US2885201A - Cooled sinter grate - Google Patents

Description

May 5, 1959 l s. T. EVENSTADl 2,885,201

cooLED SINTER CRATE Filed Ag. 14, 195e COOLED SINTER GRAT E Sydney T. Eveustad, El Monte, Calif.

Application August 14, 1956, Serial No. 603,979

6 Claims. (Cl. 266-21) The present invention relates to a sinter grate and relates more particularly to a grate utilized in a sinter ing process wherein means are provided for cooling the grate.

In the production of steel and other metals from ore, it is frequently the case that small particles of the metal are available in large quantities. If this ore is heated in conventional furnaces, extreme oxidation will take place in regard to some particles of metal and such metal will thereby be lost. Accordingly, by combining small particles in such a manner as to create larger sinters, this material can thereafter be handled in the normal processes.

Conventional practice has employed large conveyors upon which aggregate has been placed. The aggregate is premixed with coke, or the like, that is thereafter tired. Air drawn through the mixture of coke and aggregate and through openings in grates forming a portion of the conveyor, serves to create high temperatures sufficient to form sinters from the aggregate. However, inasmuch as the grates employed to support the material being heated must necessarily be made from metal, considerable wear and other damage to the grates takes place, thus requiring frequent replacement thereof. The wear that takes place on the grates usually takes the form of cracked or burnt portions, eroded sections and warped structures.

In order to prevent such destruction of the grates and the necessity for frequent replacement thereof, it has been suggested, and in some cases put into practice, that the grates be manufactured from high temperature alloys rather than the usual cast iron. The high ternperature alloys naturally possess characteristics wherein oxidation takes place at a higher temperature than cast iron, which commence at about 1l00 F. However, these high temperature alloys possess several disadvantages such as the considerably higher cost thereof, and when subjected to continued temperature differentials, tend to distort, thus causing cracks and the breaking out of sections thereof. Considerable time is often consumed in using high temperature alloy grates in the straightening of distorted sections, as by hammering or the like.

It has been found that the life of cast iron grates may be greatly extended by providing a means of cooling these grates during the use thereof. Inasmuch as the grates are utilized in situations wherein tolerances are very liberal, serious problems have existed relative to means by which the grates may be cooled while in use. The present invention provides means for such cooling of the grates.

By cooling the cast iron grates, several advantages are presented that not only increase the life thereof but also speed up production facilities. By maintaining the grates in a relatively cool condition, the sintered mass supported thereby will not adhere thereto and may be discharged without undue difficulty. Additionally, it has often been necessary to coat the grates with a thin layer of burnt sinter to support the burning mass and prevent patented May 5, 1959 its coming into direct contact with the grates. The utilization of such a burnt sinter layer helps to protect normal uncooled grates but occupies space that could otherwise more profitably be used for the burning mass.

Abrasion of the grates has also been a problem, with such abrasion considerably reduced by maintaining the grates in a relatively cool condition inasmuch as abrasion resistance increases as temperatures are lowered.

It is therefore a principal object of the present invention to provide a novel sinter grate and means for cooling such a sinter grate.

It is another object of the invention to provide a novel combination conveyor and sinter grate, together with means for cooling the sinter grate during use thereof. v

It is a further important object of the invention to provide a novel means for pivotally securing a sinter grate with respect to a conveyor mechanism.

Still another object of the invention is to provide a novel sinter grate having an integral manifold provided therein whereby to enable passage of a cooling mediu therethrough.

Other and further important objects of the invention will become apparent from the disclosures in the following detailed specication, appended claims and accompanying drawing wherein:

Figure 1 is a top plan view of a typical conveyor and support therefor showing the present grates employed therewith;

Fig. 2 is a partially schematic transverse sectional view through a sintering conveyor utilized in the present cooled sinter grates;

Fig. 3 is a side elevational view of one of the sinter grates shown partially in section;

Fig. 4 is a bottom plan view of the grates shown in Fig. 3;

Fig. 5 is an enlarged fragmentary sectional view showing the means by which the present grates are attached to the supporting structure of a conveyor; and

Fig. 6 is a fragmentary sectional view of a finger type grate employing the cooling arrangement of the present invention.

With reference to the drawing, the conveyor for supporting the present grates is shown as indicated in Fig. 1 generally at 10 and having a support structure 11 from which a plurality of rollers 12 depend. The rollers 12 are adapted for cooperation with suitable rails 13 that may be supported on suitalble leg arrangements 14. In accordance with usual practice, the support structure '11 has depended from sides thereof, side plate members 15. The grates of the present invention are shown as indicated generally at 16 and are supported by the support structure 11 in a manner to be hereinafter more fully described.

As shown in Fig. 2, the sinter mass s indicated at 17 and supported on the grates 16. The space below the grates 16 is enclosed by means of a wind box 18 from which a vacuum is drawn by means of a suitable pneumatic pump A20 and a conduit 21. Thus, as the conveyor 10 moves in a linear direction, air is drawn through the sinter mass whereby to effect complete combustion thereof. The air passing through the sinter mass passes into the wind box 18 and is discharged outwardly therefrom by means of the conduit 21 and the pump 20. In most instances, a vacuum in the nature of from 15" to 40 of water is drawn on the wind box 18.

As shown primarily in Figs. 3 and 4, each of the grates 16 includes a grate body 22 which has an integral structure generally formed as by casting from cast iron. The grate 16 has a pair of rows, each having a plurality of tapered openings 23 therein which diverge from an upper extendingrproiection of the` grate while the: other ends thereof; communicate with separate.l discharge openings,

there beinlopenings forthe conduits 29 and an opent V ingi34for theconduit 30. `Th1: Upeningsandif extend throut the lower surface25 of the grate body 22 and through portions of the web 26. t Thus, it may :beg seen that when thergrates are in position."k as shown in Figs.

rinda, urs openings `se. and s4 win commissie with Iasi Y 1 With reference now `primarily to` Fig. 5, itis `tonbe noted thateachiof the grates 16 are secured in relative tothe support structure 1l by means lof a pin 35.

The pin 35 has a passage therethrough. withone end s offthepin being adapted for disposition in the recess 32 in the end of the grate andin the projection 28. The pin extends through aligned lateral bores d1 inthe side plate members l15 and 38 in the supportstructure 11. Additionally, theouter end of the pin 35 is beveled as at 40.`

` Tolfacilitate use of the present grate securing arrangement denedrby the pin 35,.a tab 41 is welded asiat 42to existsupport structure 11 and a split pin 43is `inserted throughaligned openings 44 and 45 in thepin 35 and` taILMLrespectively.` The beveled nature of the outer end f ofi` the pin serves `to facilitate insertion and removal ofthesplit pin 43. lt is to` be noted that the passage 36 within thepin communicates with the lateral` passages 3l nndwnduits 29 and 30. i i i i `llt may thus be seen that air at room temperature is` drawn in through the passage 36 and into the manifold formed bythe cooling passages 29 `and 30 and is there-` after discharged from the openings 33 and `34` into the wind box 13, thus by radiation and convectionto cool the With reference now to Fig; 6, it is to be :noted that nger grates of the `type employing a base structure;` 50 with a plurality of individual fingers 5l positioned theremayalsotutilize the present cooling facility. In this instance, the base structure Sois provided with a suitable manifold l52 While the lingers 5l are made with` passages 53 `therein, and lateral openings 54 which are adapted to mate withsimilar openings extending through the base structure 50 to the internal passages 52 therein. Thus, airzmay be drawn through the various fingers and `hase structure of this type of grate to provide the desired cool While the present invention and description thereof has illustrated grates that are secured to the supporting struci Additionally, it is to be emphasized that while a specie form and constructon of grate is illustrated and described herein and that a specific number of passages` have been provided to `form the cooling manifold` other types of grates and specific designs therefor may be employed and any number of passages utilized in the practice of the present invention.

Having thus described the invention and the present embodiment thereof, it is desired to emphasize the fact that many `further modifications may be resorted to in a manner limited only by a just interpretation of the following claims.` j t t I claim: t

1. Acombination sinter grate and conveyor mechanism comprising: a grate body; means for gravitationally supporting said cody on said conveyor; side plate members forming a portion of said conveyor; a plurality of passages` in said body for permitting passage of gasesfrom a sinter masslcarried on said grate through said grate; means for drawing said gases through said grate; cooling medium conduits insaid `grate adjacent said passages; means for introducing a cooling medium to said conduits; and means operable in response to said drawing means for inducing tlow in and for discharging said cooling medium from said conduits. i

2. A` sinter grate and conveyor mechanism according to claim l wherein said discharge means for said cooling medium is directed toward a side of said grate remote from a side thereof carrying saidmass.

3.` A sinter grate andconveyor mechanism according to claim 2 wherein means are` provided for pivotally connecting said grate to said sideplate members, said cooling medium introducing means being operably associated with said pivotal connecting means.` t

.4." In a sinter conveyor mechanism having conveyor side members, roller means carried by a support structure formovably supporting said side member on rails, a plu i rality of sinter grates pivotally connected with said side members, a gas receiving chamber below said grates,` and `a means for drawing a vacuumon said chamber, a means for cooling said gratescomprising, in combination: a plurality of cooling medium conduits in said gratespmeans operatively associatedwith said pivotal connection between sad grates and said side members for introducing a cooling medium to said conduits;` and passage means in said grates and communicating between said conduits and said chamber for discharging` said cooling medium-from said conduits.`

. S.; A `sinter conveyor mechanism according to claim 4 wherein said ;pivotal connections comprise tubular pins adapted for free reception .t in recesses in ends ofsaid grates, said recesses communicating with said conduits.

6. A sinter conveyor mechanism according to claim 5 wherein said pins function to secure said side members to said support `structure and means are provided for removably securing said pins to said `support structure and against inadvertentrcmoval therefrom.

References Cited in the le of this patent.` i UNITED STATES PATENTS 778,149` Simons Dec. 20. 1,304,393 Sherry May 20. 2,493,421 Rolfsen Jan. 3, 2,745,364 Martin May l5.

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