front, as illustrated in the accompanying drawings, in which- Figure l is a front elevation of my furnacefront. Fig. 2 is a vertical longitudinal section. Fig. 3 is a vertical cross-sectional elevation taken on the line a a in Fig. 4. Fig. 4 is a sectional plan of the same on the line b b in Fig. 3. Fig. 5 is a vertical cross-sectional elevation of an alternative design, taken on the line c c in Fig. 7. Fig. 6 is a vertical longitudinal section, and Fig. 7 is a sectional plan of the same. Fig. Sis a detail of the fastening of the door-liner to the door, and Fig. 9 is a detail of the butterliy-valve for admission of air to the ash-pit.

Similar characters refer to similar parts throughout the several views.

My drawings show the application of the invention to the furnace of a boilerof the marine type.

. In the particular construction of my improved furnace-front the furnace-[ine 10 is extended forward, forming a casing or chamber the front rim of which is arranged on an even plane, so as to form a tight joint where the castings connect with the same, and the outer upper side of this is secured to the front wall of the hotair space b in any suitable manner and the inner wall of such hot-air space being the front of the boiler et. The upper part of the casing 10 is cut away, leaving a large aperture 1l, and on each side of this are other smaller apertures l2, through At a point just below the diameter and Within the casing 10 is a dead-plate 13,` the upper side of the inner end of which is beveled 0E downward, as 13a. This dead-plate is suitably strengthened by webs 13b and is suitably secured at each end to the opposite The dead-plate is carried rearward H IOO . metal.

to the exterior of the casing 10 and the whole being operated by a handle 16, fixed on one end of the said shaft. When the valves are open, the said handle 16 stands horizontal and when closed is down. (See Fig. 3.) The valves 14 seat, as shown in Figs. 5 and 9, on

lthe upper and under sides ofthe ledges 13,

cast for that purpose in the dead-plate.

17 indicates the sides of the doorway, which are formed in sections resting on the deadplate. These sections are projected rearwardly and curve around to engage the inner part of the casing c, against which they are made practically air-tight. As shown in Figs. 3 and 4, the walls of these'sides 17 are cast hollow, with vertical strengthening-webs securely tying the inner and outer walls together, while the walls exposed to the iire are provided with numerous apertures 17, angled toward the furnace-grate, so as to direct the air upon the fire. The outer wall, as 17", (see Fig. 3,) is discontinued atvthe lower front sides of the sections to allow the valve 14 to operate or swing upward.

Resting on the side sections 17 and forming the top of the fire-doorway is a casting 18,which is curved around on the sides and upward, continuing the closed connection with the mouth of the fire-box c and effects, with the sections 17, its complete closure above the grate-bars, save where the doorway is vlocated. This top casting 18 is made with the double Wall or air-passage to correspond with the sides where exposed to the iire and is provided with apertures 18L to direct the air to the furnace in a similar manner to the side pieces. Along the top of the casting 18 are elongated ports 18h, which are provided with a slidable valve 19, and secured to said valve is a handle 20, projecting through the front casting 21, which casting is joined to the castings 13, 17, and 18 and to the casing b by any suitable means, and thus provides an air-tight closure'for the casing 10, except the portions occupied by the doors, to be hereinafter described.

22 indicates a door for the furnace,twhich is designed to rest when closed on a mouthring 21a and make an air-tight closure. This door 22 is provided with a cast liner 22a, having front and rear walls 22, which form an air-chamber therebetween approximately the contour of the door to be closed, and these walls are tied together by Webs to stand the strain caused by the contraction of the The liner is supported on bosses 22d, projecting from the door, through which are passed retaining bolts 23. (See Fig. 8.) The sides of the liner 22b are provided with apertures similar to the air-vents in the sides 17, so .that the air will be directed into the furnace, preventing the flame from impi'nging thereonand tending to keep down the temperature, and thus preserve the liner. The square recesses-for the bolt-heads are cored in both faces, so that when one side is burned out the bolts 23 may be removed and -terfly-valves 14 properly.

evojr'si liied form, the boiler-front is flanged inward and the air-casing is a part of the general casting forming the furnace-front. In this case care has been taken so that the liners Ycan be removed for renewal or examination and repair of the furnace-tube without necessitating the removal of the whole front air-casing. It is shown in Fig. 5 that the fullest area for air-passage across thel top be- Y neath the uptake has been provided for, as before referred to. The casing is composed of a casting 25, having therein the openings for the doors 22 and 24 and dispensing with the dead-plate 13, as shown in Figs. 2, 3, and

'4. The said furnace-dooropening is formed integral with the casting and projected inward, forming a passage, as 25, to the end of which are connected the side liners 26 and the top liner 27, the latter not only forming a liner, but the parting-wall between the furnace and air-space, and these are snugly iitted to the end of the boiler to make a close lit. To the lower side of the door passageway 25a is secured the dead-plates 28, forming the support for the grate-bars, as before mentioned, as common in the other figures.

The liner 27 is double walled, as in Figs. 5, 6, and 7, and has air-directing apertures to the furnace 27n and 18, which series of apertures are also provided around the sides and above the door passageway 25, and the air is introduced between the liner'by the usual apertures and valve 18b and 19, respec tively, whence it passes to the liner 27 through ports 29 and to the side liners 26 through chambers 30. (See Fig. 5.) These chambers 30 are further designed to support the side Walls of the furnace-door at its center and clearing the ash-pit valves 14 when open, and the inner walls thereof are perforated to admit the air to the furnace, as before stated.

To avoid the expense of fitting the valveshaft 15 in the heavy casting 25, I provide apertured bosses 31 on each side, through which the shaft 15 is loosely passed, and then closely-fitted collars 32 are passed over each end of the shaft, which are adjusted and secured at the proper points to adjust the but- (See Fig. 5.)

From the foregoing it will be seen that the flow of air to the furnace is perfectly controlled by the slidable valve 19, movably mounted over the multiple ports 18b above the door passage-way, and the bu tterfly-valves 14 on each side of the ash-pit and that the draft can be adjusted to a nicety by the manipulation of the handles 16 and 20.

I am aware that prior to my invention furnace-fronts have been in use constructed With an inner and outer wall madein bell-mouth form similar to mine, but not having the pro- IIO longation of the furnace-due forming a part of the casing and not having the Areversible door-liner, as I have shown in Figs. 2, 4, and 8, and also the arrangement and adjustment of the valve-shafts 15 (shown in Fig. 5) is a desired improvement with the particular construction of casting 25, forming strengthening-webs for the sides of the doorway and at the same time admitting air to the furnace just above and close down on the dead-plate, which protects the same from the intense heat.

Having now described my invention, what I claim as new, and as an advancement in the art of the construction of furnaces, is-

1. In a furnace-front of the character described, the combination with the casing forming a continuation of the furnace, and the dead-plate dividing the casing into uppei` and lower compartments, said dead-plate having a valve at each side operated from the outside; of a fuel-passage consisting of a supplemental casing mounted on the dead-plate, which plate forms the bottom of the fuel-passage, the fuel-door, a perforated liner carried on the door, and projected forwardly into the fuel-passage, air-spaces surrounding the fuelpassage-casing sides and top, the side and top walls of the fuel-passage having air-inlets discharging to the rear of the liner and in front thereof toward the furnace-mouth, and a valve in the top of the casing for regulating the forced draft into the air-spaces surrounding the fuel-passage, as set forth.

2. In a furnace of the character described, the combination with the fuel-passage, of the hollow cast liner 22, the front and rear walls thereof having ports opening into the fuelpassage, said liner also having internal transverse hollow ribs terminating at each end in Ma countersunk bolt-head recess, the bolts 23,

and the inwardly-extending apertured doorhubs 22d, all being arranged substantially as shown and described.

3. In a furnace for the purposes set forth, a furnace-front consisting of a casing 10, being a continuation of the furnace-liuc, ports in the upper side of said casing for the passage of air; in combination with adead-plate 13, secured across the said casing and fitted into opposite sides of the furnace-fine, side plates 17 having an inner and an outer wall lying on the dead-plate, said side pieces curving around and connecting with the opposite sides of the furnace-flue, and a top or cover 18 lying on the side pieces having the airchambers therein forming the top of the doorway and curving upward and with the side pieces, forming a tight closure for the mouth of the furnace above the dead-plate, save that portion occupied by the doorway, a slidevalve 19, for admitting air through a plurality of ports between the walls of the sections 18 and 17 and apertures 18 and 17u communicating with the furnace, and butterflyvalves communicating between the upper and lower sides of the dead-plate, and means for closing the doorway, as specified.

Il. In combination with a casting 25, forming the door-opening for a furnace and to the ashpit, a shaft 15 placed at right angles through apertures in each side of said casting, and adjustable bearing-collars fitted on each projecting end of the shaft susceptible of adjusting and securing the shaft in its proper horizontal position, for the purposes specified.

5. .In a furnace of the class described, a casting 25 forming the openings and seats for the door to the furnace and to the ash-pit, an air-chamber around the sides and top of the furnace door opening, a multiple of ports communicating to the said chamber from the top and a slide-valve for controlling the airflow to same, chambers 30 having an enlarged dimension at the center in their vertical crosssection on each side of the door passage-way formed by the outer walls being curved outward and apertures from the inner wall of these chambers to the door passage-way close down on the lower wall or dead-plate, in combination with detachable liners 26 and 27 connected with and curved around on each side and above the furnace-door passage-way having apertures therein, as and for the purposes set forth.

JOHN BROADFOOT HOUSTON.

Witnesses:

W. G. TRE'rHEwEY, ROWLAND BRITTAIN.

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