JPS5919523Y2 - Smudge prevention device for cold rolled steel sheets - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for preventing the occurrence of smudges on the surface of a steel plate when an electrolysis cleaning line is omitted in the manufacturing process of cold rolled steel plates.

A cold-rolled steel sheet is normally processed into a hot-rolled coil a to a cold-rolled coil b through a manufacturing process as shown in FIG.

In the cold rolling process, rolling oil is used for lubrication and cooling, but the rolling oil adhering to the steel plate decomposes in the high-temperature atmosphere of the annealing process and remains as smudge (stain) in the form of carbides.

This smear must be removed because it deteriorates the appearance of the product and the adhesion of the plating, and is generally removed by brushing with an alkaline cleaning solution and electrolysis before the annealing process.
The steel sheet is passed through a cleaning line to remove rolling oil from the surface of the steel sheet.

However, the cleaning process is relatively costly;
In the normal cold rolling process, only those materials that require strict surface quality are passed through a cleaning line, and other materials are sent directly to the annealing line, omitting the cleaning line.

Therefore, steel plates that are directly delivered are accompanied by the occurrence of smudges, leaving problems in terms of surface quality.

An object of the present invention is to provide a device that effectively prevents the occurrence of smudges on steel plates without the need for a cleaning line, and to address the conventional problems in terms of surface quality.

The main focus of the present invention is to apply hot water or detergent liquid (hereinafter referred to as cleaning liquid) to the surface of the steel sheet after cold rolling.

) is sprayed to clean the surface, and then these liquids are removed from the steel plate surface to perform cleaning similar to an electrolytic cleaning line. In order to perform particularly effective cleaning, It is distinctive in that it has a special angle to the injection nozzle and is installed in several stages in each block.

The injection nozzle in this invention is usually about 100 to 150k
The cleaning liquid is injected at an injection pressure of g/an□, and the arrangement is as shown in FIG. 2, in which nozzle headers 11 are arranged at equal intervals in multiple stages (three stages in the example shown). ,
Each nozzle header 11 is provided with a nozzle group consisting of a plurality of nozzles 12 that can partially cover only a certain range in the board width direction.

The installation range of this nozzle group is a fraction of the width of the steel plate S, and is provided with the same installation length in any nozzle header 11, but as you go from the upstream header to the downstream direction, The nozzle headers 11 are arranged at slightly shifted positions, and only when all the nozzle headers 11 are combined can spraying over the entire width of the board.

For example, the nozzle group in the most upstream nozzle header 11 is provided at a position closer to the left (lower side in the drawing), the nozzle group in the most downstream nozzle header 11 is provided at a position closer to the right (upper side in the drawing), and the header group between them is In this case, the position ranges of the nozzle groups are sequentially and regularly shifted by a predetermined pitch P.

Originally, the nozzle 12 provided in each header is provided with an inclination of about 45° in the vertical direction toward the plate direction, but in this device, the nozzle 12 is also provided with an inclination of a predetermined angle α in the horizontal direction. Provide corners.

This inclination angle α is optimally about 45°, and is made to match the direction in which the nozzle group shifts from upstream to downstream.

The installation interval of the nozzle headers 11 and the positional shift pitch P of the nozzle group are preferably determined according to the line speed and injection pressure of the steel plate.

When using the apparatus of the present invention, for example, as shown in FIG. 3, a cleaning liquid injection nozzle 1 having the above-mentioned configuration is installed on the upstream side to spray and clean the steel plate surface, and an air injection nozzle 2 is installed on the downstream side. Install at opposite angles to blow hot air or hot air to dry the steel plate surface.

A cleaning unit (D) that is removed from these nozzle groups is installed in combination with the final stand Cn of a cold rolling tandem mill C, as shown in FIG. 3, for example.

That is, the cleaning liquid injection nozzle 1 is arranged on the entrance side of the final stand Cn, and the air injection nozzle 2 is arranged on the exit side.

In this case, in mills other than the final stand, rolling oil is injected at the entrance and exit sides of the stand, and the final stand Cn
In this case, rolling is performed using cleaning fluid without injecting rolling oil.

The above-mentioned embodiment is an example of the combined positional relationship between the cold rolling mill and the cleaning unit, and in the present invention, other installation configurations other than those shown in FIG. 3, such as the cleaning unit on the exit side of the final stand Cn)-D It is also possible to install them all at once.

The basic test results of steel plates treated with this equipment show that good cleaning results were obtained using diluted cleaning fluid, and the results of rolling the final stand with cleaning fluid showed that rolling oil was not effective at the rolling load. Almost no difference was observed compared to the case.

Furthermore, there were no practical problems with regard to rust prevention, annealing, and workability.

According to the present invention, the cleaning effect is significantly enhanced by the effect of the nozzle arrangement, so it is possible to sufficiently prevent the occurrence of smudges on steel plates that do not require a cleaning process, and it is possible to significantly improve the surface quality of steel plates that are directly sent to the annealing process. Along with, conventionally,
It has become possible to omit the cleaning line even for types of steel sheets that cannot be omitted, and it has become possible to reduce the conventional cleanliness ratio of 50% to about 35% of the production volume of cold-rolled steel sheets.

Further, since the sprayed cleaning liquid automatically flows down to the outside of the cleaning surface due to the effect of the nozzle arrangement, there is no need to provide a squeezing roll, and therefore it is extremely effective as a spraying means installed in a narrow area.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an overview of the cold rolled steel sheet manufacturing process. FIG. 2 is a top view showing the arrangement of injection nozzles according to the present invention. FIG. 3 is a structural explanatory diagram of one embodiment of the nozzle unit according to the present invention installed in a cold rolling stand. 1: Cleaning liquid injection nozzle, 11: Nozzle header, 12:
Nozzle, 2: Air injection nozzle, S: Steel plate, C: Cold rolling tandem mill, D: Cleaning unit.

Claims (1)

[Scope of utility model registration request] A cold-rolled steel sheet smudge prevention device that is installed on the entry or exit side of the final stand of a cold rolling mill and has the function of spraying hot water or detergent liquid at high pressure onto the front and back surfaces of the steel sheet, divides the steel sheet into multiple parts in the width direction. The cooling system is equipped with an injection nozzle whose injection position is shifted in the direction of progress of the steel plate for each block, and the injection angle is inclined so that the injection liquid flows from one side to the other. Smudge prevention device for rolled steel plates.