US2297783A

US2297783A - Grate

Info

Publication number: US2297783A
Application number: US299312A
Authority: US
Inventors: Stephen S Kwolek
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-10-13
Filing date: 1939-10-13
Publication date: 1942-10-06
Anticipated expiration: 1959-10-06

Description

0a. 6, 1942. KWOLEK 2,297,783

GRATE Filed Oct. 13, 1939 2 Sheets-Sheet l STEPHEN 5. KWOLEK' HIS A T7OENE r INV ENT OR.

Oct. 6, 1942. 's. s. KWOLEK GRATE Filed Oct. 13, 1939 2 Sheets-Sheet 2 INVENTOR.

mm N NM m o w w N k e s. m

-T m A p s M H 5 w Patented Oct. 6, 1942 UNITED STATEE E ATENT OFFICE GRATE Stephen S. Kwo'lek, Detroit, Mich.

Application October 13,1939, Serial No. 299,312

6 Claims.

My invention relates to a new and useful improvement in a grate adapted for use on furnaces and the like with which combustible fuel such as coal or the like is used. A type of grate construction embodying a supporting body or plate through which openings are formed leading to the air chamber or ash pit positioned below the grate. With this type of grate the space below the grate ordinarily is not used as an ash pit because of the substantially complete combustion which is obtained by this method of combustion. The ashes ordinarily are raked or hoe-d ofi of the grate directly into a wheelbarrow positioned at the front of the furnace. This operation takes the place of the operation in which dump-grates are used, in the use of which the ashes are dumped into a pit and then removed therefrom.

The space below the grate is used as an air chamber in which air is built up under pressure and maintained under pressure for effecting a constant blowing of air upwardly through the openings in the grate, the fuel being deposited upon the upper surface of the grate. Experience has shown that with this type of grate, warping and cracking of the main plate often takes place and in some instances pieces of the plate break off and fall downwardly into the chamber below.

It is an object of the present invention to provide a grate of this type arranged from a plurality of sections having each section so constructed that a maximum strength is provided and the adjacent sections serve as supporters for each other so that warping and cracking is reduced to a minimum and the dropping of a cracked-air piece into the chamber below the grate is prevented.

Another object of the invention is the provision of a grate of this type which will be simple in structure, economical of manufacture, durable, easily and quickly assembled and disassembled and highly efiicient in use.

Another object of the invention is the provision of a grate of this type which will he possessed of a minimum of weight and a maximum of strength proportionately to the weight.

Another object of the present invention is the provision of a grate of this type so constructed as to present a maximum surface to the cooling air projected through the grate so as to maintain the grate cooled to a maximum degree.

Another object of the invention is the provision of a grate of this type so constructed and arranged as to possess uniform weight and time, presenting a maximum area for combustion purposes.

Another object of the present invention is the provision of a grate having openings formed therethrough arranged in sets of a central vertical opening surrounded by a plurality of angular passages or openings with adjacent sets rotated relatively to each other preferably 45 degrees to provide uniformity of spacing and distribution so that a uniform air surface throughout the entire grate area may be obtained.

Another object of the present invention is the provision of a grate in which dead air pockets are eliminated.

Another object of the present invention is the provision of a grate in which a maximum elliciency in operation is obtained.

Another object of the present invention is the provision of a grate comprising a plurality of sections having portions interlocking with each other.

Other objects will appear hereinafter.

In the drawings I have illustrated the preferred forms of construction but it is recognized that various changes and modifications may be made which would be a departure from the precise detail of structure shown but still embody the essential features of the invention,

and it is intended that such variations and strength throughout its area while, at the same 55 modifications shall be included in this specification. The specification is amplified with drawings, in which,

Fig. 1 is a longitudinal sectional view of a furnace embodying the invention with parts broken away,

Fig. 2 is a transverse sectional view or" the invention with parts removed, Figure 2a is a top view of a segment of the connection between abutting sections,

Fig. 3 is a top plan View of the invention with parts broken away,

Fig. 4 is a sectional view taken on line 44 of Fig. 3,

Fig. 5 is a bottom plan view of a slightly modified form of the invention with parts broken away,

Fig. 6 is a top plan View of a fragment of the invention slightly enlarged over Fig. 5,

Fig. 7 is a fragmentary sectional view taken on line l-1 of Fig. 6,

Fig. 8 is a prospective view of one of the units used in the invention.

In the drawings, I have illustrated the invention used with a furnace having a rear bridge wall 9 and a front wall Ill provided with an opening il giving access to the air chamber l2 below the location of the grate. Supported by the wall or stoker front IE3, is a supporting bracket or hearth plate l3 attached to which, by means of the clamp plates l4 and the bolts I5, is one end l6 of a grate section. The opposite end ll of the grate is secured by U-shaped clips is to the adjacent end [9 of another section which is supported at its opposite end by the ledge 23 on the wall 9. Stay bolts 2! are projected through the end walls of these grate sections. These grate sections are adapted for being positioned in juxtaposition to other sections to form a complete grate. It will be noted that each section is provided with its own stay-bolts so that these staybolts do not serve as a means for binding the separate sections together.

As shown in Fig. 8, the section is of box-like structure embodying oppositely disposed side walls 22 and end walls 16 and I? so that a substantially box-like structure is provided, the bottom thereof comprising the plate 24 which forms the grate proper. Transversely extending fins in the form of plates 25, project inwardly from the inner surface of the box 24 as do, likewise, longitudinally extending fins 25. These fins project downwardly when the grate is in operative position, the box-like structure being mounted with the open end faced downwardly. It will be noted that in each of the sections the stay-bolts extend below and are substantially tangent to the downwardly projecting fin members. Each set of sections 25 and 2t defines an area on the base or bottom 2 and through the base or bottom Ed at each area is formed a centrally positioned opening 2'! which is tapered as clearly shown in Fig. '7, the narrow end thereof opening through the upper face 28 of the bottom 2 Extending through this same area is a plurality of diagonally directed or inclined passages 29 which are also tapered. These passages serve as outlets for air which may be delivered into the chamber 12 under pressure. It will be noted that the inclined passages are arranged around the central vertical passage 21 and as shown in Fig. 6 the arrangement is such that openings in adjacent sections are rotated 45 degrees so that a uniform distribution of air outlets over the entire face of the plate 2 3 is obtained. The

fins

25 and 26 form with each other on the inner surface of the bottom 24, separate box-like structures and the air forced through the passages 2? and 29 enters these box-like structures and has a cooling effect on the grate.

As shown in Fig. 1 and Fig. 2, there are no dead air pockets and there is no dead weight of the grate at its opposite ends so that the maximum area of useable surface is thus provided.

Experience has shown that when a grate is constructed in this manner, a maximum efficiency is obtained. The air, before passing through the

outlets

27 and 29, becomes preheated, so that the cooling effect of the air on the combusted fuel is reduced to a minimum. The grate is maintained at a fairly cool condition and, no blow holes in the fuel bed are effected, while clinker formation under proper air regulation is practically eliminated, regardless of the grade of fuel used.

It is intended that the grate shall be used primarily for burning solid fuel and it is adapted for burning coal and other fuels from lump sizes down to dust and the grate may be used with either a natural or forced draft pocket in con- The grate is also suitable for use in furnaces of the hand-fired type and experience has shown that it is quite well adapted for use on marine boiler of the land type and the Scotch marine type.

In assembling the grate, the various sections are abutted side to side. Each of these sections is provided on one side with a U-shaped longitudinally directed groove 3| and on the opposite side with a gripping rib 32, the rib of one section engaging in the groove of the other. At intervals, these structures are provided with the openings 33. The openings 33 of abutting sections would register so that a U-shaped connecting clip 34 may be inserted through the openings as shown in Fig. 2 to pin the sections together. In the groove 3! I prefer to pack a layer 35 of asbestos or other suitable packing so that there is no open space exposed on the upper face of the grate. It is also to be noted that there are no ribs or projections extending upwardly from the face 28 of the grate body.

Engaging at the upper edges in the space 36 between the abutting walls is a partition plate 3! which serves to partition the chamber i2 and the sections to assure proper distribution of the blast air to the entire grate structure. This permits cutting the grate into sections or permits the Zoning so that certain sections of the grate may be cut out of use when light loads are encountered.

In Fig. 1, I have illustrated a supporting I- beam 38 but the use of this I-beam is optional.

What I claim as new is:

1. A grate section comprising a unitary boxlike structure having a top, end walls, and side walls and a plurality of spaced transversely extending and spaced longitudinally extending partitions projecting inwardly from the inner surface to the top, said partitions extending at right angles to each other and said transverse partitions extending at right angles to the longitudinal edges of said structure; and a plurality of bolts extended through and connecting oppositely disposed end walls.

2. A grate construction of the class described comprising a plurality of box-like sections having oppositely disposed side walls, the side walls of adjacent sections being in substantially abutting relation, each of said sections having an opening formed therethrough on the inner side of the side wall and provided on its upper face with a groove communicating with said opening; and an inverted U clip projected through said openings and having the bight thereof lying in said groove for connecting said sections together.

3. In a grate construction of the class described, a plurality of box-like structures arranged in abutting relation with the side walls substantially in engagement, each of said sections having an opening formed therethrough adjacent the inner surface of the side wall; and inverted U clips projected through said openings for connecting said sections together.

4. A grate section of the class described comprising: a box-like structure having a pair of oppositely disposed side walls and a pair of oppositely disposed end walls and a top, the remaining side of said structure being open; a plurality of transversely extending partitions between said side walls and extending inwardly of said top; a plurality of longitudinally extending junction with overfed sprinkler type stokers.

partitions between said. walls and extending at right angles to said transversely extending partitions; and stay-bolts projected through a pair of from said top and extending at right angles to said end walls; a plurality of transversely extending partitions extending inwardly from said top at right angles to said side walls, said partitions being of less height than said oppositely disposed walls; stay-bolts projected through said oppositely disposed walls and positioned substantially tangent to the inner edges of said partitions.

6. A grate section of the class described, comprising: a box-like structure having a pair of oppositely disposed end walls, a pair of oppositely disposed side walls and a top; a plurality of intersecting partitions projecting inwardly from the inner side of said top, said partitions being of less height than said walls for providing, in said structure, a plurality of separate compartments; and stay-bolts projected through a pair of oppositely disposed walls and substantially tangent to the inner edges of said partitions.

STEPHEN S. KWOLEK.