EP0915188B1 - Conducting roll for a strip coating installation - Google Patents

Abstract

A current contact roller, for an electrolytic strip coating unit, comprises two cylindrical base components (2, 3) arranged side-by-side within and releasably attached to a roller sleeve (1). Independent claims are also included for: (i) a method of cooling the above current contact roller, in which cooling liquid is fed into (or discharged from) cooling channels (15) at the facing sides (9) of the base components (2, 3) and is discharged from (or fed into) the cooling channels (15) at the remote sides (10) of the base components (2, 3); and (ii) an acid resistant and electrically conductive (e.g. special steel) roller sleeve for the above current contact roller, in which a concentric inner ring (7) is provided (preferably welded) centrally to the sleeve inner wall (4)

Description

The present invention relates to a current roller for an electrolytic Coil coating line.

A current role generally has the task of that of coating anodes tape passing current back to a rectifier due. A distinction is made between current roller arrangements for horizontal and vertical belt run.

In the first case, the strip to be coated is passed horizontally through a Coating cell led, the current rollers in front and behind the cell are arranged, lie on the belt from above or below and with the help of a rubberized counter roller a line pressure exercise on the tape. At a speed corresponding to the belt speed Roll circumferential speed is determined by the line contact between Band and current roll the current from the band to the current roll transmitted and from this via slip ring systems to the rectifier recycled.

The strip to be coated is used in vertical coating systems after leaving the coating cell via current rollers, the at the same time also deflection rollers are deflected by 180 °, so that Belt can enter the next coating cell. about the resulting contact surface between the belt and the current roller flows the current from the belt into the current roll and from here via slip ring systems back to the rectifier. The current role has in this case not only power transmission, but also tape management tasks. Because of the bending stiffness of the bands, but also because of the relatively large distances between the coating cells the current roller for vertical systems is relatively large in diameter perform.

Due to the internal electrical resistance the heats up Current roll and increases in diameter accordingly. Another The heat source is the wrapped band, which is also through warmed the internal electrical resistance. With band thicknesses in Range below 1 mm strip thickness, the strip temperature can be values over 100 Reach ° C, with appropriate heating of the current roller.

For these reasons, current rolls are usually given an inner one Cooling, whose job is to ensure an even temperature distribution ensure over the current roller length. This is supposed to be avoided that different warm sections to different Lead diameters over the length of the bale. This should have been namely the consequence that the tape guide is no longer guaranteed and experience has shown that there is also a reduction in the quality of the coated Surfaces is coming.

There are various designs in the prior art with regard to the current roller cooling known.

In one case the current roller is in principle a round hollow body formed, the outer jacket of an acid-resistant and current-conducting Metal. The hollow body is partial or complete filled with cooling water, with cold Introduce water and drain heated water over the other spigot becomes. This solution is the cheapest, but has the following disadvantages:

Due to the low flow rate of the cooling water The inner wall has little heat transfer when the roll is full.

Furthermore, the additional mass of water increases the momentum of the Role and thereby hinders the drive control. Also one can uniform temperature distribution over the bale length is not guaranteed become.

Another known solution provides for the cavity with displacement bodies largely fill out, creating the latent water mass inside the current roller is reduced, but still the problem of uncontrollable cooling remains.

Another solution is known with which the aforementioned disadvantages be avoided. This is done in a concentric gap between the outer current roller jacket made of stainless steel and a inner cylinder made of normal steel, tightly wound copper tubes inserted, through which the cooling water with high flow rate flows. To mediate the heat transfer between the outer Sheath and the copper pipes is the remaining cavity with Poured zinc metal.

With this solution it is a controllable and uniform Heat dissipation guaranteed, however, the manufacturing costs significantly higher than with the previously described solutions. On Another disadvantage is that after repeated grinding of the Roll cover due to wear the renewal of the roll only in a special workshop, e.g. a new coat made and on the old coat turned to size is shrunk. A simple exchange of the worn roll cover can not. Consequently, operators of Coating plants in larger numbers of expensive current rolls Reserve be kept.

US-A-2 526 312 discloses a current roller for an electrolytic coil coating system known, wherein the current roller has a roller axis, wherein the current roller has a roller jacket with an inner and an outer jacket surface and has two substantially cylindrical bodies, the Basic body cylindrical surfaces, facing and facing away from each other Have sides. The basic bodies are with the roller shell by a press fit and thus inextricably linked.

The object of the present invention is a current roller to create, which avoids the aforementioned disadvantages, thereby can be produced with low costs and effort and also that No need to reserve parts of entire roles.

The task is accomplished by a current roll for an electrolytic coil coating line, solved with a roller axis, in which the current roller from a roller shell with a Inner wall and an outer wall, which is around the outer surfaces of two, each other opposite and coaxially arranged, cylindrical base bodies attached is, the base body are releasably connected to each other and the cylinder jackets the base body has cooling channels for a cooling liquid.

Because this makes the roller casing as such easily replaceable, so that spare parts can be kept whole current rolls is no longer required.

The current roller can be produced particularly cost-effectively if the base body is made of normal steel consist and the roller jacket from an acid-resistant and electrically conductive Material, e.g. Stainless steel.

If the cylinder jackets of the base body are designed to be electrically insulating, that is Current flow in the roll jacket easier to control. This can ensure even heating the current role can be guaranteed. The electrical insulation of the cylinder jackets can e.g. by using a hard, acid-proof, electrically insulating material Layer are provided.

If on the inner wall of the roll shell concentric around the roll axis Inner ring is arranged, on the one hand, the connectivity between the roller jacket and basic body particularly easy to accomplish. The other is connected with the electrical insulation of the cylinder jackets a completely symmetrical current flow in the Roll jacket enforceable.

The releasable attachment of the roller shell and base body is particularly easy, if the basic bodies correspond to one another and run parallel to the roller axis Through holes for fasteners, e.g. Tie rods.

Figur 1

eine Stromrolle in Richtung der Rollenachse gesehen,

Figur 2

einen Schnitt durch die Stromrolle von Fig. 1 entlang der Linie II-II,

Figur 3

einen Schnitt durch die Stromrolle von Fig. 2 entlang der Linie A-A und

Figur 4

einen Schnitt durch die Stromrolle von Fig. 3 entlang der Linie B-B.

Further advantages and details emerge from the further claims and from the following description of an exemplary embodiment. Show

Figure 1

seen a current roller in the direction of the roller axis,

Figure 2

2 shows a section through the current roller of FIG. 1 along the line II-II,

Figure 3

a section through the current roller of Fig. 2 along the line AA and

Figure 4

a section through the current roller of Fig. 3 along the line BB.

According to the figures, there is a current roller for an electrolytic one Coil coating system from a roll shell 1 and two base bodies 2, 3. The roller shell 1 is essentially hollow cylindrical and has an inner wall 4 and an outer wall 5. It consists of an acid-resistant, electrically conductive material, e.g. Stainless steel. On the inner wall 4 of the roll shell 1 is a concentric welded around a roller axis 6 rotating inner ring 7. As can be seen, the inner ring 7 is arranged centrally.

The base bodies 2, 3 are of essentially the same design. she are essentially cylindrical, hollow on the inside and point to their sides facing away from each other pins 8, by means of which they in Bearings, not shown, are rotatably supported. The basic body 2, 3 consist of mild steel. You fill the roll jacket 1 in essential, preferably even a perfect fit. The basic body 2, 3 thus have mutually facing sides 9, facing away from one another Pages 10 and the roller jacket 1 facing cylinder jackets 11.

The cylinder jackets 11 are hard, acid-resistant and electric insulating layer. The layer can, for example Oxide ceramics exist in which to avoid porosity Fillers are introduced. Such a coating is inexpensive and easy to apply. It protects the cylinder jackets 11 also against corrosion by a coolant (water) and also against possible electrolytic vapors. The cylinder jackets 11 are thus designed to be electrically insulating.

Because of the insulating layer between the base bodies 2, 3 and Roller jacket 1 inevitably flows all of the current through the inner ring 7 and thus in the roller jacket 1 symmetrically from the outside to the center, regardless of whether the current over one or the other or both pins 8 is continued.

Both the roller shell 1 and the base body 2, 3 are here arranged symmetrically with respect to the axis 6, which in the following is also referred to as the roller jacket axis.

The base bodies 2, 3 have through holes 12. The through holes 12 run parallel to the roller axis 6 and correspond together. In the through holes 12 are, for example. Drawbars 13 can be inserted so that the roller shell 1 and the base body 2, 3 by screw nuts screwed onto the tie rods 13 14 are releasably connectable. This can, if necessary the roller shell 1 can be easily replaced without the whole current roll must be machined. The spare parts inventory is therefore reduced to the roller shells 1.

The cylinder jackets 11 of the base body 2, 3 have cooling channels 15 for a cooling liquid, e.g. Water, on. The cooling channels 15 are as spirals formed around the cylinder jackets 11. The Cooling ducts 15 of one base body 2 are designed to run on the left, that of the other base body 3 right-handed. You are in the present Case semi-circular. But you could also use a different shape exhibit. The coolant circuit is as follows:

The cooling liquid is fed into the current roller via a feed bore 16 fed. The feed bore 16 of one base body 2 is located on the roller axis 6 and is on the other base body 3rd Side 10 facing away from a base body 2. thereupon the cooling liquid is shown via outer radial bores 17 - is only one in Fig. 2 - fed into the first longitudinal bores 18. The outer radial bores 17 are also on the another base body 3 facing away from side 10 of one base body 2 arranged. The first longitudinal bores 18 run below the Cooling channels 15 parallel to the roller axis 6 and are to the inner ring 7 open towards. The outer radial bores 17 of one body 2 are still between the cooling channels 15 and the first longitudinal bores 18 closed, e.g. welded or screwed in a threaded plug.

The other base body 3 also has first longitudinal bores 19 which will be discussed later. But he still points also second, open to the inner ring 7 towards the longitudinal bores 20, the also run parallel to the roller axis 6. The first longitudinal holes 18 of one base body 2 are with the second longitudinal bores 20 of the other base body 3 via through holes 21 connected, which are arranged in the inner ring 7. The basic body 2, 3 also have inner radial bores 22, which on each other facing sides 9 of the base body 2, 3 are arranged. The inner radial bores 22 connect the first longitudinal bores 18 of one base body 2 or the second longitudinal bores 20 of the other base body 3 with the cooling channels 15.

In this way the cooling liquid, e.g. Water into the cooling channels 15 can be fed. It then runs in a spiral from the inner ring 7 of the roll shell 1 to its outer ends.

To withdraw the cooling liquid from the cooling channels 15, the a base body 2 on the side facing away from the other base body 3 Page 10 further outer radial bores 23, which differ from the Cooling channels 15 up to second longitudinal bores 24 of one base body 2 extend. These second longitudinal bores 24 of one base body 2 also run parallel to the roller axis 6. They are open to the inner ring 7 and extend until shortly before the another base body 3 facing away from side 10 of one base body 2. They are via further through holes arranged in the inner ring 7 25 with the already mentioned first longitudinal bores 19 of the other base body 3 connected.

The first longitudinal bores 19 of the other base body 3 run also below the cooling channels 15 parallel to the roller axis 6 and are open to the inner ring 7. They are about outer radial holes 26 on the one hand with the cooling channels 15 and on the other hand with a feed bore 27 connected. The outer radial bores 26 of the other base body 3, as the name suggests, on the side 10 of the other base body facing away from a base body 2 3 arranged. The feed hole 27 is in the other base body 3 arranged and lies on the roller axis 6. From this feed opening 27 from the cooling water can be fed out of the current roller become.

With the coolant guide described above, the fresh, cold coolant the central part of the roll jacket 1 offered first. Since also the largest current in this jacket part flows and this part of the jacket is consequently the warmest thus the place of strongest warming is most intensely cooled. In this case, the cylindricity of the roll shell 1 remains best received.

But it is also possible to reverse the coolant. In this case, the current roller is cambered. This can be beneficial for tape running.

The necessary seals against coolant leakage and Electrolyte entry is carried out by conventional O-rings 28, which if necessary can be easily replaced.

LIST OF REFERENCE NUMBERS

1

roller shell

2.3

body

4

inner wall

5

outer wall

6

Roller axis / roll shell axis

7

inner ring

8th

spigot

9

sides facing each other

10

sides facing away from each other

11

cylinder jackets

12,21,25

Through holes

13

drawbars

14

nuts

15

cooling channels

16.27

feed holes

17.26

outer radial bores

18.19

first longitudinal holes

20.24

second longitudinal holes

22

inner radial bores

23

further outer radial bores

28

O-rings

Claims (15)

1. Conducting roller for an electrolytic strip coating plant, with a roller axis (6), wherein the conducting roller consists of a roller circumferential casing (1) with an inner wall (4) and an outer wall (5), which is fastened around the outer surfaces of two mutually opposite and coaxially arranged cylindrical base bodies (2, 3), wherein the base bodies (2, 3) are detachably connected together and the cylinder circumferential casings (11) of the base bodies (2, 3) have cooling channels (15) for a cooling liquid.
2. Conducting roller according to claim 1, characterised in that the base bodies (2, 3) consist of normal steel and the roller circumferential casing (1) consists of an acid-resistant and electrically conductive material, for example high-quality steel.
3. Conducting roller according to claim 1 or 2, characterised in that the cylinder circumferential casings (11) of the base bodies (2, 3) are constructed to be electrically insulating.
4. Conducting roller according to claim 3, characterised in that the cylinder circumferential casings (11) are provided with a hard, acid-proof, electrically insulating coating.
5. Conducting roller according to one of the above claims, characterised in that the base bodies (2, 3) and the roller circumferential casing (1) are connected together with precise fit.
6. Conducting roller according to one of the above claims, characterised in that an inner ring (7) encircling concentrically around the roller axis (6) is arranged at the inner wall (4) of the roller circumferential casing (1).
7. Conducting roller according to claim 6, characterised in that the inner ring (7) is welded to the roller circumferential casing (1).
8. Conducting roller according to claim 6 or 7, characterised in that the base bodies (2, 3) have mutually corresponding passage bores (12), which extend parallel to the roller axis (6), for fastening elements (13), for example tie rods (13).
9. Conducting roller according to one of the above claims, characterised in that

   the cooling channels (15) are formed as helices encircling the cylinder circumferential casings (11),

   the base bodies (2, 3) have at the mutually remote sides (10) thereof feed bores (16, 27), which lie on the roller axis (6), for feeding in and feeding out the cooling liquid,

   the base bodies (2, 3) have at the mutually remote sides (10) thereof at least one respective outer radial bore (17, 26) connected with the respective feed bore (16, 27),

   the base bodies (2, 3) have below the cooling channels (15) at least one respective first longitudinal bore (18, 19) which is connected with the outer radial bores (16, 27) and is open towards the inner ring (7) and which extends parallel to the roller axis (6),

   in the case of one of the base bodies (2) the at least one outer radial bore (17) is closed between the cooling channels (15) and the at least one first longitudinal bore (18),

   the one base body (2) has at its side (9), which faces the other base body (3), at least one inner radial bore (22) connected with the at least one first longitudinal bore (18),

   the one base body (2) has at least one second longitudinal bore (24) which is open towards the inner ring (7) and extends parallel to the roller axis (6) and which runs up to the side (10) of the one base body (2) remote from the other base body (3) and is connected with the at least one first longitudinal bore (19) of the other base body (3) by way of a first passage bore (21) arranged in the inner ring (7),

   the one base body (2) has at the side (10) remote from the other base body (3) at least one further outer radial bore (23) which extends from the cooling channels (15) to the at least one second longitudinal bore (24),

   the other base body (3) has at least one second longitudinal bore (20) which is open towards the inner ring (7) and extends parallel to the roller axis (6) and which is connected with the at least one first longitudinal bore (18) of the one base body (2) by way of a second passage bore (25) arranged in the inner ring (7) and

   the at least one second longitudinal bore (20) of the other base body (3) is connected with the cooling channels (15) by way of at least one inner radial bore (22) arranged at the side (9) of the other base body (3) facing the one base body (2).
10. Method of cooling a conducting roller according to claim 9, characterised in that the cooling liquid is fed into the cooling channels (15) at the mutually facing sides (9) of the base bodies (2, 3) and is fed out of the cooling channels (15) at the mutually remote sides (10) of the base bodies (2, 3).
11. Method of cooling a conducting roller according to claim 9, characterised in that the cooling liquid is fed into the cooling channels (15) at the mutually remote sides (10) of the base bodies (2, 3) and fed out of the cooling channels (15) at the mutually facing sides (9) of the base bodies (2, 3).
12. Roller circumferential casing for a conducting roller for an electrolytic coating plant, with a roller circumferential casing axis (6), an inner wall (4) and an outer wall (5), consisting of an acid-proof and electrically conductive material, for example high-quality steel, characterised in that an inner ring (7) arranged concentrically with respect to the roller circumferential casing axis (6) is arranged centrally at the inner wall (4) of the roller circumferential casing (1).
13. Roller circumferential casing according to claim 12, characterised in that the inner ring (7) is welded to the roller circumferential casing (1).
14. Roller circumferential casing according to claim 12 or 13, characterised in that the inner ring (7) has passage bores (12), which extend parallel to the roller circumferential casing axis (6), for fastening elements (13), for example tie rods (13).
15. Roller circumferential casing according to claim 12, 13 or 14, characterised in that the inner ring (7) has at least two passage bores (21, 25), which extend parallel to the roller circumferential casing axis (6), for a cooling liquid.

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