Liquid removal device

Abstract

To provide a novel and improved liquid removal device that can more surely remove water adhering to a metal plate.MEANS FOR SOLVING THE PROBLEM: In order to solve the problem and according to a certain stand point of the present invention, a liquid removal device, which is a liquid removal device provided in rear stage of a liquid draining roll pair for removing liquid from a metal plate to which the liquid is adhering, and is characterized in having a gas nozzle for blowing gas into a plate edge gap formed between the side face of metal plate in the width direction and the liquid draining roll pair, is provided.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to a liquid removal device. [Background technology]

[0002] Oxide scale often adheres to the surface of a hot-rolled steel sheet immediately after hot rolling. For this reason, in the manufacturing process of a hot-rolled steel sheet, pickling is performed to remove the oxide scale. In such a pickling process, the hot-rolled steel sheet is immersed in a pickling solution such as hydrochloric acid or sulfuric acid. This removes the oxide scale. Thereafter, the hot-rolled steel sheet is washed (rinsed) with water to remove the pickling solution adhering to the hot-rolled steel sheet. Moisture adheres to the hot-rolled steel sheet after the water rinsing. Such moisture may have some effect on the hot-rolled steel sheet (for example, deterioration of the appearance), so it is preferable to remove it as much as possible.

[0003] As a technique for removing moisture from a hot-rolled steel sheet, a technique using a pair of wringer rolls is known, as disclosed in Patent Document 1. The roll portion of the wringer roll (the portion that contacts the hot-rolled steel sheet from the back) is made of a flexible resin. In Patent Document 1, moisture is removed from the hot-rolled steel sheet by passing the hot-rolled steel sheet between the pair of wringer rolls.

[0004] However, as disclosed in Patent Document 1, it is often the case that moisture cannot be completely removed from the surface of the hot-rolled steel sheet by simply passing the hot-rolled steel sheet between a pair of wringer rolls. Specifically, moisture remains at the edge portion (edge ​​portion in the width direction) of the surface of the hot-rolled steel sheet. Therefore, in Patent Document 1, a gas nozzle is installed at the rear stage of the pair of wringer rolls (rear stage in the conveying direction of the hot-rolled steel sheet), and the moisture remaining at the edge portion of the surface of the hot-rolled steel sheet is removed using the gas nozzle. Specifically, gas is blown from the gas nozzle onto the edge portion of the hot-rolled steel sheet to blow off the moisture remaining at the edge portion to the outside in the width direction of the hot-rolled steel sheet. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2000-282275 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the inventors of the present invention verified the technology disclosed in Patent Document 1 in detail, it was found that even if gas is blown from a gas nozzle to the edge of a hot-rolled steel sheet, a large amount of moisture still remains on the edge of the hot-rolled steel sheet (for example, the moisture remains in the form of a thick liquid film). The moisture remaining on the edge of the hot-rolled steel sheet adheres to the edge with an extremely strong surface tension, so it is considered that a large amount of moisture remains even if gas is blown. It is also considered that more moisture can be removed by increasing the gas pressure of the gas nozzle. However, in this case, other problems such as an increase in operating costs may occur, so the above problem cannot be fundamentally solved. Here, an example of removing moisture from a hot-rolled steel sheet with a wringer roll pair has been described. However, it is assumed that a process of removing liquid attached to a metal sheet with a wringer roll pair or other liquid-removing roll pair is performed in various technical fields. In either case, it is assumed that the same problem will occur.

[0007] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a new and improved liquid removal device that can more reliably remove moisture adhering to metal plates. [Means for solving the problem]

[0008] In order to solve the above problems, according to one aspect of the present invention, there is provided a liquid removal device that is provided downstream of a pair of draining rolls that removes liquid from a metal plate having liquid adhering thereto, the liquid removal device including a gas nozzle that sprays gas into a plate edge gap formed between a side surface of the metal plate in the width direction and the pair of draining rolls, the gas nozzle having a gas discharge port that faces inward in the width direction of the metal plate, and at least a portion of the gas discharge port that is disposed in a position that overlaps with the metal plate, the gas nozzle has a single gas outlet,A liquid removing device is provided, characterized in that a portion of the gas injected from the gas nozzle flows from the edge portion of the surface of the metal plate toward the interface between the pair of liquid cutting rolls and the surface of the metal plate.

[0009] Here, the angle between the normal line to the gas outlet of the gas nozzle and the vertical direction to the surface of the metal plate may be 0 to 45°, with 0° being defined as the angle when the normal line to the gas outlet of the gas nozzle is parallel to the surface of the metal plate.

[0012] The gas nozzle may have a gas discharge port that is elongated in the width direction of the metal plate.

[0014] The gas nozzle may be movable along the width direction of the metal plate.

[0015] The gas nozzles may be provided at opposite ends of the metal plate in the width direction.

[0016] Moreover, the gas nozzles may be provided only on the upper surface side, only on the lower surface side, or on both the upper surface side and the lower surface side of the metal plate.

[0017] The apparatus may further include a drying device disposed downstream of the gas nozzle for drying the metal plate. Effect of the Invention

[0018] As described above, according to the above aspects of the present invention, it is possible to more reliably remove moisture adhering to a metal plate. [Brief description of the drawings]

[0019] [Figure 1A] 1 is a side view showing the overall configuration of a liquid removing apparatus according to an embodiment of the present invention. [Figure 1B] FIG. 2 is a plan view for explaining the configuration of a gas nozzle and its vicinity. [Figure 1C] 1C is a cross-sectional view taken along line AA in FIG. 1B. [Figure 2A]FIG. 2 is a plan view for explaining the configuration of a gas nozzle and its vicinity. [Figure 2B] FIG. 2B is a cross-sectional view taken along line BB in FIG. 2B. [Figure 2C] FIG. 11 is a plan view showing another example of the arrangement of gas nozzles. [Figure 3A] 11 is a side view for explaining the mechanism by which liquid remains on the edge portion. FIG. [Figure 3B] FIG. 13 is a plan view for explaining the mechanism by which liquid remains on the edge portion. [Figure 3C] FIG. 3C is a cross-sectional view taken along line CC of FIG. 3B. [Figure 4A] FIG. 1 is a plan view for explaining a problem with the conventional technology. [Figure 4B] FIG. 4B is a cross-sectional view taken along line DD of FIG. 4A. [Diagram 5] 1 is a graph showing the relationship between the maximum line speed (maximum LS) at which a metal sheet can be dried and the sheet thickness for each of an embodiment and a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals to avoid repetitive description. In addition, all of the figures shown in this embodiment are schematic diagrams, and the size and arrangement of each component shown in the figures may not match the actual size and arrangement of each component. Of course, the desired effects described above can be obtained by satisfying the requirements shown in this embodiment. A numerical range expressed using "~" means a range that includes the numerical values ​​before and after "~" as the lower and upper limits.

[0021] <1. Mechanism by which liquid remains on edges> As explained in the example of hot-rolled steel sheet, liquid adhering to a metal sheet may be removed by a pair of cutting rolls (e.g., a pair of wringer rolls). Note that the metal sheet in this case is often in the form of a strip. That is, the metal sheet to be treated by the pair of cutting rolls is often a metal strip.

[0022] However, as described above, it is often the case that liquid cannot be completely removed from the surface of the metal plate simply by passing the metal plate between the pair of draining rolls. Specifically, moisture remains at the edge portion (edge ​​portion in the width direction) of the surface of the metal plate. First, the mechanism by which liquid remains at the edge portion of the metal plate will be described with reference to Figs. 3A to 3B. Note that the surface of the metal plate in this embodiment is a pair of surfaces located at both ends of the metal plate in the thickness (plate thickness) direction. The surface of the metal plate has the largest area among all the surfaces constituting the metal plate.

[0023] 3A, liquid 10 adhering to the surface of a metal sheet 1 is removed by a pair of cutting rolls 2. The metal sheet 1 is transported in the X direction, and the pair of cutting rolls 2 has cutting rolls 2A and 2B. The metal sheet 1 is sandwiched between the cutting rolls 2A and 2B from above and below, thereby removing the liquid 10 adhering to the surface of the metal sheet 1.

[0024] Here, the draining rolls 2A and 2B are, for example, wringer rolls, and their roll parts are made of a flexible resin. Therefore, the roll parts of the draining rolls 2A and 2B can follow the shape of the metal sheet 1 to some extent. However, as shown in Figs. 3B to 3C, the draining rolls 2A and 2B cannot completely follow the shape of the metal sheet 1 at the side surface 1a in the width direction of the metal sheet 1. In Fig. 3B, the draining roll 2A is shown in a see-through manner to facilitate understanding. Therefore, a gap (sheet edge gap 4) with a substantially triangular cross section is formed between the side surface 1a of the metal sheet 1 and the draining roll pair 2. Then, the liquid 10 enters the sheet edge gap 4, and the liquid 10 that has entered the sheet edge gap 4 adheres to the edge portion 1b of the metal sheet 1 that has passed through the draining roll pair 2.

[0025] <2. Problems with the conventional technology> Conventionally, as shown in FIG. 4A and FIG. 4B, a gas nozzle 30 is installed at the rear of the drain roll pair 2 (the rear in the conveying direction of the metal sheet 1), and the gas nozzle 30 is used to remove moisture remaining at the edge portion 1b of the surface of the metal sheet 1. FIG. 4A is a plan view showing the arrangement of the gas nozzle 30 at one end of the width direction of the metal sheet 1. In FIG. 4A, the drain roll 2A is shown in a transparent manner. FIG. 4B is a DD cross-sectional view (cross-sectional view including the sheet edge gap 4) of FIG. 4A. The gas nozzles 30 are installed at positions facing both ends of the width direction of the metal sheet 1. In addition, the gas nozzles 30 are installed on the upper surface side and the lower surface side of the metal sheet 1. Therefore, a total of four gas nozzles 30 are installed. The gas nozzles 30 can inject gas from their gas outlets 31. In FIG. 4A and FIG. 4B, the gas 40 is shown by an arrow for convenience. Note that this arrow is a normal (more specifically, a normal vector) of the gas outlet 31. The gas 40 ejected from the gas outlet 31 flows in a normal direction to the gas outlet 31. Of course, the gas 40 may also flow in other directions.

[0026] Conventionally, the gas outlet 31 of the gas nozzle 30 faces the outside of the metal plate 1. Then, the gas 40 is sprayed from the gas outlet 31 of the gas nozzle 30 to the edge portion 1b of the metal plate 1, thereby blowing off the liquid 10 remaining on the edge portion 1b to the outside in the width direction of the metal plate 1. However, even if the liquid remaining on the edge portion 1b is removed using the gas nozzle 30, a large amount of moisture still remains on the edge portion 1b of the metal plate 1. Since the moisture remaining on the edge portion 1b of the metal plate 1 adheres to the edge portion 1b with an extremely strong surface tension, it is considered that even if the gas 40 is sprayed, a large amount of moisture remains without being blown off. In order to solve such a problem, the present inventor has earnestly studied an effective method of utilizing the gas sprayed from the gas nozzle 30. As a result, the inventor has come up with a liquid removing device that can solve the above-mentioned problem. Hereinafter, the liquid removing device according to this embodiment will be described in detail.

[0027] <3. Overall configuration of the liquid removal device> First, the overall configuration of a liquid removing apparatus 100 according to this embodiment will be described with reference to Figs. 1A and 1B. Fig. 1A is a side view showing the overall configuration of the liquid removing apparatus 100, and Fig. 1B is a plan view showing the arrangement of a gas nozzle 30 at one end of the metal plate 1 in the width direction. In Fig. 1B, a draining roll 2A is shown in a see-through manner. The liquid removing apparatus 100 is an apparatus for removing liquid 10 remaining on an edge portion 1b of the metal plate 1 that has passed through a draining roll pair 2, and is provided after the draining roll pair 2 (after the conveying direction (arrow X direction) of the metal plate 1). The liquid removing apparatus 100 includes a gas nozzle 30 provided after the draining roll pair 2, and a drying apparatus 50 provided further after the gas nozzle 30.

[0028] The type of metal sheet 1 to be treated by the liquid removing apparatus 100 is not particularly limited. For example, in addition to the above-mentioned hot-rolled steel sheet, it may be a zinc sheet, an aluminum sheet, or the like. The thickness of the metal sheet 1 is not particularly limited, but may be, for example, about 1.0 mm to 5.0 mm. The type of liquid 10 adhering to the metal sheet 1 is also not particularly limited. For example, it may be moisture (such as moisture that adheres to the hot-rolled steel sheet when the pickling solution adhering to the hot-rolled steel sheet is washed with water), or it may be an organic solvent, etc.

[0029] The draining roll pair 2 includes draining rolls 2A and 2B. The draining roll pair 2 removes the liquid 10 adhering to the surface of the metal sheet 1 by sandwiching the metal sheet 1 between the draining rolls 2A and 2B from above and below. The draining rolls 2A and 2B are, for example, wringer rolls, and their roll portions are made of a flexible resin. Of course, the draining rolls 2A and 2B are not limited to wringer rolls, and may be any rolls capable of removing the liquid 10 from the metal sheet 1.

[0030] Most of the liquid adhering to the metal sheet 1 is removed by the drain roll pair 2. However, even if the drain roll pair 2 is configured with a wringer roll pair that has high conformability to the shape of the metal sheet 1, a sheet edge gap 4 is formed. The liquid 10 enters this sheet edge gap 4, and the liquid 10 that has entered the sheet edge gap 4 adheres to the edge portion 1b of the metal sheet 1 that has passed through the drain roll pair 2. It is possible to reduce the sheet edge gap 4 to some extent by increasing the flexibility of the resin that constitutes the wringer roll pair, but it is difficult to completely eliminate it. Furthermore, if the flexibility of the resin is increased extremely, another problem may occur in that the durability of the wringer roll pair is reduced.

[0031] The gas nozzle 30 ejects the gas 40 from the gas outlet 31 to remove the liquid 10 remaining on the edge portion 1b. In Figs. 1A and 1B and Figs. 1C to 2C described later, the gas 40 is indicated by an arrow for the sake of convenience. Note that this arrow is a normal line (more specifically, a normal vector) to the gas outlet 31. The gas 40 ejected from the gas outlet 31 flows in the normal direction to the gas outlet 31. Of course, the gas 40 may also flow in other directions. Note that the normal line to the gas outlet 31 is a straight line parallel to the central axis of the gas nozzle 30.

[0032] The gas nozzles 30 are preferably provided at positions facing both ends in the width direction of the metal plate 1 (i.e., edge portions 1b). Furthermore, the gas nozzles 30 are preferably provided on both the upper surface (upper surface) side and the lower surface (lower surface) side of the metal plate 1. This makes it possible to more reliably remove the liquid remaining on the edge portions 1b of both the upper and lower surfaces. Of course, the arrangement of the gas nozzles 30 is not limited to the above example, and they may be arranged only on the upper surface side or only on the lower surface side. Furthermore, the gas nozzles 30 may be installed only at positions facing the edge portions 1b where the amount of remaining liquid 10 is particularly large. Details of the gas nozzles 30 will be described later.

[0033] The drying device 50 is provided after the gas nozzle 30. The drying device 50 is a device that removes the liquid 10 that has not been completely removed by the gas nozzle 30, and removes the liquid 10 adhering to the metal plate 1, for example, by blowing dry hot air onto the metal plate 1. In other words, the metal plate 1 is dried. The specific configuration of the drying device 50 is not particularly limited as long as it is a device that can be used to dry the metal plate 1. Furthermore, when the liquid 10 adhering to the metal plate 1 can be sufficiently removed by the gas nozzle 30, the drying device 50 may be omitted.

[0034] <4. Detailed configuration of the gas nozzle> Next, the detailed configuration of the gas nozzle 30 will be described with reference to Figs. 1A to 2C. Fig. 1C is a cross-sectional view taken along line AA in Fig. 1B (a cross-sectional view including the plate edge gap 4). In Fig. 1C, the gas nozzle 30 on the lower side is omitted. Fig. 2A is a plan view showing the arrangement of the gas nozzle 30 at one end in the width direction of the metal plate 1. In Fig. 2A, the liquid cutting roll 2A is shown in a transparent manner. Fig. 2B is a cross-sectional view taken along line BB in Fig. 2A (a cross-sectional view including the plate edge gap 4). Fig. 2C is a plan view showing another example of the arrangement of the gas nozzle 30. As described above, the gas nozzle 30 ejects gas 40 from the gas outlet 31 to remove the liquid 10 remaining on the edge portion 1b.

[0035] Specifically, the gas discharge port 31 has a shape elongated in the width direction of the metal plate 1. As shown in FIG. 1B and FIG. 1C, the gas 40 ejected from a part of the gas discharge port 31 (particularly the outer part of the gas discharge port 31) is sprayed to the plate edge gap 4. That is, the gas nozzle 30 sprays the gas 40 to the plate edge gap 4. This makes it possible to remove the liquid 10 that has entered the plate edge gap 4, so that the liquid 10 remaining in the edge portion 1b can be significantly reduced. In order to spray the gas 40 to the plate edge gap 4, for example, the gas nozzle 30 may be disposed so that the normal line of a part of the gas discharge port 31 reaches the plate edge gap 4 as shown in FIG. 1C. More specifically, the gas nozzle 30 may be disposed so that the angle θ1 between the normal line of the gas discharge port 31 of the gas nozzle 30 and the vertical direction of the surface of the metal plate 1 is 0 to 45°. The direction in which the gas nozzle 30 moves away from the metal plate 1 is the positive direction of θ1. Therefore, the gas nozzle 30 is inclined at an angle of 0 to 45° in the vertical direction toward the center point in the thickness direction of the metal plate 1. Here, the angle θ1 is 0° when the normal to the gas ejection port 31 and the surface of the metal plate 1 are parallel. When the angle θ1 is 0°, the gas nozzle 30 is disposed on approximately the same horizontal plane as the plate edge gap 4. Therefore, in this case, the gas nozzle 30 is disposed on the outer side in the width direction of the metal plate 1.

[0036] Incidentally, the metal plate 1 may move slightly in the width direction during transport, in which case the plate edge gap 4 also moves in the width direction. However, since the gas discharge port 31 has a long shape in the width direction of the metal plate 1, the gas discharge port 31 can follow the movement of the metal plate 1 in the width direction. In other words, even if the metal plate 1 moves in the width direction, some part of the gas discharge port 31 can blow the gas 40 into the plate edge gap 4. The specific width of the gas discharge port 31 (the length in the width direction of the metal plate 1) may be set according to the actual movement amount (or the expected movement amount) of the metal plate 1 in the width direction.

[0037] As shown in FIG. 2A to FIG. 2B, the gas 40 injected from the other part of the gas discharge port 31 flows from the edge part 1b of the surface of the metal sheet 1 toward the interface between the drain roll pair 2 and the surface of the metal sheet 1. In other words, the other part of the gas discharge port 31 blows the gas flowing toward the interface between the drain roll pair 2 and the surface of the metal sheet 1 onto the edge part 1b of the surface of the metal sheet 1. As described above, the liquid 10 that has entered the sheet edge gap 4 is removed by the gas 40 blown from the gas nozzle 30 into the sheet edge gap 4. Therefore, the liquid 10 remaining on the edge part 1b of the metal sheet 1 that has passed through the drain roll pair 2 can be significantly reduced. However, there are cases where the liquid 10 remains on the edge part 1b. In particular, the liquid 10 becomes more likely to remain on the edge part 1b as the line speed of the metal sheet 1 is increased. Therefore, the above-mentioned gas is blown onto the edge part 1b from the other part of the gas discharge port 31. As a result, the liquid 10 adhering to the edge portion 1b moves toward the interface between the pair of draining rolls 2 and the surface of the metal sheet 1, and then spreads along the interface in the form of a very thin liquid film toward the center point in the width direction of the metal sheet 1. Therefore, the liquid 10 remaining on the surface of the metal sheet 1 becomes very susceptible to drying. The liquid 10 may dry naturally before the metal sheet 1 reaches the drying device 50, or may dry quickly within the drying device 50.

[0038] In order to make the gas 40 flow toward the interface between the drain roll pair 2 and the surface of the metal sheet 1, the gas nozzle 30 may be arranged so that the angle θ2 (see FIG. 2C) between the normal line of the gas discharge port 31 of the gas nozzle 30 and the conveying direction of the metal sheet 1 (arrow X) in the horizontal direction is 0° or more and less than 90°. Here, θ2 is 0° when the normal line of the gas discharge port 31 of the gas nozzle 30 and the conveying direction of the metal sheet 1 are parallel. In the example of FIG. 2A, θ2=0°. FIG. 2C shows another example of the arrangement of the gas nozzle 30, and in this example, θ2 is larger than 0°. That is, in this embodiment, the gas nozzle 30 is inclined horizontally toward the center point of the width direction of the metal sheet 1 by 0° or more and less than 90°. The direction in which the normal line of the gas discharge port 31 faces the center point of the width direction of the metal sheet 1 is the positive direction of θ2. Therefore, the gas outlet 31 of the gas nozzle 30 is generally perpendicular to the conveying direction (θ2=0) or faces the inside of the metal plate 1 (0°<θ2<90°). In this embodiment, (a part of) the gas 40 is used to spread the liquid 10 remaining on the surface of the metal plate 1 over the surface of the metal plate 1. On the other hand, in the conventional technique, the gas outlet 31 of the gas nozzle 30 faces the outside of the metal plate 1. And, the gas 40 is used to blow the liquid 10 remaining on the surface of the metal plate 1 to the outside of the metal plate 1. It is presumed that the gas pressure required for the former is smaller than the gas pressure required for the latter. Therefore, in this embodiment, the liquid 10 can be removed from the surface of the metal plate 1 with a smaller gas pressure.

[0039] The distance from the gas nozzle 30 to the pair of drain rolls 2 (the distance from the contact point of the drain rolls 2A and 2B to the gas outlet 31 of the gas nozzle 30 in the side view of the liquid removing device 100) is not particularly limited. However, the higher the momentum (collision flow velocity) of the gas 40 when colliding with the liquid 10, the easier it is to remove the liquid 10. From this viewpoint, the distance from the gas nozzle 30 to the pair of drain rolls 2 may be, for example, 1000 mm (1 m) or less, or may be 500 mm or less. In addition, the lower limit is not particularly limited, but may be about 200 mm. In addition, the vertical distance from the gas nozzle 30 to the metal sheet 1 (the vertical distance from the surface of the metal sheet 1 to the lower end of the gas outlet 31 of the gas nozzle 30) is also not particularly limited, and may be, for example, about 30 to 100 mm.

[0040] As described above, according to this embodiment, the liquid 10 that has entered the sheet edge gap 4 can be removed by the gas 40 injected from a part of the gas ejection port 31. Furthermore, the liquid 10 remaining on the edge portion 1b of the metal sheet 1 can be spread over the surface of the metal sheet 1 by the gas 40 injected from another part of the gas ejection port 31. This makes it possible to more reliably remove moisture adhering to the metal sheet 1. The gas pressure of the gas 40 injected from the gas nozzle 30 can be adjusted during actual operation so that no liquid 10 remains.

[0041] The above-mentioned configuration of the gas nozzle 30 is merely an example, and other configurations are of course possible. That is, the gas nozzle 30 may be one that can remove at least the liquid that has entered the sheet edge gap 4. For example, in the above-mentioned example, the gas nozzle 30 sprays the gas 40 toward the sheet edge gap 4 as well as the interface between the drain roll pair 2 and the surface of the metal sheet 1. However, if the liquid at the edge portion 1b can be sufficiently removed by removing the liquid 10 that has entered the sheet edge gap 4, it is not necessary to spray the gas 40 toward the interface between the drain roll pair 2 and the surface of the metal sheet 1. In addition, the gas discharge port 31 has a shape that is elongated in the width direction of the metal sheet 1, but the gas nozzle 30 may have a plurality of gas discharge ports 31 arranged along the width direction of the metal sheet. In addition, the gas nozzle 30 may be movable along the width direction of the metal sheet. In this case, the gas nozzle 30 may be connected to an arbitrary driving device (for example, a motor, etc.). EXAMPLES

[0042] Next, an example of this embodiment will be described. In this example, the following tests were carried out to confirm the effects of this embodiment.

[0043] <1. Test conditions> In this test, a plurality of hot-rolled steel sheets having a thickness (sheet thickness) of 1.5 to 3.5 mm were prepared as the metal sheets 1. The width (sheet width) of the hot-rolled steel sheets was about 1200 mm. These hot-rolled steel sheets had been subjected to pickling and water rinsing in advance, and moisture was attached to the surfaces of the hot-rolled steel sheets.

[0044] A test apparatus including the above-mentioned drain roll pair 2 and gas nozzle 30 was prepared. A wringer roll pair was used as the drain roll pair 2. The gas nozzles 30 were installed at positions facing both ends of the metal plate 1 in the width direction, and further installed on the upper and lower sides of the metal plate 1. The distance from each gas nozzle 30 to the drain roll pair 2 was approximately 420 mm, and the vertical distance from each gas nozzle 30 to the metal plate 1 was approximately 50 mm. The back pressure of each gas nozzle 30 was approximately 0.3 MPa, and the gas sprayed from each gas nozzle 30 reached both the plate edge gap 4 and the interface between the drain roll pair 2 and the surface of the metal plate 1. The angle θ1 between the normal to the gas outlet 31 of the gas nozzle 30 and the surface of the metal plate 1 in the vertical direction was 20°, and the angle θ2 between the normal to the gas outlet 31 of the gas nozzle 30 and the horizontal conveying direction of the metal plate 1 was 0°.

[0045] Using such a test device, moisture was removed from the metal plate 1. Here, the thickness and line speed (LS) of the metal plate 1 were changed to remove moisture from the metal plate 1, and the surface of the metal plate 1 after the moisture removal was visually observed. The maximum LS (maximum LS) when moisture was not observed was recorded. Next, the test results were divided into plate thickness ranges of 1.5 mm or more and less than 2.0 mm, 2.0 mm or more and less than 2.5 mm, 2.5 mm or more and less than 3.0 mm, and 3.0 mm or more and less than 3.5 mm, and the arithmetic average value of the maximum LS was calculated for each range. The results are shown in FIG. 5 as an example. The horizontal axis of FIG. 5 indicates the plate thickness (mm), and the vertical axis indicates the arithmetic average value (mpm) of the maximum LS. Next, a test similar to the above example was performed except that the gas nozzle 30 was not used. The results are shown in FIG. 5 as a comparative example.

[0046] Comparing the Example and the Comparative Example, it is found that the Example can remove moisture at a higher LS. Therefore, the Example can more reliably remove moisture adhering to the metal plate 1.

[0047] Next, to verify the technology disclosed in Patent Document 1, a test similar to that of the above-mentioned embodiment was conducted except that the gas nozzle 30 was directed outward (i.e., the above-mentioned angle θ2 was set to -45°). As a result, the maximum LS for each plate thickness was higher than that of the comparative example, but lower than that of the embodiment. Therefore, it is found that the technology disclosed in Patent Document 1 cannot sufficiently remove moisture.

[0048] Although the preferred embodiment of the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not limited to such an example. It is clear that a person having ordinary knowledge in the technical field to which the present invention pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0049] 100 Liquid removal device 1 metal plate 2 Draining roll pair 2A, 2B Draining roll 1b Edge part 4 Plate edge gap 10 liquid 30 Gas Nozzle 31 Gas outlet 40 Gas 50 Drying equipment

Claims

1. A liquid removing device provided downstream of a pair of liquid removing rolls that removes liquid from a metal sheet to which liquid has adhered, A gas nozzle is provided for blowing gas into a plate edge gap formed between a side surface in a width direction of the metal plate and the pair of liquid cutting rolls, a gas discharge port of the gas nozzle faces inward in a width direction of the metal plate, and at least a portion of the gas discharge port is disposed at a position overlapping with the metal plate, the gas nozzle has a single gas discharge port, A liquid removing device, characterized in that a portion of the gas sprayed from the gas nozzle flows from an edge portion of the surface of the metal plate toward an interface between the pair of liquid cutting rolls and the surface of the metal plate.

2. 2. The liquid removal apparatus according to claim 1, wherein an angle between a normal to the gas outlet of the gas nozzle and the surface of the metal plate in the vertical direction is 0 to 45 degrees, with 0 degree being defined as an angle between the normal to the gas outlet of the gas nozzle and the surface of the metal plate being parallel to the surface of the metal plate.

3. 3. The liquid removing apparatus according to claim 1, wherein the gas ejection port of the gas nozzle is elongated in the width direction of the metal plate.

4. 4. The liquid removing apparatus according to claim 1, wherein the gas nozzle is movable along the width direction of the metal plate.

5. 5. The liquid removing apparatus according to claim 1, wherein the gas nozzles are provided at opposite ends in the width direction of the metal plate.

6. 6. The liquid removing apparatus according to claim 1, wherein the gas nozzles are provided only on the upper surface side, only on the lower surface side, or on both the upper surface side and the lower surface side of the metal plate.

7. 7. The liquid removing apparatus according to claim 1, further comprising a drying device provided downstream of said gas nozzle for drying said metal plate.

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