MILLCOOL™ : WATER INJECTION TO CEMENT MILLS
The tube mills (ball mills) to grind clinker and additives for production of cement are widely used in most cement plants as open or close circuits as well as accomplished with roller presses or not.
The temperature inside tube mill should be kept at a certain level that the requested mill discharge temperature is at its optimum value in between 90 °C – 120 °C. The finish product result in quality deterioration when the discharge temperature is out of a/m °C figures.
As an example;
If the temperature goes above 125 °C, it causes dehydration of gypsum leading to change the characteristics of finish cement quality.
If the temperature is below 90 °C, then wet clogging of gypsum occurs and cement strength problems appear.
MILLCOOL™ water injection is a tailor made system, ready to use as a complete package unit to keep mill outlet pre set temperature. Thus, finish product quality problems are eliminated due to higher or lower temperatures.
In respect to the circuit thermal balance analysis and tube mill design, MILLCOOL™ propose the following 7 alternatives for water injection;
For mono chamber tube mills:
1.- Water injection from mill inlet
2.- Water injection from mill outlet
For two chamber tube mills:
3.- Water injection from mill inlet towards intermediate diaphragm
4.- Water injection from mill outlet towards intermediate diaphragm
5.- Water injection from intermediate diaphragm towards mill outlet
6.- Water injection both from mill inlet towards to intermediate diaphragm & from mill outlet towards to intermediate diaphragm
7.- Water injection both from mill outlet towards to intermediate diaphragm & from intermediate diaphragm towards to mill outlet
Each possible solution is studied by our mill experts together with enduser specialists, so that the most efficient solution is then mutually decided in order to define the loose parts locations i.e. lances or junction boxes. MILLCOOL™ newest invention is install the hyraulic network under the shell liners by using rotary joint, thus the use of junction box is eliminated in some cases where applicable.
While the water injection system operates automatically, a purge air is fed during idle times in order to keep the lances and nozzles cool and preventing chalking formation on the nozzle head.