Plant for chemical treatment of a surface of a metal strip

Abstract

A plant is provided for chemical treatment of a surface of a material strip, particularly for pickling and/or rinsing the material strips, such as metal strips. At least one treatment stage includes guide rollers and squeezing rollers for the metal strip. The metal strip is run out of the chemical treatment plant (e.g., pickling plant) as close to the central position as possible so that a subsequent steering roller may operate without substantial difficulty. At least two rollers or two roller pairs, with one roller above and one roller below the metal strip, run in adjustable bearings on at least one side of the longitudinal axis of the plant. The adjustable bearings are synchronized with and parallel with the running direction of the metal strip. The adjustable roller assembly follows at least one treatment stage.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. § 119 of Austrian Patent Application No. A 839/2003, filed May 30, 2003, which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a plant for chemical treatment of the surface of a material. More particularly, the present invention relates to a plant for pickling and/or rinsing metal strips having at least one treatment stage, as well as guide and squeezing rolls for the metal strip. Still more particularly, the present invention relates to a treatment stage of a chemical plant having adjustable rollers to adjust the position of the metal strip being treated.

BACKGROUND OF THE INVENTION

Currently, a metal strip is guided through a pickling plant by moving the double squeezing rollers at the end of the final stage of the pickling plant in order to run the strip out of the rinsing tank in a sufficiently centered position and to avoid overtaxing the subsequent steering rollers. The steering roller/double squeezing roller set is moved as a PI (proportional integral) roller. The steering effect, however, is hampered by the subsequent squeezing rollers and requires sophisticated inductive measuring in protective tubes made of acid-resistant material. This results in considerable wear at the steering ends and at the two squeezing roller pairs. Due to the transverse movement of the PI roll, the structural design of the lateral seal of the squeezing rollers is complicated and the bearing center distance of the squeezing rollers has to be increased. This results in a wider chemical treatment plant being required (+200 mm on each side).

A need exists for a chemical treatment plant for materials having adjustable rollers to properly align the material being treated.

SUMMARY OF THE INVENTION

The present invention relates to aligning a material being treated, e.g., pickled, in a chemical treatment plant. Preferably, the material is adjusted to a central position so that a subsequent steering roller may operate without undue difficulty.

For this purpose, the chemical treatment plant according to the present invention has at least two rollers or two roller pairs, with one roller above and one below the material, e.g., a metal strip, being treated. Adjustable bearings receive the rollers and are mounted on at least one side of the material in relation to the longitudinal axis of the plant following at least one treatment stage. The rollers are synchronized with and parallel to the running direction of the material. Due to the adjustable incline of the rolls thus obtained, a steering influence may be exerted on the material without requiring any widening of the chemical treatment plant. Moreover, the squeezing rollers towards the tank are more easily sealed off to prevent acid from escaping, as well as eliminating the biggest problem in push-type pickling plants, which is that strip runs sharply to the side when leaving the plant, thus causing shutdowns.

Preferably, the bearings of all synchronously adjustable rollers or roller pairs are mounted on a bracket that is adjustable in the longitudinal direction of the plant by means of a drive.

According to a further advantageous embodiment of the invention, all bearings for the rollers are located after at least one treatment stage. The bearings are mounted on at least one side of a longitudinal axis of the plant on a bracket that is adjustable in the longitudinal direction of the plant. A drive provides for movement of the bracket in the longitudinal direction of the plant. Thus, the rollers may be inclined together without any mutual interference, which provides improved adjustability and steering of the material to be treated.

Another embodiment of the invention provides for the roller bearings of at least two rollers or two roller pairs, formed by one roller above and one below the material, being mounted on each side in relation to the longitudinal axis of the plant on a bracket that is adjustable in the longitudinal direction of the plant by a drive. Preferably, the drive is a fluid-operated working cylinder, such as a hydraulically or pneumatically actuated cylinder.

Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings that form a part of the original disclosure:

FIG. 1 is a side elevational view of a rinsing section of a plant according to an embodiment of the present invention; and

FIG. 2 is a perspective view of a set of adjustable squeezing rolls in the rinsing section of the plant.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 contains a side view of the rinsing section S of a pickling plant. The rinsing section follows a pickling section P. Between the pickling section P and the rinsing section S there is a double squeezing roller set 1, which includes at least two pairs of squeezing rollers 1a and 1b. First pair of squeezing rollers 1a has a first roller 21 above and a second roller 23 below the strip material B that has been pickled and is now entering the rinsing section S. Second pair of squeezing rollers 1b has a first roller 31 above and a second roller 33 below the strip material B that has been pickled and is now entering the rinsing section S. The chemical treatment plant includes pairs of squeezing rollers 1 that are steerable, or adjustable, and a steering roller 2 following the adjustable pairs of squeezing rollers. Preferably, the material strip B is a metal strip.

In the rinsing section S, the metal strip B is guided through several roller pairs 2. Each roller pair 2 includes one roller above and one roller below the metal strip B. At the end of the rinsing section S, a steering roller 3 is provided before the metal strip B is transferred to further subsequent treatment stages. With this steering roller 3, any deviation by the metal strip B from the center of the plant in the longitudinal direction is detected and a steering signal proportional to the deviation in the strip running direction is generated in a circuit connected thereto.

While the roller pairs 2 are mounted in a fixed location in the rinsing section S and their position is substantially unchangeable, the two pairs of squeezing rollers 1a and 1b may be swiveled around an axis that is normally at the metal strip level. The amount of swiveling movement depends on the proportional steering signal from the steering roll 3. Thus, a steering effect may be exercised on the metal strip B that counteracts the deviation from the desired strip position. The two pairs of squeezing rollers 1a and 1b shown in FIG. 2 may be used as additional steering rollers in addition to the steering roller 3, which actually does have a steering effect on the metal strip due to its inclined position. Alternatively, the separate steering roller 3 may only be used to measure the deviation of the metal strip.

As shown in an enlarged perspective view of the adjustable squeezing rollers in FIG. 2, the chemical treatment plant includes four pairs of squeezing rollers 1a, 1b, 1c and 1d. Bearings 4a to 4d for each pair of rollers of the four pairs of squeezing rolls 1a to 1d are mounted on one side in relation to the longitudinal center of the metal strip B, which travels between the upper and lower rollers. The bearings are mounted on a shared longitudinal bracket 5 and are displaced in the longitudinal direction of the plant, as indicated by arrow 13, preferably by a hydraulic cylinder or pneumatic cylinder 6, or by any other suitable means of applying force to the bracket 5. Displacement of the bracket 5 sets the squeezing rolls 1a to 1d in an inclined position in relation to the plant axis and thus, has an adjusting or steering effect on the strip B.

In another embodiment, a second set of bearings 53, 55, 57 and 59 are mounted on the other side of the rollers 1a, 1b, 1c and 1d than the first set of bearings 4a, 4b, 4c and 4d. The second set of bearings 53, 55, 57 and 59 are mounted on a second shared longitudinal bracket 51, which is also movable in the direction of the metal strip, as indicated by the arrow 61. Displacement of the second bracket 51 is independent of the displacement of the first bracket 5, and provides better adjustability of the metal strip. The second bracket 51 is also movable by a hydraulic or pneumatic cylinder or other suitable means, similar to the drive assembly 6 used to move the first bracket 5.

The adjusting or steering effect may be controlled by actuating the switching points and the directional control valves or proportional valves for the cylinder or cylinders 6 depending on the deviation of the metal strip B measured by the subsequent steering roll 3. The pairs of squeezing rollers 1a to 1d may also be positioned by a strip tracking device actuated by a strip center measuring device located after the rinsing section S.

In a simple design, a strip position measuring device 41 is provided in the metal strip running direction, preferably after the adjustable rollers 1, and which generates a signal proportional to lateral deviation of the strip from its normal position (i.e., the predetermined path). This signal actuates the drive assembly 6 of the roller bearing brackets 4, when necessary, via a signal processing unit positioned between the strip position measuring device and the drive.

Alternatively, the steering roller 3 or any steering unit may actuate directional control valves or proportional valves for activating the working cylinder drive assembly 6.

While advantageous embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.

Claims

1. An assembly for chemical treatment of the surface of a material, particularly for pickling and/or rinsing metal strips, comprising:

at least two rollers, a first roller being positioned above and a second roller being positioned below the material being passed therethrough; and

adjustable bearings on at least one side of the material in relation to a longitudinal axis of the metal strip, each said bearing receiving a pair of said at least two rollers;

wherein said at least two rollers and said adjustable bearings are positioned after at least one treatment stage of the plant.

2. An assembly according to claim 1, wherein

said adjustable bearings are mounted on a bracket adjustable in the longitudinal direction of the metal strip.

3. An assembly according to claim 2, wherein

a drive controls longitudinal movement of said bracket.

4. An assembly according to claim 3, wherein

said drive is a pneumatically or hydraulically actuated cylinder.

5. An assembly according to claim 1, wherein

said adjustable bearings are mounted on each side of the longitudinal axis of the metal strip.

6. An assembly according to claim 3, wherein

said drive is controllable by a sensor located downstream of said at least two rollers.

7. An assembly according to claim 6, wherein

said sensor measures a deviation of the material from a central longitudinal axis of a desired path of the metal strip.

8. An adjustable roller assembly for a chemical treatment plant for treating a surface of a material, comprising:

at least one pair of rollers, a first roller of each said pair being positioned above and a second roller of each said pair being positioned below the material being passed through said roller assembly;

at least one bearing on a first side of the material in relation to a longitudinal axis of the plant, each said bearing receiving one pair of said at least one pair of rollers; and

a bracket moveable parallel to the longitudinal axis of the plant, each said bearing being attached to said bracket, said bracket being movable to maintain the material on a predetermined path.

9. An assembly according to claim 8, wherein

a drive controls movement of said bracket.

10. An assembly according to claim 9, wherein

said drive is a pneumatically or hydraulically actuated cylinder.

11. An assembly according to one of claims 8, wherein

said at least one bearings are mounted on each side of the longitudinal axis of the plant on said bracket.

12. An assembly according to claim 8, wherein

said drive is controllable by a sensor located downstream of said adjustable roller assembly.

13. An assembly according to claim 12, wherein

said sensor measures a deviation of the material from a central longitudinal axis of the predetermined path of the material.

14. An adjustable roller assembly for a chemical treatment plant for treating a surface of a material, comprising:

at least two pairs of rollers, a first roller of each said pair being positioned above and a second roller of each said pair being positioned below the material being passed through said roller assembly;

at least two bearings on a first side of the material in relation to a longitudinal axis of the plant, each said bearing receiving one pair of said at least one pair of rollers;

a first bracket moveable parallel to the longitudinal axis of the plant, each of said at least two bearings being attached to said first bracket; and

a first drive to control movement of said first bracket to adjust said roller assembly to maintain the material on a predetermined path

15. An assembly according to claim 14, wherein

said first drive is a pneumatically or hydraulically actuated cylinder.

16. An assembly according to one of claims 14, wherein

said at least two bearings are mounted on a first side of the longitudinal axis of the predetermined material path on said first bracket and corresponding bearings are mounted on a second side of the longitudinal axis of the predetermined material path on a second bracket.

17. An assembly according to claim 16, wherein

said second bracket is moveable parallel to the longitudinal axis of the predetermined material path, each of said at least two corresponding bearings being attached to said second bracket.

18. An assembly according to claim 17, wherein

a second drive controls movement of said second bracket to adjust said roller assembly.

19. An assembly according to claim 18, wherein

said first and second drives are controllable by a sensor located downstream of said adjustable roller assembly.

20. An assembly according to claim 19, wherein

said sensor measures a deviation of the material from a central longitudinal axis of the predetermined material path.

21. An assembly according to claim 18, wherein

said second drive is a pneumatically or hydraulically actuated cylinder.