US2861792A

US2861792A - Sintering apparatus

Info

Publication number: US2861792A
Application number: US546972A
Authority: US
Inventors: John H Porteus; John A Anthes
Original assignee: Dravo Corp
Current assignee: Dravo Corp
Priority date: 1955-11-15
Filing date: 1955-11-15
Publication date: 1958-11-25
Anticipated expiration: 1975-11-25

Description

Nov. 25, 1958 Filed Nov. 15, 1955 J. H. PORTEUS ET AL SINTERING APPARATUS 2 Sheets-Sheet 1 INVENTOR. JOHN H. PORTEUS. BY JOHN A. ANTHES.

ATTORNEYS.

Nov. 25, 1958 PQRTEUS ETAL 2,861,792

SINTERING APPARATUS Filed Nov. 15, 1955 2 Sheets-Sheet 2 I A \\5 A INVENTOR.

JOHN H. PORTEUS.

By JOHN A.ANTHES.

ATTORNEYS.

United States Patent SINTERING APPARATUS John H. Porteus, Ben Avon Heights, and John A. Anthes,

Bridgeville, Pa., assignors to Dravo Corporation, Pittsburgh, P a., a corporation of Pennsylvania Application November 15, 1955, Serial No. 546,972

Claims. (Cl. 266-21) "drawn by the suction in the wind-box down through the charge on the pallets, it is necessary to provide some kind of a seal between the lower edges of the moving pallets and the top of the wind-box at each side of the apparatus to thereby prevent air from entering the suction or windbox under the side edges of the pallets. A simple form of seal is one in which a vertically floating seal bar in a groove on the bottom of the pallet along each side thereof rests of its own weight on a track at the top of the windbox. It is necessary that the sealing bar or strip has a close fit in the groove to preclude excessive leakage.

This condition causes the seal to fail aftera period of operation; the bars become mutilated, warped or oxidized and fail to slide up and down in the grooves, and serious leakage then occurs.

Another common form provides wheels'at the sides of the pallets rolling on resiliently supported rails. Wear strips on the bottom edges of the pallets contact slide tracks along the tops of the wind-boxes. The resiliently supported rails are so adjusted as to distribute the load of the pallet between the wheels and the slide tracks forming the seal. While providing a good seal, the apparatus must be kept in accurate adjustment and constant lubrication of the slide bars is essential.

Many variations and combinations of these ideas have been attempted, but are subject to excessive wear, sticking, or other serious defects after a sustained period of operation. t

Our invention has for its object to provide a simple seal which is protected from heat, is of relatively light weight, and which requires little attention to maintain, and which offers little friction or drag, and which is positive in its sealing action. It further provides a seal in which provision is made automatically for vertical and horizontal motion of the pallets relatively to the wind-boxes caused by misalignment, wear, etc. Moreover it provides vertical or nearly vertical sealing elements, so as to minimize accumulation of sinter thereon.

These and other objects and advantages are obtained by our invention as will be apparent from the following description in conjunction with the accompanying drawings, in which:

Fig. 1 is a transverse section through a sintering apparatus embodying our invention;

Fig. 2 is an enlarged transverse section through the apparatus at one side showing the seal on a larger scale;

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Fig. 3 is a view similar to Fig. 2 of a slightly modified construction; and

Fig. 4 is a fragmentary view of a portion of the seal, showing a joint between sections.

Referring to the drawings and first to Figs. 1 and 2, 2 designates a wind-box of sintering machine, the box being of usual construction with an outlet 3 leading to a suction fan. It may or may not be refractory lined and has parallel side walls 4, while 5 is a supporting structure.

Extending along each side of the supporting structure are parallel rails 6. A pallet is shown at 7, with axle extensions 8 on each side thereof on which are wheels 9 that roll on the rails 6 and support the pallets in fixed relation to the top of the wind-box. The pallet has a bottom 10 on which the charge of material is supported and through which air may be sucked into the wind-box. The pallet has side walls 11 and end walls 11a. It will be understood that there are a succession of such pallets in contact with each other forming an endless band, the return reach (not shown) being below the wind-box. There are also a succession of wind-boxes.

Extending along each side edge of the pallet at the bottom is a flange or apron 12, but shown in Fig. 2 located to the side of the area forming the grate. It has a smooth side face 13, preferably recessed as a channel in the outer face of the flange.

The side of the wind-box is formed in part of a vertical metal plate 14 with an inwardly turned flange 15 at its top, this flange 15 being below and being slightly spaced from the bottom edge of the flange or apron 12. The seal comprises a metal sheet 16 welded or tightly riveted to the outside of plate .14 and having a lip portion 17 that may bear directly on the flat sealing surface 13 on the flange 12, but which is preferably provided with a sealing and wear strip 18 that may be of metal, asbestos, composition or other suitable material. The intermediate portion of the sheet 16 below the lip 17 is bowed outwardly as indicated at 19 to give the sheet resilience and yieldably urge the lip 17 against the face 13.

The plate 16 extends along the entire length of the wind-box or series of wind-boxes, but may be formed in sections, as shown in Fig. 4 with outwardly bowed pieces 16a connecting adjacent ends. This provides flexibility for lengthwise expansion and contraction and greater flexibility transversely for sealing. The connector 16a may be welded to one or both of'the adjoining sections, but if welded to only one, has a sliding fit on the other.

In the modification shown in Fig. 3, the pallet 20 has a flange 21 which is here shown as inclined instead of vertical, and which has a sealing surface: 22 on its outer face. The sealing strip is designated 23, but instead of being inherently resilient, it is hinged at 24 to the side plate 25 of the wind box, while a spring 26 yieldably urges the lip 23a of strip 23 against surface 22..

The resilient spring strip 16 could of course be used with the inclined sealing surface 22, and the hinged plate of Fig. 3 could be used in place of plate 16, and various other modifications and changes may of course be made. Also, the sealing surface 22 may be at other angles. Moreover, the resilient plates of Fig. 2 may be used with the spring hinge arrangement of Fig. 3 to afford a combined resilience. In each case the wearing surface on the pallet is a shallow groove and the contacting surface of the resilient plate bears only in this groove. By reason of the bowed construction of the resilient. plates, they can flex both vertically and horizontally and therefore respond to all variations of movement that occur due to wear in the apparatus, misalignment or other causes.

With the apparatus as thus constructed, the suction in the wind box tends to draw the sealing strip into closer sealing relation with the sealing surfaces on the pallet. Such restricted leakage as occurs creates a current of air that will keep the sealing surface clean, and dust that might tend to pass out onto the seals is drawn into the wind box by the slight current of air through the narrow space between the bottom of the flange 12 and the top of the flange 15. The only movement is the slight yielding movement of the sealing strip, so that there is no likelihood of parts striking. Since the pallets have only the downwardly extending flanges on which are the sealing surfaces,v there is no problem involved by reason of the fact that the pallets in the bottom reach of the endless series are inverted and the sealing surface is protected from sinter that may sift or fall down, and this is especially true where the sealing surface is recessed in the side of the flange or protected by the angularity of the flange, as in Fig. 3.

The seal of our invention may be continuously lubricated, intermittently lubricated, or unlubricated. Because of the relatively low bearing pressures the seal will operate satisfactorily with little or no lubricant. The sliding seal of the contact faces of the sealing strips in the grooves in the flanges of the pallets and the resilience of the curved strips, automatically provide for vertical and horizontal movements of the pallets relative to the wind-box where the pallets move irregularly due to wear, misalignment, warpage or the like.

Various other advantages are provided by our invention, including simplicity and cheapness of construction, as well as case of maintenance, and various changes and modifications may be made in the construction within the contemplation of our invention.

We claim:

1. Sintering apparatus comprising a wind-box structure having parallel longitudinally extending side Walls, a succession of pallets movable in progression over the Wind-box structure, each pallet having a depending flange along each side thereof, which flanges in the travel of the pallets move in confronting vertically spaced relation to the sides .of the wind-box structure, said depending flanges each having a grooved sealing surface extending along the exterior side face thereof, and sealing plates extending upwardly from the exterior of the sides of the wind-box structure and resiliently biased to urge their upper edge portions against the sealing surfaces of the pallets as the pallets move along over the wind-box structure, said plates being bowed outwardly between their upper and lower edges whereby the only contact of the plates with the pallets is in said grooves and whereby said plates may flex laterally and vertically.

2. Sintering apparatus as defined in claim 1 in which said sealing plates are formed of a plurality of longitudinally-extending sections, and longitudinally yieldable may expand and contract lengthwise of the structure.

3. Sintering apparatus as defined in claim 1 in which the succession of pallets is in the form of an endless series with the top reach moving over the wind-box structure and the bottom reach passing under the Wind-box structure with the pallets in the bottom reach inverted, the sealing surfaces on the pallets being protected by an overhang when so inverted to diminish dust accumulation thereon when the pallets are moving in said inverted position under the wind-box structure.

4'. Sintering apparatus having a wind-box with sides thereon and a series of pallets supported for movement in progression over the top of the wind-box characterized by the provision of depending flanges on the sides of the pallets located above but in proximity to the sides of the wind-box when the pallets are moving over the windbox, said flanges having grooved sealing faces on the outer side faces thereof, the sides of the wind-box having sealing strips projecting upwardly therefrom with portions at the top thereof positioned to bear against and form a seal with the grooved sealing faces on the exterior of the pallet flanges only, said strips being resiliently biased to flex vertically and horizontally and yieldably bear against the sealing faces on said flanges.

S. A sintering apparatus having a wind box construction with parallel sides and a succession of pallets movable over the top of the wind box, each pallet having a depending flange on the bottom thereof at each side that moves along over the sides of the wind box in confronting relation thereto, said flanges each having a laterally-extending lip along the outer face thereof, and sealing plates secured to the outer sides of the wind box and having top edge portions providing contact strips which engage the outer faces of the pallet flanges above said lips each sealing plate being bowed between the said top edge to clear the pallet flange so that no part of the plate except the upper edge is contacted by the pallet, the plate being resiliently biased to flex vertically and horizontally for maintaining contact between said upper edge portion and the lip.

References Cited in the file of this patent UNITED STATES PATENTS 1,199,962 Borson Oct. 3, 1916 1,774,135 Fassotte Aug. 26, 1930 1,896,625 Hyde Feb. 7, 1933 2,070,300 Smith Feb. 9, 1937 2,213,396 Hyde et a1. Sept. 3, 1940 2,254,323 Shallock Sept. 2, 1941 2,273,821 Agnew Feb. 24, 1942 2,710,183 Urban June 7, 1955 FOREIGN PATENTS 222,748 Great Britain Oct. 9, 1924 24,670 Australia Dec. 2, 1930