US1428636A - Furnace-bridge-wall construction - Google Patents

Description

F. A. HURLBUT.

FURNACE BRlDGE WALL CONSTRUCTION.

APPLICATION FILED JULY I3. 1918.

1,428,636. PatentedSept. 1.2, 1922.

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WITNESS; [NVEN TOR.

A TTORNE Y F. A, HURLBUT.

FURNACE BRIDGE WALL CONSTRUCTION.

AFPLiCATION HLED JULY 13.1-918.

& g PatemedSept. 12, 1922.

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Patented Sept. 12, 1922..

cairn NT OFFICE.

FURNACE-BRIDGE-WALL CONSTRUCTION.

Application filed July 13,

T 0 all whom it may concern:

Be it known that I, FRANK A. HURLBUT, a citizen of the United States, residing at Flat River, in the county of St. Francis, State of Missouri, have invented certain new and useful Improvements in Furnace-BridgelVall Construction, of which the following is a full and exact specification.

The present invention relates to improvements in the construction of furnace bridge walls, and while the improvements are useful with various types of furnaces they are especially adapted for use in connection with boiler furnaces of the type fed by mechanical stokers. I

One of the principal objects in view is to provide an improved form of bridge wall suspended in position overlying the rear end of the stoker and having no supporting connection with the main rear end wall of the furnace stoker chamber.

Another object of the invention is to devise a bridge wallof this character which will permit of maintaining a damper device, such as afforded by a door or gate construction, for regulating the amount of opening which is left between the stoker and the lower edge of the bridge wall.

It is also an object to provide a damper device of the character just indicated which will be comparatively indestructible in its nature and also adapted to have more or less of a self-adjusting action to conform to unevennesses in the material carried by the stoker grate. Provision is also made for positively adjusting said damper device or gate construction to vary the amount of opening between the bridge wall and stoker as desired.

It is also sought to devise a constructio which will be not only efiicient forthe desired purpose, but also simple,-dur'able and economical, and comprising few parts which will be cheap to manufacture and to install.

With the above general objects in view, the invention will now be described in detail with referenceto the accompanying drawings illustrating one form of construction which has been devised for embodying the proposed improvements after which the novel features therein will be setforth. and defined in the appended claims.

. In the accompanying drawings Figurel is a vertical sectional view of 1918. Serial No. 244,821.

a furnace, showing a bridge wall construction embodying the present improvements;

Figures 2, 3 and 4c are detail sectional v ews taken on the lines 2-2, 83 and 4c-4, respectively, of Figure 1, but on a larger scale; and

.l lgure 5 1s a vertical section taken on the line 5-5 of Figure 3, and on a still larger scale.

The usual construction of bridge wall is to place the same approximately at the end of the grate or stoker and to support said wall by means of the main rear end wall of the furnace chamber which extends up from the floor to the vicinity of the bottom'tubes of the boiler and is built in and forward to a certain extent so as to partly overhang the stoker. With such a construction, however, it has not been practical, heretofore, to maintaln any gate or damper arrangement for regulatlng the size of the passage or opening between the stoker and bridge wall, which it is desired to maintain as small as possible while at the same time allowing all the refuse from the furnace fire chamber to pass through; the difiiculty being that with the bridge wall proper located at the rear of the stoker no gate or damper arrangement could be maintained which could effectively withstand the action of the fire and not be soon destroyed.

The present construction consists in suspending the bridge wall directly over the stoker and entirely independent of any supporting connection with the rear end wall of the stolrer chamber. Referring to the accompanying drawings in detail, these illustrate a mechanical stoker 6 operating within the stoker chamber 8 of the furnace (see Fig. '1), the rear end wall 10 ofsaid chamber 8 rising from the floor at the back edge of'the ash pit 12. Ordinarily this wall 10 is built on up to the boiler 14 and is also built inward towardthe front to form a bridgeor baffle portion jutting out partially over the rear end of'the stoker; but in my improved construction the bridge wall proper is arranged, as shown at 16, in suspended form,

overlying the rear end of the stolrer and independent of any support to be derived from the rear end wall 10.

For protecting the lower margins of the suspended bridge 16 asmuch as possible against the action of the fire of the furnace chamber, the same is equipped with a water back member 18, which may be of any preferred form, that illustrated in the drawings being of the type shown in Patent No. 1,269,083, issued to me June 11, 1918. Built into the wall 16 at the rearof the water back 18 is an iron lintel 20 having its ends embedded in the side walls 21 and 22 of the furnace and thus serving as a support for the masonry of which the bridge wall 16 is constructed; the lower face of this lintel 20 is also formed with lugs 2 1- adapted to suspend a series of firebrick tile 26 (see Figure 4) on approximately a level with the water back 18 and in position directly overlying the stoker grate.

For regulating the amount or size of opening between the lower rear margin of the bridge wall 16 and the stoker grate, a gate or damper construction is provided, as follows: A series of firebrick tile sections is suspended by means of a tubular member 32 of flattened oval section, which in turn is supported by a shaft 34: extending transversely over the stoker chamber 8 and between the side walls 21. and The opposite ends of the shaft 3% are provided with squared portions carrying eccentrics 36, each supported on a pair of rollers carried by rocker arms 10 mounted on bracket pins 12 within boxes 4A; and 46 set in the walls 21, and 22, respectively, at said opposite ends of the shaft 341. The inner closure plate 48 of the box 46 is slidingly adjustable within the box and is clamped in proper position by means of a pair of set screws 50. The closure plate -i8 and also the plate 52 of the box 4-1 are provided with elongated openings 54; whereby the shaft 34: may be raised and lowered by the action of the eccentrics 36 and at the same time the tubular member 32 prevented from turning. Thus the tubular member 32 and the tile sections 30 supported thereby are permitted only vertical movement; and in addition to the positive adjustment obtained by means of the shaft and its eccentrics, the gate structure has also a sel f-adjusting movement due to its being mounted loosely on said shaft through the medium of the tubular member 82, so that said gate structure may automatically accommodate itself bodily to the material passing beneath them on the stoker grate. A crank 56 is provided on the outer end of the shaft 3 1 (see Figure 3) or any equivalent means may be employed for operating the shaft to set the eccentrics 36 and thus determine the lowest position of the tile sections to suit any given conditions or requirements. It will also be observed, by reference to Figures 2 and 3, that the gate parts are so proportioned and arranged as to permit the same to be taken out through the box 46 and side wall. 22, whenever necessary for repair or renewal purposes, thus enabling any attention of this nature to be given without interrupting the operation or service of the furnace or boiler.

An opening or observation door 60 may be provided in one of the side walls of the furnace at the rear of the bridge wall 16, so that air may circulate at the back of the stoker and tend to lower the temperature at the back of the bridge wall and gate structure, any aircirrulation at the rear of the bridge wall 16 being of course immaterial, so far as the furnace action is concerned, since the gate construction, together with the passing refuse, constitute a seal to the fire chamber. In the present case also a cover plate structure 62 is arranged to span the space between the suspension bridge wall 16 and the top of the rear end wall 10 of the stoker chamber 8.

A practical and efiicient construction is thus provided for carrying out the desired objects of the invention. By mounting the bridge wall in advance of the end wall. 10 and suspending said bridge wall entirely separate and independent of the end wall 10, as illustrated in Figure 1 of the drawings, a bridge wall structure is obtained whereby not only all the functions and ad vantages of the usual form of bridge walls are retained, but in addition the improved construction is adapted for the maintaining of an effective gate or damper structure at the rear end of the stoker grate. The type of gate shown is adapted for self-adjusting movement to accommodate itself to the thickness or unevennesses of the layer of material carried by the grate and passing by underneath. This material before it reaches the gate is leveled andsmoothed ofii by the water back 18 and the tiling 26; and the eccentrics are set so as to permit the gate to have a maximum drop to a level somewhat below the bottom face of said tiling, and. thus the gate is allowed to drag upon the passing refuse material. The means shown and described. for raising and lowering the gate enables the same to be readily adjusted for limiting its maximum lowered position, as well as for raising it into full-open position whenever desired. Again, the arrangement and construction are such as to withstand most efiectually the action of the heat which is of course very intense around the bridge wall opening, where all the parts provided. by the applicant are of {ire-clay construction, excepting the water back 18, this being a water-circulating member the principle of which will be readily understood by reference to the patent above referred to.

lVhile I have illustrated and described what is now regarded as the preferred formi of construction for embodying the proposed improvements, T desire to reserve the right to make such formal changes or modifications as may fairly fall within the scope of the appended claims.

Having thus described the invention, what I claim is:

1. A furnace construction comprising a fire chamber having a progressive feed stoker and a bridge wall overlying the rear end of said stoker, a gate structure associated with the lower portion of said wall and comprising a. transverse shaft having a gate member provided with a bearing loosely mounted on said shaft, and eccentric supporting means for said shaft operating, on turning of the shaft, to raise and lower said gate member, the shape of said bearing being adapted to permit independent selfadjusting movement of said gate member to accommodate itself to the material carried by the stoker.

2. A furnace construction comprising a fire chamber having a progressive feed stoker and a bridge wall overlying the rear end of said stoker, agate structure associated with the lower portion of said wall and comprising a transverse shaft having a gate member provided with a bearing having a vertically elongated bearing passage accommodating said shaft, whereby said member is permitted a limited degree of free vertical sliding movement relatively to said shaft.

8. A furnace construction comprising a fire chamber having a progressive feed stoker and a bridge wall overlying the rear end of said stoker, a gate structure associated with the lower portion of said wall and comprising a transverse shaft having a gate member provided with a bearing having a vertically elongated bearing passage accommodating said shaft, whereby said member is permitted a limited degree of free vertical sliding movement relatively to said shaft, and means for restricting said bearing to sliding movement in a vertical direction.

4. A furnace construction comprising a fire chamber having a progressive feed stoker and a bridge Wall overlying the rear end of said 'stoker, a gate structure associated with the lower portion of said Wall and comprising a transverse shaft having a gate member provided with a bearing having a vertically elongated bearing passage accommodating said shaft, whereby said member is permitted a limited degree of free vertical sliding movement relatively to said shaft, and means for adjusting said shaft for varying the extent of downward sliding movement permitted said bearing.

In witness WhGI'GOfI hereto affix my signature.

FRANK A. HURLBUT.

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