JP2002233956A - Processing equipment for steel sheet and manufacturing method for steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent solid particles from remaining on the surface of a steel sheet, to provide a normal steel sheet, and to provide equipment to efficiently recover solid particles, and improve its yield. SOLUTION: A surface roughness imparting device 5 is provided with projecting machines 3a, 3b, 3c, and 3d to project solid particles against the surface and the back of the steel sheet, and a specified amount of solid particles is supplied from a solid particle supplying device 6. A steel sheet washing device 21, and a forced drying device 22 on the outgoing side are continuously situated on the side situated downstream from the surface roughness imparting device 5. A washing device 21 on the outgoing side employs a system to inject water against the steel sheet. The forced drying device 22 on the outgoing side is a device to dry the steel sheet by using hot air drier and vaporizes a moisture adhered to the steel on the washing device 21 on the outgoing side. Air wipers 24a and 24b to inject compressed air against the steel sheet and be capable of effecting air wiping are situated downstream from the forced drying device 22 on the outgoing side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a steel plate processing facility,
Particularly, in the continuous line, when fine particles are sprayed on a steel sheet to adjust the surface roughness, surface hardness, etc., the processing equipment for improving the cleanliness of the steel sheet, and the equipment for uniformly adjusting the surface properties of the steel sheet. Further, the present invention relates to a method for manufacturing a steel sheet using such equipment.

[0002]

2. Description of the Related Art In order to improve the press formability of cold rolled steel sheets or galvanized steel sheets and the sharpness after painting, it is important to appropriately control the surface roughness of steel sheets. For example, the average roughness Ra and the peak count PPI of the steel sheet are important factors for improving the oil retention between the steel plate and the die in press forming and preventing die galling. Also, in order to improve the sharpness after painting, it is necessary to reduce the undulation Wca representing the height of the long-period irregularities.

[0003] Generally, surface roughness is applied to cold-rolled steel sheets and galvanized steel sheets by temper rolling, and the roughness of the steel sheets is adjusted by transferring the surface roughness of the rolling rolls. The way to do it is taken. For example, in the production of a cold-rolled steel sheet, after passing through a hot rolling step, an pickling step, a cold rolling step, and an annealing step, temper rolling is performed to adjust the surface roughness and the like.

[0004] Note that annealing and temper rolling are usually performed continuously in a continuous annealing line, but after annealing, they may be processed by a batch type temper rolling mill. In the production of a hot-dip coated steel sheet, a temper rolling is performed after a hot rolling step, a pickling step, a cold rolling step, an annealing step, and a plating step to adjust the surface roughness and the like. Here, the annealing step, the plating step, and the temper rolling step are usually performed continuously in a hot-dip plating line, but the plated steel sheet may be processed by a batch-type temper rolling mill.

[0005] However, temper rolling is applied to steel sheets of 0.5 to
The original function is to adjust the mechanical properties such as removing the yield point elongation of the steel sheet caused by annealing by giving about 2.0% of plastic strain. Further, it is also necessary to apply a bending deformation to the rolling roll to correct the shape of the steel sheet to be flat, and a plurality of functions are required in a single process.

[0006] Therefore, even in the case where an appropriate surface roughness or the like is imparted to a steel sheet, there are certain restrictions, and it is difficult to freely control the surface roughness or the like. For example, in temper rolling, if it is desired to increase the average roughness of the steel sheet, it is possible to increase the transfer of roll roughness by increasing the rolling force, but increasing the rolling force is not This leads to an increase in the elongation rate of the product, which may result in an increase in the yield stress and a decrease in the elongation of the product, making it impossible to obtain the desired mechanical properties.

[0007] Further, since the pressure of the roll bite in the temper rolling is about several times the yield stress of the steel sheet, when the rolling roll and the steel sheet slide under such high surface pressure,
Wear of the rolling rolls occurs, and the surface roughness of the steel sheet changes with time. Therefore, with the steel plate manufactured by the initial rolling roll and the steel plate manufactured at the stage where the wear progresses,
Normally, the surface roughness greatly differs, and a steel sheet having a constant surface roughness cannot be obtained continuously.

To solve such a problem, Japanese Patent Application Laid-Open No. 3-294418 discloses a method of imparting surface roughness by directly projecting solid particles onto a steel sheet without using temper rolling. . This relates to a method for producing a cold-rolled steel sheet having excellent press formability and sharpness after coating, and a method of projecting solid particles having an average particle diameter of 30 to 100 μm onto the steel sheet to adjust the surface roughness. It is. Thereby, since the surface roughness of the steel sheet can be adjusted without using the temper rolling, there is an advantage that the surface roughness does not change with time.

On the other hand, a method of projecting solid particles on a galvanized steel sheet surface is disclosed in JP-A-59-6363. This is a method in which solid particles are projected onto a hot-dip coated steel sheet, and thereafter, pressurized water or compressed air is jetted to wash the plating film surface.

[0010] By the way, equipment for projecting solid particles onto a continuously conveyed steel sheet has been put into practical use in pickling equipment for the purpose of descaling a hot-rolled steel sheet. In particular, it is usually used for a stainless steel sheet manufacturing facility in which descaling by chemical treatment is difficult. In such shot blast equipment, grit having a particle diameter of about 300 μm to several mm and having an angular shape rather than a spherical shape is used as solid particles projected on a steel plate.

[0011] Such a manufacturing facility is disclosed in, for example, Japanese Patent Application Laid-Open No.
It is disclosed in 193018. However, since this is mainly for descaling, the higher the kinetic energy of the solid particles colliding with the steel sheet, the more effective, and the larger the particle diameter, the more advantageous. To remove the oxide layer, grit particles capable of enhancing the cleaning effect are used. In this respect, the projection technology is different from the technology described in JP-A-3-294418 and JP-A-59-6363, which are conventional techniques for adjusting the surface roughness of the cold-rolled steel sheet and the galvanized steel sheet. The size and shape of the particles to be used differ greatly.

[0012]

However, JP-A-3-294418 and JP-A-59-6363 disclose equipment for projecting fine particles onto a steel sheet.
No specific content is disclosed. Further, in the examples, although conditions for projecting solid particles on a laboratory-level cutting plate are described, equipment for continuously manufacturing wide coils required as ordinary steel products is described. Absent.

The technique described in Japanese Patent Application Laid-Open No. 9-193018 is aimed at descaling a steel sheet. Therefore, in order to obtain a large collision energy, large particles are suitable, and furthermore, oxidation is required. An angular shape is suitable in order to exert a cleaning action for removing the layer. With the use of grit that has an abrasive action,
The plating film of the plated steel sheet is damaged, and the film is peeled off, which causes a problem such that the anticorrosion effect of the original plating cannot be obtained.

[0014] In the shot blasting equipment arranged in such a pickling process, the solid particles normally projected on the steel plate fall to the lower part of the blast chamber by their own weight, are collected, circulated and reused. . Therefore, not only the collection of the projected solid particles, but also the circulation and classification equipment, etc., are intended for particles of such a size, and for the purpose of projecting fine particles to give appropriate surface roughness etc. However, it is not directly applicable.

In a conventional shot blasting apparatus, after projecting solid particles on a steel sheet, compressed air is injected to the steel sheet at a downstream position in the blast chamber to remove the particles remaining on the steel sheet, and the solid particles are ejected. It is usually removed. When the particle diameter is large as in a shot blasting device in a conventional pickling line, solid particles can be easily dropped by air purge, and the solid particles do not scatter over a wide range.

However, in the case of solid particles having an average particle diameter of less than 300 μm targeted by the equipment according to the present invention, when compressed air is injected to remove solid particles remaining on the steel sheet, Although the particles on the blast are easily scattered, they do not easily fall to the lower part of the blast chamber, but float for a long time in the flow of air. Such fine particles fall on the steel sheet again after floating in the air and accumulate, so it is difficult to effectively remove the fine particles on the steel sheet.

On the other hand, when air purging is not performed in the blast chamber after projecting the fine particles onto the steel sheet, and air purging is performed after the steel sheet exits the blast chamber, the fine particles remaining on the steel sheet are Since the particles are scattered more in the space, they are not deposited on the steel sheet again, but the fine particles scattered around adhere to each part of the production line. In particular,
The fine particles adhering to the transport roll cause scratches on the steel plate, and easily mix into lubricating oil of the machine parts and cause a failure of the machine parts. Further, when the fine particles are taken out of the system, the yield of the fine particles that should be originally used for circulation is reduced, and the production cost is increased.

Further, in the case where a measuring instrument or a surface defect meter for measuring the surface roughness of the steel sheet is arranged downstream of the surface roughness applying device,
There is also a problem that these measuring instruments malfunction due to the effect of the scattered fine particles or the fine particles remaining on the steel plate. A method of blasting a galvanized steel sheet using fine particles and then injecting pressurized water or compressed air is disclosed in JP-A-59-6363. It is only said that the fine particles can be easily removed, but does not consider the above problems.

When a conventional shot blasting equipment in a pickling line is applied as equipment for imparting surface roughness by projecting fine particles onto the surface of a steel sheet, there are the following problems. First, when the average particle diameter of the solid particles is less than 300 μm, the specific surface area per particle increases, and the surface activity increases. In particular, when the particle diameter is 100 μm or less, the expression “powder” is more intuitively matched than the expression “powder” rather than solid “particles”.

Therefore, when the solid particles contain moisture, the particles are easily aggregated and solidified. When projecting such agglomerated fine particles on a steel plate, large concave portions are locally generated, and it is impossible to obtain uniform surface roughness. In addition, the fine particles projected on the steel sheet need to be recycled, and the aggregated fine particles adhere to the piping of the fine particle circulating device, and the circulation efficiency is reduced. When the particle diameter is large, even if the solid particles are slightly wet, they do not easily agglomerate, and even if they are agglomerated, they can be easily separated by injecting compressed air. Once aggregated, it cannot be separated unless it is completely dried.

Second, as a problem when water or the like adheres to the steel plate, the following problems can be cited. Generally, in the production line of cold rolled steel sheets and galvanized steel sheets,
In some cases, a liquid such as water or a temper rolling liquid is sprayed onto the steel sheet in order to remove wear powder during temper rolling. When the projection device for fine particles is arranged in a continuous line, fine particles are projected with such a liquid remaining on the steel plate.
In this case, the liquid film on the steel plate reduces the collision speed of the solid particles, and it is difficult to provide effective surface roughness. In addition, if the liquid remains partially, the surface roughness differs from that of the dried portion, resulting in uneven appearance.

On the other hand, when the fine particles aggregate and adhere to the steel sheet, it is difficult to remove the fine particles by air purging or the like. For example, when fine particles are projected with water droplets remaining on a part of the steel plate, the fine particles adhere to the water droplets. When compressed air is sprayed on the steel sheet in this state, fine particles remaining in a dry portion other than the water droplet portion are blown up, and the falling fine particles may adhere to the water droplet portion, and more air purging is performed. Fine particles may adhere to the steel sheet.

Further, the fine particles adhering to the liquid remaining portion on the surface of the steel sheet are taken out of the blast chamber while being adhered to the steel sheet. Therefore, the yield of fine particles in the circulation device is significantly deteriorated, and the production cost is increased. (If the particle size is large, as in a conventional shot blasting device in a pickling line, solid particles can be easily dropped from the steel plate by injecting compressed air, and air purging is performed in the blast chamber. For example, solid particles fall into the system and such a problem does not occur.)

The present invention has been made in view of such circumstances, and is an apparatus for projecting fine solid particles on the surface of a continuously conveyed steel sheet, wherein the solid particles remain on the surface of the steel sheet. To provide a facility capable of efficiently collecting solid particles and improving the yield while obtaining a clean steel sheet, and when the solid particles are projected on the surface of the steel sheet, It is an object to provide a facility capable of obtaining a surface state, and to provide a method for manufacturing a steel sheet using such a facility.

[0025]

A first means for solving the above problems is a solid particle projection device for projecting solid particles having an average particle diameter of 300 μm or less on a surface of a continuously conveyed steel sheet; A steel plate processing facility (claim 1), comprising a steel plate cleaning device provided downstream thereof.

In this means, the size of the solid particles to be projected is limited to an average particle diameter of 300 μm or less. this is,
In order to impart functions such as surface roughness of cold-rolled steel sheets and galvanized steel sheets, the average roughness Ra is given a relatively large roughness of about 0.3 to 2 μm, and the pitch of the irregularities is reduced.
This is because it is desirable to provide fine irregularities. That is, if the average particle diameter exceeds 300 μm, it is not possible to obtain a fine surface roughness suitable for a cold-rolled steel sheet or a galvanized steel sheet. Further, when the size of the solid particles exceeds 300 μm, even if the solid particles adhere to the steel plate due to water droplets or the like remaining on the steel plate, the solid particles can be easily removed with an air wiper or the like. . That is, this means is to solve the problem peculiar to projecting the fine particles on the steel plate, and does not cover a particle having a particle diameter of more than 300 μm, such as a shot blasting device of a pickling line.

In the present means, as a method of projecting fine particles, a pneumatic projection device for injecting compressed air from a nozzle to accelerate solid particles, or a mechanical type for applying a centrifugal force to solid particles by rotation of an impeller and projecting them. A projection device can be used. In any case, it is assumed that a dry-type fine particle projector is used.

In the equipment according to the present invention, after the fine particles are projected on the surface of the steel sheet, the steel sheet exiting the blast chamber is passed through the cleaning device without spraying compressed air. As a result, the fine particles remaining on the steel sheet are blown up to the surroundings and fall on the steel sheet, and the fine particles scattered around do not adhere to the transport rolls and cause scratches on the steel sheet. There is no adverse effect. That is, the fine particles are washed away from the steel plate together with the cleaning liquid to clean the steel plate and not to scatter the fine particles around.

The cleaning device used here may be of such a type that the steel plate is washed with water, and may have a flow rate of such a degree that the fine particles on the steel plate are washed away. However, since the efficiency of removing fine particles is improved by injecting the pressurized water into the steel sheet, the pressure is 10 kgf / cm ^2.
It is sufficient to use the following pressure water. It is also effective to add a surfactant to the washing water to enhance the effect of washing out the fine particles.

Further, the fine particles washed out together with the cleaning liquid are accumulated in the cleaning liquid pit, so that only the fine particles can be captured by a filter or the like. After the fine particles thus captured are dried, they are resupplied to the hopper of the solid particle projection device again, and can be reused. Therefore, the fine particles taken out of the blast chamber can be reused, so that the yield of the fine particles can be greatly improved.

A second means for solving the above-mentioned problem is as follows:
The first means, wherein a forced drying device for a steel plate is disposed downstream of the cleaning device (claim 2).

In the present means, downstream of the cleaning device,
Since the apparatus for forcibly drying the steel sheet is provided, it is possible to increase the cleanliness of the steel sheet. That is, although most of the fine particles are removed from the steel plate cleaned by the cleaning device, a very small amount of fine particles may remain on the steel plate. In particular, a small crack may be generated at the end of the steel plate, and a minute amount of fine particles may be captured together with the cleaning liquid in such a portion. In this case, the fine particles cannot be easily removed because of the surface tension of the liquid, but the fine particles can be easily removed by once drying the steel sheet and evaporating the remaining liquid of the cleaning liquid.

It is sufficient that the forced drying device has an ability to evaporate the cleaning liquid remaining on the surface of the steel sheet during cleaning, and a hot air dryer or an electric heat dryer can be used. Therefore, the drying of the steel sheet and the air wiping described later can be performed simultaneously in the forced drying device.

A third means for solving the above-mentioned problem is as follows.
The second means, wherein an air wiping device for a steel plate is disposed downstream of the forced drying device (Claim 3).

In order to remove the fine particles after drying, it is sufficient to inject compressed air. Even in this case, only a very small amount of the fine particles remains, so that the floating of the fine particles as described above may occur. No problem. Therefore, it is sufficient to arrange an air nozzle as an air wiping device. Also, it is not necessary to inject compressed air over the entire surface of the steel sheet, and an air nozzle may be arranged around the plate edge of the steel sheet so that the air flow is directed from the plate center to the plate end.

A fourth means for solving the above problem is as follows.
The first means to the third means, wherein a forced drying device for a steel plate is disposed upstream of the solid particle projection device (Claim 4).

By forcibly drying the liquid film of the steel sheet remaining in the previous step and the like to evaporate the remaining liquid beforehand, the fine particles adhere to the steel sheet even if the fine particles are subsequently projected on the steel sheet surface. Does not occur. Therefore, the fine particles attached to the steel plate are taken out of the system and the yield is greatly deteriorated, and the collision speed of the fine particles is reduced due to the buffering action of a wet portion, so that appropriate surface roughness cannot be provided. Does not occur. In addition, since the fine particles themselves are circulated without containing moisture, no clogging of the fine particles occurs in the piping or the like.

A fifth means for solving the above problem is as follows.
The fourth means, wherein a cleaning device for the steel plate is arranged upstream of the forced drying device for the steel plate (Claim 5).

When fine particles are projected on a steel sheet to impart surface roughness or the like, if foreign matter such as abrasion is attached to the surface of the steel sheet, the surface roughness or the like cannot be imparted effectively. Therefore, the steel sheet can be cleaned before the projection of fine particles by washing in advance to remove foreign matter and the like remaining on the steel sheet and then drying the steel sheet. As a washing apparatus, a method of spraying water onto a steel sheet is economical, and a spray pressure of usually 10 kgf / cm ² or less is sufficient. However, in some cases, even higher pressure water is sprayed in order to remove foreign substances firmly attached to the steel sheet surface.

A sixth means for solving the above-mentioned problem is:
On the surface of a steel sheet that is continuously conveyed, a solid particle projection device that projects solid particles having an average particle diameter of 300 μm or less, and characterized by having a forced drying device for a steel plate disposed upstream thereof. This is a steel plate processing facility (claim 6).

The reason for projecting the solid particles having an average particle diameter of 300 μm or less is the same as the reason described in the first means, and the reason for providing the forced drying device before that is in the description of the fourth means. The reason is the same as stated.

A seventh means for solving the above-mentioned problem is as follows.
The sixth means, wherein a cleaning device for a steel plate is arranged upstream of the forced drying device (claim 7).

The reason for providing the cleaning device for the steel sheet on the upstream side of the forced drying device is the same as the reason described in the description of the fifth means.

Eighth means for solving the above-mentioned problem is:
Having a hot-dip plating line, on the downstream side of the cooling device or alloying furnace after the plating bath in the hot-dip plating line,
A steel plate processing facility in which an apparatus according to any one of the first to seventh means is disposed (claim 8).

In order to adjust the surface roughness and the like of a hot-dip coated steel sheet, it is more accurate to adjust the surface roughness and the like after plating than to adjust the surface roughness and the like of the steel sheet before plating. Can be adjusted. Therefore, by providing each equipment described in any one of the first means to the seventh means on the downstream side of the cooling device after the plating bath or the alloying furnace, the function of the solid particle injection device can be sufficiently achieved. And the effects of the first to seventh means can be obtained.

A ninth means for solving the above-mentioned problem is:
A steel plate processing facility (claim 9) having a continuous annealing line, wherein an apparatus is disposed downstream of an annealing furnace in the continuous annealing line.

In order to adjust the surface roughness and the like of the steel sheet in the continuous annealing line, it is more accurate to adjust the surface roughness and the like after the annealing furnace than to adjust the surface roughness and the like of the steel sheet before the annealing furnace. Roughness and the like can be adjusted. Therefore, the first
By providing each facility described in any one of the means to the seventh means on the downstream side of the annealing furnace, the function of the solid particle injection device can be fully utilized and the first equipment can be used. The effects of the seventh means can be obtained from the means.

In both the continuous annealing line and the hot-dip plating line, a temper rolling mill is often provided in the line. When a solid particle projection device for projecting fine particles is arranged in these continuous lines, it is desirable to adjust the mechanical properties in advance by temper rolling before imparting surface roughness and the like. At this time, in the temper rolling, by performing the temper rolling while supplying water, it is possible to remove abrasion powder of the steel sheet or the zinc film or abrasion powder of the rolling roll generated by the temper rolling. It is possible to prevent them from biting into each other and causing scratches. Further, by spraying water on the steel sheet in the temper rolling, the same effect as in the preceding cleaning device can be obtained, and there is no need to arrange independent cleaning equipment.

However, in temper rolling, dry temper rolling may be performed in order to stably provide an elongation rate. In particular, when a temper rolling mill is disposed in a continuous annealing facility for cold-rolled steel sheets, a dry-type temper rolling mill may be disposed. At this time, a steel plate cleaning device is arranged downstream of the temper rolling mill,
Further, on the downstream side, a forced drying device and a solid particle projection device are arranged. By this, foreign substances such as abrasion powder generated by temper rolling are removed in advance by a cleaning device, and then the remaining liquid is evaporated and dried, whereby surface roughness and the like can be effectively provided, and the appearance can be improved. No unevenness occurs on the top.

A tenth means for solving the above-mentioned problem is that a surface of a continuously conveyed steel sheet has an average particle diameter of 300 μm.
A method for producing a steel sheet, comprising a step of removing solid particles adhered or floating on the surface of the steel sheet after projecting the following solid particles (claim 10).

In this means, the first means, the second means
The operation and effect described in the means can be obtained.

An eleventh means for solving the above-mentioned problem is the tenth means, characterized by comprising a step of forcibly drying the surface of the steel sheet before projecting the solid particles on the steel sheet. (Claim 11).

In this means, the functions and effects described in the fourth means can be obtained.

A twelfth means for solving the above-mentioned problem is the eleventh means, characterized by comprising a step of cleaning the steel sheet before forcibly drying the surface of the steel sheet. Item 12).

According to this means, the functions and effects described in the fifth means can be obtained.

A thirteenth means for solving the above problems is a step of forcibly drying the surface of a continuously conveyed steel sheet, and thereafter, a step of projecting solid particles having an average particle diameter of 300 μm or less onto the steel sheet. It is a manufacturing method of a steel plate characterized by having (claim 13).

According to this means, the functions and effects described in the sixth means can be obtained.

A fourteenth means for solving the above-mentioned problem is the thirteenth means, wherein the steel sheet is washed before the steel sheet is forcibly dried.
4).

According to this means, the functions and effects described in the seventh means can be obtained.

[0060] A fifteenth means for solving the above-mentioned problems is to apply hot-dip plating to a steel sheet and cool and solidify the plated layer or after alloying the plated layer,
A method for producing a steel sheet, comprising performing the step described in any one of the zeroth means to the fourteenth means.
5).

In this means, the functions and effects described in the eighth means can be obtained.

A sixteenth means for solving the above-mentioned problems is that, after annealing a steel plate, the tenth means
A method for producing a steel sheet, wherein the step described in any one of the means is performed.

In this means, the functions and effects described in the ninth means can be obtained.

[0064]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Drawing 1 is a figure showing an example of a 1st embodiment of the present invention, and shows an equipment line for adjusting surface roughness by surface roughness giving device 5 while conveying steel plate 1 continuously. ing. As the steel sheet 1, a cold-rolled steel sheet or a galvanized steel sheet is usually used. In the case of a cold-rolled steel sheet, it is desirable that cold rolling, continuous annealing, and temper rolling be performed to adjust mechanical properties. When the surface roughness is to be imparted to the hot-dip coated steel sheet, a sheet that has been subjected to cold rolling, annealing, galvanization, and temper rolling is suitable.
However, it is also possible to pass through the main line before performing the temper rolling, impart surface roughness, and then perform the temper rolling. Further, the steel sheet 1 is not limited to a cold-rolled steel sheet or a galvanized steel sheet, but may be another surface-treated steel sheet.

In the equipment shown in FIG. 1, such a steel sheet is loaded on a payoff reel 30 and wound up by a tension reel 31. At this time, the steel sheet 1 is continuously conveyed in a state where tension is applied between the entrance bridle roll 11 and the exit bridle roll 13.

The surface roughness imparting device 5 comprises a blast chamber surrounded by a chamber and projectors 3a, 3b, 3c, 3d. Inside the blast chamber, there are projectors 3a, 3b, 3 for projecting solid particles on the front and back surfaces of the steel plate.
c and 3d are arranged, and a fixed amount of solid particles is supplied from the solid particle supply device 6. As the type of the projector, a pneumatic projector shown in FIG. 8 or a mechanical projector shown in FIG. 9 can be used.

In the case of a pneumatic projector, the solid particles 40 are stored in a hopper 41, and the air compressed by a compressor 43 is supplied to a blast nozzle 42. In the blast nozzle, the compressed air is accelerated, and at the same time, the solid particles 41 are entrained to accelerate the solid particles and are injected toward the steel plate.

On the other hand, in the case of a mechanical projector, the solid particles 40 are stored in a hopper 41, and an impeller 44 is rotated by a motor 45. The solid particles 40 are accelerated by the centrifugal force of the impeller and are projected toward the steel plate.

In the case of a pneumatic projector, the solid particles can be greatly accelerated even when the average particle size is small, but it is difficult to increase the projection area, and therefore, the width direction or longitudinal direction of the steel sheet is difficult. Need to arrange a plurality of blast nozzles. On the other hand, in the case of a mechanical projector,
Although energy efficiency is high and the projection area can be large, the speed of solid particles is smaller than that of a pneumatic projector. However, if the particle size of the solid particles is 30 μm or more,
Even with a mechanical projector, a sufficient projection speed for adjusting the surface roughness of a cold-rolled steel sheet or galvanized steel sheet can be obtained.

The projectors 3a, 3b, 3c, 3d shown in FIG.
Indicates a mechanical projector, and a solid particle supply device 6
Is sent to the impeller which is rotated by the motors 4a to 4d, accelerated by the projectors 3a to 3d, and projected onto the steel plate 1. With mechanical projectors,
By changing the rotation speed of the impeller or the supply amount of the solid particles sent from the supply device 6, the projection speed and the projection amount of the solid particles can be changed. Projector 3
It is necessary to arrange a plurality of a, 3b, 3c, and 3d such that the projection density in the width direction of the steel plate becomes constant.

FIG. 1 shows a mode in which two rows of projection nozzles are arranged on each of the front side and the back side. In the traveling direction of the steel sheet, the projection density on the steel sheet is constant according to the line speed. A single or a plurality are arranged so as to be in a range. However, the projection of the solid particles on the steel sheet does not necessarily have to be on the front and back surfaces, and may be on only one surface depending on the purpose.

Inside the surface roughness imparting device 5, the solid particles projected on the steel plate scatter and float around, but are sucked from the lower part of the blast chamber, sent again to the supply device 6, and used for circulation. Normally, the solid particle supply device 6 is provided with a separator, and zinc powder mixed with the solid particles and crushed and fine solid particles are separated and sent to the dust collector 8. This prevents the average particle size of the solid particles from changing over time and keeps the state of the solid particles constant.

On the other hand, in the blast chamber, fine particles floating without being sucked from the lower part are removed by the cleaner blower 7.
And collected by the dust collector 8. However, when the average particle size of the solid particles is as small as 300 μm or less, it is impossible to completely prevent the solid particles from being taken out of the blast chamber system together with the accompanying flow of the steel sheet continuously conveyed from the blast chamber. Can not.

Furthermore, in the present invention, in order to adjust the surface morphology of the galvanized steel sheet, a measuring device for the surface morphology is arranged downstream of the bridle roll 13, and based on the measurement result, the projection speed and the solid particle The projection amount may be changed. As a measuring device for the surface morphology, a measuring device for the average roughness Ra, or a peak count PPI, or a device for photographing the surface of a steel sheet with a CCD camera or the like and determining the size of indentations of the solid particles by image processing may be used. .

In the embodiment shown in FIG. 1, a steel plate cleaning device 21 and a discharge forced drying device 22 are continuously arranged downstream of the surface roughness imparting device 5. It is characterized in that fine particles remaining on the steel plate are not removed by air wiping or the like until 21.

Here, the outlet-side cleaning device 21 uses a system in which water is sprayed onto a steel plate. The flow rate may be sufficient to wash water and fine particles on the steel plate. However, spraying the pressurized water onto the steel plate improves the efficiency of removing fine particles.
It is sufficient to use pressure water having a pressure of 10 kgf / cm ² or less. It is also effective to add a surfactant to the washing water to enhance the effect of washing out the fine particles.

A waste liquid pit 26 is arranged below the outlet-side cleaning device 21, and solid particles are separated and collected by a fluid cyclone or the like. Since the solid particles thus collected contain moisture, they are supplied to the particle circulation system of the surface roughness imparting device 5 after drying the solid particles. Therefore, it is possible to solve the problem that the yield is deteriorated due to the solid particles being taken out of the blast chamber.

The outlet forced drying device 22 is a device for drying a steel sheet using a hot air dryer, and evaporates water adhering to the steel plate by the outlet cleaning device 21. However,
Since a large-capacity apparatus is required to remove all the water on the steel sheet as washed with the hot air dryer, compressed air is supplied between the outlet cleaning apparatus 21 and the outlet forced drying apparatus 22. It is desirable to arrange an air wiper capable of air wiping by spraying on a steel plate. As a result, most of the water can be removed from the steel plate, and the remaining water may be evaporated by the outlet forced drying device 22.

Further, air wipers 24a and 24b capable of performing air wiping for injecting compressed air to the steel plate are disposed downstream of the outlet forced drying device 22. This may be achieved by injecting compressed air over the entire surface of the steel plate, but it is sufficient to arrange an air nozzle around the plate edge so that the air flow is directed from the plate center to the plate end. is there. In particular, it is possible to easily remove a small amount of fine particles captured together with the cleaning liquid in a small crack portion seen at the end of the steel plate,
The cleanliness of the steel sheet is improved.

FIG. 2 is a view showing an example of the second embodiment of the present invention. A temper rolling mill 20 is disposed downstream of a plating bath 34 of a hot dip galvanizing line. Nozzles 25a and 25b for injecting water are arranged on the side, and an inlet forced drying device 27 is arranged downstream of the nozzles 25a and 25b, and a steel plate surface roughness imparting device 5 and an outlet cleaning device 21 are arranged further downstream thereof. . In the following drawings, the same components as those shown in the preceding drawings are denoted by the same reference numerals, and detailed description of the operation thereof may be omitted. The components denoted by the same reference numerals perform the same operation and have the same effect in each embodiment.

In the hot-dip galvanizing line, the cold-rolled steel sheet is charged into a pay-off reel 30, and the cleaning device
2, recrystallization annealing is performed in the annealing furnace 33. Then, after a galvanized film is formed in the plating bath 34, the film thickness is adjusted by the air wiper 35. Thereafter, when manufacturing an alloyed hot-dip galvanized steel sheet, the alloying furnace 36 is operated to perform an alloying process. However, a galvanized steel sheet in which a film produced without using this is mainly composed of an η layer is also produced on the same line.

In a normal hot-dip galvanizing line, after a temper rolling by a temper rolling mill 20 is performed, a chemical conversion film is applied by a chemical conversion treatment device 37, or a rust-preventive oil is applied and wound as it is. May be taken. On the other hand, FIG.
In the embodiment of the present invention, nozzles 25a and 25b for injecting water or a temper rolling solution are arranged on the inlet side of the temper rolling, and further, the surface roughness imparting device 5 is arranged downstream thereof, and further, the outlet side of the steel sheet The cleaning device 21 is arranged.

Here, the so-called wet pressure control, in which the temper rolling is performed while supplying water to the steel plate and the rolling rolls in the temper rolling, is performed. The water sprayed on the steel sheet has the effect of washing away foreign substances such as abrasion powder generated by temper rolling, but when solid particles are projected in that state, the solid particles remain on the steel sheet, so a large amount of solid particles The solid particles are taken out together with the steel plate, and the yield of solid particles deteriorates. Therefore,
It is desirable to arrange the entry-side forced drying device 27 on the upstream side of the surface roughness imparting device 5 to dry the steel plate in advance.

By the way, the steel sheet that has passed through the surface roughness imparting device 5 can pass through the exit side cleaning device 21 to wash away solid particles remaining on the steel sheet surface. These fine particles are collected in the waste liquid pit 26, and solid particles are separated by a fluid cyclone or the like. The solid particles collected in this manner are dried and re-supplied to the particle circulation system of the surface roughness imparting device 5, so that the yield does not deteriorate.

By arranging in the above-described equipment row, the plating step, the temper rolling for adjusting the mechanical properties of the material, and the surface roughness applying device 5 for imparting an appropriate surface roughness are arranged on the same line. Thus, the productivity can be significantly improved as compared with the batch-type surface roughness adjusting equipment shown in FIG.

FIG. 3 is a view showing an example of the third embodiment of the present invention. In the continuous annealing line, a temper rolling mill 20 is disposed downstream of an annealing furnace 33, and further downstream thereof. This is a facility row in which the surface roughness imparting device 5, the outlet cleaning device 21, and the outlet forced drying device 22 are continuously arranged on the side.

In the continuous annealing line, the cold-rolled steel sheet is charged into a pay-off reel 30, and recrystallization annealing is performed in an annealing furnace 33. In a normal continuous annealing line, after the temper rolling by the temper rolling mill 20 is performed, rust-preventive oil is applied and the tension reel 31 winds up. On the other hand, in the embodiment of FIG. 3, the surface roughness imparting device 5, the outlet cleaning device 21, and the outlet forced drying device 22 are disposed downstream of the temper rolling mill 20.

The temper rolling mills arranged in the ordinary continuous annealing line include dry pressure control performed in a dry process and wet pressure control in a wet condition. FIG. 3 shows the case of dry pressure control. In this case, foreign matter such as abrasion powder generated by the temper rolling remains on the steel sheet. Therefore, it is desirable to remove the foreign matter by air wiping or the like in advance.

By arranging them in the above-described equipment row, the annealing step, the temper rolling for adjusting the mechanical properties of the material, and the surface roughness imparting device 5 for imparting appropriate surface roughness are arranged on the same line. Thus, the productivity can be significantly improved as compared with the batch-type surface roughness adjusting equipment shown in FIG.

FIG. 4 is a diagram showing an example of the fourth embodiment of the present invention. FIG. 4 shows an equipment row for adjusting the surface roughness by the surface roughness imparting treatment 5 while continuously transporting the steel sheet 1. As the steel sheet 1, a cold-rolled steel sheet or a galvanized steel sheet is usually used.
It is desirable that temper rolling is performed after cold rolling and continuous annealing to adjust mechanical properties. In addition, when imparting surface roughness to a hot-dip galvanized steel sheet, a sheet that has been subjected to cold rolling, annealing, galvanizing, and temper rolling is suitable.
However, it is also possible to pass through the main line before performing the temper rolling, impart surface roughness, and then perform the temper rolling. Further, the steel sheet 1 is not limited to a cold-rolled steel sheet or a galvanized steel sheet, but may be another surface-treated steel sheet.

FIG. 1 shows a form in which such a steel sheet is loaded on a pay-off reel 30 and wound on a tension reel 31. At this time, the steel sheet is continuously conveyed in a state where tension is applied between the entrance side bridle roll 11 and the exit side bridle roll 13.

The surface roughness imparting treatment 5 comprises a blasting room surrounded by a chamber and projectors 3a, 3b, 3c, 3d. Inside the blast chamber, there are projectors 3a, 3b, 3 for projecting solid particles on the front and back surfaces of the steel plate.
c and 3d are arranged, and a fixed amount of solid particles is supplied from the solid particle supply device 6. As the type of the projector, the pneumatic projector shown in FIG. 8 or the mechanical projector shown in FIG. 9 as described above can be used.

The projector shown in FIG. 4 is a mechanical projector, and the solid particles supplied from the solid particle supply device 6 are sent to the impeller rotating by the motors 4a to 4d, and the projectors 3a to 3d. It is accelerated by 3d and projected on the steel plate 1. In the mechanical projector, the projection speed and the projection amount of the solid particles can be changed by changing the rotation speed of the impeller or the supply amount of the solid particles sent from the supply device 6. Also, the projectors 3a, 3b, 3c, 3d
It is necessary to arrange a plurality of steel sheets so that the projection density in the width direction of the steel sheet is constant. FIG. 4 shows a configuration in which two rows of projection nozzles are arranged on each of the front surface and the back surface. However, in the traveling direction of the steel sheet, the projection density on the steel sheet is within a certain range according to the line speed. Singly or plurally arranged. However, the projection of the solid particles on the steel sheet does not necessarily have to be on the front and back surfaces, and may be on only one surface depending on the purpose.

In the surface roughness imparting treatment 5, the solid particles projected on the steel plate scatter around and float, but are sucked from the lower part of the blast chamber, sent again to the supply device 6, and used for circulation. Normally, the solid particle supply device 6 is provided with a separator, and zinc powder mixed with the solid particles and crushed and fine solid particles are separated and sent to the dust collector 8. This prevents the average particle size of the solid particles from changing over time and keeps the state of the solid particles constant.
On the other hand, in the blast chamber, fine particles floating without being sucked from the lower part are captured by the cleaner blower 7 and processed by the dust collector 8.

Further, in the present invention, in order to adjust the surface morphology of the galvanized steel sheet, a measuring device for the surface morphology is arranged downstream of the bridle roll 13, and based on the measurement result, the projection speed and the solid particle The projection amount may be changed. As a measuring device for the surface morphology, a measuring device for the average roughness Ra, or a peak count PPI, or a device for photographing the surface of a steel sheet with a CCD camera or the like and determining the size of indentations of solid particles by image processing may be used. .

In the embodiment shown in FIG. 4, a steel sheet entry forced drying device 27 and an entry cleaning device 28 are continuously arranged upstream of the surface roughness imparting treatment 5. Payoff reel 3
The steel sheet charged in No. 0 is a steel sheet that has been subjected to temper rolling or the like in the previous step, and metal powder and a liquid residue of the temper rolling liquid remain on the surface. Even in this case, the entrance-side cleaning device 28
Thus, such foreign matter and liquid residue can be washed out, and the steel sheet is further dried by the entry-side forced drying device 27. Therefore, since the solid particles do not adhere firmly to the steel sheet that has passed through the surface roughness imparting treatment 5, the yield of the solid particles does not decrease, and erroneous detection may occur in the downstream surface morphology measuring instrument. Absent.

Here, the inlet-side cleaning device 28 uses a method of injecting water onto a steel plate, and is used by circulating. However, when the oil component is attached to the steel sheet 1, cleaning water containing a cleaning agent may be used. Further, when a large amount of fats and oils components such as rolling oil adhere to the steel sheet 1, an alkali degreasing equipment may be provided.

The entry-side forced drying device 27 is a device for drying a steel sheet using a warm air dryer, and the entry side cleaning device 28 evaporates moisture adhering to the steel plate. However, in order to remove all the water on the steel plate that has been washed with a hot-air dryer, a large-capacity device is required. Therefore, between the inlet-side cleaning device 28 and the inlet-side forced drying device 27, It is desirable to arrange an air wiper capable of air wiping injecting compressed air to a steel plate. As a result, most of the water can be removed from the steel plate, and the remaining water may be evaporated by the inlet forced drying device 28.

FIG. 5 is a view showing an example of the fifth embodiment of the present invention, in which a temper mill 20 is provided downstream of a plating bath 34 of a hot-dip galvanizing line, and an inlet and an outlet thereof. This is an equipment row in which nozzles 25a to 25d for injecting water are arranged, and an inlet forced drying device 27 and a surface roughness imparting treatment 5 are further arranged downstream thereof. In the hot-dip galvanizing line, the cold-rolled steel sheet is charged into a pay-off reel 30, passed through a cleaning device 32 on the entry side, and then subjected to recrystallization annealing in an annealing furnace 33. Then, after a galvanized film is formed in the plating bath 34, the film thickness is adjusted by the air wiper 35. Thereafter, when manufacturing an alloyed hot-dip galvanized steel sheet, the alloying furnace 36 is operated to perform an alloying process. However, a galvanized steel sheet in which a film produced without using this is mainly composed of an η layer is also produced on the same line.

In a normal hot-dip galvanizing line, after a temper rolling by a temper rolling mill 20 is performed, a chemical conversion film is applied by a chemical conversion treatment device 37, or a rust-preventive oil is applied and the product is wound as it is. May be taken. On the other hand, FIG.
In the embodiment of the present invention, nozzles 25a to 25d for spraying water or a temper rolling liquid are arranged on the inlet side and the outlet side of the temper rolling, and further on the downstream side thereof, an inlet forced drying device 27, a surface roughness imparting treatment. 5 is arranged.

Here, the so-called wet pressure control, in which the temper rolling is performed while supplying water to the steel plate and the rolling rolls in the temper rolling, is performed. The water sprayed on the steel plate has the effect of washing away foreign substances such as abrasion powder generated by temper rolling,
There is no need to arrange a separate cleaning device before passing through the surface roughness imparting treatment 5. Therefore, it is only necessary to dispose the inlet-side forced drying device 27 upstream of the surface roughness imparting treatment to evaporate the moisture adhering to the steel plate.

By arranging them in the above-described equipment row, the plating step, the temper rolling for adjusting the mechanical properties of the material, and the surface roughness applying treatment 5 for imparting appropriate surface roughness are performed on the same line. It is possible to significantly improve productivity as compared with the batch type surface roughness adjusting equipment shown in FIG.

FIG. 6 is a view showing an example of the sixth embodiment of the present invention. In the continuous annealing line, a temper rolling mill 20 is disposed downstream of an annealing furnace 33, and further downstream thereof. This is an equipment row in which an inlet-side cleaning device 28, an inlet-side forced drying device 27, and a surface roughness imparting treatment 5 are continuously arranged. In the continuous annealing line, the cold-rolled steel sheet is charged into a pay-off reel 30, and recrystallization annealing is performed in an annealing furnace 33.

In the ordinary continuous annealing line, the temper rolling mill 2
After the temper rolling by 0 is performed, the rust-preventive oil is applied and wound on the tension reel 31. On the other hand, in the embodiment of FIG. 6, on the downstream side of the temper rolling mill 20, the inlet-side cleaning device 28 and the inlet-side forced drying device 27,
Place.

The temper rolling mills arranged in the ordinary continuous annealing line include dry pressure control performed in a dry process and wet pressure control in a wet condition. FIG. 6 shows the case of dry pressure control. In this case, since foreign matters such as abrasion powder generated by the temper rolling remain on the steel sheet, it is desirable to wash the steel sheet in advance with the inlet-side cleaning device 28. Therefore, the forced drying device 22 for evaporating the moisture adhering to the steel sheet is disposed downstream thereof, and the surface roughness of the steel sheet is adjusted by the surface roughness imparting treatment 5.

By arranging them in the above-described equipment rows, the annealing step, the temper rolling for adjusting the mechanical properties of the material, and the surface roughness imparting treatment 5 for imparting appropriate surface roughness are performed on the same line. It is possible to significantly improve productivity as compared with the batch type surface roughness adjusting equipment shown in FIG.

FIG. 7 is a diagram showing an example of the seventh embodiment of the present invention. The steel sheet 1 unwound from the pay-off reel 30 passes through the bridle roll 11, and after its surface is cleaned by the entrance cleaning device 28, the entrance forced drying device 27.
As a result, the moisture remaining on the surface is removed by evaporation. Thereafter, the surface roughness is adjusted by projecting solid fine particles on the surface by the surface roughness imparting device 5. Thereafter, the exit side cleaning device 21 is used to wash away the solid fine particles remaining on the surface.

Further, the remaining moisture is removed by evaporation by the outlet drying device 22. Thereafter, the solid fine particles that have not been completely removed by the outlet cleaning device 21 are blown off by the air wiping nozzles 24a and 24b, and are removed from the surface of the steel sheet 1. The steel sheet 1 is then wound on a tension reel 31 after being inspected by an inspection table 23.

[0109]

(Embodiment 1) As an embodiment of the present invention, a sheet thickness of 0.
The equipment shown in Fig. 1 uses a hot-dip galvanized steel sheet whose base is a cold-rolled steel sheet with a thickness of 5 to 1.8 mm and a width of 750 to 1850 mm, with a 0.8% elongation rate applied by temper rolling. The result of adjusting the surface roughness will be described. The provision of the elongation rate in the temper rolling is for the purpose of material quality adjustment, and the temper rolling is performed using a bright roll. Further, in the present embodiment, a galvanized steel sheet in which a plating film mainly consists of an η phase is targeted.

The line speed of the equipment shown in FIG. 1 is up to 100 mpm
The operation was carried out. The solid particles used in the surface roughness imparting treatment 5 are fine stainless steel particles having an average particle diameter of 55 μm. As a projector, use a mechanical projector,
The impeller had a diameter of 330 mm and was projected onto a steel plate at a rotation speed of 3000 rpm. The projection density of solid particles is 2 kg / m per steel plate.
A galvanized steel sheet for automobiles having an average roughness Ra of 1.3 μm and a peak count PPI of 400 was produced.

In the outlet-side cleaning device 21, water was sprayed from a spray nozzle at a flow rate of 5 L / min onto a steel plate to perform cleaning. The outlet forced drying device 22 uses a hot air dryer to set the hot air temperature.
The operation was performed at 100 ° C and a hot air injection speed of 100 m / s. An air wiping nozzle is disposed downstream of the forced drying device 22.

As a result, most of the solid particles remaining on the steel plate from the surface roughness imparting treatment 5 and taken out of the blast chamber are washed away by the cleaning device, and are discharged from the outlet cleaning device 2.
In comparison with the case where No. 1 was not disposed, the basic unit, that is, the replenishment amount of solid particles was reduced by 30%. Also, the amount of fine particles adhering to peripheral mechanical parts has been greatly reduced, and the failure rate of the deflector roll bearing and the like has been greatly reduced.

(Example 2) As an example of the present invention, the
A hot-dip galvanized steel sheet with a base of a cold-rolled steel sheet with a thickness of 0.5 to 1.8 mm and a width of 750 to 1850 mm is used. The result of adjusting the roughness will be described. The provision of the elongation rate in the temper rolling is for the purpose of material quality adjustment, and the temper rolling is performed using a bright roll. Further, in the present embodiment, a galvanized steel sheet in which a plating film mainly consists of an η phase is targeted.

The line speed of the equipment shown in FIG.
The operation was carried out. The solid particles used in the surface roughness imparting treatment 5 are fine stainless steel particles having an average particle diameter of 55 μm. As a projector, use a mechanical projector,
The impeller had a diameter of 330 mm and was projected onto a steel plate at a rotation speed of 3000 rpm. The projection density of solid particles is 2 kg / m per steel plate.
With an average roughness Ra of 1.3 μm and a peak count PPI of 4.
No. 00 automotive galvanized steel sheet was manufactured.

In the inlet-side cleaning device 28, cleaning was performed by spraying water onto the steel plate at a flow rate of 10 L / min from the spray nozzle. The inlet forced drying device 27 uses a hot air dryer to
The operation was performed at 100 ° C and a hot air injection speed of 100 m / s. In addition, an air wiping nozzle was disposed between the entrance-side cleaning device 28 and the entrance-side forced drying device 27, and a system was used in which most of the cleaning water was removed and then dried.

As a result, the amount of solid particles remaining on the steel plate and taken out of the blast chamber from the surface roughness imparting treatment 5 is significantly reduced, and the inlet forced drying device 27 and the inlet cleaning device 28 are disposed. The unit consumption, that is, the replenishment amount of solid particles, was reduced by 60% compared to the case where no sample was provided. In addition, the remarkable effect of significantly reducing the amount of foreign matter mixed into the blast chamber and reducing the frequency of foreign matter that could not be separated by the separator from being projected from the projector and causing scratches on the steel plate by 35% is obtained. Was done.

(Embodiment 3) As an embodiment of the present invention, the plate thickness
A hot-dip galvanized steel sheet with a base of 0.5 to 1.8 mm and a width of 750 to 1850 mm was used as the base, and a temper-rolled steel sheet with an elongation of 0.8% was used. The result of adjusting the surface roughness will be described. The provision of the elongation rate in the temper rolling is for the purpose of material quality adjustment, and the temper rolling is performed using a bright roll. Further, in this embodiment, the plating film mainly has η
The target was a galvanized steel sheet consisting of phases.

In the equipment shown in FIG. 7, the operation was performed at a maximum line speed of 100 mpm. The solid particles used in the surface roughness imparting treatment 5 are fine stainless steel particles having an average particle diameter of 55 μm. A mechanical projector was used as the projector, and the diameter of the impeller was 330 mm and the rotation speed was 3600 rpm. The projection density of the solid particles was 5 kg / m onto the steel sheet to produce a galvanized steel sheet for automobiles having an average roughness Ra of 1.3 μm and a peak count PPI of 400.

In the inlet-side cleaning device 28, cleaning was performed by spraying water onto the steel plate at a flow rate of 10 L / min from the spray nozzle. The inlet forced drying device 27 uses a hot air dryer to
The operation was performed at 100 ° C and a hot air injection speed of 100 m / s. In addition, an air wiping nozzle was disposed between the entrance-side cleaning device 28 and the entrance-side forced drying device 27, and a system was used in which most of the cleaning water was removed and then dried.

In the outlet cleaning device 21 downstream of the surface roughness imparting treatment 5, water was sprayed onto the steel plate at a flow rate of 5 L / min from the spray nozzle to perform cleaning. The outlet forced drying device 22 was operated at a hot air temperature of 100 ° C. and a hot air injection speed of 100 m / s using a hot air dryer. Air wiping nozzles 24a and 24b are arranged downstream of the outlet forced drying device 22.

As a result, the amount of solid particles remaining on the steel plate from the surface roughness imparting treatment 5 and taken out of the blast chamber is greatly reduced, and the forced drying device 27 on the inlet side, the cleaning device 28 on the inlet side, The unit consumption, that is, the replenishment amount of the solid particles was reduced by 75% as compared with the case where the forced drying device 22 and the outlet cleaning device 21 were not provided. In addition, the remarkable effect of significantly reducing the amount of foreign matter mixed into the blast chamber and reducing the frequency of foreign matter that could not be separated by the separator from being projected from the projector and causing scratches on the steel plate by 35% is obtained. Was done.
Furthermore, the amount of fine particles adhering to peripheral mechanical parts has been greatly reduced, and the failure rate of the deflector roll bearing and the like has been greatly reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a second embodiment of the present invention.

FIG. 3 is a diagram showing an example of a third embodiment of the present invention.

FIG. 4 is a diagram showing an example of a fourth embodiment of the present invention.

FIG. 5 is a diagram showing an example of a fifth embodiment of the present invention.

FIG. 6 is a diagram illustrating an example of a seventh embodiment of the present invention.

FIG. 7 is a diagram showing an example of a seventh embodiment of the present invention.

FIG. 8 is a diagram showing an outline of a pneumatic projector.

FIG. 9 is a diagram showing an outline of a mechanical projector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Steel plate, 3a, 3b, 3c, 3d ... Projector of solid particles, 4a, 4b, 4c, 4d ... Motor, 5 ... Surface roughness imparting treatment, 6 ... Supply device of solid particles, 7 ... Cleaner blower, 8 … Dust collector, 10, 11, 13… bridle roll,
Reference Signs List 20: Temper rolling mill, 21: Discharge cleaning device, 22: Discharge forced drying device, 23: Inspection table, 24a, 24b: Air wiping nozzle, 25a, 25b: Water or temper rolling liquid spray nozzle, 26 ... waste pit, 27 ... forced drying device on entry side, 28 ... cleaning device on entry side, 30 ... pay-off reel, 31
... tension reel, 32 ... inlet side cleaning device, 33 ... annealing furnace, 34 ... plating bath, 35 ... air wiper, 36 ... alloying furnace, 40 ... solid particles, 41 ... hopper, 42 ... blast nozzle, 43 ... compressor, 44 … Impeller, 4
5 ... motor

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C21D 7/06 C21D 7/06 A (72) Inventor Yasuhiro Soya 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Within Nippon Kokan Co., Ltd. (72) Inventor Shogo Tomita 1-2-1, Marunouchi, Chiyoda-ku, Tokyo F-term within Nippon Kokan Co., Ltd. 4E002 AD06 BD09 BD10 CB03 4K027 AA02 AA05 AA22 AB42 AC52 AC73 AC86 AC87 4K043 AA01 EA04 HA01 HA02 HA04

Claims (16)

[Claims] 1. A solid particle projection device for projecting solid particles having an average particle diameter of 300 μm or less on a surface of a continuously conveyed steel plate, and a cleaning device for the steel plate provided downstream thereof. A steel sheet processing facility characterized by the following. 2. The steel sheet processing facility according to claim 1, wherein a forced drying apparatus for the steel sheet is disposed downstream of the cleaning device. 3. The steel sheet processing facility according to claim 2, wherein an air wiping apparatus for the steel sheet is disposed downstream of the forced drying device. 4. One of claims 1 to 3
Item 3. The steel sheet processing equipment according to Item 1, wherein a forced drying apparatus for the steel sheet is disposed upstream of the solid particle projection device. 5. The steel sheet processing equipment according to claim 4, wherein a cleaning apparatus for the steel sheet is disposed upstream of the forced drying apparatus for the steel sheet. 6. A solid particle projection device for projecting solid particles having an average particle diameter of 300 μm or less onto a surface of a continuously conveyed steel plate, and a forced drying device for the steel plate disposed upstream thereof. A steel plate processing facility, characterized in that: 7. The steel plate processing facility according to claim 6, wherein a cleaning apparatus for the steel sheet is disposed upstream of the forced drying device. 8. A hot-dip galvanizing line, wherein the hot-dip galvanizing line is provided downstream of a cooling device or an alloying furnace after a plating bath.
A steel plate processing facility, wherein the apparatus described in the above item is disposed. 9. A continuous annealing line, wherein the apparatus according to any one of claims 1 to 7 is arranged downstream of the annealing furnace in the continuous annealing line. Characteristic steel plate processing equipment. 10. A method comprising: projecting solid particles having an average particle diameter of 300 μm or less onto the surface of a continuously conveyed steel sheet, and removing solid particles adhering or floating on the surface of the steel sheet. Steel plate manufacturing method. 11. The method for producing a steel sheet according to claim 10, comprising a step of forcibly drying the surface of the steel sheet before projecting the solid particles on the steel sheet. 12. The method of manufacturing a steel sheet according to claim 11, further comprising a step of cleaning the steel sheet before forcibly drying the surface of the steel sheet. 13. A method for producing a steel sheet, comprising: forcibly drying the surface of a continuously conveyed steel sheet; and thereafter, projecting solid particles having an average particle diameter of 300 μm or less onto the steel sheet. . 14. The method for manufacturing a steel sheet according to claim 13, wherein the steel sheet is washed before forcibly drying the steel sheet. 15. The method according to any one of claims 10 to 14, wherein the steel sheet is subjected to hot-dip plating, and the plated layer is cooled and solidified, or after the plated layer is alloyed. A method for producing a steel sheet, comprising performing a process. 16. A method for manufacturing a steel sheet, comprising performing the process according to any one of claims 10 to 14 after annealing the steel sheet.