US2070894A

US2070894A - Grate

Info

Publication number: US2070894A
Authority: US
Publication date: 1937-02-16
Anticipated expiration: 1954-02-16

Description

Feb. 16, 1937.

G. J. GORSUCH 2,070,894

GRATE Fil ed March 9, 1935 2 Sheets-Sheet 2 Patented Feb. 16, 1937 UNITED STATES PATE GRATE Application March 9, 1935, Serial No. 10,165

4 Claims.

This invention relates to grates for stoves, furnaces, and the like.

An object of the invention is to provide an improved grate capable of burning small sizes of 5 filial, .such as pea coal, buckwheat coal, and the Another object is the provision of a grate of this character which can be easily and quickly installed in existing stoves and furnaces, and which 10 will burn fine coal in an easy manner without the necessity of using a fan or blower.

Still another objectis the provision of such a grate so designed that it may be constructed easily and relatively economically.

l5 To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel-features being pointed out in the claims at the end of the specification.

20 In the drawings:

Fig. l'is avertical section through a part of a fire pot showing in side elevation a grate constructed in accordance with a preferred embodiment'of the invention;

Fig. 2 is a vertical'section taken substantially centrally through the grate shown in Fig. 1;

Fig. 3 is 'avertical section through a fragment of the grate and associated parts, on a larger scale;

30 Fig. 4 is a perspective view of one'of the grate supporting members;

Fig. 5 is a plan of the grate installed in the fire P 13;

Fig. G is a view ofthe grate'looking'upwardly 35' from underneath; and

Fig. 7 is a perspective view of part of a grate supporting ring.

Thesame reference numerals throughout the several views indicate the same parts.

40' At I0 there is indicated diagrammatically a fire potof a'stove or furnace, this fire pot being of frusto-conical form with its smaller end downwardly, in the usual manner;

According to the present invention, there is 45' mounted at the lower end of this fire'pot'a ring II, conveniently made of two semi circular portions such as :shown in Fig. 7, which ringis suitably secured in the fire pot, by resting upon the conical walls thereof'or otherwise; and which has 50 an inwardy projecting rim or ledge having a flat top surface I2. The main body of the grate is indicated at I3 and may conveniently be made in two halves which, when secured together by bolts or screws I4, form a somewhat frusto-con- 55 ical member as. shown plainly in the drawings.

The bottom edge of this frusto-conical grate might, under some circumstances, rest directly upon the ledge I2 of the supporting ring II, but

it is preferred to elevate it slightly above the ledge I2, resting the grate I3, for example, on a plurality of supporting members I6 each of which has a flat bottom to rest on the ledge I2, and a curved outer edge I! fitting against the vertical peripheral wall of the ring II, and sides I8 extending obliquely inwardly at an angle and meet- 10 ing at a point, as plainly shown in Figs. 4 and 6. Each of these supporting members I6 may also carry an upstanding tooth I9 if desired.

The bottom of the grate I3 is of sufficient diameter to overlap somewhat on the ledge I2, and is supported slightly above this ledge by any suitable number of supporting elements l6, four .of such elements being shown in Fig. 6. A pin It may extend from each element It upwardly into a hole in the bottom of the grate I3, to hold the elements in predetermined position on the grate. The elements I6 are not pinned to the ring I I, however, but are free to slide circumferentially around the ledge I2 on this ring II when the grate is shaken, as will be explained in detail hereafter.

The grate itself comprises frusto-conical wall portions tapering upwardly as shown, and provided with a series of circumferential rings or ridges 25 of the shape best shown in Fig. 1. In the grooves between these ridges are air holes 26 which, as shown in Figs. 2 and 3, extend obliquely upwardly and inwardly. Each air hole 26 is protected from entrance of fine coal thereinto by means of the overhanging ridge 25 next above it, and also by reason of the sharp upward inclination of the hole itself, which prevents flow of coal any substantial distance into the hole and thus avoids any clogging of the air holes by the fine coal.

Any suitable number of such air holes 26 may be provided. Preferably they are arranged in several circumferentially spaced series, the air holes or slots of each series being alined with each other in a direction up and down the grate, as plainly shown in Fig. 1. These holes permit air within the hollow conical body of the grate to escape through the air holes into the mass of fine coal surrounding the grate, in order to support combustion in the surrounding fine coal.

It is found that improved results may be obtained by supplying air also to the coal at various points spaced outwardly from the main body of the grate. To this end, the upper end of the grate is provided with a series of tubes or conduits 30 communicating with the hollow space within the body of the grate, as shown in Fig. 2, and extending radially outwardly therefrom as shown in Fig. 5. Six such conduits may be conveniently employed, as indicated in the drawings, although obviously the number may be varied depending upon the size of the grate and the kind of coal to be burned. These conduits have outer ends curved downwardly as shown with outlet openings 3| on their under or bottom sides, as plainly indicated in Fig. 2. Air from within the main interior chamber of the grate may pass upwardly into the conduits 30, thence radially outwardly, and be discharged through the outflow openings 3| which are surrounded by coal, so that the air is delivered directly into the body of the coal at some distance outwardly from the main body of the grate and at some distance from the air supplied through the air holes 26. The fire pot is preferably filled with coal to a level some inches above the tops of the conduits 30, the preferred fuel level being indicated diagrammatically in Fig. 1 by the dotdash line 33. Sometimes it is desired to supplystill more air, at a point somewhat above the top of the fuel, in order to promote thorough combustion of any gases rising from the fuel. When such additional air supply is desired, it may be furnished by means of a substantially vertical conduit 35 rising from the center of the top of the main body portion of the grate and extending to a point somewhat above the fuel level 33, where it has an open top covered and protected by a conical hood 36 which prevents coal or other matter from falling into the top of the conduit 35, while nevertheless allowing easy escape of air from the conduit. A damper 3'! may be placed in the conduit 35 and may be controlled by the handle 38 to regulate the amount of air flowing through this conduit.

In order to promote the fiow of air through the lateral conduits 30 and insure delivery of air through them to the coal, it is preferred to construct the grate in such manner that some degree of air pressure will be exerted to drive the air through these conduits. This may be accomplished by the use of bafiie means extending downwardly within the main body of the grate for a substantial distance from the conduits 3B and so constructed that air confined by these bafiie means has no chance to escape laterally but must rise upwardly and flow out through the conduits 35 or the conduit 35. In the present preferred form of construction, this is readily accomplished by providing air ducts 40 within the side walls of the main conical body of the grate, in alinement with the air holes 26. These ducts 40 communicate with the space inside the grate only through inlet openings 4 I at their bottom ends, and the air holes 26 do not extend all the way through the entire thickness of the walls of the grate, but pass only from the ducts 40 outwardly and downwardly to the exterior. Consequently, air for the air holes 26 may easily pass from the inside of the grate through the openings M and upwardly through the ducts 30, to escape laterally through the holes 26. But the interior of the grate from the upper edges of the duct inlet openings ll up to its top, forms, in effect, a pressure chamber, and any air inside the grate, once it passes above the top edges of the openings 4!, is no longer able to escape laterally and thus, due to the draft or stack effect produced in the pressure chamber, is forced on upwardly to the lateral conduits 3!]. The damper 31 in the conduit 35, is, of course, so

adjusted as to restrict the amount of air passing through the conduit 35, so that the desired volume of air is forced into the lateral conduits 30 and discharged into the coal at points radially outwardly from the main body of the grate.

For shaking the grate, it may be rotated or oscillated back and forth about its vertical axis, in any convenient manner. For example, a strong rod 50 may extend diametrically across the main body of the grate near its bottom. A broad bar 5! having a hook-shaped end 52 may be inserted through the ash pit door of the stove or furnace and this hook-shaped end may be hooked over and engaged with the rod 50 as indicated in Fig. 2. Then, since the bar 5! is sufiiciently broad to provide a substantial bearing on the rod 53 in a direction lengthwise of the rod, the outer end of the bar 5! protruding through the ash pit door may be swung back and forth in a horizontal direction, and its movement will be transmitted through the rod 50 to the main body of the grate, which will oscillate back and forth about its vertical axis, the supporting members It sliding circumferentially on the ledge l2 during such movement. The ashes will then drop out through the annular space between the bottom of the main body of the grate and the ring II. The upwardly projecting parts !9 of the members l6, as they travel circumferentially, will break up and disturb the packed ashes surrounding the lower part of the grate and thus put these ashes in condition to fiow readily downwardly and over the ledge l2 into the ash pit. Likewise, the inclined sides l8 of the supporting members l6 will act as cams or deflectors to displace ashes resting on the ledge I2 and to move such ashes inwardly in a radial direction until they drop 01f the inner edge of the ledge 12.

It is now apparent that a simple grate has been provided which can be readily installed in existing stoves and furnaces by merely taking out the existing grates and setting the new grate in place on a supporting ring I I of appropriate size. This new grate has given exceedingly satisfactory service in actual use, and operates eificiently with fine coal, such as buckwheat coal, without the necessity of using any fan or blower. It is also apparent that the fine coal can not run accidentally out of the fire pot, because of the overlap between the inner edge of the ledge l2 and the outer peripheral edge of the main grate member l3. The fine coal, or the ash resulting therefrom, is supported on the ledge l2 until the grate is purposely rotated to shake it, whereupon the agitation of the mass above the ledge l2 causes it to run over the edge of the ledge and fall into the ash pit.

I claim:

1. A grate for burning fine coal comprising a hollow body tapered upwardly to provide inclined side walls against which the coal may rest, said walls having openings for outflow of air therethrough, a plurality of separate conduit means extending radially outwardly in difierent directions adjacent the top of said hollow body to deliver air into coal surrounding and covering said hollow body, and conduit means extending upwardly from said hollow body to deliver air to a point above the top of the coal.

2. A grate construction for burning fine coal comprising a supporting ring having an inwardly projecting circular flange, a plurality of spaced supporting members resting upon and slidable circumferentially on said flange, a hollow grate body resting upon said supporting members and spaced thereby above said fiange in overlapping iii relation therewith, said body having air holes therein for outflow of air from the interior of said body to the exterior thereof, and means for rotating said body with relation to said supporting ring to shake down ashes.

3. A grate for burning fine coal comprising a hollow body of substantially frusto-conical shape tapered upwardly to provide inclined side walls against which coal may rest, the outer surface of said body having a series of circumferentially extending ridges projecting outwardly therefrom, a, plurality of air ducts each opening into the interior of said body near its lower end and extending thence upwardly, and a series of air outlet openings extending from each air duct to the exterior of the side wall of the body, each air outlet opening extending downwardly and outwardly and opening substantially at the under side of one of said circumferential ridges so as to be protected thereby.

4. A grate for burning fine coal comprising a hollow body of substantially frusto-conical shape tapered upwardly to provide inclined side walls against which coal may rest, the outer surface of said body having a series of circumferentially extending ridges projecting outwardly therefrom, a plurality of air ducts each opening into the interior of said body near its lower end and extending thence upwardly, a series of air outlet openings extending from each air duct to the exterior of the side wall of the body, each air outlet opening extending downwardly and outwardly and opening substantially at the under side of one of said circumferential ridges so as to be protected thereby, and a plurality of air conduits communicating with the interior of said hollow body adjacent the top thereof and extending radially outwardly to deliver air into the body of the coal at points outwardly from the top of said hollow body.

GEORGE J. GORSUCH.