JPH05302190A - Method and equipment for cleaning dummy coil in continuous annealing line - Google Patents

Abstract

(57) [Summary] [Structure] When cleaning a dummy coil that is repeatedly passed through the continuous annealing line a number of times, the dummy coil is provided on the front and back sides of the dummy coil at the inlet side of a continuous annealing furnace for heat treatment of steel strip. A grinding process is performed so that the grinding amount is at least 5 μm and the total grinding amount on the front and back surfaces is at least 10 μm, and then a cleaning process for removing sludge generated by the grinding process is performed. [Effect] It is possible to reduce the deterioration of the product quality due to the dummy coil used in the continuous annealing line. Moreover, the life of the dummy coil can be further extended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning treatment method for dummy coils used in a continuous annealing line and equipment therefor, and in particular, a stainless steel strip obtained by cold rolling is passed through continuous annealing equipment. The purpose of the present invention is to avoid the deterioration of the quality of the product due to the dummy coil (made of stainless steel), which is noticeable during the processing, and to further extend the life of the dummy coil. Hereinafter, the continuous annealing of the stainless steel strip will be described as an example.

[0002]

2. Description of the Related Art A continuous annealing equipment for stainless steel strips is produced by an annealing furnace for maintaining the steel strip to be treated at a predetermined temperature (a direct-fired horizontal furnace is generally used) and this annealing furnace. No report has yet been made on the method of cleaning the dummy coil, which is composed of a pickling tank for the purpose of removing surface scale and is mainly used for joining steel strips in such an annealing line.

[0003]

The dummy coil described above is used not only to connect the steel strip that is previously conveyed and the steel strip that is subsequently conveyed, but also to the temperature of the annealing furnace. It is used to change the operating conditions such as when changing the acid concentration in the pickling tank, repairing the line, stopping the line when an operating trouble occurs, and preparing for operation. It was customary to repeatedly pass through the annealing line many times in order to suppress the cost increase.

The use of the dummy coil a plurality of times as described above firmly adheres the scale produced by annealing in the furnace in the atmosphere to the coil surface, and completely removes it even after passing through the pickling tank following the annealing furnace. Steel strip that passes through such rolls (steel strip to be the product) that passes through such rolls in order to stain various rolls of the annealing equipment or to attach scale debris to pinch rolls or skin pass rolls. Contamination on the surface was unavoidable and was a cause of increasing surface scratches.

For this reason, normally, the dummy coil, which has been passed through the annealing line 5 to 6 times, must be discarded, resulting in an increase in the cost involved and an increase in the frequency of replacement of various rolls arranged in the equipment. There was a tendency to do so, and there was a need for a solution.

With respect to this point, the inventors examined the effectiveness of descaling the dummy coil on the outlet side of the annealing furnace (see Japanese Patent Laid-Open No. 3-158483). Although the processing shows some improvement,
The effect is not satisfactory enough.

An object of the present invention is to propose a method and equipment for preventing deterioration of product quality due to a dummy coil which is repeatedly used many times and further extending the life of the coil.

[0008]

DISCLOSURE OF THE INVENTION In cleaning a dummy coil which is repeatedly passed through a continuous annealing line a plurality of times, the present invention provides a dummy coil at the inlet side of a continuous annealing furnace for heat treatment of steel strip. The continuous annealing is characterized in that the front and back surfaces are subjected to a grinding treatment such that the grinding amount is at least 5 μm and the total grinding amount on the front and back surfaces is at least 10 μm, and then a cleaning treatment for removing sludge generated in the grinding treatment is performed. A method for cleaning a dummy coil used in a line (first invention).

Further, according to the present invention, a grinding device for grinding the front and back surfaces of a dummy coil is provided on the inlet side of an annealing furnace for heat treatment of a steel strip, and a cleaning device for removing sludge generated by the grinding process by this device. Equipment for cleaning the dummy coil used in the continuous annealing line, where
Invention).

[0010]

The dummy coil used for connecting the steel strips to each other is passed through the annealing furnace, the pickling tank, etc., and then wound around the outlet reel via each outlet facility. Then, the wound dummy coil is then transferred to the inlet side reel of the annealing equipment, and unwound into the annealing line again from here. Here, the technique related to the treatment of the dummy coil on the outlet side of the annealing furnace is effective in removing the scale generated in the annealing furnace, as proposed in Japanese Patent Laid-Open No. 3-158483, While passing through various rolls, wipers, etc. of the downstream equipment, a small amount of stains adhered to them adhere to the dummy coil, and such stains cause the scale generation of the dummy coil in the annealing furnace. It became clear that it would be the starting point. That is, the dirt on the surface of the dummy coil that has already adhered before entering the annealing furnace becomes the center of heat absorption in the annealing furnace, the temperature rises from the clean area, and the scale generation is excessive in the high temperature area. Therefore, this scale remains even after pickling, which causes contamination of various rolls and scratches on the surface of the steel strip as a product.

According to the present invention, before the dummy coil is introduced into the continuous annealing line, a grinding process for removing scale and other deposits adhered to the front and back surfaces of the dummy coil is performed on the inlet side of the annealing furnace. The cleaning process for removing the sludge generated by this grinding process is carried out. According to this, since all the contaminants adhering to the dummy coil can be removed, the scale of the scale in the annealing furnace can be removed. Excessive generation is effectively suppressed, and stains and scale adhesion to various rolls in the annealing equipment are extremely reduced.

In the present invention, it is essential that the dummy coil is ground on the inlet side of the annealing furnace, and subsequently, the cleaning process is performed. The reason is that the grinding process alone is not enough to remove sludge from grinding. Remains on the dummy coil and becomes a nucleus of excessive scale generation during the annealing process, so that the effect is reduced.On the other hand, only the cleaning process cannot remove all the scale and the like adhering to the dummy coil surface. , Because this alone cannot be expected to have a sufficient effect.

As shown in FIG. 2, the grinding amount in the grinding process is at least 5 μm on each of the front and back surfaces of the dummy coil,
Grinding with a total amount of at least 10 μm on both sides is advantageous from the viewpoint of extending the life, and any means such as a belt grinder or an elastic grindstone can be applied as a means for this. Regarding the cleaning means, if sludge generated by grinding can be removed, the method is not particularly limited, and brush cleaning with a nylon brush or the like is advantageously applicable.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the structure of equipment according to the present invention. In the figure, 1 is a dummy coil made of stainless steel, 2 is a grinding device for grinding the front and back surfaces of the dummy coil 1, and Is an endless belt (made of cloth, etc.) 2a, 2b wound around a roller r and driven by the dummy coil 1
In the example, one set is arranged for each of the front and back surfaces, and the grinding process is performed with the grindstones attached to the surfaces of the belts 2a and 2b. 3 is a dummy coil after grinding 1
This is a cleaning device for performing a cleaning process on a nylon brush 3a and a nylon brush 3a which are driven to rotate under the combined use of a cleaning liquid (sodium orthosilicate solution, etc.). The rinse 3b is used to remove sludge generated by the grinding process.

A grinding device 2 having belts 2a and 2b to which # 80 grindstones are attached and a cleaning device 3 using a 2% sodium orthosilicate solution as a cleaning liquid are provided as shown in FIG. Apply the equipment, at the entrance side of the annealing furnace,
The surface of the stainless dummy coil was ground by 10 μm each, and the total grinding amount on the front and back was 20 μm. Then, it was washed by the nylon brush 3a with a 2% sodium orthosilicate solution, and then rinsed. 3b
After washing with water (drying after washing is not necessary), the annealing furnace (temperature of 1150 ° C, atmospheric atmosphere) and passing through the pickling tank are repeated several times to investigate the usage limit. did. As a result, conventionally, it had to be discarded after repeated use of about 6 times, but the limit of use when treated according to the present invention was about 16 times, and it was confirmed that the life of the dummy coil is extended by about 2.7 times. Was given. Further, the replacement period of rolls and the like arranged in the continuous annealing line could be extended to about twice that of the conventional one.

[0016]

According to the present invention, since a dummy coil used for connecting steel strips in a continuous annealing line can be introduced into the annealing line without adhesion of scales and stains, the inside of the annealing furnace In this case, excessive generation of scale is suppressed, and as a result, quality deterioration of the strip product due to the dummy coil can be reduced. Also, the dummy coil can have a very long life.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of equipment according to the present invention.

FIG. 2 is a graph showing the relationship between the life of a dummy coil and the grinding amount (total amount of front and back surfaces).

[Explanation of symbols]

 1 Dummy coil 2 Grinding device 2a Belt 2b Belt 3 Cleaning device 3a Nylon brush 3b Rinse

Claims (2)

[Claims] 1. When cleaning a dummy coil, which is repeatedly passed through a continuous annealing line a plurality of times, at the entrance of a continuous annealing furnace for heat treatment of steel strip, the grinding amount is applied to each of the front and back surfaces of the dummy coil. Cleaning of a dummy coil used in a continuous annealing line, characterized by performing a grinding treatment for at least 5 μm and a total grinding amount on the front and back sides of at least 10 μm, and then performing a cleaning treatment for removing sludge generated by the grinding treatment. Processing method. 2. A grinding device that grinds the front and back surfaces of a dummy coil and a cleaning device that removes sludge generated by the grinding process are disposed on the inlet side of a continuous annealing furnace used for heat treatment of steel strip. Equipment for cleaning the dummy coil used in the continuous annealing line.