DE8901064U1 - Attachment for coolant-flowing support tubes in heating furnaces, especially walking beam furnaces - Google Patents

Description

REINING HEISSKÜHLUNG GmbH & Co. KG, Hauweg 18, 4330 Mülheim a. d. Ruhr

Attachment for coolant-flowing tubes in heating furnaces, especially walking beam furnaces

Description:

The invention relates to attachments for support tubes through which coolant flows in furnaces for heating material to be heated, in particular steel, with a locking element that can be connected directly or indirectly to the tube and with a recess for receiving the locking element.

Such attachments, support tubes and furnaces and the requirements placed on them are known from WO 81/03537. The attachments sitting on the support tubes through which the coolant flows carry the material to be heated over as small an area as possible in order to impede the heating of the material to be heated as little as possible. In walking beam furnaces, which are the preferred area of application for attachments according to the invention, the material to be heated is transported step by step through the furnace in a rectangular movement sequence, i.e. raised, carried further and lowered again. This results in loads in the horizontal and especially in the vertical direction on the attachments. The latter because the contact surfaces of the attachments tend to stick to the material to be heated. The attachments must therefore be secured to the support tube in the vertical as well as the horizontal direction to prevent them from coming loose or slipping.

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It is known to weld attachments to the support tube on two sides over the entire length with longitudinal seams running in the direction of the pipe. This method has the disadvantage that differences in wax expansion between the attachments and the support tubes can lead to tensions and cracks in the material after a while, which continue into the support tube and lead to coolant leakage.

It is also known to fix the attachments to the support tubes using locking elements. According to WO 81/03 537 (^ this is done using perforated plates welded to the support tubes in pairs, between which the fastening arms of the attachments, which are drilled in alignment, engage; a bolt passed through all three holes then serves as a locking element. Furthermore, attachments of this type have been used in practice, which are each provided with four recesses in their inner area, each forming an angle, and are placed on bolts corresponding to them in an angled movement and then secured against coaxial slipping with further bolts. These bolts protrude laterally from a web arranged on the support tube parallel to the axis and projecting radially outwards.

* / The two fastening methods mentioned above essentially have three disadvantages: Firstly, the tolerances between the locking elements on the support tube side and the corresponding recesses for accommodating the locking elements in the attachment pieces must be adhered to very precisely, whereby the problems of different thermal expansion must also be taken into account. Secondly, this fastening method is completely inflexible with regard to any desired change in the position of the attachment pieces on the support tubes, e.g. when it comes to changing the mutual distances between the attachment pieces. Thirdly, dismantling the attachment pieces from the support tubes, for example for repair or replacement purposes, is extremely difficult because the various bolts can only be removed with great effort, if at all, due to the high mechanical and thermal stress.

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Based on this, the invention is based on the task of achieving an improved fastening of the seat pieces in the case of attachment pieces for support tubes of the type mentioned at the beginning. Preferably, the attachment piece should also be prevented from falling off and/or the occurrence of cracks in the support tubes and the associated ^coolant leaks.

The object is achieved according to the invention in that the recess or a further recess in the attachment piece connected to the recess for receiving a part of the locking element is/are shaped in such a way that a part of the locking element received in the attachment piece is accessible from outside the attachment piece in such a way that the locking piece can be welded to the support tube or to a web-shaped intermediate piece to the support tube at the point of accessibility. Cumulatively or alternatively to this solution, it is proposed that the locking element received in the attachment piece protrudes from the attachment piece at least at one point in such a way that the locking element can be welded to the support tube or to a web-shaped intermediate piece to the support tube in this installation position.

The invention ensures, among other things, that only relatively rough tolerances need to be observed when manufacturing and assembling the attachments, the locking elements and the ^ support tubes, |i that the position of the support pieces on the support tubes can be changed without great effort, and that for disassembly, such as when replacing the attachment pieces, only short and easily accessible weld seams need to be removed, which can be located in a surface area of the support tube construction that is particularly suitable for this purpose. Overall, the assembly and disassembly of the attachment pieces is simplified without old or new problems arising; in particular, tensions or cracks due to thermal expansion effects are avoided in the simplest way possible.

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especially since a relatively large clearance can be provided between the attachment parts and the locking elements.

For the purposes of the invention, "recess" is primarily understood to mean those recesses in the attachment pieces that are incorporated into the surfaces that determine the general contour of the attachment pieces, such as depressions, in particular in the form of grooves or straight, curved or angled grooves. However, "recesses" for the purposes of the invention also arise from the attachment pieces having projections in the form of shoulders, webs, noses or the like at certain points, which can be gripped behind by a locking element that is shaped accordingly and secured against tensile stress in the appropriate direction, so that the locking element comes into contact with these projections.

A "direct" connection of the attachment pieces to the support tubes means that the locking pieces are welded directly to the support tube or - preferably - to the longitudinal webs formed in one piece with them. The attachment pieces can be connected "indirectly" to the support tube by first attaching intermediate pieces, preferably in the form of longitudinal webs, to the support tubes and then connecting the attachment pieces to these connecting pieces.

In the sense of the invention, "locking elements" are to be understood as independent components which are shaped, arranged with respect to the attachment pieces and welded with respect to the support tubes in such a way that the attachment pieces are thereby fixed with respect to the support tubes, whereby the locking element rests in the "recess" of the attachment piece and rests against a part of the attachment piece protruding next to the recess in such a way that the attachment piece is fastened with respect to the support tube - in the broadest sense in the manner of a lock.
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In principle, the recesses, corresponding projections and corresponding locking elements (except on the support surface for the goods to be heated) can be provided at any point on the attachment piece, i.e. also in the area of the outer surface when fully mounted on the support tube. If, however, according to a preferred embodiment of the invention, the recesses, corresponding projections and corresponding locking elements are provided on the contact side between the attachment pieces and the support tubes, the rolling resistance is thereby increased.

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_/( because the attachment then covers the locking elements almost completely except for the relatively small area of the welding points.

The locking elements can have a very simple shape, in particular they can be rod-shaped and made of round or square material, i.e. also of completely straight rods. However, if, according to another development of the invention, the locking elements are U-shaped, it is thereby possible to use the U-legs to secure the attachment pieces against displacement and to use the U-bends to secure the attachment pieces against lifting. In particular, the icrric2SxünySci.omoni«c \j 3 &Ggr;&idigr;&Ggr;&idigr; VCrbclxiiai b Xm uc?clCli uuT U &mdash; «JO11G &Pgr; iv &bgr;&Lgr; , and, very particularly preferably, at the free leg ends they can be welded to the support tubes or the longitudinal webs located thereon. Especially when the U-legs point away from the support surface of the top piece and their free ends are welded to the support tube, the welding points are, as is preferred, located in relatively cool areas of the support tube construction.

The attachments can be shaped in any way and can also be attached, for example, to the free ends of the longitudinal webs of the support tubes. However, if they partially enclose the support tube or a web-shaped intermediate piece to the support tube, thermal improvements can be achieved, among other things.

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In principle, it is conceivable to attach each attachment piece to the support tube with only one or with several recess(es) and locking element(s) arranged one behind the other along the tube. Preferably, however, several locking elements and associated recesses are arranged per attachment piece, in particular in a symmetrical arrangement with respect to a radial direction of the tube and in particular symmetrical with respect to the main load line.

With many goods to be heated, such as wet or dry metal pieces with a flat contact surface, the preferably highly heat-resistant metal attachments can come into direct contact with the goods to be heated. However, if the goods to be heated consist of pipes or similar pieces of material which do not have a flat contact surface, the contact surface for the goods to be heated on the attachment is preferably profiled, in particular in the form of holding jaws to secure the position of the goods to be heated. However, such profiles can quickly become clogged by caking scale. It is therefore preferred if the attachment has a contact surface for the goods to be heated made of insulating material. Heat-insulating materials, in particular those which consist entirely or partially of ceramic material, and their thermal advantages are known (WQ 81/03537 and EP-A-12 49 210). ^ To secure the position of such heat-insulating materials with respect to the attachment pieces, the attachment pieces - according to another development of the invention - preferably have recesses, in particular window- or pocket-shaped recesses, preferably preventing the ceramic material from lifting off, for accommodating the heat-insulating material. Any more frequent, currently unknown, need to replace such insert pieces does not pose a problem due to the simplified assembly and disassembly according to the invention.

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Further details, features and advantages of the subject matter of the invention emerge from the subclaims and the following description, the associated drawing, in which preferred

Embodiments of attachments according to the invention are shown. The drawing shows:

Fig. 1 a support tube with top piece in fiadial section in a schematically indicated walking beam furnace with a partial representation of the support tube;

Fig. 2 left half of the picture: a side view of the support tube with attachment piece according to Fig. 1 (view A) and

right half of the image: alternative embodiment in the same representation;

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Fig. 3 from the support tube with attachment according to Fig. 1 a |

with respect to the support tube axially parallel section along U

the line III-III according to Fig. 1 with dashed lines |§

alternative version of the locking element |>

mentes and welding; |

Fig. 4 a second embodiment of a support tube with attachment piece in a corresponding representation as in Fig. 1 in two alternative versions (right and left half of the picture) ;

( Fig. 5 of the same support tube with attachment two side views (corresponding to Fig. Z), left half of the picture corresponding to view C and right half of the picture | corresponding to view B in Fig. 4); |

Fig. 6a/b another alternative embodiment of a support tube i

res with top piece in side view (Fig. 6a - Dar- *

position as in Fig. 2) and in radial section (Fig. 6b - |

Sections along lines VIa-VIa and VIb-VIb according to:

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Fig. 7 shows another design of a support tube with attachment piece in axial section (section along the line | VII-VII according to Fig. 8) and I

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Fig. 8 the same support tube with attachment in radial section right half of the picture: section along the line VIIIa-VIIIa according to Fig. 7,

left half of the image: section along the line VIIIb-VIIIb according to Fig. 7.

In Fig. 1, a walking beam furnace 1 known per se is shown schematically with dashed lines in vertical section. Inside the walking beam furnace 1, a large number of support tubes 2 through which coolant flows run in a manner also known per se, with attachments 3 placed on them, on the support surfaces 4 of which a piece of material (heating material) 5 to be heated in the walking beam furnace, e.g. a slab, rests. As a rule, a large number of support tubes 2, particularly extending parallel to one another and in the transport direction of the heating material, are provided within the walking beam furnace 1, with the attachments consisting of sections e.g. 5 to 50 cm long, which have certain distances from one another in the direction of the tube extension. For the sake of clarity, the support tube, the top piece and the material to be heated are shown in Fig. 1 on a significantly enlarged scale in relation to the walking beam furnace 1 and only in sections in order to illustrate the essence of the invention. In the right half of the picture, the support tube 2 and the top piece 3 are shown according to the radial section Ia-Ia according to Fig. 2 (approximately in the middle area of the support piece). In the left half of the picture in Fig. 1, the section was shown according to line Ib-Ib according to Fig. 2, i.e. in such a way that a front view (view 0 according to Fig. 2) results in relation to the top piece 3.

The support tube 2 has a longitudinal web 6 formed in one piece with it. Support tubes of this type can be manufactured using the extrusion process. The attachment piece 3 encompasses the upper area of the longitudinal web 6 in an approximately U-shape. On the inside of the attachment piece 3 (contact side) facing the web 6 and thus also the support tube 2, there is a

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A recess 7 is provided, which consists of a region 7A parallel to the pipe and regions 7B adjoining the front ends of the attachment piece 3 on both sides. In this way, a projection 8 remains on the attachment piece 3 in the immediate vicinity of the recess 7.

U-shaped round bars made of heat-resistant steel in particular are inserted into both of the recesses 7 of the top piece 3 as locking elements 9. As can be seen from the left half of Fig. 1, it is not necessary for the projection 8 to be as high or the recess 7 to be as deep as the thickness of the locking element 9. Such dimensional differences can even take different thermal expansions into account particularly well.

Because the free ends of the U-shaped locking elements 9 in their installed position point away from the support surface 4 of the attachment piece 3, i.e. towards the support tube 2 and are welded there by means of weld seams 10 relatively close to the jacket of the support tube 2 to the longitudinal web 6, the welding zone is exposed to lower temperatures than the known welds at the upper end of the longitudinal web, and the support tube/longitudinal web is exposed to significantly lower welding-related stresses. The ( ; welding is moved from a zone of high stress intensity to a zone with significantly reduced stress intensity, so that the harmful notch effect of the welding is reduced. In addition, the welding seams 10 can be comparatively small compared to the known welding seams over the entire length of the attachment piece. This also leads to a faster and easier disassembly option, since only the welding seam 10 has to be severed or the ends of the locking element 9 protruding from the attachment piece have to be severed. This advantageous effect also takes effect when the end faces of the locking elements 9 are flush with the general surface contour of the attachment piece 3, but

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open freely accessible from the outside or even step back a little behind the surface contour of the top piece 3. The design according to Fig. 1 to 3 also makes it possible to keep the volume of the relatively expensive material of the top pieces comparatively small. Furthermore, it is now possible to select more favorable material pairings for the locking element support tube/longitudinal web for the welding than with the known weldings with highly heat-resistant top pieces.

The fastening method according to Fig. 1 to 3 is in principle also reversible in such a way that the recesses 7 and the projection 8 on the top piece 3 do not point towards the contact side of the longitudinal strut 6 or the support tube 2, but point away from there, i.e. are provided on the outside of the top piece 3. Although this eliminates the thermal protection for the locking elements 9, which is ensured by the downwardly projecting legs of the top piece 3 according to Fig. 3, it can also significantly reduce the volume of the top pieces 3, not only when the locking elements 9 are attached further up on the top piece 3 and lie relatively close to the longitudinal web 6 (as shown in Fig. 1), but also when the longitudinal web 6 is laterally encompassed by the top piece 3 (as in Fig. 1) and the locking elements 9 have to project downwards sufficiently far beyond the top pieces 3 in order to be able to be welded to the longitudinal web 6 or the support ("") tube 2. This latter possibility is shown as an alternative in the right half of Fig. 2.

Furthermore, it is possible to use two locking elements interrupted in the U-bend area instead of a U-shaped locking element 9, as shown in Fig. 3 approximately in the middle of the picture by the two dashed vertical lines. This allows the locking (partial) elements to be inserted to facilitate assembly and disassembly when the attachment piece is already in its final position.

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It is also possible to connect adjacent locking elements or

&bull;partial elements are formed in one piece and - cheaper- §

wise - particularly close to the pipe. This is shown in Fig. 3 |

The alternative is shown dashed on the left. &iacgr;

In the alternative embodiment of the invention shown in two versions in Fig. 4 and 5, a flat iron is used as the locking element 9 instead of a bracket-shaped element. According to the illustration in the right half of Fig. 4 and the corresponding left half of Fig. 5, the attachment

s-piece 3 with a recess 7 in the form of a window-like opening. This opening is located laterally in the side walls surrounding the longitudinal web 6. While in the embodiment according to Fig. 1 to 3 (alternative with solid lines) the locking elements 9 are first hung in the attachment pieces 3 and the insert piece is then placed on the support tube, in the embodiment according to Fig. 4, right half of the picture and Fig. 5, left half of the picture, the locking element 9 designed as a flat iron or plate can also be inserted into the window-shaped recess 7 when the attachment piece 3 is already in its final position on the support tube. The funnel shape of the recess 7 allows a weld seam 10 to be made to connect the locking element 9 to the

( Longitudinal web 6. If the locking element 9 takes up the full width of the recess 7, which can be seen in Fig. 5, left half of the image, the attachment piece 3 is thereby also fixed in position in the longitudinal direction of the support tube 3. It goes without saying that with the appropriate shape of the recess 7, an upper and a lower weld seam can also be laid. -

In the alternative version according to Fig. 4, right and Fig. 5, §

right half of the picture, the recess 7 has two areas, namely |

A closed groove 7A is provided on the front side to accommodate the we- %

essential part of the plate or rod-shaped locking element |

mentes 9 and a relatively shorter area 7B, which extends to |

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to the lower edge of the attachment part 3, so that the weld seam 10 can be placed particularly easily on the underside of the locking element 9. The accessibility of the locking elements 9 from the outside is therefore limited to the area 7B of the recess 7.

Mixed forms of the versions/embodiments shown in the figures are of course also possible.

The embodiment according to Fig. 6a/b differs from the embodiment according to Fig. 1 to 3 only in that according to Fig. 6a/b the recess 7B is significantly larger, namely in such a way that the entire U-leg of the locking element 9 is accessible from the outside. It is therefore also possible to let the U-legs protrude laterally from the longitudinal web 6 to the outside, as can be seen in particular in Fig. 6b, and to weld the locking element 9 in the bending area accordingly.

In the embodiment according to Fig. 7 and 8, the same attachment fastening technique is used as in the previous embodiments - this time with two pairs of locking elements 9, whereby the support surface 4 consists of a particularly good heat-insulating material, in particular of ceramic material, which can be inserted in the form of an insert 11 into a conical, window-shaped recess 12 of the attachment 3. In this embodiment, the support surface 4 is preferably lowered towards the middle, as can be seen in Fig. 7. This results in holding jaws 13 in the lowered area as a position securing device for thermal goods with uneven support surfaces, such as round materials. The conicity of the window-shaped recess 12 and the insert 11 prevents the insert 11 from lifting off the mounted attachment 3 and facilitates any necessary replacement of dismantled attachments. Due to the window shape the recess 12 can

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Insert piece 11 with its contact surface 15 opposite the support surface 4 can be placed directly on the longitudinal section 6 or the support tube 2, which is mechanically and thermally advantageous. If several insert pieces 11 are used per attachment piece 3 instead of one, this can be advantageous for the mechanical stability and cooling of the attachment piece. Such an arrangement is indicated in Fig. 7 with the dashed lines 14; these represent lateral boundary surfaces for two axially spaced insert pieces, which are then separated by a connecting web of the attachment piece lying between them - in the drawing, for the sake of clarity, this web is also shown in the double hatching of the insert piece 11.

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I Becugezeichen list: Walking beam furnace &bull; · «
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ti <« \ Support tube It· «· ···· ·· -« I 2 Attachment 3 Support surface 4 WSrmgut 5 Longitudinal web &KHgr;: 6 Recess 7A/B areas i 7 head Start 8th Locking element 9 Welds 10 Insert 11 Recess 12 Holding jaws 13 Boundary lines 14 Contact surface 15 Opinion A Opinion I B Opinion C Opinion I D

Claims (16)

- 14 - Claims: 1. Attachment for support tubes (2) through which coolant flows in furnaces (1) for heating material (5) with at least one locking element (9) that can be connected directly or indirectly to the support tube (2) and with a recess (7) for receiving the locking element (9) characterized, that the recess (7, 7A) or a further recess (7B) of the attachment piece (3) connected to the recess (7A) for receiving a part of the locking element (9) is/are shaped such that a part of the locking element (9) received in the attachment piece (3) is accessible from outside the attachment piece (3) such that the locking element (9) can be welded to the support tube (2) or a web-shaped intermediate piece (longitudinal web 6) to the support tube (2) at the accessibility point. 2. Attachment for support tubes (2) through which coolant flows in ovens (1) for heating material (5) with at least one locking element (9) that can be connected directly or indirectly to the support tube (2) and with a recess (7) for receiving the locking element (9), in particular according to claim 1, V characterized by that the locking element (9) accommodated in the attachment piece (3) protrudes from the attachment piece (3) at least at one point or is still accessible from the outside in such a way that the locking element (9) in this installation position can be welded to the support tube (2) or a web-shaped intermediate piece (longitudinal web 6) to the support tube (2). 3. Attachment piece according to claim 1 or 2, characterized in that the further or both recess(es) (7, 7A ₁ 7S) is/are provided on the contact side between the attachment piece (3) and the support tube (2) or the web-shaped intermediate piece. - 15 - 4. Attachment piece according to one of claims 1 to 3, characterized in that the at least one locking element (9) is U-shaped. 5. Locking element according to claim 4, characterized in that the left legs of the locking element (9) point away from the support surface (4) of the attachment piece (3) and their ends can be welded to the support tube (2) or the web-shaped intermediate piece. 6. Attachment piece according to one of claims 1 to 5, characterized in that the at least one locking element (9) is designed as locking part elements formed in pairs. 7. Attachment piece according to one of claims 1 to 6, characterized in that adjacent locking elements (9) or locking part elements of adjacent locking elements (9) are connected or formed integrally with one another. 8. Attachment piece according to one of claims 1 to 7, characterized in that the attachment piece (3) partially encompasses the support tube (2) or the web-shaped intermediate piece (6) or both. 9. Attachment piece according to one of claims 1 to 8, characterized in that it has at least two locking elements (9) and associated recesses (7, 7A, 7B). IU. Attachment piece according to one of claims 1 to 9, characterized in that the attachment piece (3) has at least one support surface (4) for the heat-insulating material (5) made of heat-insulating material (insert piece 11). 11. Attachment piece according to claim 10, characterized in that it has at least one recess (12) for receiving at least one insert piece (11) made of heat-insulating material. - 16 - 12. Attachment piece according to claim 11, characterized in that the at least one insert piece (11) has a contact surface (15) for direct contact with the support tube (2) or the longitudinal web (6). 13. Attachment piece according to one of claims 10 to 12, characterized in that the insert piece (11) has a securing element (12, 14) against lifting off from the mounted attachment piece (3). 14. Attachment according to one of claims 1 to 13, characterized in that the support surface (4) has holding jaws (13) for securing the position of the material to be heated (5). 15. Attachment according to one of claims 1 to 14,
characterized, that the locking element (9) is directly or indirectly connected to the support tube (2). 16. Attachment according to claim 15,
characterized, that at least one support tube (2) connected to at least one attachment piece (3) is arranged in a walking beam furnace (1). M t ·< I < · (IM ■· ■ &igr; >>·< · J · Il J ' ' j'