Maintenance of roller pressDate: 2019-07-16 Views:
The combined grinding system composed of roller press and ball mill has been widely used in various grinding operations.The biggest disadvantage of the roller press is the serious wear of the roll surface.After the installation and use of the roller press, generally, after six months of continuous operation, the wear pattern on the surface of the roller wears very little.The problem of roll surface wear has been bothering the superiority of roller press.How to improve the wear resistance of roll surface, improve the service life of roll surface, some research institutes and design units have done a lot of research work.
1..Wear mechanism of roller surface of roller press
The roller press consists of two rollers with the same speed and relative motion.The material is unloaded through the upper feed port of the roller and enters the gap between the rollers.Under the action of high pressure grinding force (the pressure between rollers is between 50 and 300MPa), the material is squeezed, and the compressed material becomes a compact but cracked flat material cake, which can significantly improve the grindability of the material.
2..Selection of surface repair materials:
According to the failure mode of roller, the selected surface material not only has good wear resistance, but also has high toughness and fatigue resistance.In the past roll surface repair, cement plants are mostly used:
(1) wear resistant electrode for high chromium cast iron mold.The microstructure of this electrode is mainly distributed on the cast iron matrix, the C content is more than 3%, and the hardness of the surfacing layer is about HRC60, which has good wear resistance, but its adhesion, crack resistance and fatigue resistance are poor, and there are staggered cracks on the surface of the first layer of the roller surface.In the roller gymnastics process, due to the impact of stress, it is easy to appear large area peeling, which is almost the cause of the monthly repair.
(2) long repair time for online arc surfacing welding after shutdown, which will affect normal production.At the same time, the cross-cracks in the surfacing layer can easily extend to the drum substrate, causing a large number of defects on the surface of the drum, directly affecting the quality of the roller, and possibly causing the overall damage.The roll body will be scrapped for a long time.
Therefore, it is recommended to maintain good maintenance of cement plant when using roller press, and not to wear the surface of roller, so as not to weld again.If the wear pattern wears away, the outermost wear layer is lost, and the transition layer underneath wears away faster, causing fatal damage to the roller press.The maintenance of roller surface is the key to the service life of roller press.Good maintenance of roll surface can greatly reduce the number of stop welding, provide guarantee for normal production, give full play to the advantages of roller press in grinding system.