US3719354A

US3719354A - Travelling grate machines

Info

Publication number: US3719354A
Application number: US00175438A
Authority: US
Inventors: C Burgess
Original assignee: Carves Simon Ltd
Current assignee: Simon Carves Ltd; Carves Simon Ltd
Priority date: 1971-08-27
Filing date: 1971-08-27
Publication date: 1973-03-06
Anticipated expiration: 1990-03-06

Abstract

Apparatus for the gaseous treatment of solid materials comprising a plurality of pallets each having a base in the form of a grate and which are adapted to be moved in end-to-end abutting relationship through a treatment zone where a gaseous medium is passed through the material on the pallets from static wind boxes located below the pallets, characterized by the provision of dead plates extending over the width of the apparatus at the positions where the pallets enter and leave the treatment zone and by the provision of wear strips extending transversely of each pallet at the leading and trailing ends thereof and depending from the underside of the pallet to make contact with the dead plates as they pass thereover, said wear strips being of a softer material than the material of the dead plates, whereby the wear strips are worn away to accommodate for distortion of the pallets while maintaining a proper seal with respect to the dead plates.

Description

Unite Burgess States Patent 1 TRAVELLING GRATE MACHINES [75] Inventor: Charles David Burgess, Cheshire,

England [73] Assignee: Simon-Carves Limited, Cheshire,

England [22] Filed: Aug. 27, 1971 [21] Appl. No.: 175,438

Primary ExaminerGerald A. Dost Attorney-James E. Nolan 1 March 6, 1973 5 7 ABSTRACT Apparatus for the gaseous treatment of solid materials comprising a plurality of pallets each having a base in the form of a grate and which are adapted to be moved in end-to-end abutting relationship through a treatment zone where a gaseous medium is passed through the material on the pallets from static wind boxes located below the pallets, characterized by the provision of dead plates extending over the width of the apparatus at the positions where the pallets enter and leave the treatment zone and by the provision of wear strips extending transversely of each pallet at the leading and trailing ends thereof and depending from the underside of the pallet to make contact with the dead plates as they pass thereover, said wear strips being of a softer material than the material of the dead plates, whereby the wear strips are worn away to accommodate for distortion of the pallets while maintaining a proper seal with respect to the dead plates.

5 Claims, 3 Drawing Figures PAIE NTED MAR 61973 SHEET 1 OF 2 InVQfl/O/L Chara: D/wlo EUECESS' Y GJJOYM SI TRAVELLING GRATE MACHINES This invention concerns apparatus for the gaseous treatment of solid materials particularly, though not exclusively, apparatus for the agglomeration of ores and minerals, and being of the kind (hereinafter termed of the kind referred to) wherein a plurality of pallets each having a base in the form of a grate are adapted to be moved in end-to-end abutting relationship through a treatment zone where a gaseous medium is passed through the material on the pallets by means of static windboxes.

For efficient operation and to prevent the escape of dust and noxious gases it is desirable to form a seal at the points of contact between the pallets and the windboxes.

A variety of means have been proposed for effecting a seal between the sides of the pallets and the windboxes.

A further major potential source of leakage exists at the ends of the treatment zone of the apparatus. In these regions it is customary to provide so-called dead plates across the width of the machine, which are adjustable for height so that the under-surfaces of pallet cross-members supporting the grate pass over the dead plates sufficiently closely to form an adequate seal. Variations are known for the design of the dead plates including the use of beds of granular material which are maintained at the appropriate level by the scraping action of the pallet cross-members, and the use of springsupported dead plates which are urged upwardly against said cross-members.

It has been found that conventional dead plates as described above have a serious disadvantage in that the pallets may become distorted due to the repeated heating and cooling to which they are subjected. Such distortion is commonly in the form of a downward bowing of the pallet. It will be apparent that the dead plates must then be modified to accommodate the pallet having maximum distortion with the result that other pallets which are not distorted to the same degree do not form an adequate seal with the dead plates.

It is an object of the present invention to provide improved sealing means at the ends of a treatment zone of apparatus of the kind referred to, and which overcome, at least to some extent the disadvantage aforesaid.

According to the present invention apparatus for the gaseous treatment of solid materials comprising a plurality of pallets each having a base in the form of a grate which are adapted to be moved in end-to-end abutting relationship through a treatment zone where a gaseous medium is passed through the material on the pallets by means of static wind boxes is characterized by the provision of dead plates extending over the width of the apparatus at the positions where the pallets enter and leave the treatment zone and by the provision of wear strips extending transversely of each pallet at the leading and trailing ends thereof and depending from the underside of the pallet to make contact with the dead plates as they pass thereover, said wear strips being of a softer material than the material of the dead plates, whereby the wear strips are worn away to accommodate for distortion of the pallets whilst maintaining a proper seal with respect to the dead plates. The invention will be further apparent from the following description with reference to the several figures of the accompanying drawings, which show, by way of example only, one form of apparatus embodying the invention.

Of the drawings:

FIG. 1 shows a general arrangement drawing the apparatus;

FIG. 2 shows a cross-section of the apparatus on the line IlII of FIG. 1 on an enlarged scale; and

FIG. 3 shows a cross-section of part of the apparatus on the line III-III of FIG. 2.

Referring firstly to FIG. 1 it will be seen that the apparatus comprises a plurality of pallets 10 which are adapted to be moved continuously on rails 11 around an endless path having upper and lower runs. The pallets 10 are in endto-end abutting relationship as they move along the upper run through a treatment zone defined above windboxes 12 for the supply of treatment gas disposed beneath the run.

Turning now to FIG. 2 it will be seen that each pallet has a base in the form of a grate 10a supported by transversely extending cross members 10b. The number of cross members 10b is not critical so long as there is one such member located beneath the grate 10a adjacent both the leading and trailing ends of each pallet 10. The pallets are equipped with wheels 13 which engage the rails 11 to enable the pallets to be progressed around the apparatus. Sliding sealing means generally indicated at 15 are provided between the sides of the pallets and the sides of the windboxes 12.

In accordance with the invention dead plates 16 are provided adjacent the entry to and exit from the treatment zone and extend transversely in a horizontal plane between the rails 11 at these positions. The dead plates 16 extend longitudinally so as to overlap the extreme ends of the windboxes 12 as clearly shown in the drawings. As can be seen from FIGS. 1 and 3 each of the dead plates 16 has end portions of ramp-like form which incline downwardly from a central portion of maximum height. The leading and trailing cross members 10b on each pallet 10 are provided with slots 17 in their under-surfaces which locate wear strips 18 which depend therefrom and which are adapted to abut the dead plates 16 as they pass thereover.

The wear strips 18 are formed from a material, such as a bronze which is softer than the material from which the dead plates 16 are formed. The arrangement is such that as the pallets enter and leave the treatment zone above the windboxes 12, the strips 18 slidably contact the plates 16 forming a seal preventing escape of gases at these regions. In operation, as any pallet 10 becomes distorted, the wear strips 18 become worn by engagement with the plates 16 to accommodate such distortion. It follows that the strips 18 on each pallet are worn by different extents depending upon the degree of distortion experienced by each pallet and that adequate seals are maintained for each pallet.

It will be understood that the wear strips 18 canbe made of sufficient depth to accommodate considerable distortion of any pallet frame before other remedial action need be taken.

It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible without departing from the scope thereof.

What is claimed is:

1. Apparatus for the gaseous treatment of solid materials comprising a plurality of pallets each having a base in the form of a grate which are adapted to be moved in end-to-end abutting relationship through a treatment zone where a gaseous medium is passed through the material on the pallets by means of static wind boxes, characterized by the provision of dead plates extending over the width of the apparatus at the positions where the pallets enter and leave the treatment zone and by the provision of wear strips extending transversely of each pallet at the leading and trailing ends thereof and depending from the underside of the pallet to make contact with the dead plates as they pass thereover, said wear strips being of a softer material than the material of the dead plates, whereby the wear strips are worn away to accommodate for distortion of the pallets whilst maintaining a proper seal with respect to the dead plates.

2. Apparatus according to claim 1, wherein said wear strips are located in slots on the under-surfaces of cross members which support the grates of the pallets.

3. Apparatus according to claim 1, wherein the dead plates extend longitudinally so as to overlap the extreme ends of the wind boxes.

4. Apparatus according to claim 2, wherein the dead plates extend longitudinally so as to overlap the extreme ends of the wind boxes.

5. Apparatus according to claim 1, wherein the ends of each dead plate are defined by ramp portions which incline downwardly from a central portion of maximum height.