GB2262978A

GB2262978A - Furnace charge support

Info

Publication number: GB2262978A
Application number: GB9225104A
Authority: GB
Inventors: Alfred Hinz
Original assignee: Preussag Stahl AG
Current assignee: Preussag Stahl AG
Priority date: 1991-12-11
Filing date: 1992-12-01
Publication date: 1993-07-07
Anticipated expiration: 2012-12-01
Also published as: IT1256183B; DE4141422A1; GB2262978B; ITMI922753A0; ITMI922753A1; DE4141422C2; GB9225104D0

Description

2262978 1 - APPARATUS FOR SUPPORTING HEATED MATERIAL ON SKID-PIPES OF

HEAT-TREATMENT FURNACES The present invention relates to an apparatus for supporting heated material on skid pipes of heattreatment furnaces, preferably pusher furnaces, comprising a cooled pipe with a support web with sliders mounted friction-lockingly thereon, the lateral legs of said sliders surrounding the support web and the upper side of the skid pipe at least in part with an insulating interspace, such as are used for heating slabs in wide-strip rolling mills. Their use can also however be envisaged for cooled support pipes in walking beam furnaces.

In order to support heated material on skid pipes, the use of co-called sliders, mounted on skid pipes of heat-treatment furnaces, is generally known.

In pusher furnaces, the heated material is pushed along on sliders, and in walking beam furnaces it is lifted along. In order to prevent displacement of the sliders along the skid pipes, which for example have on their upper side a support web, said support web can be provided, for each slider, with a plurality of recesses extending transversely to the push direction, and the underside of the slider can have a plurality of ribs, as is described in DE 22 31 223 B2. In the case of such solutions, the sliders can drop down, requiring the furnace to be cooled in order that the fallen slider can again be set up. Furthermore, the cams for accommodating the sliders on the skid pipes can become damaged, requiring time-consuming subsequent work.

Other solutions, such for example as DE 39 39 582 Al, propose for walking beam furnaces that the sliders be connected by means of a locking member which is rigidly connected to the skid pipe. The connection of the locking member to the skid pipe is effected in this solution by means of a welded connection. This involves complex and time- consuming assembly and dismantling of the sliders. Furthermore there is the risk of cracking by the notch effect on the weld seams, which can lead to leakage in the skid pipes.

Proceeding from DE 22 31 223, the purpose underlying the invention is to develop an apparatus of such type for supporting heated material on skid pipes of heat-treatment furnacest in which the sliders are prevented from falling off the skid pipes, and in which a simple and easily-releasable connection is produced between the slider and the skid pipe, without the necessity of carrying out welding operations on the skid pipe.

According to the present invention there is provided apparatus for supporting heated material on skid pipes of heat-treatment furnaces, particularly for pusher furnaces, comprising a cooled pipe with a support web with sliders mounted friction-lockingly thereon, the lateral legs of said sliders surrounding the support web and the upper side of the skid pipe at least in part with an insulating interspace, in which:

a) b) c) the legs of the slider are elongated; the elongated legs of the slider form with the skid pipe hollow spaces beneath the centre line of said skid pipe; and locking members are releasably disposed in the hollow spaces, said locking members preventing the slider from being removed in an upward direction.

Preferably, the hollow spaces are defined from below by horizontal surfaces which are formed on the elongated legs of the slider, and whose spacing apart is - 3 greater than the diameter of the skid pipe.

Further preferably, the locking members are wedge-shaped and cams have on both sides in which the height of the forward cam is smaller than the distance by which the locking member can be raised in the free hollow space between the leg of the slider and the skid pipe, and in which the height of the rear cam is greater than such distance.

In accordance with preferred embodiments, both locking members are introduced on the right and lefthand sides of the slider in different directions into the hollow spaces, the cams of the locking members form on both sides an interlocking connection with the legs of the slider and the spacing between the cams is greater than the length of the surface of the slider defining the free hollow space from below.

Accordingly, in the solution according to the invention, provision is made for the legs of the slider to be elongated, so that they f orm with the skid pipe hollow spaces beneath the horizontal centre line. In these hollow spaces there are located releasable locking members which prevent the removal of the slider in an upward direction. The locking members may be metal components, internally frictionally or interlockingly connected to the slider legs, but may also be metal rods with different crosssections, which are inserted into the hollow spaces. For this purpose, the hollow spaces must have a lower limiting surface which prevents the locking members from dropping downwards. These limiting surfaces are more advantageously formed on the elongated legs of the slider. Their spacing apart must be greater than the diameter of the skid pipe upon which the slider is mounted. In order to ensure that the locking members 4 - cannot drop out of the hollow spaces as a result of concussion, they have on both sides limiting means by means of which they are securely frictionally held on the slider. These limiting means may be thickened portions in the case of metal rods, which are thrust through the hollow space or are subsequently secured. It has proved of advantage to use wedge-shaped metal components as locking members. The wedge shape enables clamping of slider and skid pipe by the locking member. Both ends of the wedge are def ined by cams. In this case, the height of the forward cam should be so selected that the wedge can be thrust straight into the hollow space between elongate slider leg and skid pipe, while the rear cam should be higher than this hollow space. In this way, the rear cam represents a securing means which prevents the wedge from being knocked through the hollow space. The spacing between the cams on the locking members should be so dimensioned that it is greater than the length of the surface of the slider which defines the free hollow space from below. This is necessary in order that the locking members can still be moved a small distance upon this surface in order to achieve their wedging effect. In the case of any loosening of the locking members, the cams applied on both sides of the locking members, which project beyond the edges of the surface defining the slider leg, prevent the locking members by means of their interlocking effect, from dropping out, and thus represent an additional securing means.

As the forces act on the sliders along the skid pipe in different directions, it is advantageous to insert the locking members on the lefthand and righthand sides of the sliders into the hollow spaces in different directions.

Assembly of the apparatus on the skid pipes is effected in such a way that the sliders are mounted on the skid pipes from above, the locking members are placed in the hollow spaces formed by the legs of the sliders beneath the centre line of the skid pipes, said locking members being, if necessary, knocked in until they are secure. Dismantling is effected by pressing or knocking the forward, and if necessary also the rear, cam in an upward direction in order to loosen the locking member, the locking members then being removed or knocked out. Thereafter the sliders can be taken off.

In comparison to prior art, the apparatus of the invention has the advantage that the sliders are prevented from falling off the skid pipes by a simple and releasable connection between slider and skid pipe; no welding operations are required on the skid pipe.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 a cross-section taken on the line A-B and a cross-section taken on the line C-D in accordance with Fig. 2, through the apparatus according to the invention, only one half being shown in each case; and Fig. 2 a cross-section taken longitudinally through a skid pipe with a slider and locking member mounted thereon.

The slider 1, symmetrical in form with respect to its longitudinal plane, has cams on its underside, and sits by means of such cams on a support web 3, which likewise has cams, and to which the skid pipe 2 is securely attached. The skid pipe 2 contains a skid pipe interior space 7, in which water flows for cooling the skid pipe. The heated material 6 to be supported lies upon the slider 1. The legs 8 of the slider 1 are elongated to reach beneath the horizontal centre line 13 of the skid pipe, the elongation in the illustration being given by way of example relating only to part of the length of slider 1. The limited elongation prevents the slider from becoming unnecessarily heavy. The elongated legs 17 of slider 1 f orm, with the skid pipe 2, beneath the horizontal centre line 13 of the skid pipe, a hollow space 20, into which the locking 'members 5 are introduced. As Fig. 1 shows, the locking members 5 have been inserted into the hollow spaces 10 in different directions relative to the longitudinal axis 13a of the slider 1. The lower limit of the hollow spaces 10, in which the locking members 5 lie, is formed by the elongated slider legs 17, the spacing 9 between the ends of these surfaces being greater than the diameter of the skid pipe 2.

The position of the locking members 5 along the slider 1 can be seen in Fig. 2. The height 14 of the rear cam 11 of the locking member 5 in this case should be greater than the spacing 15 between the centre line 13 of the skid pipe 2 and the upper edge of the locking member 5. Thus the cam 11 prevents the locking member 5 from being thrust or knocked through. The cam 12 on the other hand should be of a lesser height 14a than that represented by the spacing 15. This ensures that the locking member 5 can with certainty be placed into the hollow space 10. The cans 11, 12 prevent the locking member from dropping out of the hollow space 10 if the locking member has become loose. The spacing 16 between the cams must be greater than the spacing 4 representing the length of the surface defining the hollow space 10 from below. because of its wedge-shaped geometry, the 1 locking member 5 has the effect of a frictional connection on its rearward portion 11. On the f orward portion there is a degree of play between the skid pipe 2 and the locking member.

Claims

1. Apparatus for supporting heated material on skid pipes of heattreatment furnaces, particularly for pusher furnaces, comprising a cooled pipe with a support web with sliders mounted friction-lockingly thereon, the lateral legs of said sliders surrounding the support web and the upper side of the skid pipe at least in part with an insulating interspace, in which:

2. Apparatus as claimed in claim 1, in which the hollow spaces are defined from below by horizontal surfaces which are formed on the elongated legs of the slider, and whose spacing apart is greater than the diameter of the skid pipe.

3. Apparatus as claimed in claim 1 or 2, in which the locking members are wedge-shaped and cams have on both sides, in which the height of the f orward cam is smaller than the distance by which the locking member can be raised in the free hollow space between the leg of the slider and the skid pipe, and in which the height of the rear cam is greater than such distance.

Apparatus as claimed in claim 1, 2 or 3, in which both locking members are introduced on the right and left-hand sides of the slider in different 1 directions into the hollow spaces.

5. Apparatus as claimed in any preceding claim, in which the cams of the locking members form on both sides an interlocking connection with the legs of the slider.

6. Apparatus as claimed in any preceding claim, in which the spacing between the cams is greater than the length of the surface of the slider defining the free hollow space from below.

7. Apparatus for supporting heated material on skid pipes of heattreatment furnaces, substantially as hereinbefore described with reference to the accompanying drawings.