RU1814569C - Method of cleaning strip surface at cold rolling - Google Patents

Abstract

Usage: improving the efficiency of cleaning during surface treatment of the rolled strip. SUMMARY OF THE INVENTION: The supply of a washing liquid is combined with blowing, using a liquid heated to a temperature of at least 40 ° C. The liquid is dispersed in air in an amount of 0.01-5.0 vol.%. 1 tablet, 1 ill. ate with

Description

The invention relates to rolling production, in particular to surface treatment of a strip to be rolled - cleaning. :. . .

The drawing shows a device that implements the proposed cleaning method.

The device comprises a washing liquid supply pipe 1, a compressed air supply pipe 2, a mixer 3, a mixture supply pipe 4, collectors 5. Values 6, 7, 8 indicate valves, strips and rolls, respectively.

The supply of washing liquid in the proposed method is combined with blowing, while using a liquid heated to a temperature of at least 40 ° C, which is dispersed in air in an amount of 0.01-5.0 vol.%

The supply of washing liquid by air provides a more active mechanical interaction with the surface of the strip, resulting in an increase in

removable soils. An increase in the temperature of the liquid ensures its better dispersion and dissolution of oil pollution on the strip surface.

The method also makes it possible to rationally use a washing liquid, which is almost completely used for cleaning. In addition, less cleaning fluid remains in the strip after cleaning, which is further contaminated ....

On a four-stand mill 2500, a pilot rolling of a steel strip was carried out using the proposed cleaning method. The thickness of the rolled was 1-3 mm, the total reduction - about 70%. The rolls were cooled by an emulsion of 3% concentration in an amount of 900 m3 / h.

After the last stand, the strip was blown with air containing a washing liquid heated to a temperature of 40-100 ° С, dis00

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pergenerated into the air in an amount of 0.01-5.0 vol.%.

The table shows the results of industrial tests of the proposed method for cleaning the surface of the strip. The effect of temperature and concentration of the washing liquid on its effectiveness was radiated. The effectiveness of the washing liquid was evaluated by the contamination of the rolled surface and its sorting from the second group, the surfaces were separated into the third group.

The method was replicated on a four-stand mill 2500 for cold rolling steel. Detergent was supplied to the rolled surface and blown with air. Moreover, the washing liquid, heated to a temperature of 38-100 ° C, was dispersed in air in an amount of 0,, 2 vol.%.

For arbitrary temperature values and the amount of washing liquid in the air within the specified limits (tests 1,2, 5), the contamination of the rolled surface was 430-500 mg / m2, and the sorting of rolled products into the third group was 6.1-7.0%. In the prototype, these parameters were 1315 mg / m2 and 17%, respectively (experiment 12). A positive effect was achieved.

A positive effect was also achieved by maintaining one or two parameters at the lower acceptable limits (experiments 3, b, 8) and at the upper acceptable limits (experiments 5, 9). The upper permissible temperature limit of the washing liquid is equal to its boiling point. For all contaminants of the temperature of the washing liquid from 40RS and above, a positive effect was achieved (experiments 1, 2, 5, b, 8, 9). When the parameters were at the level of lower or upper transcendental values, a positive effect was achieved (experiments 1,2.5, b, 8.9). When the parameters were at the level of lower or upper transcendental values, a positive effect was not achieved (experiments 4, 7, TO, 11).

Example (experiment 1). On a four-stand mill 2500 cold rolling rolled steel strip 1-3 mm thick with a total compression of 65%. The rolls were cooled by an emulsion of 3% concentration in an amount of 900 m3 / h. After the last stand, the strip was blown with air in an amount of 300 m3 / h. After the last stand, the strip was blown with air in an amount of 300 m3 / h. In this case, the washing liquid, heated to 60 ° C,

dispersed in air in an amount of 1 vol.% (3 m3 / h).

The contamination of the rolled surface was 430 mg / m2, and the sorting of rolled products from the second group to the third was 6.1%. A positive effect was achieved.

PRI me R 2 (experiment 8). On a four-stand mill 2500 cold rolling rolled steel strip with a thickness of 1.5-3 mm with a total compression of 67%. The rolls were cooled with an emulsion concentration of 2.5 in an amount of 100 m3 / h. Heated liquid heated to 40 ° C was dispersed in the air in an amount of 0.01 vol. % (0.04 m3 / h).

The contamination of the rolled surface was 556 m / m; the sorting from the second to the third group was 7.2%. A positive effect was achieved.

Example 3 (experiment 9). A steel strip 1-2 mm thick with a total compression of 65% was rolled on a four-stand mill 2500. The rolls were cooled by an emulsion of 2.8% in an amount of 800 m3 / h. After the last stand, the strip was blown with air in an amount of 500 m3 / h. A washing liquid heated to 100 ° C was dispersed in air in an amount of 5 vol% (40 m3 / h).

Pollution of the rolled surface was 494 m3 / h, sorting from the second group to the third - 6.4%. A positive effect was achieved.

Compared with the prototype, the proposed method, as a result of increasing the surface cleanliness of the cold-rolled strip, will reduce the sorting of rolled products from the second surface finishing group into the third by 5,000 tons in the cold-rolling sheet shop. With a difference in metal cost of 24 rubles / ton, the economic effect amounted to 12,000 rubles per year.

The use of this method provides more active mechanical interaction with the surface of the band of the washing liquid, improving the solubility and amount of contaminants removed, as well as the rational use of the washing liquid.

Claims (1)

The claims A method of cleaning the surface of a strip during cold rolling, comprising supplying a strip of liquid to the strip and blowing the strip with air, characterized in that the washing liquid is heated to a temperature of at least 40 ° C and dispersed in air in an amount of 0.01-5.0 vol%.