DEVICE FOR TREATING A METAL STRIP

Abstract

The invention relates to a device for processing a metal strip (200) after said metal strip has exited a coating tank (300) having liquid coating material (310). Above the coating tank, the device has a blow-off apparatus (110) having an air outlet slot (112) for blowing liquid parts of the coating off of the metal strip. Arranged above the blow-off apparatus (110) is an electromagnetic stabilization apparatus (140) for stabilizing the metal strip by means of electromagnetic forces after the exiting of the coating tank and the blow-off apparatus. According to the invention, in order to design known devices for treating a metal strip to be more favorable in respect of energy and in order to increase the accessibility of said devices for an operating person, the stabilization apparatus (140) is arranged above the blow-off apparatus (110) in such a way that the distance d between the line of action of the maximum force of the stabilization apparatus on the metal strip and on the air outlet gap (112) of the blow-off apparatus (110) is limited to a range of 100-1200 mm.

Description

The invention relates to a device for treating a metal strip after this has exited a coating container with liquid coating material, for example zinc.

Devices of that kind are basically known in the prior art, thus, for example, from WO 2012/172648 A1 and German Patent Applications DE 10 2009 051 932 A1, DE 10 2007 045 202 A1 and DE 10 2008 039 244 A1. In concrete terms, these specifications disclose a coating container filled with a liquid coating material. For coating, the metal strip is conducted through the container with the coating material. After leaving the coating container the material strip runs through a blow-off device or a nozzle, which is arranged above the coating container, for blowing off excess parts of the still-liquid coating material adhering to the surface of the metal strip. Arranged above the blow-off device is an electromagnetic stabilising device, which is supported by the blow-off device and which is also called dynamic electromagnetic coating optimiser (DEMCO), for stabilising the strip after leaving the coating container and the blow-off device. The electromagnetic stabilising device generates electromagnetic forces, with the help of which the metal strip is kept centrally in a centre plane of the overall device; oscillation of the metal strip during transit of, in particular, the blow-off device is in this way at least reduced.

However, in these described constructions in reality there is the disadvantage—apart from in the case of the construction according to DE 10 2008 039 244 A1—that the electromagnetic stabilising device is arranged quite far above the blow-off device. This is disadvantageous insofar as the stabilising effect, which is exerted by the stabilising device, on the metal strip acts only to a limited extent at the blow-off device. Moreover, the forces which are to be generated by the stabilising device and which are necessary in order to stabilise the metal strip in the region of the distant blow-device are comparatively large in the prior art. Accordingly, energy consumption for operating the stabilising device is also comparatively high. Finally, it is disadvantageous that the stabilising device is arranged above the nozzle support or the cross member, since as a consequence access to the metal strip in the region of the nozzle support is significantly hampered.

The invention has the object of developing a known device for treating a metal strip in such a way that access to the metal strip in the region of the nozzle support is significantly eased.

This object is fulfilled by the subject of claim 1.

By virtue of the claimed closer arrangement of the stabilising device to the blow-off device it is advantageously achieved that less force has to be generated by the stabilising device in order to stabilise the metal strip in the region of the blow-off device or nozzle. The energy requirement of the stabilising device is thereby also reduced and the device is more efficient overall.

A horizontal cross member, also called nozzle support, is mounted between two vertical posts. The blow-off device is secured to the cross member to hang below the cross member. In addition, the stabilising device is secured below the cross member to hang thereat, but between the cross member and the blow-off device. The mounting of the stabilising device on the cross member is independent of the attachment of the blowing-off device to the cross member.

The arrangement of not only the stabilising device, but also the blow-off device below the cross member offers the advantage that the region above the cross member and thus also a slot, which is spanned by the cross member, for passage of the metal strip is accessible in very simple manner to an operator.

According to a first embodiment the respective individual securing of the blow-off device and the stabilising device to the cross member takes place by way of independent displacing devices. In concrete terms, the blow-off device is secured to the cross member by way of a blow-off displacing device, but is displaceable relative to the cross member. In addition, the stabilising device is secured to the cross member by way of the stabilising-displacing device, but is displaceable relative to the cross member. The two displacing devices enable respectively different degrees of freedom for movement of the blow-off device and the stabilising device relative to the centre plane of the device and also relative to the metal strip.

In particular, the two devices enable displacement of the blow-off device and the stabilising device relative to one another. Apart from the individual degrees of freedom, which are realised by the blow-off displacing device and the stabilising-displacing device, for the respective devices it is advantageous that the cross member together with the blow-off device and stabilising device suspended thereat is mounted on the vertical posts to be vertically movable. The vertical posts are displaceable together with the cross member parallel to one another in the horizontal plane. Because the cross member is mounted on one of the vertical posts to be pivotable in the horizontal plane about a fixed fulcrum (fixed side) and the cross member is movably mounted on the other vertical post (movable side), pivotation of the cross member in the horizontal plane is also possible. These degrees of freedom of the cross member are applicable to the blow-off device and the stabilising device equally, since the two mentioned devices are secured to the cross member.

Accompanying the description are two figures, wherein:

FIG. 1 shows a width view of the device according to the invention,

FIG. 2 shows a cross-section through the device according to the invention and

FIGS. 3 and 4 show plan views of the slot of the blow-off device according to the invention or of the electromagnetic stabilising device according to the invention, each with marking of the target centre position and different desired actual positions of the metal strip.

The invention is described in detail in the following in the form of embodiments with reference to the mentioned figures. In all figures, the same technical elements are denoted by the same reference numerals.

FIG. 1 shows the device 100 according to the invention. It comprises two lateral, vertically extending posts 150, on which a cross member 130—also termed nozzle support—is mounted to be vertically and horizontally movable; see the double arrow in FIG. 1. The device 100 is additionally pivotable in the horizontal plane. For this purpose, one of the two posts 150 is constructed as fixed side A on which the cross member is mounted to be pivotable about a vertical axis of rotation. By contrast, the opposite post is constructed as movable side B and supports the cross member merely vertically. Through this construction of the posts as fixed side and movable side the device 100 and, in particular, the cross member 140 can be oriented, in the case of a skewed metal strip 200, symmetrically relative thereto by pivotation in the horizontal. As a result, the wide sides of the cross member shall always be aligned parallel to the metal strip and the two have the same spacing therefrom.

A blow-off device 110 or nozzle is suspended at the cross member 130. The coupling of the blow-off device 110 to the cross member 130 is carried out not rigidly, but by way of a blow-off displacing device 115 constructed to displace the blow-off device 110 relative to the cross member 130 in the horizontal plane, i.e. in particular perpendicularly to the centre plane 160 of the device. In addition, the blow-off displacing device 115 is constructed to pivot the blow-off device 110 about its own longitudinal axis L and thus suitably adjust it relative to the metal strip 200.

A stabilising device 140, also termed dynamic electromagnetic coating optimiser (DEMCO), is secured by way of a stabilising-displacing device 145 to the cross member between the cross member 130 and the blow-off device 110. This stabilising-displacing device 145 enables translational displacement of the stabilising device 140 in the horizontal plane relative to the cross member, in particular perpendicularly and parallel to the centre plane 160 of the device 100. In addition, the stabilising-displacing device 145 can also be constructed to pivot the stabilising device 140 in the horizontal plane relative to the cross member 130 and relative to the blow-off device 110 about a vertical axis of rotation.

FIG. 2 shows the device of FIG. 1 according to the invention in a cross-sectional view. The reference numeral 170 denotes a control device for controlling the stabilising-displacing device 145. A coating container 300 can be seen, which is basically arranged below the device 100. The metal strip 200 to be coated is conducted in transport direction R into the coating container 300 with the liquid coating material 310 and deflected thereat into the vertical with the help of a deflecting roller 320. It then runs from the bottom to the top initially through the blow-off device 110 and subsequently the stabilising device 140. The present invention provides that the spacing d between the line of action of the maximum force F of the stabilising device on the metal strip 200 and the air outlet gap 112 lies in a range of 200 to 800 millimetres, preferably in a range of 300 to 500 millimetres.

For realisation of the changed positioning or arrangement of the stabilising device 140 obviously all necessary electrical and pneumatic feed lines or pipe runs have to be suitably adapted. The same also applies to diverse housing panels. By comparison with the known device 100 it can be required to place the mounting devices 130-1, 130-2 further apart, for example by 100 millimetres, than in the prior art so as to not only be able to accommodate the stabilising device 140 in the intermediate space between the mounting devices, but also to make possible horizontal movability thereof with the help of the stabilising-displacing device 145 or to create sufficient space for that purpose.

The blow-off device 110 spans a slot 122 through which the metal strip 200 is guided. Excess coating material is blown off the surface of the metal strip 200 with the help of the blow-off device.

In order that the blowing-off on the upper side and lower side of the metal strip 200 takes place uniformly it is important that the metal strip 200 runs through the slot 122 of the blow-off device 110 in a predetermined target centre position, also called centre plane 160, as is symbolised in FIG. 3 in the form of the solid line in X direction. This target centre position is distinguished by, in particular, uniform spacings or spacing distributions from the inner edges of the slot 122 of the blow-off device 110. Apart from the desired predetermined target centre position, possible undesired actual positions of the metal strip are also illustrated in FIG. 3 as dashed lines. Thus, undesired actual positions for the metal strip 200 consist of, for example, twisting thereof relative to the target centre position or a parallel shift thereof in Y direction.

FIG. 4 shows a third possible undesired actual position in which the metal strip 200 is shifted parallelly relative to the target centre position in X direction, i.e. in width direction.

The electromagnetic stabilising device 140 for its part has a slot 142 through which the metal strip 200 is similarly guided. It is also applicable here that the metal strip 200 runs through the slot 142 preferably in a predetermined target centre position 160, as shown in FIGS. 3 and 4, so that the forces provided by the electromagnetic stabilising device 140 can act in desired manner uniformly on the metal strip 200 with stabilising effect. The same applies to the slot 142 and the target centre position, which is also desired there, as previously stated with reference to FIGS. 3 and 4 for the slot 122 of the blow-off device 110.

In addition, a first detecting device 154 for detecting a departure of the actual position of the metal strip 200 from a predetermined target centre position in the slot 122 of the blow-off device 110 is arranged between the stabilising device 140 and the blow-off device 110. Alternatively, the first detecting device 154 can also be constructed for detecting the actual position of the metal strip. Moreover, a regulating device 180 is provided for regulating the actual position of the metal strip 200 to the predetermined target centre position 128 in the slot 122 of the blow-off device, as explained above with reference to FIGS. 3 and 4, by displacement of the blow-off device 110 with the help of a blow-off displacing device 115, i.e. by displacing the cross member 130 at which the blow-off device 110 is suspended. The regulation is carried out in response to the detected departure. If the determination of the departure of the actual position from the target centre position does not take place in the first detecting device 154, it can also take place, for example, within the regulating device 180. The displacement of the blow-off device 110 is carried out in a horizontal plane transversely to the transport direction R of the metal strip as a function of the detected departure of the actual position of the metal strip from the predetermined target centre position in the slot 122 of the blow-off device. In other words, if it is established that the metal strip 200 does not run through the slot 122 and the target centre position 128, then the blow-off device 110 is displaced with the help of the blow-off displacing device 115 in such a way that the metal strip again runs through the slot 122 of the blow-off device in the predetermined target centre position 128. The first detecting device 154 is so constructed for this purpose that it can preferably detect all three actual positions of the metal strip 200 departing from the target centre position 128 as described above with reference to FIGS. 3 and 4.

The said displacement of the blow-off device 110 should not have any effect on the electromagnetic stabilising device 140. For this purpose, the control device 170 is constructed to control the stabilising-displacing device 145 in such a way that the electromagnetic stabilising device 140 in the case of a displacement of the blow-off device 110 relative to a pass line reference position is not moved therewith, but can remain in its original location. The pass line reference position 160 denotes a fixedly defined centre plane of the device. By contrast, the target centre positions 128 refer to the slots 122, 142. The control device 170 accordingly acts on the stabilising-displacing device 145 in such a way that in the event of displacement of the blow-off device 110 the electrical stabilising device 140 executes preferably precisely the opposite movement to the blow-off device 110, i.e. as a result preferably remains at the original location thereof.

In order to realise this special form of control for the stabilising-displacing device 145 the control device 170 can evaluate different situations. On the one hand, the control device 170 can be constructed to carry out displacement of the electromagnetic stabilising device 140 as a function of the departure, which is detected by the first detecting device 154, of the actual position of the metal strip from the predetermined target centre position of the metal strip in the slot 122 of the blow-off device 110.

Alternatively or additionally, the control device 170 can be constructed to carry out displacement of the electromagnetic stabilising device as a function of and in opposite direction to the displacement, which is detected by a second detecting device 155, of the blow-off device 120. The second detecting device 155 serves for detecting the displacement of the blow-off device 110 relative to a pass line reference position 160 of the device 100.

Finally, in accordance with a further alternative or in addition the control device 170 can be constructed to effect displacement of the electromagnetic stabilising device 140 in dependence on a detected departure of the actual position of the metal strip from a predetermined target centre position in the slot 142 of the electromagnetic stabilising device. A precondition thereof is that a third detecting device 156 is present for detecting the said departure of the actual position of the metal strip from the predetermined target centre position in the slot 142 of the electromagnetic stabilising device 140.

The first, second and third detecting devices 154, 155, 156 are respectively constructed to recognise preferably all conceivable departures of an actual position of the metal strip from the desired target centre position. Amongst those are, in particular, a (parallel) displacement of the metal strip in X or Y direction or a twisting as explained above with reference to FIGS. 3 and 4. Correspondingly, the stabilising device 145 and the blow-off displacing device 115 are, in the case of appropriate control by the regulating device 180 or the control device 170, constructed to move the blow-off device 110 and the electromagnetic stabilising device 140 in desired manner in horizontal plane transversely with respect to the transport direction R of the metal strip, in particular to displace (parallelly) or rotate about a vertical axis of rotation in order to realise transit of the metal strip in the target centre position.

The first and third detecting devices 154, 156 and optionally also the second detecting device 155 can be realised in the form of one or more optical sensor devices 190. To that extent, the sensor device forms a constructional unit for the said detecting devices. For preference a sensor device 190 is provided for each coil in the electromagnetic stabilising device 140. The measurement values of all sensor devices are typically averaged. The sensor device 190 can also be generally termed spacing detection device.

REFERENCE NUMERAL LIST

100 device

110 blow-off device

112 air outlet gap

115 blow-off displacing device

122 slot of the blow-off device

128 target centre plane

130 cross member

130-1 mounting device

130-2 mounting device

140 stabilising device

142 slot of the stabilising device

145 stabilising-displacing device

150 lateral posts

154 first detecting device

155 second detecting device

156 third detecting device

160 pass line reference position of the device

170 control device

180 regulating device

190 sensor device

200 metal strip

310 coating material

A fixed side

B movable side

d spacing

F force

L longitudinal axis of blow-off device

R transport direction of the metal strip

X width direction of the metal strip in target centre position

Y direction transverse to the plane spanned by the metal strip

Claims

1. A device (100) for treating a metal strip (200) after it has exited a coating container (300) with liquid coating material (310), wherein the device comprises: a blow-off device (110), which is arranged above the coating container, with an air outlet gap (112) for blowing excess parts of the still-liquid coating material (310) off the surface of the metal strip (200) after passage of the metal strip through the coating container;an electromagnetic stabilising device (140), which is arranged above the blow-off device (110), for stabilising the metal strip (200) after leaving the coating container and the blow-off device, wherein the stabilising device (140) is so arranged above the blow-off device (110) that the spacing (d) between the line of action of the maximum force (F) of the stabilising device on the metal strip (200) and the air outlet gap (112) lies in a range of 100 to 1200 millimetres; anda horizontal cross member (130) mounted between two vertical lateral posts (150), wherein the blow-off device (110) is secured to and hangs below the cross member (130), and whereinthe stabilising device (140) between the cross member (130) and the blow-off device is secured—independently of the blow-off device—to the cross member (130) and hangs below the cross member.

2. The device according to claim 1, wherein the blow-off device (110) is secured by way of a blow-off displacing device (115) to the cross member (130), the blow-off displacing device (115) being constructed to displace the blow-off device (11) in a horizontal plane relative to the cross member (130) and/or to pivot it about its own longitudinal axis; andwherein a regulating device (180) is provided for activating the blow-off displacing device (115).

3. The device (100) according to claim 1, wherein the stabilising device (140) is secured to the cross member (130) by way of a stabilising-displacing device (145), the stabilising-displacing device (145) being constructed to translationally displace and/or pivot the stabilising device (140) relative to the cross member (130) and relative to the blow-off device (110) in the horizontal plane; and whereina control device (170) is provided for controlling the stabilising-displacing device (145).

4. The device (100) according to claim 1, wherein the cross member (130) and, together with the cross member also the blow-off device (110) and stabilising device (140) secured thereto, are mounted at the vertical posts (140) to be vertically displaceable.

5. The device (100) according to claim 2, wherein a first detecting device (154) is provided for detecting a departure of the actual position of the metal strip (200) from a predetermined target centre position (128) in a slot (122) of the blow-off device (110); and whereinthe regulating device (180) is constructed for regulating the actual position of the metal strip (200) to the predetermined target centre position of the metal strip (200) in the slot (122) of the blow-off device (110) by displacing the blow-off device (120) with the help of the blow-off displacing device (115) in the horizontal plane in dependence on the detected departure of the actual position of the metal strip (200) from the predetermined target centre position in the slot (122) of the blow-off device (110).

6. The device (100) according to claim 5, wherein the control device (170) is constructed for displacing the electromagnetic stabilising device (140) in dependence on the departure, which is detected by the first detecting device (154), of the actual position of the metal strip from the predetermined target centre position of the metal strip (200) in the slot (122) of the blow-off device (110).

7. The device (100) according to claim 3, wherein a second detecting device (155) is provided for detecting the displacement of the blow-off device (110) relative to a pass line reference position (160) of the device (100); and whereinthe control device (170) is constructed to control the stabilising-displacing device (145) for displacing the electromagnetic stabilising device (140) in dependence on and in opposite direction to the displacement, which is detected by the second detecting device (155), of the blow-off device (110).

8. The device (100) according to claim 3, wherein a third detecting device (145) is provided for detecting a departure of the actual position of the metal strip (200) from a predetermined target centre position in a slot (142) of the electromagnetic stabilising device (140); and whereinthe control device (170) is constructed to control the stabilising-displacing device (145) to displace the electromagnetic stabilising device (140) in dependence on a detected departure of the actual position of the metal strip from the predetermined target centre position in the slot (142) of the electromagnetic stabilising device (140).

9. The device (100) according to claim 3, wherein the stabilising-displacing device (145) for displacing the electromagnetic stabilising device (140) is arranged between the cross member (130) and the electromagnetic stabilising device (140).