Cement and Energy

I HOROMILL ON THE HORIZON T he Horomill system is especially well adapted for cement purposes, since it is capable of grinding raw materials of any moisture content or grindability. The system's efficiency also increases with the fineness of the material. When grinding abrasive raw materials with free si lica, the system's benefits are particuIarty notable due to its non-airswept principle. The system's low pressure is also beneficial to tming break-age because it is low risk, limits wear and helps avoid the creation of slabs. The principle of the roller inside the shell is to obtain a high pressure angle which gives a thick material bed, in proportion to the shel l diameter. Meanwhile, the circuit is completed by a TSV classifier which is fed by an elevator, while the ground, finished, product exits the process via the TSV fil ter. Such a system has recently been commissioned at the Cimentas lzmir plant When drying is necessary, one advantage with the Horomill system is that drying occurs in the classifier circuit and is eventually completed by a special low speed flash dryer, permitting a lower pressure loss than when gas fl ow passes through the mill. ECB Horomill grinding system in Turkey. Here the average Inside the horizontal roller mill is a rotary shell, driven by girth-gears. A roller applies a moderate pressure on the material bed, which is formed by a patented system making an even bed. The high speed of the mill, then maintains this even bed (the material rotates with the shell), and by centrifugation avoids material sliding on the shell. production level is 85-88 t/h with a guaranteed 80 t/h minimum level. Mill motor .•. consumption is 17.5 kWhlt with a maximum of 22 ...., •. kWhlt guaranteed (corresponding consumption for a 4 :,. ball mill according to FCB tests is 32 kWhlt), fmeness is of Blaine 4200. [Courtesy: lntemational Cement Review, April 1996} IMPROVING BURNER TECHNOLOGY I Flame modelling T he modelling of burner flames within kilns, heaters, driers and other combustion vessels is known to produce advantages based on reduced energy consumption and improved process control. Modelling has been used to good effect to provide numerous clients with efficient combustion in the plants. The warm-up burner in use in one ofthe two Lepol grate kilns at Blue Circle's Weardale plant.