ROLL CONNECTION.

Abstract

The present invention relates to a method and equipment for optimally handling and supporting a roll made from at least one inert material and transferring torque from a bearing to a roll or vice versa without damaging them. The roll and the bearing are immersed in molten metal.

Description

The present invention relates to a method and equipment for optimally handling and supporting a roll made from at least one inert material and transferring torque from a bearing to a roll or vice versa without damaging them. The roll and the bearing are immersed in molten metal. (57) Abstract The present invention relates to a method and an equipment permitting to optimally handle and support a roll made of at least an inert material and transfer the torque from a bearing to a roll or the other way around damaging them. Said roll and bearing being immersed in molten metal. ROLL CONNECTION The present invention relates to a method and equipment that allows for the optimal handling and support of a roll. The roll is immersed in molten metal. To coat a substrate, it can pass through a bath of the desired coating, for example, a steel strip passing through a bath of molten metal. Most often, a dip roll and two guide rolls are immersed in a coating bath to guide the substrate, as shown in Figure 1. The dip roll is positioned at the bottom of the bath to allow the strip to deflect and pass through, while the two guide rolls are used at the bath's exit to position the strip vertically, reduce vibrations, and correct sag. All these rolls are immersed in the bath and are therefore subject to chemical attack, corrosion, and wear due to the operating conditions, i.e., the nature of the bath and its temperature. Consequently, new rolls with greater resistance to corrosion and wear have been developed to replace the traditional metal ones.These new inert rolls are generally made of ceramic, carbon, or carbon compounds. However, new problems arise when using these reels due to their mechanical properties. Specifically, reels made entirely of ceramic, carbon, or carbon composites, with a protruding section on both sides, are prone to breakage due to a concentration of force between the reel and the shaft during use, as verified in experimental tests. This is primarily due to the pressure of the tape on the reel. Consequently, reels with a hollow section on each side, where a shaft is inserted, are used. This configuration introduces further challenges, particularly regarding their handling and transport. Therefore, it is necessary to develop a way to connect an inert roll, made of ceramic or carbon, to the hub to handle and support the roll and allow it to rotate without damaging it. No prior art documents have been found that allow the aforementioned problem to be resolved. The purpose of this invention is to provide a solution to the problem mentioned above. This is achieved by providing equipment according to claim 1. The equipment may also comprise any feature according to claims 2 to 6. This is achieved by providing a method according to claims 7 to 8. Other features and advantages of the invention will become evident from the following detailed description of the invention. To illustrate the invention, several embodiments and non-limiting examples will be described, particularly with reference to the following figures: Figure 1 is a schematic view of one modality of a coating bath with one immersion roll and two guide rolls. Figure 2 is a schematic view of one type of roll showing a hub, sleeve, shaft, and plate. Figure 3 shows an exploded view of one type of roll connector and how it can be inserted into a roll. Figures 4a and 4b show one modality of a roll connecting piece. Figure 5 represents one type of roll and its two side holes that allow the insertion of the roll connection pieces. Figure 6 represents a possible arrangement of the different layers of a roll. Figure 7 shows different modalities (A to D) for the fastening means. The invention relates to a continuous hot immersion apparatus 1 comprising a tank 2 having a molten metal bath 3, an immersion roll 4, and at least one guide roll 5. At least one of the guide rolls 5 is supported by a bearing 6. The bearing 6 comprises at least one connecting piece 7 and a hub 8. The connecting piece 7 comprises three successive pieces: - a first piece 9 connecting to the hub 8, - a second piece 10 comprising at least one fastening means 11 attached to one side of the roll 5 and - a third piece 12 having a parallelepiped section with curved angles 13, the third piece 12 is inserted into the roll 5, the connecting piece 7 is made of a material having a coefficient of thermal expansion higher than the roll 5, the coefficient is chosen so that the third piece 12 and the roll 5 are pressed together by thermal expansion when they are in the molten metal bath 3. The following description relates to the use of at least one connecting piece 7 with at least one guide roll 5. But the use of the connecting piece is not limited to at least one guide roll, but it can also be used or inserted into an immersion roll 4. With the equipment according to claim 1, the roll is held securely and can rotate without noticeable damage due to the curved edges of the third piece. Furthermore, the clamping means allow for safe handling of the roll at room temperature, as well as correct positioning of the roll before use. At room temperature, there is a gap between the shaft and the carbon core; in other words, there is no press fit at room temperature. As illustrated in Figure 1, the continuous hot immersion apparatus 1 comprises a tank 2 filled with molten metal 3 inside and comprising an immersion roll 4, at least one guide roll 5 and a belt S passing through the molten metal. As illustrated in Figure 2, at least one of the rolls 5, an immersion roll and / or at least one guide roll, is supported by a bearing 6 consisting of a connecting piece 7 and a bushing 8. In addition, a sleeve 16 can be used between the connecting piece 7 and the bushing 8. As illustrated in Figures 3 and 4 (a and b), the connecting piece 7 comprises: - a first connecting piece 9, - a second piece 10 comprising at least one fastening means 11 fixed to one side of roll 5S, iviA / a / zuzz / uuo i ai - a third piece 12 which is a parallelepiped wrapped by the roll, the parallelepiped has curved edges 13. Although shaft 7 is manufactured from three successive pieces, it is preferable to machine a single block to form shaft 7. This improves the mechanical properties of the part. The function of the first part 9 is to be inserted into the sleeve 16 or the bushing 8. When a sleeve is used, it must fit snugly and at least partially cover the first part to reduce wear. A small clearance, usually about 5 mm, is required between the first part or the sleeve and the bushing during use to allow the roll to rotate. The second piece 10 is wide enough to be attached to one side of roll 5S using the fastening means 11. The function of the third part 12 is primarily to connect the roll 5 to the connecting piece 7 and also to transmit the roll's rotation to the connecting piece. When the roll 5 and the connecting piece 7 are immersed in the bath, at a temperature typically between 400 °C and 700 °C, this part conforms to the roll 5. The press fit occurs due to a difference in the coefficient of thermal expansion between the roll 5 and the connecting piece 7; the connecting piece has a higher coefficient of thermal expansion than the roll. Three parameters—the risk of breakage, the mechanical properties of the roll core and the third part, and the torque transmission—significantly influence the desired press fit. If the press fit is too tight, the third part and / or the roll core may break or be damaged, which must be avoided.On the other hand, if the press fit is too weak, the roll's torque is not efficiently transmitted to the connecting piece. Although it depends on the material used for the connecting piece and the carbon core and therefore its coefficient of thermal expansion, the press fit generally consists of between -0.10 mm and -0.25 mm. The third part 12 is a parallelepiped because if wear or crumbling occurs, the torque is still apparently transmitted. If the third part were cylindrical, the press fit might not be sufficient, leading to a loss of torque transmission. In other words, wear or crumbling has less effect on torque transmission in a parallelepiped third part than in a cylindrical or round one. Furthermore, it is important that the parallelepiped edges 13 are neither sharp nor straight, as breakage would occur more frequently in those cases. A sleeve 50 can be used to adjust the snap fit if the snap fit is insufficient. It allows the connecting piece to be used on rolls with different side hole sizes, increasing the flexibility and usability of the connecting piece. The third piece 12 must be fitted into sleeve 50, and sleeve 50 must be fitted onto roll 5. This sleeve must not obstruct the use of the fastening means 11. As illustrated in figure 5, the roll is a cylinder that is hollow around its pivot axis 17 on both sides allowing the connecting pieces 7 to be installed in these holes 18, the hollow pieces. Preferably, the roll is manufactured from at least a carbon or ceramic matrix reinforced with carbon or ceramic fibers. Such rolls allow for increased corrosion resistance because they are inert to the bathing conditions. Preferably, the roll is made from two different carbon matrices reinforced with carbon fibers or ceramics. Apparently, rolls made solely from carbon fiber reinforced (CFG) matrices have better resistance to thermal shock than those comprising at least one ceramic matrix. As illustrated in Figure 6, the core of the roll can be made from a carbon base material 19 and a CFC layer 20 around the carbon base material. Ideally, the roll should be made of ceramic. Ceramic offers excellent corrosion resistance because it is inert to the bathing environment. Preferably, the connecting piece 7 is made of metal. More preferably, the connecting piece 7 is made of steel. The metal connecting piece improves mechanical strength. Furthermore, it facilitates the attachment of the connecting piece 7 to the sleeve 16 because welding is possible. Preferably, the fastening means 11 is a screw. Such fastening means have the advantage of being removable, thus improving the reuse of the equipment. The screw is preferably screwed into a helical insert. Preferably, a part, such as a washer, is used to impede the penetration of liquid through the holes of the fastening means. On one hand, the fastening means allow the shaft axis to be centered relative to the roll axis, maintaining good centering during handling. On the other hand, they allow the shaft, the second part 10, to remain in contact with a side roll 5S while in use, as well as sealing the third part from the molten metal. This is essential because, due to the different coefficients of thermal expansion between the roll and the connecting part, the connecting part tends to move away from the roll. Preferably, as illustrated in Figure 7 ABCD, the second part 10 comprises holes 21 for inserting at least three clamping means 11. Providing at least three clamping means ensures better handling of the roll as well as better centering of the shaft. It also reduces the stress on each clamping means compared to cases where there are only one or two. Preferably, the centroid of the clamping means 11 is the roll's pivot axis 17. Apparently, this arrangement allows for equal distribution of stress and increases the service life of the clamping means. The invention also relates to the method of installation, in an installation as described in claims 1 to 9 where the molten metal is at a temperature Tmetai molten, at least one of the rolls 5 comprises the following steps: - Insert the third piece 12 of the connecting piece 7 onto roll 5, - attach the connecting piece 7 to the roll 5 using the fastening means 11, - Preheat roll 5 and fixed connecting piece 7 to a preheating temperature of between: 100 °C < Tpreheating < Tmelt metal + 100 °C for a period of between 8 hours and 5 days, - Place roll 5 and fixed connecting piece 7 inside molten metal 3. These steps allow for optimal roll installation. Preheating the roll above 100°C leads to a tight fit or at least reduces the clearance, allowing for safe movement of the roll and any connecting pieces attached to it. It also eliminates residual moisture. When choosing the preheating temperature, the roll's resistance to oxidation must be considered to avoid damaging it during preheating. Furthermore, when selecting the preheating temperature, its resistance to thermal shock must also be taken into account to prevent damage to the roll during its placement within the molten metal. The preheating period must be long enough to ensure a uniform temperature throughout the roll. This period depends on several factors, including the roll size and its thermal properties. Preferably, seal 15 is a carbon felt. Preferably, washers are used with fasteners whenever possible. Preferably, a protective coating is applied to the connecting piece 7 and the clamping element 11 before preheating the roll and after inserting the connecting piece into the roll 5. Apparently, the coating protects the connecting piece and prolongs its service life. The protective layer can be made of boron nitride.

Claims

1. A continuous hot immersion apparatus (1) including a tank (2) comprising an internal molten metal bath (3), an immersion roll (4), and at least one guide roll (5), at least one of the guide roll (5) being supported by a bearing (6), the bearing (6) comprising at least one connecting piece (7) and a hub (8), the connecting piece (7) comprising three successive pieces: - a first piece (9) connecting to the hub (8), - a second piece (10) comprising at least one clamping means (11) attached to one side of the roll (5), and - a third piece (12) having a parallelepiped section with curved angles (13), the third piece (12) being inserted into the roll (5), the connecting piece (7) being made from a material having a coefficient of thermal expansion higher than that of the roll (5),The coefficient is chosen so that the third piece (12) and the roll (5) will fit together by thermal expansion when they are in the molten metal bath (3).

2. The equipment according to claim 1, wherein the roll (5) is manufactured from at least one carbon or ceramic matrix reinforced with carbon or ceramic fibers.

3. The equipment according to any of claims 1 to 2, wherein the roll is manufactured from two different carbon matrices reinforced with carbon or ceramic fibers.

4. The equipment according to any of claims 1 to 3, wherein the connecting piece (7) is made of metal.

5. The equipment according to any of claims 1 to 4, wherein the fastening means (11) is a screw.

6. The equipment according to any of claims 1 to 5, wherein the second piece (10) comprises at least three fastening means (11).

7. A method for installing, in an installation according to claims 1 to 7 where the molten metal is at a temperature Tmetai molten, at least one of the rolls (5) comprises the following steps: - inserting the third piece (12) of the connecting piece (7) into the roll (5), - fixing the connecting piece (6) to the roll (5) using the clamping means (11), - preheating the roll (5) and the fixed connecting piece (7) to a temperature Tpreheating of between: 100 °C < Tpreheating < Tmetai molten + 100 °C for a period of between 8 hours and 5 days, - placing the roll (5) and the fixed connecting piece (7) inside the molten metal (3).

8. The method according to claim 8, wherein a protective coating is applied to the connecting piece (7) and the clamping means (11) before preheating the roll and after inserting the connecting piece into the roll (5).

Images