When the hot rolling mill rolls soft alloys and PS plates, the brush rolls are required to have a higher surface quality. The soft alloys will adhere to the surface of the rolls during the rolling process, causing metal intrusion, which directly affects the surface quality of the rolled products. The brush roll can improve the surface quality of the work roll, reduce the number of roll replacements, reduce the amount of grinding, increase the service life of the roll, improve the surface quality of the rolled piece, and reduce various costs.
The material of the brush roll is different, and the effect of removing the aluminum sticking on the surface of the work roller is also different. The cleaning ability of the wire brush roll is relatively strong, but the wire brush roll has the following points that need attention:
1. The service life is short, generally about 3000 hours, the steel wire is easy to break during long-term use, and the fallen steel wire is pressed into the surface of the strip, causing the fatal metal indentation defects. The falling steel wire damages the surface of the roll, and forms roll marks on the surface of the strip.
2. The use of steel wire brush rolls will cause large wear on the rolls, reducing the service life of the rolls.
3. The friction between the steel wire wheel brush and the roller produces a large amount of iron powder mixed into the emulsion to contaminate the emulsion, which has a greater impact on the stability of the emulsion of the soap-free technology. The cleaning ability of the nylon brush roll is weak, but the nylon brush roll has better cleaning uniformity in the width direction of the strip, and it is easier to obtain a uniform surface quality. It overcomes the shortcomings of the wire brush roll, and the "aging" time is easy to master. At present, more and more hot rolling mills use nylon brush rolls.
The brush roll should spray a certain amount of emulsion on the brush roll when it is working. The main purpose is to cool the working surface temperature and clean the bristles of the brush roll. The spray volume is about 3%-5% of the total flow. Take the machine as an example, the total flow is 12000l/min, the spray volume of the brush roll is 440l/min, and the spray pressure is 0.2-0.4MPa.
In the working process of the brush roll, cooling and lubrication is very important. It can not only improve the cleaning effect, but also prolong the service life of the brush roll. Therefore, the separate cooling and lubrication of the cleaning roller is not only necessary, but also more and more demanding.