The cement plant at Mfamosing, located 30 km north-east of Calabar, capital of Cross River State, Nigeria, has been fully operational since February 2009 and equipped with the latest technology. With a capacity of 2.5 million tpy of cement, the UNICEM plant was ready to be extended by Loesche.
The customer ordered two vertical roller mills, including one LM 60.4 for the grinding of cement raw material with a product rate of 500 tph.
Cement clinker will be ground with the brand-new highlight of the Loesche range, the mill type LM 70.4+4 CS. This mill is designed for a capacity of more than 370 tph to a fineness of 4700 Blaine. In combination with this enormous capacity a new drive system for an operation power up to 8800 kW is necessary. Close cooperation between Renk AG Augsburg and Loesche GmbH Düsseldorf established this development. Input from the end user LafargeHolcim was also taken into consideration.
The innovative result is the COPE (Compact Planetary Electrical) drive. The new concept is designed for mill drive powers ranging from 4000 kW to 15 000 kW. The fast-running and error-prone first stage gear of conventional gearboxes becomes obsolete. The new concept is equipped with an active redundancy.
The innovative COPE gearbox is equipped with 8 individual drive units that are designed for a capacity of 8800 kW. The decisive customer benefit lies in the fact that in the unlikely case of a drive unit failure, the guaranteed mill capacity can be 100% achieved and a loss in production will not occur.
Some more advantages:
- Εqual size as standard drive units for vertical roller mills and thus exchange of existing, conventional gearboxes eminently suitable.
- First with 8 drive units for a VRM gearbox.
- First time multiple drive in VRM to operate with or without VFD (Variable Frequency Drive).
- Easy removal of individual drive units to minimise down times.
- Extremely compact design with motors directly attached to gearbox housing.
The most important aspect of this development is the fact that long standstills of a mill (for several months) due to the repair of any of the conventional gearboxes will be a something of the past. Implementing the COPE drive requires the standard foundation only. The replacement of one of the 8 small drive units will be easily conducted as they are easily accessible and easy to install.
The delivery started in October 2015. First production of cement was in September 2016. The guaranteed values could be achieved after only 40 operational hours.
Read the article online at: https://www.worldcement.com/africa-middle-east/30112016/loesche-receives-order-for-two-vertical-roller-mills/