EP0302057B1 - Process and device for the surface treatment of strips with fluids - Google Patents

Abstract

PCT No. PCT/AT87/00005 Sec. 371 Date Jul. 22, 1988 Sec. 102(e) Date Jul. 22, 1988 PCT Filed Feb. 5, 1987 PCT Pub. No. WO88/05832 PCT Pub. Date Aug. 11, 1988.Apparatus for the surface treatment of strips with liquid, in particular for the pickling of rolled metal strip. The apparatus comprises a pickling vessel (3), through which the strip (10) is advanced, closed by a cover (4). Between the strip (10) and the cover (4) a means is provided which if the strip rises upwards, guides the latter back into the direction of movement. This means can be formed of profiles providing a sawtooth-like configuration. Such profiles may be formed by guide means (11) which are chamfered on the side from which the strip enters.

Description

The invention relates to a device for the surface treatment of strips with liquids, in particular for pickling rolled metal strips according to the preamble of claim 1.

In the case of a large number of strip rolling mills, there are production requirements for which the pickling problem is difficult to solve due to the type and scope of the hot strip to be pickled. However, the conditions are often such that these productions, with regard to their tonnage and the demands placed on the pickled surfaces, probably require a pickling line that processes the strip in a continuous pass, a so-called continuous pickling line, but this is due to the widely spread strip dimensions or poor weldability cannot be used.

For these conditions, there is now a pickling line known as thrust pickling, in which the hot strip is pushed through the system, at most when several strips are run through at the same time, the qualitative advantages of a continuous pickling line being achieved in a simple manner.

The known thrust pickles consist of an elongated, cross-sectionally shaped pickling tank, which is at most provided with dividing walls for the simultaneous treatment of several strips, which divide the channel into several parallel channels and can be inserted into or lifted from the container depending on the desired channel width . The strip is pushed, for example, by a straightening machine provided at the entrance of the pickling tank through the tank, which is flooded with pickling acid. It is known to inject the pickling acid on the bottom, for example, in order to achieve a buoyancy by means of which the strip is also supplied with fresh pickling acid on the underside and is guided through the pickling container. The pickling tank is usually closed by a lid which, according to DE-OS 30 00 408, can be provided on the bath side with box-shaped internals immersed in the pickling bath in order to reduce the bath surface and thus reduce the energy consumption, which is largely due to the evaporation of the Pickling acid is caused. In order to protect the diving lid against damage from the band, wear ribs are provided which run on the bath-side surface of the internals transversely to the direction of movement of the band. During the operation of pusher pickling, it has been shown that especially the incoming beginning of the band at higher throughput speeds of the band can cause damage to the cover due to a whip-like installation. If any wear strips running transversely to the band movement are arranged, the beginning of the band can bump against them, tear them off and / or even suffer damage.

The object of the invention is to provide measures to remedy the last-mentioned risk of damage to the system and the belt by lashing up the end of the belt on the inlet side. This object is achieved in a device of the type mentioned by the measures according to the characterizing part of claim 1.

Such bevels can also extend over the entire width of the guide beam; they can be chamfered along a curve or several times.

This enables throughput speeds of over 200 m / min to be achieved.

• Fig. 1 und 1a eine abschnittweise Längsansicht der Vorrichtung teilweise im Schnitt,
• Fig. 2 und 2a eine Draufsicht der Abschnitte der Vorrichtung nach Fig. 1,
• Fig. 3 den Abschnitt A der Vorrichtung nach Fig. 1 in größerem Maßstab,
• Fig. 4 einen Schnitt nach der Linie IV-IV der Fig. 3,
• Fig. 5 den Abschnitt B der Vorrichtung in größerem Maßstab,
• Fig. 6 einen Schnitt nach der Linie VI-VI der Fig. 5,
• Fig. 7 einen Schnitt nach der Linie VII-VII der Fig. 5,
• Fig. 8 einen Querschnitt durch den Beizbehälter,
• Fig. 9 ein Detail des Behälters nach Fig. 8,
• Fig. 10 eine Draufsicht auf den Behälter nach Fig. 8,
• Fig. 11 eine Draufsicht auf einen anderen Bereich des Beizbehälters,
• Fig. 12 einen Schnitt der Linie XII-XII der Fig. 11, und
• Fig. 13a bis 13c verschiedene Ausführungsbeispiele von bei der Vorrichtung verwendeten Führungsbalken.

In the drawing, an embodiment of the device according to the invention is shown. Show it

• 1 and 1a is a partial longitudinal view of the device partially in section,
• 2 and 2a is a plan view of the portions of the device of FIG. 1,
• 3 shows section A of the device according to FIG. 1 on a larger scale,
• 4 shows a section along the line IV-IV of FIG. 3,
• 5 section B of the device on a larger scale,
• 6 shows a section along the line VI-VI of FIG. 5,
• 7 shows a section along the line VII-VII of FIG. 5,
• 8 shows a cross section through the pickling tank,
• 9 shows a detail of the container according to FIG. 8,
• 10 is a plan view of the container of FIG. 8,
• 11 is a plan view of another area of the pickling tank,
• Fig. 12 is a section on the line XII-XII of Fig. 11, and
• 13a to 13c different embodiments of guide beams used in the device.

The device consists of a decoiler 1, which can possibly consist of independent drain drums for the simultaneous recording of several bundles. From there, the strip 10 is advanced to a straightening machine 2 after the federal government has been opened. This machine not only serves to straighten the belt, it also ensures that the belts are pushed through the system to the first pair of transport rollers 6 and further until the beginning of the belt is taken up by the reel 9.

The strip enters the pickling tank 3 and is pushed there through shallow pickling cups which are flooded with pickling acid from an underlying pickling tank.

Subsequent to the pickling, the strip is rinsed, possibly post-treated and finally dried and runs to the reel 9 via pulling rollers (FIGS. 1, 2).

The pickling tank 3 is closed by a lid 4. To protect it from damage by whipping the beginning of the tape or building up tape sections are below the lid on opposite longitudinal shoulders 5 of the side walls 7 guide beams 11, one behind the other, which can reach up to the liquid level. In order to prevent the beginning of the tape from getting stuck or jamming in the gaps running transversely to the tape running direction of the colliding guide beams 11, or to prevent the initial edge of the guide bars running transversely to the tape running direction from being knocked off or damaged when wavy or poorly rolled tapes pass through, these are the leading tape facing, transverse to the tape running edges 12 of the guide beams 11 beveled, so that the consecutive guide beams 11 above the tape 10 form a sawtooth-like ceiling with sloping rising in the running direction of the tape or sloping edges in the present upstanding teeth. If the band 10 rises with a longitudinal section of the same or with the leading beginning and arrives at the guide beam 11, it is deflected downwards by the latter or by the inclined surfaces 12 '(FIG. 3).

The steering devices and the lids, which are independent of this, form a double seal against the atmosphere. An intermediate space is formed between the steering devices and the lids independent thereof, in which an air cushion is formed, in which a limited part of the hydrogen gas formed during the pickling process can pass through the gaps remaining between the steering devices. Together with this hydrogen gas, a small amount of acid vapor inevitably gets into the gap. These gases and vapors, which are now diluted by air, are sucked out of this space through a nozzle 14 in the cover 4. Despite the fact that the pickling bath surface is not reduced, the acid evaporation and thus the loss of thermal energy is reduced (FIG. 4).

As already mentioned at the beginning, instead of the guide beams 11 shown, other devices which deflect the belt downward can also be provided.

A number of pickling tanks of the type described can be provided, a transport or squeezing roller pair 8 (FIG. 3) between which each of these pickling tanks can be provided, between which the belt 10 passes and the majority of the pickling acid is removed. Hiebei are the two rollers 8 ', 8 "of the pair of squeezing rollers 8 offset from each other, such that the upper roller 8' seen in the direction of the belt 10, behind the lower roller 8" and which is to separate the pickling liquids of the individual sections is provided with a sealing lip 13. At least one of the two squeeze rollers can be driven. This separation of the liquids in the individual sections will result in a different iron and acid concentration in such a way that in the first pickling section the highest iron content is present in the lowest free acid concentration and in the last section the lowest iron and highest acid concentration. This significantly reduces the pickling time. At least one of the two squeeze rollers can be driven.

For the central belt guide with respect to the longitudinal axis of the system, belt side guides 15 (FIGS. 1 and 2), which can be set for the different belt widths, are arranged, for example, in front of the last pair of squeeze rollers of the pickling tub. 5 and 7, there are two opposing carriages 16, 16 ', each of which runs on two pairs of rollers 17 and 17', which are guided in guides 18, each carriage having a rack 19 and a rack 19, respectively 19 'carries which mesh with a gearwheel located jointly in the longitudinal central axis and thereby ensures a synchronized movement of the two carriages 16, 16'. Each of the two carriages 16 and 16 'is connected to a hydraulic cylinder 21 and 21', which move the carriages 16 and 16 'to each other and against each other. With regard to the gearwheel 20, it is also possible for one cylinder 21 to move the carriages 16, 16 'to one another and the other cylinder 21' to move the carriages from one another or vice versa. Each of the two carriages 16, 16 'carries on the underside a carrier 22, 22', which consists of a plate 23, 23 "made of acid-resistant material, preferably of ceramic, wear-resistant material, which is brought up to the beginning of the tape in order to do this The centering of the belt start occurs at the point in time when the belt start has just passed the centering jaws but has not yet been pinched by the transport rollers.

Fig. 8 shows a cross section of the pickling tank 3 with a preferred embodiment of the bottom, which starts on both sides from the side walls 7, slightly inclined down to the center of the bottom. As can be seen from FIGS. 8 and 10, pipe connections 24 are arranged on the side walls 7 at intervals along the pickling tank 3, which open out laterally at an angle and serve to supply pickling liquid. In continuation of the pipe socket 24, semicircular depressions 25 are provided in the bottom, which also run obliquely to the center and meet there. The longitudinal component of the flow of the pickling liquid is thus directed in the opposite direction to the strip running. So that the tape does not get caught on the edges of the depressions 25, an edge 26 thereof is rounded (FIG. 9).

The measures mentioned, namely a slightly sloping shape of the bottom and arrangement of the depressions with the pipe sockets result in a fluidically favorable guidance of the pickling liquid within the pickling tank 3. In particular, the pickling liquid is prevented from shooting up when there is no band in the pickling tank 3. Due to the slightly sloping shape of the floor, there is also a certain amount Self-centering of the band achieved in its longitudinal movement.

So that no, or as little as possible, pickling liquid flows out of the pickling tank 3 to the transport and squeeze rollers when the strip exits, overflow chambers 27 are provided at the side walls 7 at a distance in front of the transport and squeeze rollers, as shown in FIG vertically arranged sliders for overflowing the pickling liquid are provided.

The liquid level in the pickling tub can be adjusted by means of the height-adjustable slide 28 or flaps and the like.

As can be seen from FIGS. 13a to 13e, various forms of guide beams can be used. In the guide bar 11 according to FIG. 13a already shown in FIG. 3, the bevel runs on the underside on the belt inlet side and only over part of the width of the guide bar 11. In the guide bar 11a according to FIG. 13b, the bevel runs over the entire width of the guide bar 11a . In the guide beam 11b according to FIG. 13c, the bevel runs on the strip outlet side over part of the width of the guide beam 11b.

In the guide beam 11c according to Fig. 13d, the bevel extends over the entire width of the guide beam 11c along a curve, e.g. circular arc or exponential. Finally, with the guide beam 11d there is a multiple bevel, e.g. twice, provided.

The angle or maximum angle (with curved bevel) is 2 to 10 °, preferably 5 °.

Claims (7)

1. Device for the surface treatment of strips with fluids, in particular for corroding rolled metal strips in a duct-like corrosion container closed by a lid, wherein guide bars, formed from resistant material, are provided as covering for the corrosion chamber, such bars succeeding one another in the direction of travel of the strip and being inserted in the corrosion container, and the base of the corrosion container (3) extends from the lateral walls (7) and is inclined slightly downwardly towards the centre of the base, characterised in that the guide bars (11), on the underside, are inclined downwardly over at least a portion of the width of the guide bar (11), at the strip discharge end, extending in the direction of travel of the strip (10) and guide the incoming start of the strip into the desired direction of movement when such is raised.

2. Device according to claim 1, characterised in that the guide bars (11 on the underside, are inclined over the entire width of the guide bar (11) extending in the direction oftravel of the strip (10) (Fig. 13b).

3. Device according to claim 1, characterised in that the guide bars (11 on the underside, are inclined over the entire width of the guide bar (11), extending in the direction of travel of the strip (10), along a curve (Fig. 13d).

4. Device according to claim 1, characterised in that the guide bars (11), on the underside, are repeatedly inclined (Fig. 13e).

5. Device according to one of the preceding claims, characterised in that the angle, i.e. maximum angle, of inclination is 2° to 10°, preferably 5°.

6. Device according to claim 1, wherein connection pipes (24), which extend inclinedly into the corrosion container (3), are disposed laterally on the lateral walls (7) at intervals along the corrosion container (3) and are used for supplying the corrosion fluid, characterised in that, as extensions of the connection pipes (24), semicircular recesses (25) are provided in the base of the corrosion container (3), which recesses extend inclinedly towards the centre of the base of the corrosion container (3), at least one edge (26) of the recesses (25) being radiused.

7. Device according to claim 1, characterised in that overflow chambers (27) for the discharge of the corrosion fluid are provided on the lateral walls (7) upstream of the outlet where the strip emerges from the corrosion container (3), the overflow chambers (27) being spaced from one another and being disposed upstream of the carrier and squeeze rollers, and they have adjustable slide members (28) or valves for the adjustment of the fluid level.

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