EP1156893B1 - Method and device for drying and keeping dry especially cold-rolled strip in the delivery area of cold-rolling and strip-rolling plants - Google Patents

Abstract

In a method for drying and keeping dry rolled strip in a delivery area of strip-rolling plants, a partition is arranged in the delivery area for separating a damp area of the rolling mill from a dry area. The partition extends from the base plate to the stand platform. The strip is subjected to pressurized gas by the ends of the partition facing the strip at a right angle to the strip surface from above and below. Across the strip width a cushion of a compressed gas is generated and seals a gap between the ends of the partition facing the strip and the upper and lower strip surfaces. The compressed gas is guided away above and below the strip parallel to the strip surface as a split flow toward the rolling mill or the damp area and as a split flow in the opposite direction toward the dry area.

Description

The invention relates to a method and an apparatus for Drying and keeping dry, especially of rolled strips (Cold strip) up to approx. 10 mm thickness, preferably less than 0.2 mm thickness, in the outlet area of cold rolling and strip plants, in compared to those for separating the "damp room" of the rolling mill the further outlet area behind the last rolling stand "Dry room" a partition is arranged, the upper Part above the belt up to the scaffolding platform and its lower part below the belt to the base plate followed.

The required quality of the is in the outlet of rolling mills Product "cold strip" in addition to good flatness and optimal Thickness tolerance also includes dryness and cleanliness of the Belt surface, because otherwise during the further processing of the Band surface defects, for example stains, are inevitable.

To get a dry belt surface and this shield against the wet area of the rolling mill and so to protect against rewetting, for example by undesired condensation of haze emanating from the roll stand are different Devices and measures known, such as foreclosures, Suction, blowing off and their combinations.

For example, DE 28 44 434 A1 proposes liquid residues from passing through Sheets and strips, particularly in rolling mills and strip processing plants in a defined area across the sheet surface vacuum generated by suction pipes or by the suction air streams generated thereby suck. At the suction pipes provided with a longitudinal slot Rubber, plastic or brush sealing lips attached to the side Seal the suction area laterally against the tape.

In order to remove cooling liquid adhering to the rolled strip, use the nozzles the inlet side is sprayed against the work rolls of a mill stand, in the US-A-4,400,961 proposed, at a distance from the outlet side of the work rolls to arrange a blow-off device. In this blower, which itself The adhering coolant extends over the entire width of the rolled strip blown away with compressed air through adjustable nozzles below and above is guided against the surface of the rolled strip.

GB-A-1 481 022 discloses a device for removing adherent Liquid from the surface of a rolled strip by a blow-off device known from the air over the entire width of the rolled strip towards Work roll is blown onto the top and bottom of the roll belt. The blow-off device for the top of the rolled strip is to adapt to Different rolled strip thicknesses are arranged and can be moved vertically with the help of the blow-off air similar to an air cushion at a distance from the surface of the rolled strip held.

For the removal of adhering cooling liquid it is known from US-A-4,552,003 at a distance from the outlet side of the work rolls above and below the roll belt to order a foreclosure. This partition ends towards the rolled strip with a device that air on the top and on the bottom of the Roll strip blows and immediately next to it towards the work rolls again sucked off and thereby removed adhering liquid on the rolling belt.

DE 44 22 422 A1 describes a device for non-contact sealing a gap between a partition and a work roll in the outlet of a Roll stand known. The end of the partition is non-contact with a small gap-like distance approximately tangential to the surface the work roll. The gap formed in this way between the partition and the work roll is made with one in the end part of the partition arranged slit nozzle emerging high-energy flow (by means of Compressed air) sealed. The cut through this flow due to the tapered formation of the end part and its arrangement relative to the work roll caused negative pressure causes additional large amounts of Air is sucked in through the gap and towards the wet area towards the work roll flock there. This creates a defined flow between the bulkheads and rolling stock, in the area of which wet air is sucked off with drops and other particles.

• Eine Ballenabblasung zum Abweisen von abgequetschtem Walzmedium vom fertiggewalzten Band
• eine zur Abdichtung des oberhalb vom Band gelegenen Walzenraums gegen das Band ausgebildete Ballenspaltabdichtung
• eine zur Erzeugung einer zum Band rechtwinkligen Luftströmung im auslaufseifigen Walzenspalt oberhalb des Bandlaufs ausgebildete Bandkantenabblasung, durch die das mitgerissene Walzöl seitlich der Bandkanten vom Band abgelenkt wird
• eine zur Erzeugung einer parallelen Luftströmung gegen die Bandlaufrichtung oberhalb und unterhalb des Bandes ausgebildete Dunstabsaugung.

Another type of partitioning for keeping cold strip dry in the outlet of a roll stand with means for repelling liquid rolling medium and / or for removing spray or spray liquid adhering to surfaces of the strip is described in DE 195 35 168 A1. The bulkhead, consisting of a permanently installed part and a moving part arranged on the hinge side (to enable problem-free roll changes), extends above the belt outlet to the scaffolding platform and below the belt outlet to the base plate. The following device parts are arranged on the movable part of the partition:

• A bale blow-off to repel squeezed rolling medium from the finished rolled strip
• a bale gap seal designed to seal the roll space located above the belt against the belt
• a strip edge blow-off designed to generate an air flow at right angles to the strip in the outlet-nip roller gap above the strip run, by means of which the entrained rolling oil is deflected from the strip at the side of the strip edges
• a fume extractor designed to generate a parallel air flow against the belt running direction above and below the belt.

Starting from this known prior art, in which often vacuumed the tape or an air flow against the Work roller is directed, the object of the invention based on a simple procedure and one based on it Device made of simple and rolling mill-compatible components for contactless sealing of a gap between one Foreclosure and a strip in the outlet of cold rolling and Design conveyor systems in such a way that Energy consumption and low noise both dry belt surface as well as a complete separation of the wet-wet roll area from the finished rolled strip Further development of the known devices is achieved.

The task is solved procedurally at one Method of the type mentioned in the preamble of claim 1 by the characterizing measures of claim 1 and device-wise with the characteristic features of the Claim 3.

By the measure of the invention, the gap between the Foreclosure and the band above and below the band to seal with an air cushion-like compressed gas cushion, the pressurized gas above and below the belt additionally in the form of a gap flow parallel to Strip surface in the direction of the rolling mill and in the opposite direction is dissipated, even at high belt speeds 1000 m per minute regardless of the bandwidth Penetration of rolling oil or emulsion with success prevented and non-contact belt drying achieved.

Due to the formation parallel to the belt surface running gap flow is also reliably prevented, that passes through the side of the strip of rolling oil or emulsion. Also running down at the top bulkhead Liquid becomes targeted by this gap flow Rolling mill returned.

The pressure at which the gas is at right angles from above and from below against the belt surface is approximately 1 to 10 bar, preferably about 5 bar, which ensures that the structure of a required for an optimal seal air cushion-like compressed gas cushion and the subsequent gap flow is high enough to energy Prevent moisture penetration. So that too with as little energy and noise as possible is the gap between the foreclosure and the tape if possible to 0.1 to 1 mm, preferably to 0.2 mm plus the strip thickness set to at given Gas pressure with the smallest possible gas quantities the desired To achieve effect.

An apparatus for performing this method exists from one arranged above and below the band Foreclosure, the parts of which are installed above the Belt up to the scaffolding platform and below the belt up to connect the base plate. These are fixed towards the hinge side installed bulkhead parts by moving (movable) Foreclosure parts extended so far between them movable bulkhead parts and the belt surface narrow gap is set. This gap can be made by procedures of the movable bulkhead parts against a fixed or adjustable stop to a predetermined gap width be set or he sets himself due of the compressed gas cushion. After an advantageous Embodiment of the invention, it is independent of the Band thickness 0.1 to 1 mm, preferably 0.2 mm.

The hinge-side end of the movable partition is in each case formed by a blow nozzle bar into the holes (Blowing nozzles) are arranged, through which a gas with pressure against the belt surface is guided. After another advantageous embodiment of the invention are in the Blow nozzle bar per meter bar length approx. 250 blow nozzles arranged with a diameter of approx. 1 mm. Are advantageous here the blow nozzles one behind the other across the entire Band width arranged in the center of the blow nozzle bar. It is but also possible, instead of the blow nozzle holes continuous slot nozzle with a slot width of for example, to form 1 mm in the blow nozzle bar.

Due to the size of the blow nozzle bar - its length corresponds at least the bandwidth and its width is about 10 to 500 mm, preferably about 60 mm and parallel to Band surface trained band side Blower nozzle area is in the middle (in relation to the Blower nozzle width) Compressed gas emerging from the blower nozzles able for a reliable seal Build up the necessary air cushion-shaped compressed gas cushion. Furthermore, the broad training of the band-side Blower nozzle area, the width of which is clearly over the range the blow nozzle openings goes out and parallel to the Belt surface runs, reached that the one to be sealed Gap is wide enough in the direction of a tape length reliably acting gap flow parallel to the belt surface towards the rolling mill and in the opposite direction using the To maintain compressed gas.

Further advantages, details and features of the invention are subsequently based on one in drawing figures illustrated embodiment explained in more detail.

Fig. 1

in Seitenansicht in einem Ausschnitt die Abschottung und Spaltabdichtung am Auslauf eines Walzgerüstes (teilgeschnitten),

Fig. 2

eine schematische Ausschnittvergrößung der Blasdüsenleisten gemäß Fig. 1.

Show it:

Fig. 1

in a side view in a cutout the partition and gap seal at the outlet of a rolling stand (partially cut),

Fig. 2

2 shows a schematic enlargement of the blow nozzle strips according to FIG. 1.

In Figure 1, the outlet area of a roll stand (the The mill stand was not shown, it is on the right next to Fig. 1) with the band 10, the 11 is transported, shown schematically.

Above and below the belt 10 there is one permanently installed partitioning 12, 13, the upper part 12 extends to the scaffolding platform (not shown) and its lower part 13 for the return of separated liquid runs diagonally down towards the rolling stand. The Foreclosure 12, 13 opens into a frame 14, 15 on the hinge side which is also fixed in place or movable is formed and in the movable blow nozzle carrier 16, 16 ', 17, 17' are arranged. The end of the band on the band side Partitioning 12, 13 with the blow nozzle carriers 16, 16 ', 17, 17' form the blowing nozzle strips 18, 19 with centrally arranged Blow nozzles 23 in the form of bores on the hinge side Blower nozzle carriers 16 ', 17' are attached and by the movable arrangement of the frame 14, 15 and the movable Arrangement of the blow nozzle carrier 16, 16 ', 17, 17' to close the belt 10 can be moved up. An adjustable or fixed stop 20 ensures that a certain gap width between the blowing nozzle strips 18, 19 and the surface of the band 10 is adjustable or itself automatically sets due to the pressure gas cushion, whereby due to the possibility of moving the blow nozzle bars this gap thus also at different strip thicknesses can be customized. Together with the components of the Blower nozzle carriers 16, 16 ', 17, 17' form the blower nozzle strips 18, 19 chambers 24, 25, 26, 27 from, namely inner chambers 24, 25 and outer chambers 26, 27, which via the chamber openings 28, 29 are connected. The inner chambers 24, 25 are with the pressurized gas via inlet openings 21, 22 fillable, which then via the chamber openings 28, 29 in the flows into outer chambers 26, 27 and from there via the Blow nozzles 23 perpendicular to the surface of the belt 10 to be led. By forming chambers above or A reservoir beneath the blow nozzle bar is advantageous as well as an equalization for the compressed gas.

In Figure 2, the resulting flow directions of the Compressed gas, starting only from the outer chambers 26, 27, in a schematic enlargement shown. Although the components of Fig. 2 are shown very schematically are and differ in shape from the components of FIG. 1, were also used to better understand the same components same reference numerals selected.

The device according to the invention functions as follows: Compressed gas 33 flows out of the inner chambers 24, 25 (the chambers are not shown in Fig. 2) through the chamber openings 28, 29 into the outer chambers 26, 27 and from there the blowing nozzles 23 perpendicular to the surfaces of the belt 10 and here forms a pressure gas cushion in the gap 30 above and below the band 10. This divides in the gap 30 Compressed gas 33 and flows in a gap flow 32 to Wet room 35 of the roll stand (to the right in FIG. 2) and in Opposite direction as gap flow 31 to the drying chamber 34 of the finished rolled strip (to the left in Fig. 2). As a result of that the blowing nozzle strips 18, 19 with a wide hinge side Blower nozzle strip surface formed parallel to the belt surface are the width of the blow nozzle bars correspondingly long gap, so that here too desired gap flow 31, 32 can build.

For further understanding, the Foreclosure 12, 13 also shown to indicate that by the interaction of the foreclosure with the Compressed gas cushion and the gap flow 31, 32 a separation of the drying room 34 with the finished rolled strip from Damp room 35 of the roll stand is reached.

The embodiment shown in the drawing figures represents only one possible application of the invention it is possible, for example, to train the Blower nozzle strips, the number and arrangement of the blower nozzles as well the formation of the blow nozzle carrier different from to execute the example shown, if so Basic principle of the invention, the formation of a Air cushion-like compressed gas cushion with a gap flow remains on both surface sides of the tape. Also those formed above or below the blow nozzle bar Compressed gas chambers are not essential to the To carry out the subject of the invention. Furthermore, they are inventive method and dei device also for Suitable for drying and keeping dry for any profiles applicable. The corresponding constructive adjustment is in that At the discretion of the professional.

Claims (6)

1. Method of drying and keeping dry, particularly of rolled strips (cold strip) up to approximately 10 mm thickness, preferably less than 0.2 mm thickness, in the exit region of cold rolling and strip plants, in which for separation of the moist area (35) of the rolling mill relative to the further exit region behind the last roll stand there is arranged at the dry area (34) a bulkhead, the upper part of which above the strip (10) is connected as far as the stand platform and the lower part of which below the strip (10) is connected as far as the base plate, characterised in that the strip (10) is acted on under pressure from above and below by a gas, preferably air, from the ends, which are at the strip side, of the bulkheads (12, 13) and the components (14, 15, 16, 16', 17, 17') thereof by way of blast nozzles (23) at right angles to the strip surface so that over the entire strip width a pressure gas cushion similar to an air cushion builds up in the 0.1 to 1 mm, preferably 0.2 mm, wide gap (30) between the end, which is at the strip side, of the bulkhead (12, 13; 14, 15) and the upper and lower strip surface and the pressure gas (33) above and below the strip (10) is discharged in the form of a gap flow (32) parallel to the strip surface in direction towards the rolling mill or towards the moist area (35) and a gap flow (31) in opposite direction towards the dry area (34).
2. Method according to claim 1, characterised in that the pressure gas (33) is conducted at a pressure of approximately 1 to 10 bars, preferably of approximately 5 bars, from below and above onto the strip surfaces.
3. Device for carrying out the method according to the preceding claims, consisting of a bulkhead (12, 13) arranged in stationary position above and below the strip (10), the upper part (12) of the bulkhead above the strip (10) being connected as far as the stand platform and the lower part (13) of the bulkhead below the strip (10) being connected as far as the base plate, as well as a movable bulkhead (16, 16', 17, 17') which extends the stationary bulkhead (12, 13) by way of frames (14, 15) to be dose above and below the strip surface, characterised by blast nozzle rails (18, 19), which are arranged over the entire strip width at the strip-side ends (16', 17') of the movable bulkheads, with blast nozzles (23) directed perpendicularly to the strip surface and blast nozzle rail surfaces formed at the strip side to be parallel to the strip surface, wherein the gap (30) formed between the surfaces of the strip (10) and the blast nozzle rail surfaces at the strip side has a width of 0.1 to 1.0 mm, preferably approximately 0.2 mm.
4. Device according to claim 3, characterised in that the lengths of the blast nozzle rails (18, 19) correspond with at least the strip width and the width of the blast nozzle rails (18, 19) amounts to approximately 10 mm to 500 mm, preferably approximately 60 mm.
5. Device according to claim 3 or 4, characterised in that approximately 250 blast nozzles (23) with a nozzle diameter of approximately 1 mm are arranged in the blast nozzles rails (18, 19) per 1 m blast nozzle rail length.
6. Device according to claim 3, 4 or 5, characterised in that the blast nozzles (23) are arranged in the blast nozzle rails (18, 19) centrally with respect to the blast nozzle rail width and in succession transversely over the entire strip width.

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