Assembly and method for hot-dip galvanizing semi-finished products

Abstract

A plant for hot-dip galvanizing semi-finished products (2) comprises a conveying device (6) for conveying the semi-finished products (2) through a zinc bath (5) and a rolling device (8) connected to the conveying device (6) for rolling off the semi-finished products (2) conveyed from the zinc bath (5).

Description

[0001] The invention relates to a system and a method for hot-dip galvanizing semi-finished products.

[0002] Hot-dip galvanizing of semi-finished products in the form of threaded rods involves applying a zinc layer. This zinc layer must be applied in such a way as to maintain thread engagement. In high-temperature galvanizing, the molten zinc is heated to a temperature of at least 530 °C to reduce its viscosity. This low-viscosity melt allows for a comparatively thin layer thickness of up to 70 µm, thus ensuring thread engagement. High-temperature galvanizing for certain semi-finished products, particularly threaded rods, does not comply with EN ISO 10684.

[0003] A method and a plant for hot-dip galvanizing are known from DE 10 2016 106 660 A1 and EP 0 462 397 A1. Components are fed into a galvanizing bath, immersed, and then removed by means of a singulation device. A scraper is provided to remove excess zinc from the component. Additionally, the singulation device can be controlled to perform a rotary motion such that zinc drips off the component and / or is evenly distributed on its surface. Such a process is complex and costly. The singulation device requires sophisticated kinematics and plant control.

[0004] US Patent 5,985,365 discloses a plant for hot-dip galvanizing threaded rods. An inclined ramp is provided for centrifuging off the molten zinc.

[0005] DE 16 96 613 A discloses a pipe extraction machine.

[0006] DE 12 95 475 A discloses a device for the automatic bath treatment of objects.

[0007] The invention is based on the objective of enabling the galvanizing of semi-finished products, whereby the galvanized semi-finished products are manufactured in accordance with standards and are functional.

[0008] The problem is solved by the features of claims 1 and 10. According to the invention, it was discovered that semi-finished products can be zinc-plated if the semi-finished products, conveyed through a zinc bath, can roll off a unwinding device. During this rolling action, the still-liquid molten zinc is flung off the semi-finished product, particularly automatically, especially in uneven external contour areas, particularly in the area of ​​an external thread. The flinging off of the molten zinc occurs passively. Active flinging agents are unnecessary. The semi-finished products are threaded rods with a metric external thread. Surprisingly, it was found that the thread engagement of a rod with a zinc-plated external thread is retained. High-temperature zinc plating is unnecessary. The zinc-plated semi-finished products are manufactured in accordance with standards, particularly those for low-temperature zinc plating. The unwinding device enables, in particular, the automatic, especially gravity-driven, unwinding of the semi-finished products.The unwinding device is designed to ensure that the semi-finished products removed from the zinc bath roll around their longitudinal axis, i.e., they do not slide. A conveying device transports the semi-finished products through the zinc bath. This conveying device enables continuous transport. The system is suitable for providing a continuous process of zinc plating and subsequent centrifugal removal of the molten zinc. The system is also known as a thread-spinning machine.

[0009] A centrifugal section for removing the molten zinc from the semi-finished products improves the centrifugal removal of the liquid zinc. This section has a curvature, i.e., a non-linear profile, such that the threaded rods within the centrifugal section are additionally accelerated, particularly due to gravity. This acceleration of the rolling motion of the threaded rods increases their rotational speed. The increased centrifugal forces on the surface of the threaded rods cause the liquid zinc to be spun off. The curvature in the centrifugal section is achieved primarily through the radius of the contour of the rolling device.

[0010] A conveying device according to claim 2 simplifies the continuous operation of the plant.

[0011] A conveying unit according to claim 3 ensures reliable conveying and transport of the semi-finished products through the zinc bath.

[0012] An embodiment of the drive unit according to claim 4 ensures simplified, fault-resistant handling of the system. In particular, the drive unit can be arranged automatically between a closed transport arrangement and an open transfer arrangement. In the transport arrangement, the semi-finished products can be transported securely and without loss using the drive unit. In the transfer arrangement, reliable and straightforward loading of the drive unit with a semi-finished product and unloading of the drive unit from a semi-finished product are ensured. In particular, a receiving element and a closing element interacting with it are attached to the drive chain. The receiving element and the closing element extend substantially perpendicular to the conveying direction of the drive chain. Along a linear conveying path, in particular between two deflection and / or drive tooth edges, the receiving element and the closing element form the closed transport arrangement.In the deflection area of ​​the drive chain, where the drive chain is deflected by at least 90°, in particular at least 135°, in particular at least 150°, in particular at least 160°, in particular at least 165°, in particular at least 170° and in particular at most 180°, an open transfer arrangement is formed. The drive unit can be loaded and / or unloaded automatically.

[0013] An excavation device according to claim 5 enables automated removal of the semi-finished products from the zinc bath.

[0014] An excavation device according to claim 6 enables a continuous excavation movement of the semi-finished products from the zinc bath, in particular adapted to the conveying device.

[0015] A lifting unit according to claim 7 simplifies the further transport of the semi-finished products from the zinc bath to the unwinding device.

[0016] A lifting unit according to claim 8 enables an automatic, in particular gravity-induced, transfer of the threaded rods to the unwinding device.

[0017] The unwinding device, which includes a starting section for rolling the semi-finished products, wherein the starting section has a slope away from the conveying device with a specific angle of inclination, is designed to be fault-resistant. Galvanized semi-finished products, in particular, can roll automatically into the starting section of the unwinding device from the lifting unit. The angle of inclination relative to the horizontal in the starting section is, in particular, at least 1°, 2°, 3°, 4°, 5°, 6°, 7°, and 10°. This ensures, in particular, that the semi-finished products reliably roll around their own longitudinal axis.

[0018] Slippage of the zinc-coated semi-finished products is prevented. In particular, the unwinding device is designed such that the angle of inclination in the area of ​​the initial roll-off section is variably adjustable. The angle of inclination can be adapted to different requirements. Depending on the geometry, especially the diameter of the semi-finished products, the angle of inclination can be changed to ensure the initial roll-off of the semi-finished products.

[0019] A centrifugal section in which the curvature is defined by a radius corresponding to the contour of the uncoiling device improves the centrifugation of the molten zinc. The centrifugal section, in particular, has a curvature, specifically a non-linear profile, such that the threaded rods within the centrifugal section are additionally accelerated, especially due to gravity. This acceleration of the rolling motion of the threaded rods increases their rotational speed. The increased centrifugal forces on the surface of the threaded rods cause the molten zinc to be spun off. The curvature in the centrifugal section is defined, in particular, by a radius corresponding to the contour of the uncoiling device.

[0020] The unwinding device, which has at least two unwinding skids, is of a simple design. The semi-finished products can roll stably on two spaced-apart unwinding skids, which in particular have identical geometry. The surface contact between the unwinding skids and the semi-finished products is minimized. Rolling resistance is minimized. The molten zinc can be flung off unhindered. The contact area between the unwinding device and the semi-finished product is minimized.

[0021] A discharge device according to claim 9, which is particularly connected to the centrifugal section of the unwinding device, enables a controlled discharge of the unwinding motion of the semi-finished products. In the area of ​​the discharge device, a stop unit, particularly in the form of a horizontal end stop, is provided, which controls the unwinding motion of the semi-finished products, in particular by braking it. The discharge device serves in particular for the onward transport of the galvanized semi-finished products, for example, automatically and / or continuously. The discharge device can also serve as a storage area, in particular an intermediate storage area, for the semi-finished products. The discharge device can also be used for drying the semi-finished products. The discharge device, which is at least partially horizontally oriented, is in particular arranged at a height level that is lower than the transfer point of the semi-finished products to the unwinding device.This ensures that the semi-finished products can pass through the unwinding device and reach the discharge device solely by gravity. Additional drive elements are unnecessary. The system is designed to be particularly simple.

[0022] The hot-dip galvanizing process for the semi-finished products according to claim 10 essentially has the advantages already explained with reference to the annex, to which reference is hereby made. The process is robust and straightforward.

[0023] A method according to claim 11 enables the standard-compliant production of galvanized semi-finished products using a low-temperature process. The energy required for heating the molten zinc is reduced. The process is particularly economical.

[0024] A method according to claim 12 enables the application of a reliable zinc coating. It has been found that by centrifuging the molten zinc, a comparatively higher viscosity of the zinc melt can be accepted while still achieving a homogeneous coating thickness, even in the area of ​​the external thread of the semi-finished product. It is not necessary to heat the zinc melt to an elevated temperature level to reduce its viscosity. The method successfully applies a zinc coating with a thickness greater than 70 µm, particularly in the range of 80 µm to 200 µm, especially between 100 µm and 180 µm, and particularly between 120 µm and 150 µm. The applied zinc coating is robust and durable.

[0025] Both the features specified in the claims and those specified in the following exemplary embodiments of the system according to the invention are each suitable, individually or in combination with one another, for further developing the subject matter of the invention. The respective combinations of features do not constitute a limitation with regard to further developments of the subject matter of the invention, but are essentially merely exemplary.

[0026] Further features, advantages, and details of the invention will become apparent from the following description of exemplary embodiments with reference to the drawings. The drawings show: Fig. 1 a side view of a system according to the invention for hot-dip galvanizing semi-finished products, Fig. 2 an enlarged detail view of detail II in Fig. 1 , Fig. 3 an enlarged detail view of detail III in Fig. 1 , Fig. 4 Fig. 3 corresponding representation at an earlier stage of the plant, at which a semi-finished product is transferred from the conveying device to the excavation device, and Fig. 5 an enlarged detail view of detail V in Fig. 1 .

[0027] Corresponding parts are in Fig. 1 bis 5 provided with the same reference numerals. Details of the embodiments explained in more detail below can also, in themselves, constitute an invention or be part of an invention.

[0028] A system designated as a whole by 1 is used for hot-dip galvanizing semi-finished products, in particular in the form of threaded rods 2. The threaded rods 2 have a longitudinal axis 3 and an external thread not shown in detail, in particular a metric external thread.

[0029] The system 1 comprises a feeding device 4, a zinc bath 5, a conveying device 6 for continuously conveying the semi-finished products 2 through the zinc bath 5, a lifting device 7, a rolling device 8 and a discharge device 9.

[0030] The feeding device 4 is connected to the conveying device 6. The feeding device 4 is designed as a rod magazine. The rod magazine has a lower opening 10, and the rod magazine is arranged at an inclination such that the threaded rods 2 can be automatically ejected from the feeding device 4 through the lower opening 10 by gravity. A closing device (not shown) can be arranged at the lower opening 10 to prevent the rods 2 from falling out of the rod magazine due to gravity.

[0031] The closer is opened manually or automatically, in particular time-controlled or clocked, when a bar is to be dispensed from the bar magazine.

[0032] The feeding of the semi-finished products to the conveying device 6 can also be done manually. The feeding device can also be omitted.

[0033] The conveyor device 6 has a frame 11 formed from several interconnected truss-like strips. Several pairs of sprockets, four in the illustrated embodiment, each with two identical sprockets 12, are rotatably mounted on the frame 11 about a pivot axis 13. The sprockets 12 are fixed to the frame and therefore cannot be displaced relative to it. At least one of the sprockets 12 is connected to a first drive motor 14. This sprocket is a drive wheel.

[0034] According to the illustrated embodiment, the sprockets 12 are arranged essentially at the vertices of a flat rhombus, with the opening angles of the rhombus being essentially the same at opposite corners. The rhombus-shaped arrangement of the sprockets 12 is inclined relative to the horizontal with a slope away from the feed device 4. According to the illustrated embodiment, the slope angle g is approximately 15°.

[0035] Each of the sprockets 12 arranged on one side of the frame 11 has a drive chain 15 running continuously around it as the first drive element. The drive chains 15 are each guided around the sprockets 12 in the conveying direction 16 via the driven sprocket 12.

[0036] The two drive chains 15 are arranged one above the other in the plane of the drawing.

[0037] Because the conveyor device 6 has a pair of chains and both drive chains 15 are driven, the synchronization of the conveyor device is improved.

[0038] Several drive units 17 are directly attached to each of the chain links of the drive chains 15. It is essential that at least one drive unit 17 is provided. According to the illustrated embodiment, twelve drive units 17 are provided. The number of drive units 17 depends on the cycle time of the conveying device 6 and the required residence time of the semi-finished products in the zinc bath 5.

[0039] The drive unit 17 comprises an angled receiving element 18. The receiving element 18 is rod-shaped and has a bend. The receiving element 18 is essentially L-shaped. The receiving element 18 has a first web extending substantially radially with respect to the respective drive chain 15 or the conveying direction 16, and a second web integrally connected to it, angled at approximately 90°. The second web is oriented substantially parallel to the respective drive chain 15 or the conveying direction 16. The second web of the receiving element 18 extends from the first web in the opposite direction to the conveying direction 16.

[0040] The drive unit 17 further comprises a closing element 19, which interacts with the receiving element 18. The closing element 19 is rod-shaped. The closing element 19 is attached to another chain link of the respective drive chain 15. The attachment points of the receiving element 18 and the closing element 19 on the respective drive chain 15 are spaced apart from each other in the conveying direction 16. Along the conveying direction 16, the closing element 19 trails the receiving element 18, i.e., it is arranged upstream. The closing element 19 is inclined relative to the respective drive chain 15 at a mounting angle b that is less than 90°. According to the illustrated embodiment, the mounting angle b is approximately 80°.The drive unit 17 is essentially closed by the locking element 19 and the receiving element 18, such that the rod of the locking element 19 is arranged essentially parallel to the first web of the receiving element 18. The first and second webs of the receiving element 18 and the locking element 19 form a closed, U-shaped rod contour of the drive unit 17, in which the threaded rod is reliably and captive held. Unintentional loss of the threaded rod 2 from the drive unit 17 is thus prevented.

[0041] The receiving element 18 and the closing element 19 are each rigidly attached to the chain links of the respective drive chain 15. The receiving elements 18 and the closing elements 19 are directly moved along with the conveying movement of the respective drive chain 15 and its chain links. During the conveying of the carrier units 17 between the upper sprocket 12 facing the conveying device 6 and the lower chain edge 12 facing the lifting device 7, the carrier units 17 are in the previously described, closed transport arrangement.

[0042] As the drive chains 15 rotate around the upper sprockets 12 or the lower sprockets 12 with a wrap angle of approximately 160°, the drive units 17 are automatically moved into the open transfer arrangement. Because the rod-shaped receiving elements 18 and closing elements 19 are attached directly to the chain links, the rods are moved away from each other circumferentially by the deflection of the conveying direction at the respective sprockets 12 and then back towards each other.

[0043] The transfer arrangement of a driver unit 17 in the area of ​​the feed device 4 is in Fig. 2 Shown enlarged. As seen from Fig. 2 As is immediately apparent, the unloaded drive unit 17 on the upper run of the drive chain 15 is closed, just as the loaded drive unit 17 is on the lower run of the drive chain 15. To load the drive unit 17 with the threaded rods 2 from the rod magazine, the drive units 17 open in the area of ​​the respective upper sprocket 12.

[0044] Because the second web of the receiving elements 18 projects beyond the respective locking element 19, it is ensured that the drive units 17 remain in the closed transport arrangement even in the area of ​​the intervening sprockets 12, which have a wrap angle of no more than 30°, in particular no more than 20°, and especially no more than 15°. This ensures the safe transport of the threaded rods 2 along the conveying direction 16.

[0045] The conveying device 6 is arranged such that at least the respective lower run of the drive chain 15, on which the drive units 17 loaded with threaded rods 2 are conveyed, is immersed at least partially in the zinc bath 5. The zinc bath 5 has a melting basin 20 and a heating device (not shown) to heat the molten zinc to the required temperature. Additionally, a temperature sensor may be provided, which is in signal communication with the heating device, particularly via a control unit, to maintain the molten zinc at a constant temperature.

[0046] In the area of ​​the lower sprocket 12 of the first drive element, the conveying device 6 is connected to the lifting device 7. The lifting device 7 serves to lift the semi-finished products 2 conveyed through the zinc bath 5. For this purpose, the lifting device 7 has a second drive element in the form of a pair of drive chains 21, which are guided endlessly around two sprockets 22. At least one of the second sprockets 22 is driven by a second drive motor 36. Several lifting units 23 are attached to each of the second drive chains 21, which are moved endlessly around the drive chain 21 along the lifting direction 24. According to the illustrated embodiment, the lifting direction 24 is essentially vertically oriented.

[0047] The lifting unit 23 comprises angled lifting elements 25, each attached to the second drive chains 21 and guided directly by them. The lifting unit 23 also includes a stationary guide column 26, spaced apart from the vertical column of the frame 11. The guide column 26 has a guide contour 37 facing the second drive chains 21, along which the semi-finished products 2 are guided by means of the lifting elements 25. The guide contour 37 has a lower, essentially horizontal section 38, which transitions via a continuous radius section 40 into a section 39 inclined relative to the vertical.

[0048] The lifting elements 25 are each attached to the second drive chain 21 at their apex. The opening angle θ of the lifting elements 25 is less than 90°, in particular greater than 80°, in particular greater than 82°, and in particular greater than or equal to 85°. The lifting element 25 has a first leg extending substantially perpendicular to the excavation direction 24 and a second leg integrally connected to it, extending substantially parallel to the excavation direction 24. The first leg serves to carry the threaded rod 2. The free end of the first leg of the lifting element 25 has a chamfer 27. The lifting element 25 is supported on the vertical column of the frame 11 by the second leg.

[0049] The length of the first leg of the lifting element 25 is greater than the distance between the guide contour 37 of the guide column 26 and the second drive chain 21.

[0050] At the upper, in Fig. 5 The guide contour 37 of the guide column 26 ends at the illustrated sprocket 22 of the lifting device 7.

[0051] The uncoiling device 8 is designed by two substantially identical uncoiling skids 29, which define a uncoiling contour of the threaded rods 2 along the uncoiling device 8. The uncoiling skids 29 are oriented in a direction perpendicular to the plane of the drawing according to Fig. 1 arranged one behind the other. More than two roller skids 29 can also be provided. The distance between the roller skids 29 is, in particular, less than the length of the threaded rods 2.

[0052] At the in Fig. 5 At the transfer point of the threaded rod 2 from the lifting device 7 to the unwinding device 8 shown, the threaded rod 2 has a first height level H 1. The length of the first leg of the lifting element 25 is selected such that at the Fig. 5 In the upper position of the lifting element 25 shown, the threaded rod 2 reliably rolls from the lifting element 25 over the ramp 27 to the unrolling device 8. The unrolling device 8 has a rolling section 28 onto which the threaded rods 2, coming from the lifting device 7, are to roll in a controlled manner. For this purpose, the rolling section 28 has a slope with an angle of inclination n of 7°. The angle of inclination n is, in particular, adjustable. The lifting device 7 has, in particular, a frame-like structure that rests on the ground via height-adjustable feet. The height-adjustable feet are not shown for illustrative reasons. Such feet can have a metric threaded connection with which they can be screwed in and out of a threaded receptacle on the frame in a height-adjustable manner.

[0053] According to the illustrated embodiment, the roller skids 29 are made in multiple parts. The individual sections of the roller device 8 are articulated together. This makes it possible to adjust the height of individual sections of the roller device 8.

[0054] The rolling section 28 is immediately followed by a spinning section 30. Along the rolling direction 31, the spinning section 30 initially exhibits an acceleration curvature 32. The inclination of the rolling skids 29 increases continuously along the rolling direction 31 in the region of the acceleration curvature 32. In the region of the acceleration curvature 32, the inclination of the rolling device is increasing, i.e., not constant. In the region of the acceleration curvature 32, the respective surfaces of the rolling skids 29 are convex.

[0055] The acceleration curve 32 is followed by the transition curve 33, which is then followed by a substantially horizontal valley section 34. The horizontal valley section 34 has a slight gradient before the rolling device 8 transitions into the run-out device 9 via a braking curve 35. The run-out device 9 is at least partially horizontally oriented and has a second elevation H2. The second elevation level H2 is lower than the first elevation level H1.

[0056] The function of system 1, i.e. the process for hot-dip galvanizing the threaded rods 2, is explained in more detail below.

[0057] A threaded rod 2 is discharged from the feed device 4 and falls by gravity into the drive unit 17, which is located in the open transfer position on the upper sprockets 12 of the conveyor device 6, as shown in Fig. 2 depicted.

[0058] The subsequent circular conveying of the drive unit 17 on the first drive chains 15 automatically closes the drive unit 17, i.e., transfers it into the closed transport arrangement, by moving the closing element 19 towards the receiving element 18. In the closed transport arrangement, the drive units 17, each equipped with a threaded rod 2, are conveyed along the conveying direction 16 into and through the zinc bath 5.

[0059] The threaded rods 2, coated with molten zinc, are released by opening the drive units 17 on the respective lower sprocket 12 of the conveying device 6 and placed onto the horizontal section 38 of the guide column 26. The placement of the coated semi-finished product 2 is in Fig. 4 The semi-finished product 2, wetted with molten zinc and placed on the guide column 26, is picked up by the lifting elements 25 of the lifting unit 23 at the lifting device 7 (see figure). Fig. 3 ) and conveyed along the guide contour 37 of the guide column 26 over the rounding section 40 upwards to the uncoiling device 8.

[0060] Because the lifting element 25 has an opening angle o of less than 90° and the guide contour 37 of the guide column 26 is inclined relative to the vertical, the threaded rod 2 is located in the area of ​​the front free end of the lifting element 25, i.e., in the area of ​​the rolling slope 27, during conveying along the excavation direction 24. The threaded rod is reliably conveyed upwards between the lifting elements 25 and the guide column 26.

[0061] When the lifting elements 25 are in an upper position, as in Fig. 5As shown, the semi-finished product 2 rolls, due to gravity, over the rolling ramp 27 of the respective lifting element 25 into the rolling device 8, in particular into the rolling section 28. Due to the inclined arrangement of the rolling section 28, it is ensured that the threaded rod 2 rolls about its longitudinal axis 3.

[0062] In the subsequent centrifugal section 30 with the acceleration curvature 32, the displacement speed of the threaded rod 2 along the rolling direction 31, and in particular the rotational speed of the threaded rod 2 about its longitudinal axis 3, is increased. The centrifugal forces caused by the rotational speed of the threaded rods on the still liquid zinc melt ensure reliable centrifugal discharge of the melt. During the rolling of the threaded rods along the rolling device 8, the melt cools down, at least partially.

[0063] Since the first height level H1 at the beginning of the unwinding device 8 is greater than the second height level H2 at the end of the discharge device 9, the threaded rods 2 automatically pass through the unwinding device 8 in any case due to gravity-induced acceleration. Additional drive elements are unnecessary. The unwinding device 8 is designed without moving parts and requires little maintenance. The construction is simple and robust.

[0064] In the horizontal area of ​​the discharge device 9, the galvanized threaded rods 2 can cool down and in particular be stored or at least temporarily stored before being transported to the goods dispatch area and / or a further processing stage.

Claims

1. Assembly for hot-dip galvanizing semi-finished products (2), the assembly comprising a conveyor device (6) for conveying the semi-finished products (2) through a bath (5) of zinc, the semi-finished products (2) being rods with metric external threads, and wherein a roll-off device (8) is provided that is connected to the conveyor device (6) in order to roll off the semi-finished products (2) conveyed out of the bath (5) of zinc about their longitudinal axes (3), wherein the roll-off device (8) has at least two roll-off skids (29), wherein the roll-off device (8) has a spinning section (30) to remove the zinc melt from the semi-finished products (2) by spinning, wherein the roll-off device (8) has a roll-on section (28) to roll on the semi-finished products (2), the roll-on section (28) having a slope, facing away from the conveyor device (6), with an angle of inclination (n), characterized in that - the spinning section (30) directly adjoins the roll-on section (28), - the spinning section (30) initially has an acceleration curvature (32) in the rolling direction (31), wherein the inclination of the roll-off skids (29) along the rolling direction (31) in the region of the acceleration curvature (32) continuously increases.

2. Assembly as claimed in claim 1, characterized in that the conveyor device (6) has an, in particular endless and circumferential, first drive member, in particular a pair of drive chains (15).

3. Assembly as claimed in any one of the preceding claims, characterized in that the conveyor device (6) has at least one carrier unit (17) to carry along the semi-finished products (2).

4. Assembly as claimed in claim 3, characterized in that wherein the carrier unit (17) has a receiving member (18) and a closing member (19) interacting therewith, wherein the receiving member (18) and the closing member (19) are displaceable in relation to one another between a closed transport arrangement and in an open transfer arrangement.

5. Assembly as claimed in any one of the preceding claims, characterized by a lifting device (7) connected to the conveyor device (6) to lift out the semi-finished products (2) conveyed through the bath (5) of zinc.

6. Assembly as claimed in claim 5, characterized in that the lifting device (7) has an, in particular endless and circumferential, second drive member, in particular a pair of drive chains (21).

7. Assembly as claimed in claim 5 or 6, characterized in that the lifting device has at least one lifting unit (23) to lift the semi-finished products (2) out of the bath (5) of zinc.

8. Assembly as claimed in claim 7, characterized in that the lifting unit (23) has a lifting member (25) fastened to the second drive member and a stationary guide rail (26).

9. Assembly as claimed in any one of the preceding claims, characterized by a run-off device (9) connected to the roll-off device (8), the run-off device (9) being oriented horizontally at least in sections.

10. Method for hot-dip galvanizing semi-finished products, the method comprising the method steps of - providing an assembly for hot-dip galvanizing semi-finished products (2) according to any one of the preceding claims, - conveying the semi-finished products (2) configured as rods with metrical external threads through a bath (5) of zinc by means of a conveyor device (6), - removing liquid zinc melt by rolling off the semi-finished products (2) about their longitudinal axes (3) by means of the roll-off device (8) connected to the conveyor device (6), characterized in that the semi-finished products (2) are accelerated additionally along a curvature (32, 33, 35) in a spinning section (30) of the roll-off device (8), causing the excess liquid zinc melt to be removed by spinning.

11. Method as claimed in claim 10, characterized in that the zinc melt in the bath (5) of zinc is heated to a temperature of at most 460°C, in particular at most 455°C, and in particular at most 450°C.

12. Method as claimed in claim 10 or 11, characterized in that after removing the excess zinc melt by spinning, the zinc melt is arranged on the semi-finished product (2) with a layer thickness of at least 80 µm.

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