JPH08141632A - Method for cleaning surface of steel sheet and device therefor - Google Patents

Abstract

PURPOSE: To provide a cleaning method capable of fully removing scales from the surface of the steel sheet before hot rolling. CONSTITUTION: Water 42a, 46a is discharged from each of the nozzles 42, 46 of a descaler 40 at a discharge pressure of 100kg/cm<2> , flow rate of 60 liters/min and discharge angle of 20 deg. to the normal of the surface of the steel sheet, for example. Meantime, water 44a, 48a is discharged from each of the nozzles 44, 48 at the discharge pressure, flow rate and discharge angle as the nozzles 42, 46 with the discharge direction on the upstream side of the advancing direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel sheet surface cleaning method and a cleaning apparatus for cleaning a steel sheet surface, for example, a steel sheet surface preferably used for removing scale from the steel sheet surface before hot rolling. A method and a cleaning device.

[0002]

2. Description of the Related Art In the production of hot rolled steel sheet by hot rolling, a slab is usually charged in a heating furnace having an oxidizing atmosphere and heated in a temperature range of 1100 to 1400 ° C. for several hours. Repeated hot rolling a plurality of times with a rolling mill to obtain a predetermined thickness. A scale is generated on the surface of the slab by heating at a high temperature for several hours, but when the slab is hot-rolled again in a state where the scale is not sufficiently peeled off, the scale digs into the surface of the slab and remains as a scale flaw. If scale flaws remain, the surface quality will be significantly impaired, and it will become the starting point of cracks during bending, etc.
It has a serious adverse effect on product quality. Therefore, a method for preventing the generation of scale flaws on the slab surface (steel plate surface) has been conventionally proposed, for example, about 100 to 15
A water jet descaling device (hereinafter referred to as a descaler) that discharges water at a pressure of 0 kg / cm ² is arranged in a direction (width direction of the steel plate) substantially orthogonal to the conveying direction of the steel plate, and the descaler is applied to the surface of the steel plate. Discharge high pressure water,
A method of peeling and removing the scale formed on the surface of the steel sheet is known.

Usually, the above-mentioned descalers are arranged in a plurality of rows, and a plurality of nozzles are arranged in the longitudinal direction (width direction of the steel sheet) of the descalers in each row, and water is directed from each nozzle toward the surface of the steel sheet. Is ejected. In order to prevent the scale separated by the water discharged from each nozzle from entering the rolling mill on the downstream side of the steel sheet in the transport direction, water is discharged from the descalers in each row toward the upstream side in the transport direction.
However, the water discharged from the descaler arranged on the downstream side in the conveying direction toward the upstream side in the conveying direction flows on the steel plate surface to the collision area where the water discharged from the descaler on the upstream side in the conveying direction collides with the steel plate surface. Therefore, the water discharged from the descaler on the upstream side in the conveying direction does not directly collide with the steel plate surface, but once collides with the water discharged from the descaler on the downstream side in the conveying direction and flowing on the steel plate surface. As a result, the water discharged from the descaler on the downstream side in the transport direction serves as a cushion, and the impact force of the water discharged from the descaler on the upstream side in the transport direction on the surface of the steel plate is reduced, and there is a problem that sufficient descaling cannot be performed. is there.

Further, as shown in FIG. 8, water 14a is discharged from the cooling header 14 arranged on the upstream side of the steel plate 10 in the transport direction 12 toward the upstream side in the transport direction, and the downstream side in the transport direction 12 is discharged. The water 16a is discharged from the cooling header 16 arranged on the downstream side toward the downstream side in the transport direction, whereby the water 14a from the cooling header 14 arranged on the upstream side is discharged.
a from the cooling header 16 arranged on the downstream side by flowing a to the upstream side on the surface of the steel sheet as indicated by the arrow 14b.
A method has been proposed in which 6a is caused to flow downstream on the steel plate surface as indicated by arrow 16b, and the water discharged from the cooling headers 14 and 16 does not interfere with each other on the steel plate surface, so that the water directly collides with the steel plate surface. (See JP-A-59-502113).

[0005]

According to the method described in the above publication, the water discharged from each cooling header does not interfere with each other on the surface of the steel sheet, but from the plurality of nozzles arranged in one cooling header. Since water is sprayed from each nozzle in a spread manner, the water discharged from each nozzle interferes with each other on the surface of the steel sheet. The interference of cooling water on the surface of the steel sheet will be replaced with the case of descaling, and the state of this interference will be described with reference to FIG. FIG. 9 is a schematic view showing the state of this interference in a plan view.

When performing descaling, the arrow 1
Since it is necessary to collide water over the entire width direction of the steel plate 10 conveyed in the direction indicated by 2, the water discharged from the nozzles adjacent to each other arranged in one descaler (not shown) Water is discharged from each nozzle so that the collision regions 20 and 22 that collide with the steel plate surface 10a partially overlap. It is desirable that the partially overlapping region be as narrow as possible.
The width of the collision areas 20 and 22 changes due to the change in the nozzle distance, and the difference in the width of the collision area occurs due to the manufacturing error of the nozzle.
The nozzles are arranged so that an overlapping region of -10 mm is formed.

In the overlapping region, the water discharged from the nozzles adjacent to each other collide with each other to reduce the collision force, so that the scale cannot be removed sufficiently. In order to narrow the overlapping area, as shown in FIG. 10, the collision areas 24 and 26 of water discharged from the nozzles adjacent to each other are shifted so as to move back and forth with respect to the transport direction 12 of the steel plate 10,
A method is conceivable in which water is discharged from each nozzle toward the upstream side in the transport direction 12, for example. However, since the water discharged toward the upstream side in the transport direction 12 is jetted with a spread, the water in the collision region 24 spreads upstream in the transport direction 12 on the steel plate surface 10a, and a part thereof is discharged into the collision region 26. It becomes a cushion for water. As a result, in the area indicated by the arrow 28, the water discharged from the nozzle does not directly collide with the steel plate surface, and the scale in this area cannot be sufficiently removed.

In order to solve this problem, the nozzles are sufficiently separated from each other in the conveying direction so that the water discharged from each nozzle is
A method of removing the water discharged from other nozzles from the surface of the steel sheet before spreading to the collision area of the water can be considered. But,
In this method, a space is required to install the nozzles sufficiently apart in the carrying direction, and the temperature conditions of the steel plate surface where the water from each nozzle sufficiently separated in the carrying direction collides with each other are different. , Undesired problems such as different descaling conditions or descaling cooling conditions occur.

In view of the above circumstances, it is an object of the present invention to provide a method and apparatus for cleaning the surface of a steel sheet that can sufficiently remove scale from the surface of the steel sheet before hot rolling.

[0010]

A method for cleaning a surface of a steel sheet according to the present invention for achieving the above-mentioned object is to supply a liquid toward a surface of the steel sheet from a plurality of nozzles arranged in a direction intersecting a conveying direction of the steel sheet. In a method of cleaning a steel plate surface for discharging the steel plate surface, the liquid is discharged from nozzles adjacent to each other in the plurality of nozzles in the conveying direction upstream side and the conveying direction downstream side, respectively. Then, the liquid is collided with the surface of the steel plate to clean the surface of the steel plate.

Here, it is 5 ° with respect to the normal line to the surface of the steel sheet.
It is preferable to eject the liquid from the nozzle at an ejection angle within the range of 45 ° or less. The steel sheet surface cleaning apparatus of the present invention for achieving the above object is a steel sheet surface cleaning apparatus which cleans the steel sheet surface by discharging a liquid toward the surface of the steel sheet being conveyed in a predetermined conveying direction. (1) A supply pipe that extends in a direction intersecting with the transport direction and is supplied with the liquid (2) Along the longitudinal direction of the supply pipe, alternately in the state of being directed toward the transport direction upstream side and the transport direction downstream side. It is characterized by comprising a plurality of nozzles connected to the supply pipe and discharging the liquid supplied to the supply pipe toward the surface of the steel sheet being conveyed in the predetermined conveying direction.

Here, the plurality of nozzles have a central axis 141a extending in the longitudinal direction of the supply pipe 141 (141 ').
The plane 150 (150 ′) orthogonal to the pass line (170) from (141′a) and the nozzles 146 and 148.
(146 ', 148') injection direction axis 146c, 148
The intersection point X (X ') with c (146'c, 148c') is
It is preferable that the supply pipe 141 (141 ′) is arranged so as to be located closer to the steel plate 32 than the central axis 141a (141′a) extending in the longitudinal direction.

Further, among the plurality of nozzles, between adjacent nozzles 48, 148 connected to the supply pipe in a state of being directed to the upstream side in the conveying direction along the longitudinal direction of the supply pipe 41, 141. The tip 48a of this nozzle,
It is preferable to provide a guard plate located closer to the steel plate being conveyed in the above-mentioned conveying direction than 148a.

[0014]

In the method for cleaning the surface of a steel sheet according to the present invention, the liquid is discharged from the nozzles adjacent to each other in the directions away from each other on the upstream side and the downstream side in the transport direction of the steel sheet.
That is, one of the nozzles adjacent to each other ejects the liquid to the upstream side in the transport direction, and the other nozzle ejects the liquid to the downstream side in the transport direction. For this reason, the liquid discharged from the nozzles adjacent to each other flows and spreads in the direction away from each other on the steel sheet surface in the transport direction upstream side and the transport direction downstream side, and the liquid discharged from the other adjacent nozzles on the steel sheet surface. Does not reach the collision area. As a result, the liquid ejected from each nozzle directly collides with the steel plate surface, so that the steel plate surface can be sufficiently cleaned. Further, before the liquid discharged from each nozzle collides with the steel plate surface, the directions of discharging the liquid from the adjacent nozzles are separated from each other, so the liquids discharged from each nozzle do not interfere with each other, The collision force of is not reduced. Furthermore, in the method for cleaning the surface of the steel sheet according to the present invention, the nozzles are not sufficiently separated from each other in the transport direction, and the directions of the liquids to be ejected are alternately changed while the nozzles are adjacent to each other. There is no undesired problem in operation such that a wide space is required in the conveying direction for arranging the nozzles, and descaling conditions or cooling conditions due to descaling are different.

Here, when the liquid is discharged from the nozzle at a discharge angle of less than 5 ° with respect to the normal to the surface of the steel sheet, the flow of the liquid on the surface of the steel sheet may be in the direction opposite to the discharge direction. Further, the impact force exerted by the discharged liquid on the steel plate surface exceeds 45 ° with respect to the normal line of the steel plate surface because it is determined by the component of the flow velocity of the liquid colliding with the steel plate surface, which is perpendicular to the steel plate surface. When the liquid is ejected from the nozzle at the ejection angle, the impact force applied to the steel plate surface is weakened.
Therefore, it is preferable to discharge the liquid from the nozzle at a discharge angle within the range of 5 ° or more and 45 ° or less with respect to the normal line of the steel plate surface.

Further, in the apparatus for cleaning the surface of a steel sheet according to the present invention,
Since a plurality of nozzles are connected to the supply pipe in a state of alternately facing the transport direction upstream side and the transport direction downstream side along the longitudinal direction of the supply pipe, the liquid discharged from the nozzles adjacent to each other are respectively steel plates. On the surface, it flows and spreads in a direction away from each other on the upstream side and the downstream side in the transport direction,
The liquid discharged from the other adjacent nozzle does not flow to the collision area on the steel plate surface. As a result, the liquid ejected from each nozzle directly collides with the steel plate surface, so that the steel plate surface can be sufficiently cleaned. Further, before the liquid discharged from each nozzle collides with the surface of the steel sheet, the directions of discharging the liquid from the nozzles adjacent to each other are separated from each other, so the liquids discharged from each nozzle do not interfere with each other,
The impact force on the surface of the steel sheet does not decrease.

Here, in the plurality of nozzles, an intersection of a plane orthogonal to a pass line from a central axis extending in the longitudinal direction of the supply pipe and an ejection direction axis of the nozzle is defined in the longitudinal direction of the supply pipe. If it is arranged so as to be located on the side of this steel plate with respect to the extending central axis, so that the equipment and the nozzles arranged around the cleaning device do not interfere,
The distance between the nozzle and the steel plate and the discharge angle of the liquid can be maintained at predetermined values. As a result, not only can the space for the cleaning device be reduced, but also the space for the entire facility including the facilities arranged around the cleaning device can be reduced.

Further, among the plurality of nozzles, the tip of the nozzle is provided between adjacent nozzles connected to the supply pipe in a state of being directed to the upstream side in the transport direction along the longitudinal direction of the supply pipe. In the case where a guard plate located on the side of the steel plate being conveyed in the above-mentioned conveying direction is provided, even if a steel plate with a bad shape in which the tip or tail end is warped is conveyed, the tip or tail is Since the end portion contacts the guard plate and does not contact the nozzle, the nozzle can be prevented from being damaged by the steel plate. As a result, the frequency of nozzle replacement can be reduced, maintenance costs can be reduced, line stoppage due to nozzle damage can be prevented, and the economic efficiency of improving the facility operating rate can be improved.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, two scales (an example of a cleaning device according to the present invention) in which a plurality of nozzles are arranged in a direction substantially orthogonal to the steel sheet conveying direction are used to remove scale from the steel sheet surface before finish rolling. The case will be described. FIG. 1 is a schematic view showing a descaler discharging water from a nozzle from above the steel plate, and FIG. 2 is a schematic view showing the descaler shown in FIG. 1 from a side of the steel plate.

Descalers 40 and 50 are arranged above the steel plate 32 being conveyed in the direction indicated by the arrow 30. The descalers 40 and 50 include cooling headers 41 and 51, respectively.
, Four nozzles 42, 44, 46, 48 and 52, 54, 56, 58 are arranged in each. The descaler 50 is provided downstream of the descaler 50 in the transport direction.
A descaler 60 for stopping the water discharged from the tank is arranged, and the descaler 60 also has four nozzles 6
2, 64, 66 and 68 are arranged. Further, a rolling roll 70 that rolls the steel plate 32 is arranged downstream of the descaler 60 in the transport direction.

From the nozzles 42 and 46 of the descaler 40, a discharge pressure of 100 kg / cm ² , a flow rate of 60 liters / minute, a discharge angle of 20 ° with respect to the normal to the surface of the steel sheet, and water 42a toward the downstream side in the conveying direction. , 46a are discharged. On the other hand, from the nozzles 44 and 48, the nozzles 42 and 4
Water 44a, 48a with the same discharge pressure, flow rate and discharge angle as 6
Is discharged, but the discharge direction is on the upstream side in the transport direction.
That is, the water 42a, 44a, 46a, 48a is alternately discharged from the nozzles 42, 44, 46, 48 in the direction away from each other on the upstream side in the transport direction and the downstream side in the transport direction. The water 42a, 44a, 46a, 48a discharged from each nozzle 42, 44, 46, 48 collides with the surface 32a of the steel plate 32 in the collision areas 42b, 44b, 46b, 48b, and as a result, the adjacent nozzles 4
The water discharged from the nozzles 2, 44, 46, and 48 flows and spreads on the steel plate surface 32a in a direction away from each other on the transport direction upstream side and the transport direction downstream side, respectively, and is discharged from the other adjacent nozzle on the steel plate surface. No flow into the collision area at 32a. Therefore, since the water discharged from each nozzle directly collides with the steel plate surface 32a, the scale can be sufficiently removed from the steel plate surface 32a. Before the water discharged from the nozzles 42, 44, 46, 48 adjacent to each other collides with the steel plate surface 32a, the directions of the water discharged from the nozzles adjacent to each other are separated from each other. Do not interfere with each other, and the collision force on the steel plate surface does not decrease.

From the nozzles 54 and 58 of the descaler 50, water 54a and 58a are discharged under the same conditions as the nozzles 42 and 46, and the steel plate surface 32a in the collision areas 54b and 58b.
Is colliding with. On the other hand, water 52a, 56a is discharged from the nozzles 52, 56 under the same conditions as the nozzles 44, 48, and collides with the steel plate surface 32a in the collision areas 52b, 56b. Therefore, the same effect as in the case of the descaler 40 is produced.

Water 46a, 56 discharged from both the nozzle 46 of the descaler 40 and the nozzle 56 of the descaler 50
a collides with each other in the region 80 on the steel plate surface 32a and is blocked. Therefore, the water 46a discharged from the nozzle 46 does not spread to the collision area 56b, while the water 56a discharged from the nozzle 56 does not spread to the collision area 46b. The same applies to the water 42a discharged from the nozzle 42 and the water 52a discharged from the nozzle 52.

The water 54a and 58a discharged from the nozzles 54 and 58 of the descaler 50 spread and flow toward the downstream side of the steel plate surface 32a in the conveying direction, that is, toward the rolling roll 70. The water 54a, 58a contains foreign matter such as scale, and when the foreign matter flows into the rolling roll 70, the steel plate 32 may be flawed. Therefore, water 62 is discharged from the nozzles 62, 64, 66, 68 of the descaler 60.
a, 64a, 66a, 68a are discharged, and the steel plate surface 32a
The water flowing in the area is dammed in the area 90. This can prevent foreign matter from flowing into the rolling roll 70.

FIG. 3 is a schematic diagram showing a method of damming the water flowing on the steel plate surface 32a in the region 90 with a pair of rolls 100 instead of the nozzle 60 of FIG.
The same components as those of the above are denoted by the same reference numerals. The water that has flowed on the steel plate surface 32a can be blocked by the roll 100 as well, and foreign matter can be prevented from flowing into the rolling roll 70.

Next, the structure of the descaler 40 will be described. The descaler 50 has the same structure. FIG. 4 shows an example of the structure of the descaler 40, and FIG.
Another example of the structure of the descaler 40 is shown. As shown in FIG. 4, the descaler 40 includes a cooling header (an example of a supply pipe referred to in the present invention) 41 that extends in a direction intersecting the transport direction of the steel plate 32 (direction of arrow 30) to supply water. The cooling header 41 includes four nozzles 4 described above.
2, 44, 46 and 48 are connected (in FIG. 4, nozzles 46 and 48 are shown). In addition, the descaler 40 is
A cooling header 41 'is provided at a position facing the cooling header 41 with the steel plate 32 interposed therebetween, and four nozzles 42', 44 ', 46', 48 'are also connected to this cooling header 41' (Fig. 4 shows nozzles 46 'and 48'). Further, an apron 34 that prevents the tip of the steel plate 32 from being caught in a steel plate guide (not shown) is installed upstream of the cooling header 41 ′ in the steel plate transport direction (arrow 30 direction).

Each nozzle 42, 44, 46, 48 (4
2 ', 44', 46 ', 48') are cooling headers 41
The cooling header 41 (4) is placed in a state in which the cooling header 41 (4 ′) alternately faces the upstream side and the downstream side in the transport direction along the longitudinal direction.
1 '). Nozzles 46, 48 (46 ',
48 ') extending in the longitudinal direction of the central axes 46c, 48c (4
6'c and 48'c) intersect the central axis 41a (41'a) extending in the longitudinal direction of the cooling header 41 (41 '). The tip ends of the nozzles 46 and 48 are separated from the steel plate 32 by a distance H1, and the central axes 46c and 48c and the steel plate 32 are separated from each other.
The positions where and intersect are separated by a distance L1.

On the other hand, the descaler 140 shown in FIG.
The basic components are the same as those of the descaler 40, but the connection position of the nozzle and the length thereof are different from those of the descaler 40. As shown in FIG. 5, the descaler 140 includes a cooling header 141 that extends in a direction intersecting the conveying direction of the steel plate 32 (direction of arrow 30) and is supplied with water. Two nozzles 142, 144, 146, 148 are connected (in FIG. 5, nozzles 146, 148 are shown). Further, the descaler 140 has a cooling header 141 ′ at a position facing the cooling header 141 with the steel plate 32 interposed therebetween.
The cooling header 141 ′ is also connected to the four nozzles 142 ′, 144 ′, 146 ′, 148 ′ (in FIG. 5, the nozzles 146 ′, 148 ′ are shown). Further, the tip of the steel plate 32 is a steel plate guide (not shown).
An apron 134 that prevents the sheet from being caught in the sheet is installed on the upstream side of the cooling header 141 ′ in the steel plate conveying direction (direction of arrow 30).

Each nozzle 142, 144, 146, 148
(142 ′, 144 ′, 146 ′, 148 ′) are arranged in a state in which the cooling header 141 (141 ′) is alternately turned along the longitudinal direction of the cooling header 141 (141 ′) toward the upstream side and the downstream side in the transport direction. ') And the connection position is as follows. That is, the nozzles 146 and 148
(146 ', 148') injection direction axis 146c, 148
c (146'c, 148'c) is the cooling header 141
A central axis 141a (14 ') extending in the longitudinal direction of (141')
The point X intersecting with the plane 150 (150 ′) orthogonal (drooping) from 1′a) to the pass line (170) is the central axis 14
It is positioned closer to the steel plate 32 than 1a (141'a). Further, the tips of the nozzles 146 and 148 and the steel plate 32
Are separated from each other by a distance H2, and the central axis 146c,
The position where 148c and the steel plate 32 intersect is separated by a distance L2.

Comparing the descaler 40 shown in FIG. 4 with the descaler 140 shown in FIG. 5, although there is no difference in the basic constituent elements between them, as described above, the lengths of the nozzles and their connecting positions are different. . As a result, the nozzle 1
42, 144, 146, 148 (142 ', 144',
146 ', 148') the nozzles 42, 44, 4
The distance H1 and the distance H2 can be the same distance even if the distance is shorter than the length of 6,48 (42 ', 44', 46 ', 48'), and the distance L2 is about 0.8 times the distance L1. Can be shortened. Therefore, the descaler 140 shown in FIG. 5 can sufficiently prevent the interference between the equipment arranged around the descaler 140 and the nozzles, and can reduce the space of the descaler 140.
It is also possible to achieve a small space for the entire equipment arrangement including the equipment arranged around 0. Further, for maintenance of the descaler 140, the cooling header 141 is rotated around its central axis 141a and the nozzles 142, 14 are rotated.
The nozzles 142, 144, 146, and 146, 148 may also be rotated.
Since the turning radius of 148 can be shortened, interference with surrounding equipment can be sufficiently prevented. The nozzles 142, 144, 1
The turning radii of the nozzles 46, 148 are the same as those of the nozzles 42, 44, 46,
It is about 0.9 times the turning radius of 48. Furthermore, the distance L2
Since the apron 134 can be made longer than the apron 34 by the amount by which the apron can be shortened, the apron entrainment prevention function can be sufficiently achieved.

Next, the guard plate provided on the descaler 140 will be described. In addition, the descaler 15
0 also has a similar guard plate. FIG. 6 is a side view showing the guard plate, and FIG. 7 is a plan view showing the guard plate, showing a case where a large number of nozzles are connected to the cooling header. The guard plate 160 is a steel plate 3
2 prevents the nozzle 2 from coming into contact with or colliding with the nozzle, and its shape is a comb tooth shape. The guard part 162 of the guard plate 160 is provided between the nozzles 148 that are adjacent to each other and are connected to the cooling header 141 in a state of being directed toward the upstream side in the conveying direction of the steel plate 32 (arrow 30 direction).
It is installed so as to be located closer to the steel plate 32 than the tip 148 a of the 48.

For example, as shown in FIG. 6, when a poorly shaped steel plate having a warped tip portion 33 or a tail end portion (not shown) is conveyed, the steel sheet 32 is transferred to the guard portion 162 of the guard plate 160. Contact or collision between the steel plate 32 and the nozzle 148 is prevented until the steel plate 32 comes into contact with or collides with each other and is pinched by a pinch roll or the like installed on the downstream side of the descaler 140 in the steel plate conveyance direction. Therefore, the nozzle 148 can be prevented from being damaged by the steel plate 32, and the nozzle 14
Since the replacement frequency of No. 8 can be reduced, the maintenance cost can be reduced, and the line stop due to the damage of the nozzle 148 can be prevented, and the economic efficiency of improving the facility operation rate can be improved. In the above example, the guard plates having the guard portions 162 are installed in all of the nozzles 148 that are adjacent to each other. However, it is not necessary to install the guard plates in all the nozzles. You may arrange | position the guard part 162 every two. Further, preferably, as shown in FIGS. 6 and 7, the guard portion 162 is provided with the nozzle 148 (48).
It is positioned in a comb shape between them, and the nozzle central axis 148c (4
8c), the nozzle 148 (4
8), 146 (46) can be protected and liquid can be ejected from the nozzle. Further, the guard plate may be installed on a descaler as shown in FIG.

[0033]

As described above, according to the method for cleaning a steel sheet of the present invention, the liquid is discharged from one of the nozzles adjacent to each other to the upstream side in the transport direction, and the liquid is discharged from the other nozzle to the downstream side in the transport direction. In order to discharge the liquid, the liquid discharged from the nozzles adjacent to each other, respectively, flows and spreads in the direction away from each other on the steel sheet surface in the transport direction upstream side and the transport direction downstream side, of the liquid discharged from the other adjacent nozzle,
It does not flow into the collision area on the steel plate surface. As a result, the liquid ejected from each nozzle directly collides with the steel plate surface, so that the steel plate surface can be sufficiently cleaned.

Further, in the apparatus for cleaning the surface of a steel plate according to the present invention,
Since a plurality of nozzles are connected to the supply pipe in a state of alternately facing the transport direction upstream side and the transport direction downstream side along the longitudinal direction of the supply pipe, the liquid discharged from the nozzles adjacent to each other are respectively steel plates. On the surface, it flows and spreads in a direction away from each other on the upstream side and the downstream side in the transport direction,
The liquid discharged from the other adjacent nozzle does not flow to the collision area on the steel plate surface. As a result, the liquid ejected from each nozzle directly collides with the steel plate surface, so that the steel plate surface can be sufficiently cleaned.

[Brief description of drawings]

FIG. 1 is a schematic view showing a nozzle discharging water by a method for cleaning a steel sheet according to the present invention, as observed from above the steel sheet.

FIG. 2 is a schematic view showing the descaler of FIG. 1 as observed from the side of a steel plate.

FIG. 3 is a schematic diagram showing a state in which water flowing on the surface of a steel sheet is blocked by a roll.

FIG. 4 is a schematic diagram showing an example of the structure of a descaler.

5A and 5B show an example of a structure of a descaler, FIG. 5A is a schematic view, and FIG. 5B is a perspective view.

FIG. 6 is a side view showing a guard plate.

FIG. 7 is a plan view showing a guard plate.

FIG. 8 is a schematic view showing a nozzle discharging water by a conventional method as observed from the side of a steel plate.

FIG. 9 is a schematic diagram showing a state in which water discharged from adjacent nozzles interferes with each other.

FIG. 10 is a schematic view showing another state in which water discharged from adjacent nozzles interferes with each other.

[Explanation of symbols]

30 Steel plate conveying direction 32 Steel plate 32a Steel plate surface 40, 50 Descaler 41, 51 Cooling header 42, 44, 46, 48, 52, 54, 56, 58 Nozzle 42a, 44a, 46a, 48a, 52a, 54a, 5
6a, 58a water 42b, 44b, 46b, 48b, 52b, 54b, 5
6b, 58b Collision area 141a, 146c, 148c Central axis 160 Guard plate 162 Guard part

Front page continued (72) Inventor Naotoshi Aoyama 1 Kawasaki-cho, Chuo-ku, Chiba City Kawasaki Steel Co., Ltd. Steel Development & Production Division Chiba Steel Works (72) Inventor Akio Adachi Kawasaki-cho, Chuo-ku, Chiba City Kawasaki Steel Co., Ltd. Steel Development & Production Headquarters Chiba Steel Works (72) Inventor Hiroshi Kuwako 1 Kawasaki-cho, Chuo-ku, Chiba City Kawasaki Steel Co., Ltd. Steel Development & Production Division Chiba Steel Works (72) Inventor Kensei Sekine 1-Kawasaki-cho, Chuo-ku, Chiba City Kawasaki Steel Co., Ltd. Chiba Works, Steel Development & Production Division

Claims (5)

[Claims] 1. A method for cleaning a steel sheet surface, comprising: cleaning a steel sheet surface by discharging a liquid toward the steel sheet surface from a plurality of nozzles arranged in a direction intersecting a steel sheet conveying direction. Among the nozzles adjacent to each other, the liquid is ejected in a direction away from each other in the transport direction upstream side and the transport direction downstream side, and the steel sheet surface is cleaned by colliding the liquid with the liquid. The characteristic method of cleaning the steel plate surface. 2. An angle of 5 ° or more with respect to a normal line to the surface of the steel plate 4
The method for cleaning a surface of a steel sheet according to claim 1, wherein the liquid is discharged from the nozzle at a discharge angle within a range of 5 ° or less. 3. A steel sheet surface cleaning device for cleaning a steel sheet surface by discharging a liquid toward a surface of a steel sheet being conveyed in a predetermined conveying direction, the apparatus comprising: A supply pipe to which a liquid is supplied, and a supply pipe connected to the supply pipe in a state of alternately facing the upstream side and the downstream side in the transfer direction along the longitudinal direction of the supply pipe, and supplied to the supply pipe. A steel sheet surface cleaning device comprising: a plurality of nozzles for ejecting liquid toward the surface of the steel sheet being conveyed in the predetermined conveying direction. 4. The plurality of nozzles include a plane 150 (150 ′) orthogonal to a pass line (170) from a central axis 141a (141′a) extending in the longitudinal direction of the supply pipe 141 (141 ′). The nozzle 14
6, 148 (146 ', 148') injection direction axis 146
Intersection X with c, 148c (146'c, 148c ')
(X ′) is arranged so as to be located closer to the steel plate than the central shaft 141a (141′a) extending in the longitudinal direction of the supply pipe 141 (141 ′). The cleaning device for the steel plate surface according to claim 3. 5. The supply pipe 4 among the plurality of nozzles.
1, 141 is conveyed between the nozzles adjacent to each other connected to the supply pipe in the state of being directed to the upstream side in the conveying direction along the longitudinal direction, and is conveyed in the conveying direction rather than the tips 48a and 148a of the nozzles. The steel plate surface cleaning device according to claim 3 or 4, further comprising a guard plate located on the side of the steel plate.