The improved solutions of rotary kilns in steel pellet plants, U.LUBE team on-site service
The rotary kiln of a steel pellet plant is driven by the edge drive of large open gears, and the lubricant currently used is a brand of lubricant for spray lubrication of the pinion. Spraying system is a company's spraying system, the system only has a nozzle, and the nozzle is also far from the tooth surface, using manual spraying method, no fixed spraying period (manual control).
During the on-site service, our U.LUBE team conducted a comprehensive inspection of the rotary kiln open gears. From the inspection, the main problems of the rotary kiln open gears in this plant at present are manifested as abrasion, wear and pressure damage caused by hard impurities; there are also more pitting/spalling on the tooth surface of the large teeth. The causes of the current tooth surface damage as followed:
1. From contact traces of tooth surfaces, damage distribution, the equipment has an obvious bias load or assembly problems. The load distribution is more on the left end and less on the right end.
2、从喷洒系统情况来看，约 700mm 的齿宽，仅仅配置一个喷嘴，无法对整个齿面进行覆盖，这也是齿面左端出现严重的干磨现象的原因。
2. From the situation of the spraying system, the approx. 700mm width tooth which only has one nozzle configuration can not cover the whole tooth surface, this is the reason for the severe dry wear on the left end on tooth surface.
3. From the environmental situation, the whole cover of gear is poorly sealed, with a large gap. In the environment of a pellet plant with serious dust, the tooth surface is easily contaminated by environmental dust (a large amount of mud and sand and other hard impurities accumulate at the root of the tooth) and cause crushing of the tooth surface and abrasive wear.
4、目前使用的某牌的润滑剂，40℃时粘度仅为 500 cSt，这对于回转窑开式齿轮来说，目前选用的油品所形成的油膜强度无法支撑齿轮啮合时的压力，容易造成齿面损伤的出现，如过度磨损，点蚀/剥落，疲劳裂纹，甚至断齿等严重损伤，造成齿轮无法达到其预期的设计寿命。
4. The viscosity of the lubrication product currently used is only 500 cSt at 40℃, which for rotary kiln open gear, the oil film formed by the current choice of oil strength can not support the pressure of gear meshing, easy to cause tooth damage, such as excessive wear, pitting/spalling, fatigue cracks, and even broken teeth and other serious damage, resulting in the gear can not reach its expected design life.
▲ The dynamic inspection of the pinion shows that there is obviously no oil in the middle of the left end of the tooth surface, the tooth surface is in a dry grinding state, a large amount of sand and metal abrasive chips are accumulated at the root of the tooth, the tooth surface is seriously abraded, and there is a serious bias load.
▲ The dynamic inspection of the big tooth, the left middle end of the tooth surface is obviously without oil, the tooth surface is in dry grinding state, the root of the tooth accumulates a lot of sand particles and metal abrasive chips, the tooth surface is seriously abraded, pitting and spalling, and serious bias load.
For the current problems of rotary kiln open gear, the U.LUBE team recommends:
1. WE should fully check the offset load or assembly problems asap, timely contact the equipment manufacturers for adjustment, to solve the problem of more load distribution at the left end and less at the right end.
2、喷洒系统仅有一个喷嘴不能覆盖全齿面，建议对齿轮的配合进行检查以及调整，消除齿轮的偏载现象，增加喷嘴数量（按每个喷嘴覆盖 150mm 齿宽计算，应设置5个喷嘴）缩短喷嘴到齿面的距离，采用压缩空气对喷出的油品进行雾化，以便更均匀的覆盖齿面。
2. The spraying system with only one nozzle can not cover the whole tooth surface, it is recommended to check and adjust the gear fit, eliminate the gear bias load phenomenon, increase the number of nozzles (according to each nozzle covers 150mm tooth width, should be set up 5 nozzles) to shorten the distance from the nozzle to the tooth surface, the use of compressed air atomization of the sprayed oil, in order to more uniform coverage of the tooth surface.
3. Regarding the poor sealing problem of whole gear cover , it is recommended to use the opportunity of the overhaul of the gear cover seal to improve, reduce the environmental dust on the equipment, oil and other pollution.
4、目前使用的某牌的润滑剂，40℃时粘度仅为 500 cSt，这对于回转窑开式齿轮来说，目前选用的油品所形成的油膜强度无法支撑齿轮啮合时的压力，容易造成齿面损伤的出现，如过度磨损，点蚀/剥落，疲劳裂纹，甚至断齿等严重损伤，造成齿轮无法达到其预期的设计寿命。为了满足大型开式齿轮的润滑要求，通常对其采用一个完整的润滑体系，如优润开式齿轮ET G-OG/O-OG系列润滑体系：包括齿轮初始安装时的涂底润滑，运行初期的磨合润滑，正常生产时的操作润滑，以及齿轮出现损伤是采用的修复润滑。同时，还需要结合定期的设备检测，及时对设备存在的问题（安装问题，环境问题等等）进行调整，才能使设备得到良好的润滑，建议使用合乎大型开式齿轮润滑规范的润滑剂如优润开齿润滑剂，以达到良好的保护齿轮的运行，抑制疲劳性损伤，齿面裂纹的扩展以及齿面磨损，擦伤等问题的进一步恶化，延长齿轮的使用寿命。
4. The viscosity of the lubrication product currently used is only 500 cSt at 40℃, which for rotary kiln open gear, the oil film formed by the current choice of oil strength can not support the pressure of gear meshing, easy to cause tooth surface damage, such as excessive wear, pitting / spalling, fatigue cracks, and even broken teeth and other serious damage, resulting in the gear can not reach its expected design life. In order to meet the lubrication requirements of large open gears, a complete lubrication system is usually used for them, such as the U.LUBE open gear ET G-OG/O-OG series lubrication products: including the initial installation of the gear primer lubrication, break-in lubrication at the beginning of operation, operation lubrication during normal production, and gear damage repair lubrication. At the same time, it also needs to be combined with regular equipment testing, timely adjustment of equipment problems (installation problems, environmental problems, etc.), in order to make the equipment get good lubrication, it is recommended to use lubricants in line with the large open gear lubrication specifications such as the excellent U.LUBE open gear lubricants, in order to achieve good protection of gear operation, inhibit fatigue damage, tooth surface crack expansion and tooth surface wear, abrasion and other problems of further deterioration, and extend the service life of gears.