The function of brush roller in galvanizing line unit_FAQ

Anhui Meixin Brush Factory introduces the role of brush rollers in the galvanizing line unit. Strip steel having a good surface condition and cleanliness before hot-dip galvanizing is a prerequisite for obtaining a good coating. On the surface of the strip steel with oil stains, it is impossible to obtain a bright, good bonding force, and superior corrosion resistance coating. Therefore, the strip must pass through the cleaning section of the scrubbing unit before entering the annealing furnace. The cleaning section mainly includes chemical alkaline washing, electrolytic alkaline washing and brush roller cleaning. (1) Spray cleaning and cyclic spray cleaning are mainly to complete the heating and rough washing of strip steel. It is carried out in the form of spraying, using the chemical action of hot lye to remove thick rolling oil and iron powder on the surface of cold rolled strip steel. These rolling oils are often contaminated by lubricating oil and hydraulic oil, and must be removed by chemical alkaline washing first, and then electrolytic alkaline washing. (2) Alkaline scrubbing Because there are a lot of grease and iron powder on the surface of the rolled hard coil, only the chemical caustic scrubbing effect is not very good, and the chemical caustic scrubbing and brush roller cleaning must be used for treatment together. Brush roller cleaning can mechanically remove oil and dust to improve the cleaning effect. For the brushing of this unit, in addition to controlling the concentration, temperature and spray pressure, the brush roller current must also be controlled. The brush roller current reflects the degree of compression of the brush roller on the strip steel, and the reduction of the brush roller can be adjusted by the motor. During the brushing process, the bristles of the brush roller will continue to wear out, and the length of the bristles of the brush roller must be checked frequently. When the bristles are too short, the brush roller should be replaced in time. (3) Electrolytic cleaning The mechanism of electrolytic cleaning is that when strip steel is used as a cathode or anode, hydrogen bubbles or oxygen bubbles are correspondingly precipitated on the surface of the strip steel due to the electrolyzed water, which destroys the oil film attached to the surface of the strip steel. Small bubbles break away from the steel strip to which the oil droplets are attached and stay on the surface of the oil droplets, and stay at the interface between the oil and the degreasing liquid. As new bubbles continue to precipitate out, the small bubbles gradually become larger, so the oil droplets stay in the bubbles. It is separated from the surface of the steel strip under the action of, and is carried into the degreasing liquid by air bubbles. At the same time, the generated small bubbles can bring out the oxide scale on the surface and some dirt in the voids. (4) Hot water scrubbing tank Hot water scrubbing uses mechanical methods to remove dust and dirt attached to the steel plate after electrolytic cleaning, further enhancing the cleaning effect. The difference from the previous alkaline spray operation is that the spray liquid is hot water, and the roller is brushed. The operation is similar. (5) After hot water rinsing strip steel is brushed with hot water, it is squeezed dry by the squeezing roller, but there is still a certain amount of degreasing liquid on the surface. If it enters the annealing furnace directly, it is easy to form stains on the surface of the strip. Therefore, it must be rinsed with hot water to clean the surface of the strip. Hot water rinsing adopts three-stage overflow, in which the last stage is supplemented with new water, and the temperature, overflow flow and circulation volume must be controlled during operation. (6) Strip drying removes the moisture on the surface of the strip. During operation, the circulation of hot air and the temperature of the hot air should be controlled, and the nozzle should be checked frequently to prevent it from clogging. (7) Inspection after cleaning For the effect of cleaning, the strip steel that has just been dried by hot air can be observed with the naked eye. If the surface of the board is black and there is black gray on the surface, it means that the cleaning is not good. Check the concentration, temperature and the condition of the brush roller; if the surface of the board is stained, it means that the rinsing is insufficient, and the amount of supplementary water and circulating water should be increased. And overflow. If there are water marks on the surface of the board, it means that the drying is not good. The temperature of the hot air should be adjusted and the nozzle condition should be checked. Welcome to visit Meixin Brush Factory www.mxbrushmachinery.com