United Cement Company of Nigeria (UNICEM) has ordered the largest Loesche mill to date, an LM 70.4+4. The new mill, with an output of 370 tph at 4700 Blaine, will be installed at the company’s new line in Calabar, Nigeria. The delivery period is 14 months.
Cement producers' requirements for mill output continue to increase, and as a result Loesche has adapted its module concept to meet this demand. Now, alongside mill types with 2+2 and 3+3 rollers, mills with 4+4 rollers are also available. Loesche has been building on this patented technology for over two decades. In the early 90s the 2+2 concept was patented, and later extended to the 3+3 module design. Now, a few years later, the company has developed the 4+4 grinding concept, which offers the customer outstanding flexibility. On the one hand, this allows the desired high throughput capacity to be achieved, and on the other hand, it offers the possibility of running just as well in 2+2 roller operation, thereby generating a mill output of 60%.
The Loesche mill type LM 4+4 not only includes the expanded module concept, but also the drive. The increasing performance requirements of cement producers led the company to rethink further developments in drive technology. Particularly for larger mill outputs, Loesche favours a drive system with multiple motors and gearboxes with milling force decoupling. The company will use the COPE gearbox developed in cooperation with Renk, which offers a redundancy of up to 8 motors at the motor end. With all 8 motors in operation, a capacity totalling 8.8 MW is achieved. The new COPE gearbox works without a variable speed drive and operates with a reduced number of motors. This means the new drive concept allows for operation with, for example, 7, 6 or only 4 of the available motors. Even in operation with only 7 motors, 100% mill output can be achieved.
As this drive train works with the normal dimensions, the system is also suitable for retrofit gearboxes in existing mills. With this drive concept, Loesche is able put a highly redundant, innovative drive system for the new mill type LM 70.4+4 on the market with short delivery times and low investment and construction costs.
Adapted from press release by Rosalie Starling
Read the article online at: https://www.worldcement.com/africa-middle-east/05122014/unicem-orders-lm-70-4-4-mill-from-loesche-961/