EP4140593A1 - Nozzle device and method for the production thereof - Google Patents

Abstract

The invention relates to a nozzle device 100 for applying at least one first medium to the surface of a flat body. The nozzle device consists of an elongated primary nozzle 110 with a primary slot 112, which is in fluid communication with a pressure chamber 114 inside the nozzle device for emitting a primary jet 113 in the form of a flat curtain, consisting of at least the first medium, onto the surface of the flat body. In order to effectively prevent the formation of a pool of liquid prior to the process, the invention provides that the primary slit of the elongated nozzle is V-shaped.

Description

The present invention relates to a nozzle device for applying at least one first medium to the surface of a flat body, in particular to the surface of a metal strip. The invention also relates to a method for producing the nozzle device and a use of the nozzle device.

Background of the invention:

When cold rolling metal strips, fluids (emulsions, rolling oils, etc.) are usually used to lubricate the roll gap, which have a positive effect on the rolling process. However, residues of these fluids are undesirable on the surface of the cold-rolled strip as the end product. The strip dryness represents an essential quality criterion with outstanding importance for the customer.

Nozzle devices for blowing off moisture, in particular from metal strips, are generally known on the market. However, these often do not lead to satisfactory results. For example, classic blower bars are known in the prior art for drying surfaces. These blow bars typically consist of a compressed air manifold with compressed air nozzles mounted on it. Such blow bars have the disadvantage that the blow cones of the individual nozzles influence each other in the overlapping area. This can lead to stripe-shaped residual moisture on the surface of the belt in the overlapping area of the blower cones. In order to reduce this effect, the relevant nozzle manufacturers recommend arranging several blower bars in a row, which have different nozzle arrangements. However, this approach does not solve the actual problem, but it is in the sum of the blower bars arranged one behind the other only reduces the overall effect on the belt surface.

So-called "air knives" are known in addition to the blower bars. These air knives generate a continuous curtain of compressed air, which preferably extends over the entire strip width of the metal strip being produced and beyond. The negative effects described for the classic blower bars due to the interference of the different blower cones do not occur here, but the known air knives with straight slot nozzles have the disadvantage that they cause the liquids to be blown off to accumulate in front of the compressed air curtain. If the accumulated pool of liquid becomes too large, it can happen that part of the accumulated liquid passes through the compressed air curtain and the drying result on the surface of the metal strip is not optimal. Since the liquid is not actively guided away to the edges of the strip, a straight slot nozzle must also be constantly pressurized with compressed air. In reversing cold rolling mills, however, there is only a large amount of emulsion on the surface of the strip shortly after the direction of rolling has been reversed, and this has to be removed.

Known V-shaped blower bars, such as those in the Chinese patent applications CN 2010 76872 Y and CN 2012 75559 Y and in the Chinese utility model application CN 212419119 U are described, try to compensate for exactly this disadvantage. However, the functional principle of the V-shaped blower bars disclosed there is based - as with the classic blower bars - on overlapping blower cones that influence each other. The said strip-shaped residual moisture can therefore occur on the surface in the overlapping areas. Furthermore, it has been shown that the theoretical blast cones of the blast beam nozzles determined under laboratory conditions do not match those in real rolling operation. The reason for this are various boundary conditions in the real application environment, e.g. B. fume extraction, high belt speeds, cross currents Body edges, turbulence caused by rotating components, etc. This means that it is difficult to optimally align the nozzles with well-coordinated overlaps, and problems often arise at these points during commissioning.

The invention is based on the object of further developing a known nozzle device with an elongated primary nozzle and a method for its production and use for the nozzle device in such a way that the undesirable formation of a liquid lake in front of the curtain, which is produced by the nozzle device by dispensing at least one first medium is generated is effectively prevented.

This object is achieved for the nozzle device by the subject matter of claim 1. Accordingly, the primary slit of the elongated primary nozzle of the nozzle device is V-shaped.

The terms “flat body” and “flat product” are used synonymously below.

The claimed V-shaped design of the primary slit ensures that the liquids to be discharged from the surface do not accumulate in front of the compressed air curtain of the slit nozzle, but are actively discharged towards the edges of the strip. In this way, an optimal drying result is achieved because excessively large accumulations of liquid in front of the compressed air curtain of the elongated slot nozzle and thus a breakthrough of the liquid through the curtain, consisting at least of the first medium, is effectively prevented by the claimed V-shape. In this way, the remainder of residual moisture, especially in the form of streaks, is prevented on the surface.

In addition, the V-shape of the slotted nozzle offers the advantage that compressed air does not have to be applied permanently, but only briefly, until the said pool of liquid in front of the curtain has been eliminated.

According to a first exemplary embodiment, in the nozzle device according to the invention, secondary nozzles with secondary slots are preferably formed on both sides adjacent and parallel to the primary nozzle with the primary slot for outputting secondary jets of a second medium onto the surface. The secondary beams preferably serve to stabilize the primary beam. The curtain then consists of the first and second medium.

According to another embodiment, the first and second media may be the same; for example, both media can be air. However, the first medium can be compressed air, for example, and the second medium can be ambient air that has been sucked in. Both media are preferably gaseous.

According to a further exemplary embodiment of the invention, at least the primary slot is not interrupted over its entire length, in particular also in the area of the kink or the curvature of its V-shaped configuration, but is formed continuously.

The elongated primary slot nozzle can be designed over its entire length in the form of a plurality of slot nozzle segments which are connected to one another at their end faces in such a way that the primary slot is continuous.

Further advantageous configurations of the nozzle device according to the invention are the subject matter of the dependent claims.

The above object of the invention is further achieved by a method for manufacturing the nozzle device. Accordingly, the inventive Nozzle device with additive manufacturing, in particular manufactured using the 3D printing process.

The production can be made of metal or plastic, the production from plastic has the advantage of a lower weight.

The additive manufacturing claimed according to the invention also offers advantages in particular in the design of the feed line, the branched feed lines and preferably also valves in the branched feed lines within the nozzle device according to the invention. In the case of additive manufacturing, the components mentioned can be formed in one piece or integrated in the nozzle device.

Finally, the above object is achieved by a claimed use for the nozzle device according to claim 14 according to the invention.

Figur 1

die erfindungsgemäße Düsenvorrichtung beim Abblasen von Feuchtigkeit von einem Metallband in einem ersten Betriebsmodus;

Figur 2

die erfindungsgemäße Düsenvorrichtung beim Betrieb des Primärschlitzes in einem zweiten Betriebsmodus, und

Figur 3

eine Querschnittsdarstellung der erfindungsgemäßen Düsenvorrichtung

zeigt.The description is accompanied by three figures, where

figure 1

the nozzle device according to the invention blowing off moisture from a metal strip in a first operating mode;

figure 2

the nozzle device according to the invention during operation of the primary slot in a second operating mode, and

figure 3

a cross-sectional view of the nozzle device according to the invention

shows.

The invention is described in detail below with reference to the figures mentioned in the form of exemplary embodiments. The same technical elements are denoted by the same reference symbols in all figures.

figure 1 shows the nozzle device 100 according to the invention for applying a first medium to the surface of a flat body, here by way of example a metal strip 300. The first medium has the reference number 210. The nozzle device 100 consists of an elongated primary nozzle 110 with a primary slot, which preferably extends over the entire Width B of the primary nozzle 110 extends continuously. The width of the primary nozzle should be chosen so that it is wider than the width B of the metal strip 300 to be dried.

A pressure chamber 114 is formed within the nozzle device 100 behind the primary slot 112 and is in fluid communication with the primary slot 112 for emitting a primary jet 137 of the first medium in the form of a curtain onto the surface of the metal strip 300. The pressure chamber 114 preferably extends over the same Length or width as the primary nozzle 112. The pressure chamber typically has a slit-shaped exit which also extends over the length of the primary slit and which is either identical to the primary slit 112 or which opens directly into the primary slit for supplying the primary slit over its entire length with the first medium.

According to the invention, the primary slot is V-shaped, similar to a snow plow. The V-shaped design offers the advantage that liquid that collects in front of a curtain formed at least by the primary nozzle 112 by dispensing the first medium is immediately diverted to the edge of the flat body 300, in particular the metal strip. The primary slot 112 is preferably V-shaped throughout its length and also in the region of its V-shape, ie, in the region of its kink or curvature continuous, ie not interrupted. Accordingly, the curtain he generates, consisting of the first medium, is continuous over its entire length.

At least one feed line 118 is provided for feeding the pressure chamber 114 and the primary slot 112 with the first medium, which on its way to the pressure chamber 114 - distributed over its width - increasingly branches out into a plurality of feed lines 119 . Due to the increasing ramifications, the compressed air supply is optimized in terms of flow and ensures a constant dynamic pressure in the primary nozzle over the bandwidth. This is what makes a compressed air curtain that is constant across the bandwidth possible. A plurality of blow-off zones may be formed across the width of the elongate spray nozzle, each of the blow-off zones being represented by at least one, but typically a plurality of the branched supply lines 119 which open directly into the pressure chamber. Valves 121 can be provided in the branches 119 for individually controlling the inflow of the first medium into the individual blow-off zones. In figure 1 it can be seen that in the nozzle device 100 three blow-off zones I, II and III are formed here by way of example. At the in figure 1 shown embodiment, the blow-off zone II is switched off, while the blow-off zones I and III are switched on (= first operating mode).

At the in figure 1 shown embodiment, the shutdown of the blow-off zone II can make sense, because, as in figure 1 can also be seen that the surface of the metal strip is only moist in its edge area, while it is already dry in the middle of the metal strip. The distribution of the dryness over the width B of the metal strip can be detected, for example, by a moisture detector 400, which generates a corresponding measurement signal. The blow-off zones I, II and III can then be switched on or off according to the moisture distribution over the width B of the metal strip 300 represented by the measurement signal. At the in figure 1 shown embodiment, the drying of the surface in the middle of the metal strip 300 can be carried out by an in figure 1 not shown drying device, z. a dry strip system, placed upstream of the nozzle device 100 and preferably also upstream of the moisture detector 400. At the in figure 1 In the exemplary embodiment shown, the nozzle device 100 according to the invention is primarily used to remove residual moisture, in particular residual emulsion, on the upper side at the edge of the metal strip, which has accumulated there, for example, after a previous rolling pass of the metal strip and optionally also after its first drying by the dry strip system is still left.

Said activation of the valves 121 takes place via a control device 500 according to the measurement signal output by the moisture detection device 400, which represents the distribution of the moisture over the width B of the flat body, in particular the metal strip. In other words, the stronger the (residual) liquid still present on the strip indicated by the measurement signal for a latitude, the stronger the blow-off is set for this latitude. As in figure 1 As can be seen, the nozzle device 100 according to the invention is adjusted during operation in relation to the metal strip 300 to be dried in such a way that its V-shaped configuration is directed against the rolling direction, ie against the transport direction of the metal strip. Only then can the desired removal of the liquid to the edge of the metal strip be guaranteed.

The terms "moisture" and "liquid" are used synonymously in the present description.

In figure 2 the nozzle device 100 according to the invention is shown again. In contrast to figure 1 is in the figure 2 however, it can be seen that all three blow-off zones I, II and III are activated, ie are supplied with the first medium, for example compressed air, via the feed line 118 . That equals one second mode of operation. For such a use, no valves 121 are required in branched supply lines 119, as in figure 1 shown. Such valves can be used in the in figure 2 shown embodiment can be saved.

figure 3 shows a cross section through the device 100 according to the invention figure 3 First, the primary nozzle 110 can be seen with the pressure chamber 114, which opens into the primary slit 112 with its slit-shaped outlet. The primary nozzle generates the primary jet 113. Secondary nozzles 115 are preferably formed on both sides adjacent to and parallel to the primary slit 112 of the primary nozzle 110 and have a secondary slit 116, which is also V-shaped over its length, for dispensing secondary jets 117 of a second medium 220 onto the surface of e.g. B. the metal strip 300. The secondary jets 117 are used primarily to stabilize the primary jet 113. The secondary nozzles 115 can in turn be fed from a plurality of tertiary nozzles 200 with the second medium, with the output flows of the tertiary nozzles collected in the secondary nozzles 115 or to the Secondary beam 117 are bundled. In addition to the flows from the tertiary nozzles 200, the channels of the secondary nozzles 115 are designed in connection with the outer surface of the nozzle device 100 in such a way that larger quantities of air from the area surrounding the nozzle device 100 are sucked into the channels of the secondary nozzles 115 and the secondary jets 117 are intensified. Ambient air can be sucked in due to the Coanda effect. With parallel operation of the primary nozzle and the secondary nozzles, the generated curtain consists of both the first and the second medium.

The nozzle device 100 according to the invention with the formation of the pressure chamber 114, with the feed line 118, with the branched feed lines 119 and preferably also with the valves 121 in the branched feed lines is preferably produced in one piece with additive manufacturing, in particular using the 3D printing process. In this way, the nozzle device 100 with its many cavities can be manufactured very easily in an integrated manner. she can be made of metal or plastic, for example. The nozzle device made of plastic is significantly lighter than a comparable 3D-printed nozzle device made of metal, which simplifies its assembly and the actuators required for its positioning can be designed to be smaller and therefore cheaper. Finally, metal parts tend to form condensation on their surface. This effect does not usually occur with plastic parts due to the lower heat conduction.

Reference List

100

nozzle device

110

primary jet

112

primary slot

113

primary beam

114

pressure chamber

115

secondary jet

116

secondary slot

117

secondary rays

118

inlet line

119

supply line

121

Valve

200

tertiary jets

210

first media

220

second medium

300

Flat product, in particular metal strip

400

moisture detection device

500

control device

B

Width of the metal band

I, II, III

blow-off zones

Claims (14)

Nozzle device (100) for applying at least one first medium (210) to the surface of a flat product, in particular the surface of a metal strip (300), having: an elongate primary nozzle (110) having a primary slit (112) preferably continuous the entire length of the primary nozzle and in fluid communication with a pressure chamber (114) internal to the nozzle assembly for dispensing a primary jet (113) in the form a curtain consisting of at least the first medium on the surface, characterized in that the primary slot (112) is V-shaped. Nozzle device (100) according to claim 1, characterized, in that a secondary nozzle (115) with a secondary slot (116) that is also V-shaped is preferably formed on both sides adjacent to and parallel to the primary slit (112) of the primary nozzle (110) for dispensing secondary jets (117) of a second medium (220). the surface for stabilizing the primary beam, the curtain then being formed from the first and second media. Nozzle device (100) according to claim 2,
characterized,
that the first and the second medium are the same and it is preferably air. Nozzle device (100) according to claim 2,
characterized,
that the first medium is compressed air and the second medium is ambient air that has been sucked in. Nozzle device (100) according to one of the preceding claims, characterized in that
that at least the primary slit (112) of the primary nozzle (110), but preferably also the at least one secondary slit, is/are uninterrupted over its entire length, in particular also in the area of the kink or the curvature of its V-shaped configuration. Nozzle device (100) according to one of the preceding claims, characterized in that
that the elongate primary nozzle (110) is formed over its length in the form of a plurality of primary nozzle segments which are connected to one another at their end faces in such a way that the primary slot is continuous. Nozzle device according to one of the preceding claims, characterized, that the pressure chamber (114) of the primary nozzle extends at least substantially the same length as the primary slot; and that the pressure chamber has a slit-shaped outlet which preferably extends over the entire length of the primary slit and which is identical to the primary slit or which opens directly into it for supplying the primary slit with the first medium over its entire length. Nozzle device (100) according to one of the preceding claims, characterized in that
that there is at least one feed line (118) for supplying the pressure chamber (114) with the first medium, the feed line to the pressure chamber being distributed over its width (B) and increasingly branching out into a plurality of feed lines (119). Nozzle device (100) according to claim 8, characterized, that a plurality of blow-off zones are formed across the width (B) of the elongated spray nozzle, each of the blow-off zones being represented by at least one, but typically a plurality of branched supply lines (119) which open directly into the pressure chamber (114). Nozzle device (100) according to claim 9, marked by a moisture detection device (400) for generating a measurement signal which represents the distribution of the moisture over the width (B) of the flat body, in particular the metal strip; valves (121) in the branched supply lines (119); and a control device (500) for individually controlling the inflow of the first medium in the individual blow-off zones by controlling the valves (121) as actuators according to the measurement signal output by the moisture detection device. Method for manufacturing the nozzle device (100) according to any one of the preceding claims,
characterized,
that the nozzle device (100) with additive manufacturing, in particular in 3-D printing process is produced. Method according to claim 11,
characterized,
that the feed line (118), the branched feed lines (119) and preferably also the valves (121) in the branched feed lines are produced in one piece with additive manufacturing and are thus integrated into the nozzle device. Method according to one of claims 11 or 12,
characterized,
that the nozzle device (100) is 3D-printed from metal or plastic, preferably from thermoplastic material. Use of the nozzle device according to one of claims 1 to 10, for removing residual moisture, in particular residual emulsion, on the underside and / or the top at the edge of a metal strip, for example on the inlet side of a roll stand, the z. B. after a previous rolling pass of the metal strip and optionally also after its previous drying by a dry strip system (DS system) is still left.

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