US1954741A - Grate - Google Patents

Description

Pril 10 1934- E. o. MARTY 1,954,741

Filed Deo. 2l, 1931 2 Sheets-Sheet l ('ATTORNEY E. O. MARTY pril 10; 1934;

GRATE Filed Dec. 2l, 1931 2 Sheets-Sheet 2 INVENTOR Tc/gdr O. Marty Patented Apr. 10, 1934 GRATE Edgar O. Marty, Pottsville, Pa..

Application December 21, 1931, Serial No. 582,311

3 Claims.

This invention relates to grates and methods of forming the same, and particularly to grates adapted to be cooled by a circulating fluid.

An object of the invention is to so employ standard steel bars, beams and tubes in forming a grate as to minimize its weight and cost.

Another object is to provide in a simple manner for maintaining an upflow of air throughout substantially the entire fuel-burning area of the grate to support combustion.

A further object is to establish, in an improved and simplified manner, a circulation of cooling fluid through the hollow frame of a. grate and through tubular fuel-supporting members carried by said frame.

A still further object is to so establish welded connections between tubular end headers of a grate and spaced fuel-carrying tubes connecting said headers as to permit location of the welds interiorly of said headers, or a ready drawing out of the margins of openings in said headers to form annular flanges to which the tubes may be conveniently flash welded.

Still another object is to equip a grate with a fuel-delivering forward extension having a width considerably less' than that of the grate proper, whereby said extension may project through one of the usual openings in the front wall of a furnace and may continuously receive and deliver fuel to a grate responsive to a vibratory actuation of the grate.

It is also an object of the invention to so mount an ash chute upon the rear end of a grate that vibratory actuation 'of the grate will deliver ashes to said chute and further induce travel of said ashes in said chute.

These and various other objects the invention attains by the construction hereinafter described, and illustrated in the accompanying drawings, wherein:

Fig. l is a top plan view of the improved grate.

Fig. 2 is a side elevational view of the same.

Fig. 3 is a cross sectional view of the grate, taken upon the line 3--3 of Fig. l.

Fig. 4 is an elevational view of the rear end of the grate.

Fig. 5 is a fragmentary enlargement of a portion of Fig. 1.

Fig. 6 is a fragmentary enlargement of a portion of Fig. 3.

' header.

In these views, the reference character l designates a plurality of spaced, elongated metallic tubes rigidly connecting and communicating with a pair of tubular front and rear headers 2 and 3. The headers 2 and 3 are rigidly connected at their ends by a pair of tubular members 4 which, together with said headers, form a rectangular open frame within which the tubes l extend.

Surmounting said tubes and bridging the spaces therebetween, is a plurality of elongated tuyre strips 5, preferably slightly arched from tube to tube, and each formed with a plurality of apertures 6 distributed with approximate uniformity through the length of the strip.

Carried by the described grate therebeneath is a sheet metal air box 7 substantially coextensive in area with the grate, the apertures 6 forming air outlets from said box, to which air under suitable compression may be delivered from any desired source, such as a blower 8a, through a passage 8.

The front end header 2 carries a forwardly projecting, channel shaped fuel delivery extension 9 formed preferably of sheet metal, having its bottom member approximately flush with the top surface of said header and having side walls and an end wall coextensive in height with the members 4. Said extension is preferably symmetrical with respect to the longitudinal center line of the grate, but its width is considerably less than that of the grate, permitting it to project through the usual fuel delivery clinker, or ash door opening l0 in the front wall 10a of a furnace.

To the rear end header 3 of the described grate is secured an ash chute l1 coextensive in width with the grate` and inclined transversely to the latter, and preferably having its lower end portion projecting laterally somewhat beyond the grate. Said chute is positioned slightly below the fuel-supporting surface of the grate, providing for a gravity discharge of ashes from said surface into said chute.

Cooling water is delivered to the grate through a pipe 12, upwardly opening into the front end header 2. Such water flows rearwardly through the several tubes l, returning to the forward end of the grate through the side frame members 4. Delivery of the water to the members 4 is effected through the rear end header 3, which preferably has full communication with said frame members, throughout its cross-sectional area. The front end header has a very restricted communication at its extremities with the members 4, established through apertures 13 closely adjacent to the top of the header. These apertures serve to prevent any trapping of air in the top portion of the front header. The forward ends of the side frame members are in communication through a pipe 14 connecting the upper portions of said members and the circulating water is withdrawn from the grate through a pipe 15 opening into the front end of one of the members 4 at the top thereof. The described circulation is clearly indicated by the arrows in Fig. 1.

In constructing the described grate, it is preferred to form each of the tubular end headers and side members of the frame by positioning a pair of standard steel angle beams or bars in complementary relation with their edges abutting and then establishing continuous welds between the abutting edges.

Before thus forming the end headers, one of the angle bars selected for each of said headers is formed with a row of circular openings for terminally receiving the tubes 1, and the ends of said tubes are either welded within said openings so that the welds will be concealed within the headers after their completion, or the margins of said openings are annularly drawn out, exteriorly of said angle bar, to form iianges 15 to which the tubes may be ash welded. The flash welding of all of the tubes to one of the apertured angle bars may be accomplished in a single operation. This method of forming the grate procures for it a minimum weight for a given strength, and minimizes cost by use of standard material and a highly simplified welding process.

In use of the described grate, fuel (preferably in a finely divided form) is continuously delivered in any desired manner to the extension 9, and the grate is continuously vibrated (preferably at a very rapid rate) by any suitable means to induce a continuous gradual rearward travel of the fuel. In the course of such travel, the described vibration uniformly distributes the fuel throughout the grate area, and further maintains it in a condition of fluid mass, greatly facilitating combustion. The rate of rearward fuel travel is so regulated as to insure a complete transformation of the fuel to ashes in the course of such travel. Upon reaching the rear end of the grate and discharging therefrom into the chute 11, the ashes are conveyed down the incline of the latter also responsive to the described grate vibration.

The members 4, it will be noted, rise sufficiently above the tubes and headers 2 and 3 to serve as walls preventing lateral discharge of the fuel from the grate.

A provision for vibrating the grate, and delivering fuel thereto and compressed air to the air box 7 is exemplified in my copending application, Serial No. 582,309, filed Dec. 21, 1931.

While it is apparent that the illustrated embodiment of my invention is well calculated to adequately fulfill the objects and advantages primarily stated, it is to be understood that the invention is susceptible to variation, modification and change within the spirit and scope of the subjoined claims.

What I claim is:

1. A grate comprising a rectangular frame formed by a pair of tubular end headers and a pair of tubular side members rigidly connecting said end headers and communicating with one thereof, a large opening being formed in the central region of said frame, a fluid circulating tube rigidly connecting and communicating with said side members adjacent to the other end header, a plurality of spaced tubes rigidly connecting and communicating with said end headers within said frame opening, a plurality of tuyre strips bridging the spaces between said tubes and apertured for the upflow of air, and connections for delivering a cooling fluid to the grate and for withdrawing such fluid from the grate, one of said connections communicating with the last mentioned end header, and the other communicating with one of said side members adjacent to the last mentioned end header.

2. A grate comprising a rectangular frame formed by a pair of tubular end headers and a pair of tubular side members rigidly connecting said end headers and communicating with one thereof, a large opening being formed in the central region of said frame, a fluid circulating tube rigidly connecting and communicating with said side members adjacent to the other end header, a fuel supporting structure carried by said frame within said opening thereof and establishing communication between said end headers, and connections for delivering a cooling fluid to the grate and for withdrawing such fluid from the grate, one of said connections communicating with the last mentioned end header, and the other communicating with one of said side members adjacent to the last mentioned end header.

3. A grate comprising a substantially rectangular frame formed by a pair of front and rear tubular headers, and a pair of tubular side members, rigidly connecting the front and rear headers and inclined downwardly toward the rear header and freely communicating with the latter, a large opening being formed in the central region of said frame, a fuel supporting structure 'carried by said frame within said opening thereof, and forming a fluid passage between the front and rear headers, and means for delivering a cooling liquid to the front header and withdrawing it from one of said side members at a point elevated above the front header, the front header having restricted communication near its top with said side member to avoid the trapping of air in the front portion of the grate.

EDGAR O. MARTY.

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