US2557013A - Dump grate for refuse burning furnaces - Google Patents

Description

June l2, 1951 A. D. SIMPSON DUMP GRATE FOR REFUSE BURNING FURNACES 3 Sheets-Sheet 2 Filed May 3, 1949 ||..Nv l |.ws ||s| o E N e w mw 7^ m5, m Mr r @n 3%# MM June 12, 1951 A D, 5|MP5ON 2,557,013

DUMP GRATE FOR REFUSE BURNING FURNACS Filed May 3, 1949 5 Sheets-Sheet 3 Plq.

Patented June 12,Y 1951 DUMP GRATE FOR REFSE BURNING FURNACES Albert D. Simpson, Macon, Ga., assignor to The Hoft Company, Inc., Indianapolis, Ind., a corlporation Application May 3, 1949, Serial No. 91,039

4 Claims.

This invention relates to the construction of a dump grate for a refuse burning furnace of the type adapted for burning such fuels as bark, cotton seed, coconut hulls, sewer sludge, garbage, and like material having a high moisture content. Reference is made to application for Letters Patent of Henry C. L. Miller, `Serial No. 67,802, filed December 29, 1948, for Refuse Burning Furnace, and Letters Patents of Morris A. Hofft and Nick T. Puckett, No. 2,257,957, granted October 7, 1941, for Furnace Grate.

More particularly, the object of the invention is to provide such a furnace structure as disclosed in said patent and application for letters patent above mentioned with a Water cooled dump grate. In furnaces of this 'character involving the burning -of refuse having a high content of moisture and foreign matter such as dirt, sand, and the like, the dump grates are caused to rapidly deteriorate due to excessive temperatures developed at this section of the furnace. Thus, the usual cast iron uncooled dump grates are apt to burn out necessitating replacements with the resultant requirement that the furnace be periodically shut down.

It is, therefore, the object `of this invention to prolong the life of the dump grate by not only so constructing them as to permit of air cooling, but additionally causing them to be water cooled in order that they may withstand the eiects of prolonged high temperatures, while at the same time providing for air passage and movement of fthe grates from fuel supporting to fuel dumping positions.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

Fig. 1 is a horizontal section through a portion of a three cell furnace with parts removed.

Fig. 2 is a section taken on the line 2-.-2 of Fig. 1 with the intermediate cell wall and other parts removed for showing therelation of the dump grates in adjacent cells, said grates being shown in fuel supporting position by full lines and the outer cell grate being shown in fuel dumping position by dotted lines.

Fig. 3 is a plan view of the dump grate for one furnace cell with parts broken away.

Fig. 4 is an enlarged section taken on the line 4-4 of Fig. 3.

Fig. 5 is a vertical section taken on the line 5--5 of Fig. 1,

In the drawings reference is made to the refuse vburning furnace of the general type shown and and application for Letters Patent wherein fuels are fed on to a downwardly sloping grate including, as shown herein, a series of parallel spaced water cooled tubes itl terminating at their lower end in a transverse header tube I I to provide for a flow of cooling water throughout said grate surface. The grate surface intermediate the tubes I0 may comprise a series of grate bars of the stepladder type as shown inA said application for Letters Patent, or of the T apertured type as shown in said Letters Patent, the lower portion of the grate as illustrated therein including a series of pushers for feeding the burning fuel from the lower portion of the grate on to the pump grate to which this lapplication is directed.

The pump grate is mounted over the ash pit I2 and normally extends substantially horizontally adjacent the lower portion of the grates and tubes I@ and transversely of the bridge walls i3.

As shown in Figs. 3 and 4, the dump grate for each cell of the furnace consists of a series of grate tubes I4 connectedat opposite ends to a longitudinally extending pivot tube I5 and an opposed longitudinally-extending header tube I6, respectively. Opposite ends of the grate tubes I 4 are inV communication with the respective pivot tube and header tube. Each of the grate tubes I4 has formed on opposite sides thereof opposed grate lbars Il in the form of laterally extending fins substantially coextensive with the space be tween the pivot tube and header tube. Said grate tubes with their opposed grate bars are so spaced as to permit of an air passage between each pair of adjacent grate bars.

Extending a substantial distance through the pivot tube from one end thereof there is provided ,a water pipe I8 having suitable connection with the cooling water source. Adjacent the same end of the pivot tube it is provided with an outlet conduit I9. The water pipe I8 extends through a rst baffle 29 and a second baflie ZI mounted in the pivot tube, said baffles dividing the pivot tube into three sections. A single bailleV 22 is provided substantially centrally of the header tube IS, dividing said header tube into two sections. Shown in Fig. 3, and noting the direction of the arrows, the several bales in effect divide the dump grate into a series of water passages, the three grate tubes I4 farthest from the water inlet permitting flow of water from section Afof the pivot tube to section B of the header tube. y

The baille 2 I prevents back flow in the pivot tube so; that the only outlet comprises the last said three grate tubes. As section B of the header tube is blocked off by the baiiie 22, the water owing therein is caused to iiow in the reverse direction through the next adjacent group of grate tubes into section C of the pivot tube which is blocked oif by the baiiies 20 and 2l. The flow of water is then permitted to return from section C of the pivot tube to section D of the header tube on the other side of the baiile 22 from section B thereof. The ow is then reversed to pass from section D of the header tube into section E of the pivot tube and be discharged therefrom through the outlet I9. Through this system of grate tubes and baiiles there is provided a circuitous flow of water through the entire dump grate from one end thereof to the other. The Water passage therethrough not only directly cools the grate tubes, but also cools through convection the grate bars formed thereon.

The dump grate of Fig. 3 is shown in Fig. 1 as mounted in the center cell of the three cell furnace. A dump grate similar thereto in all respects is mounted in each of the outer cells. Thus, the dump grate structure of the outer cells is provided with a pivot tube 15a of precisely the same arrangement as above described in respect to pivot tube I5, including a water inlet pipe IBa, outlet I9a, and bafiles 20a, 2Ia, and 22a. Each of the grate tubes Ida carry the laterally extending grate bars Ila. The pivot tubes of the grate bars of all three cells extend throughout the full width thereof, the pivot tube Ia immediately underlying the pivot tube I5. Thus, the center dump grate is supported by the pivot tube I5, whereas the two outer cell dump grates are supported by the pivot tube Ia. The respective pivot tubes are cradled in the bearings 23 and 24, the bearings 23 being mounted in the outer bridge Wall i3d, and the bearings 24 being mounted in the intermediate bridge walls I3.

The header tubes of all three dump grates are normally in axial alignment when the grates are in their upper fuel supporting position, the header I6 of the center dump grate being in axial alignment with the headers IBa of the outer dump grates, as shown in Fig. 2; the intervening cell separating Wall being removed to show the relative positions of the center and outer grates.

For dropping the dump grates from their approximately horizontal fuel supporting position to a downwardly extending dumping position, each dump grate is provided with a pair of downwardly extending arms 25, which are pivotally connected at their lower ends by the links 26 to the dump rods 2l extending toward the front end of the furnace, Said rods 21 may be notched at 28 to hook over a latch bar 29 for latching the dump grates in raised fuel supporting position as shown in full lines in Fig. 2. When the rods 21 are released to move inwardly to the position shown in dotted lines of Fig. 2, the dump grate is permitted to drop down to its dumping position about the axial center of its pivot tube header.

From the foregoing, it will be observed that through a simple arrangement of tubing a water cooled dump grate is provided not only for one grate cell, but for a plurality of adjacent grate cells, which may be independently dumped while maintaining a constant now of water therethrough, the iioW being substantially equalized throughout the entire length and area of the respective grates. The passage of the cooling iiuid through and about the tubular sections of each vgrate both directly cools the tubular portion 4 I thereof and indirectly, through convection, cools the adjacent grate bars upon which the fuel is supported and through which air is permitted to pass.

The invention claimed is:

l. In a refuse burning furnace having a pluralityA of grate cells, a dump grate for each cell comprising a pair of opposed parallel tubular headers extending transversely of each cell, a series of equally spaced parallel tubular fuel supports connected with said headers in communication therewith, one of said headers of each grate being supported upon said furnace in vertical offset relation With the corresponding header of an adjacent grate, inletl and outlet connections with said last mentioned respective headers for introducing and exhausting a cooling fluid for circulation through said headers and connecting fuel supporting tubes, and a manually operable dump control mechanism operably connected with the opposed header of each grate for raising them to aligned fuel supporting position and lowering them to fuel dumping position about the axis of their respective offset headers.

2. In a refuse burning furnace having a plurality of grate cells, a dump grate for each cell comprising a pair oi opposed parallel tubular headers extending transversely of each cell, a series of equally spaced parallel tubular fuel supports connected with said headers in communication therewith, one of said headers of each grate being supported upon said furnace in Vertical offset relation with the corresponding header of an adjacent grate, inlet and outlet connections with said last mentioned respective headers for introducing and exhausting a cooling iiuid for circulation through said headers and connecting fuel supporting tubes, a manually operable dump control mechanism operably connected with the opposed header of each grate for raising them to aligned fuel supporting position and lowering them to fuel dumping position about the axis of their respective oset headers, and bearing supports provided in said furnace for rotatably supporting said respective offset headers in vertically aligned adjacent position.

3. In a refuse burning furnace having a plurality of grate cells, a dump grate for each cell comprising a pair of opposed parallel tubular headers extending transversely of each cell, a series of equally spaced parallel tubular fuel supports connected with said headers in communication therewith, one of said headers of each grate being supported upon said furnace in vertical oset relation with the corresponding header of an adjacent grate, inlet and outlet connections with said last mentioned respective headers for introducing and exhausting a cooling fluid for circulation through said headers and connecting fuel supporting tubes, a manually operable dump control mechanism cperably connected with the opposed header of each grate for raising them to aligned fuel supporting position and lowering them to fuel dumping position about the axis of their respective offset headers, and a series of baffles in said headers so arranged therein relative to said fuel supporting conduits as to direct the flow of iiuid for even distribution therethrough.

4. In a refuse burning furnace having a plurality of grate cells, a dump grate for each cell comprising a pair of opposed parallel tubular headers extending transversely of each cell, a series of equally spaced parallel tubular fuel supports connected with said headers in communication therewith, one of said headers of each 5 grate being supported upon said furnace in vertical offset relation with the corresponding header of an adjacent grate, inlet and outlet connections with said last mentioned respective headers for introducing and exhausting a cooling fluid for circulation through said headers and connecting fuel supporting tubes, a manually operable dump control mechanism operably connected with the opposed header of each grate for raising them to aligned fuel supporting position and lowering them to fuel dumping position about the axis of their respective offset headers, and laterally extending grate bars on each of said tubular fuel supports extending laterally in the plane thereof toward and in spaced relation to adjacent grate bars.

ALFRED D. SIMPSON.

REFERENCES CITED The following references are of record in the me of this patent:

Number Number 6 UNITED STATES PATENTS Name Date Nevins Jan. 28, 1866 Seddon Sept. 23, 1873 Shackelford Sept. 23, 1884 Pollock Apr. 4, 1893 Thurell Feb. 5, 1901 Sawyer June 10, 1902 Johnson Dec. 27, 1904 Schmidt Mar. 30, 1909 MacKay Aug. 24, 1915 Nye Feb. 1, 1916 Barnett Feb. 15, 1916 Frechette June 17, 1924 Von Mattekovich June 2, 1936 Hofft et al. Nov. 7, 1941 FOREIGN PATENTS Country Date Austria Dec. 15, 1900

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