DD294886A5 - DEVICE FOR MECHANICAL PILOT PREVENTATION - Google Patents

Abstract

The invention relates to a device for the mechanical descaling of hot strip. It can be used advantageously in push-pickling plants. The goal is to increase the overall effectiveness of descaling. It is an object of the invention to achieve with the help of bending or deflection rollers as optimal as possible breaking up of the scale layers located on the belt. The solution must be suitable for push-pickling operation. This task is solved by arranging a plurality of bending roller armatures, each equipped with a pair of bending rollers, after a discharge reel. The zusammengehoerenden bending rollers are in profile each concave and convex. From Bend-Roller-Framework to Bend-Roller-Framework, the bending-roller pairs alternate in arrangement so that the passageway profile between the bending rollers once reveals upward and once downward. Fig. 1 {tape; Bending rolls; Bending roll stand; descaling; Thrust pickling plant; Blowing reel set; guide rollers; Device; pre-descaling; Hot strip; Scale layer}

Description

For this 4 pages drawings

Application blot of the invention The invention relates to a device for the mechanical descaling of hot strip. The device is advantageous for use in push-pickling plants, where no bending-stretch straightening units used

can be suitable.

Characteristic of the known state of the art

For continuous pickling it is known to arrange bending-stretching straightening units for breaking up and partially removing the scale before the strip enters the pickling plant. Thus, the effectiveness of the pickling plant is increased by the already mechanically removed scale no longer needs to be resolved chemically. In addition, the loosened residual scale of the pickling liquid offers greater attack surface. If the acid temperature remains the same, the pickling time can be shortened or the acid temperature can be lowered while the pickling time remains constant. Likewise, the amount of pickling solution to be regenerated decreases.

Overall, these measures serve to increase the effectiveness of pickling plants and, above all, to reduce polluting technologies or processes.

By way of example, reference is made here only to the German Pat. No. 650,540, which proposes a device for winding strip-like rolling stock. In this publication, a bending-stretching straightening unit is already comprised of a plurality of staggered and vertically adjustable to the continuous axis of the belt deflection rollers.

Another solution discloses u.a. DE-OS 2942270, which describes a Entzunderungsanlage for descaling hot strip. In this Entzunderungsanlage a stretch-bending roller unit of known type is arranged as a unit or module of the entire system.

DE-OS 2536605 describes a device for descaling steel strip, in which a driven pair of rollers is provided, via which the steel strip is guided S-shaped.

The relaxation of the scale or the breaking up of the same take place in this case due to the changing extreme deformation beyond the elastic limit of the strip.

It is pointed out as advantageous in a design variant that the use of spherically shaped rollers is much more advantageous, as a result, on the one hand, a central course of the steel strip is ensured and on the other a Eqalisierung the steel strip.

The increased deformation of the band in its center also allows edge waves to be eliminated. On other solutions in which the scale layer by material removal - such. As milling or grinding, presented in DE-OS 3600143 and DE-OS 3600144 - is carried out, will not be discussed further, as this represents a separate discipline.

All known solutions which result in the scale layer being broken up or loosened by deformation as a result of deflection of the strip in the direction of travel by means of deflection rollers have disadvantages or appear to be in need of improvement.

Thus, bending-stretching devices can not be used in push-pickling systems, since in such systems relatively short belts and especially belts with larger thicknesses are processed, which are guided as straight as possible and without large bends when threading in the system in the strip running direction should be. In order for the strip tension required in bending-straightening to reach the high levels required for thick strips and materials with a higher yield strength, S-roll systems are required to produce this high strip tension.

However, since in a push-pickling plant each beginning of the tape must be re-threaded and the tape tension and thus the Rieht and descaling effect can only act when the tape tip has reached a drive roller frame after the last S-roll set is It is technically and economically unreasonable to use bending-straightening systems or S-roll bending systems in push-pickling plants.

In such cases, several meters of the beginning of the tape and analogously several meters of the tape end could not be descaled or insufficiently descaled.

In addition, it should also be noted that a strong S-shaped deflection of the belt require high bending and tensile forces and thus a high drive energy.

The object of the invention is to avoid the deficiencies of the prior art and to increase the effectiveness of the mechanical descaling of hot strip in push-pickling plants.

The device should optimize the descaling in push-pickling plants so far that set against the known solutions, especially in the downstream pickling voprteilhafte effects by reducing the pickling time and the reduction of acid consumption.

Explanation of the essence of the invention Based on the prior art, the object of the invention is an apparatus for the descaling of hot strip

develop with the help of bending or deflection rollers as optimal as possible breaking the tape located on the tape

Scale layer allows. The plant must be suitable for push-pickling operation and a discontinuous Allow operation. According to the invention, this object is achieved by the device consists of a η-th number of bending roller stands, the

are arranged in the least possible distances from each other and each have a drive.

The arrangement of one additional drive roller set in front of and behind the beige roller stands is possible. It is essential to the invention that the bending-roller pairs arranged in the bending-roller stands each consist of a profile

matched concave and convex bending roll consists. The bending-roll pairs change from

Biege roller frame to Biego roller frame according to their profile from above the tape to below the Tape running, so that the passage profile between the bending rollers once a curvature up and once a curvature

down.

The tape is pulled through the device using the powered Bioge reel pairs. If the bending-roller pairs are not driven, then the transport takes place with the aid of the drive-roller sets, wherein during retraction

the top of the band are raised in the bending-roller scaffolds.

If the beginning of the tape has passed through the area of the device, the upper bending rollers are again in Working position lowered. Due to the changing bending-roller-profiles concave - convex-concave, etc.

especially in the axis transverse to the tape passage direction, alternately deformed by bending-roller-Panr. In addition, the

Rib edges stretched in the longitudinal direction and thereby the tinder loosened especially in dienern area, since the distance

between the axes of the bending-roller pairs due to the formation of the roller gap in the region of the band edges is greater than in the central axis of the system or the band.

The distribution of the stretch of the tape in the direction of tape travel depends on the determination of the size of the roll diameters of one Roller pair to each other and from the design of the roll shape. In driven bending-roller pairs with different average diameters, it is for easier synchronization of Belt speed advantageous to drive each of the identically designed roles of bending-roller pairs. Zi, - Increasing the effects, the bending-roller pairs can be alternately from bending roller frame to bending roller frame

arrange offset in height to the ribbon passage axis. This results in an additional deformation by bending in

Longitudinal direction of the band. embodiment The invention will be explained in more detail with reference to an embodiment. The accompanying drawing shows in 1: a descaling system for hot strip, consisting of a decoiler, drive-roller set, five bending-roller stands,

Drive roller set, pickling bath and then again a propulsion roller set; Figure 2; Part of a standard mechanical descaling unit;

Fig. 3: Part of a mechanical descaling with height offset arranged bending roller pairs; 4 shows the section A-A of Figure 2undFig.3; 5 shows the section B-B according to Fig.2 and Fig.3.

In the exemplary embodiment, with reference to FIGS. 1, 2, 4 and 5, a device for mechanical pre-descaling

presented by hot strip for the discontinuous thrust pickling operation, which consists of five bending-roller stands 6

exists, which Treib-Rollon scaffolding 3 upstream and downstream.

This is followed by the first pickling tape 7. The bending-roller stands 6 are each provided with a concave-shaped bending roller 4 and a convex-shaped bending roller 5, the

geometrically fit into each other, equipped.

In Figure 3, these different profiled bending rollers 4 and 5 of the bending roller stands 6 are alternately above and below the Bandlaufachse arranged. Within the bending roller scaffolds 6, the respectively overhead bending rollers 4 and 5 can be lifted. Possibly

the bending rollers 4 and 5 may also be arranged within the bending roller stands so that they are to a certain

Amount can be moved apart. Sinrl in a device for Vorentzunderung of hot strip as shown in Fig. 1 - the bending rollers 4 and 5 within the Bend-roller scaffolds 6 are not driven, so are the initiation of the technological process, each top Bending rollers 4 and 5 raised. With the aid of the first drive-roller frame 3, the belt 2 is moved into the area of the bending ro- Scaffolds 6 up to the second drive-roller frame 3 advanced. By applying a corresponding pressing force

are then the upper bending rollers 4 and 6 successively brought into working position, so that the band 2 in the passage corresponding to the bending of the roll frame 6 to bending roller frame 6 changed profile alternately convex - concave convex, etc. deformed.

This transversely to the strip running direction deformation in the formula of an upward or downward curvature and

The stretching in the longitudinal direction at the strip edges cause the break-up and thus - depending on the scale formation - also a

Flaking of the scale top and bottom band adhering scale layers. After> Volume 2 has escaped from the area of mechanical preliminary descaling, it passes through the first pickling bath 7

guided and then fed to the next pickling bath or other downstream equipment for further processing with the downstream propellant roller set 3.

In the embodiment of Fig. 2, the bending rollers 4 and 5 are driven. This is in contrast to the execution after Fig. 2 with non-driven Biegorollen 4 and 5 a pre-descaling of the belt 2 already during the retraction of Band lace instead. In addition, the drive-roller pair 3 can be omitted before the pickling bath in this case. If the device, if necessary - as shown in Flg.3 - work, so it may also be advantageous, all Bending rollers 4 and 5 to be provided with a drive. As a result, the drive roller stands 3 can be omitted.

Claims (2)

1. Device for the mechanical pre-dewatering of hot-rolled strip, which is placed next to a decoiler before a pickling bath, characterized in that said device consists of an η-th number of bending-roller-scaffolds (6), each of which is equipped with a concave and a convex-shaped bending roller (4) or (5), said bending-roller pairs of bending roller frame (6) to bending roller frame (6) change according to their role profile so that the passageway profile between the bending rollers (4) and (5) once has a curvature upwards and einrtial a curvature downwards. 2. An apparatus for the mechanical descaling of hot strip according to claim 1, characterized in that in the bending roller stands (6) contained bending roller pairs seen in the strip running direction of bending roller frame (6) to bending roller Scaffold (6) - similar to a bending-stretching-straightening unit in the alternately up or down offset.