Cement Plant

Cement Facility

Cement Plants

With the dramatic increase in the cost of natural gas, the Cement/Lime industry has had to search for a way to reduce costs. This has resulted in the near standardization of coal-fired systems for firing up the kiln.  These systems are indirect-fired, with the coal crushed (pulverized) in mills, then ‘sucked out’ of the mill by a strong fan located downstream of a cyclone and dust collector.  When the coal particles are created, they move up the duct system to the cyclone where they are captured (smaller coal particles move on while the heavier/larger ones are reprocessed). NOTE: Not all such systems utilize a cyclone. After leaving the cyclone, the coal particles are captured by the dust collector; after falling to the bottom of the collector, they are further conveyed to storage bins from which the coal is withdrawn and conveyed, as needed, to the burners at the kiln.

In the process, the coal is dried and heated (in the mill) and crushed, thereby increasing the temperature and surface area of the coal.  All the elements are there for self-ignition of the coal, unless this is prevented. When required, the Chemetron (Cardox) fire suppression/inerting/safety system inerts the coal mill, floods the duct (and cyclone) and the dust collector with a CO2 liquid discharge in accordance with the requirements of NFPA Standard #12. The accumulated coal dust at the bottom of the collector is prevented from spontaneously heating by inerting with CO2 vapor. This inerting includes the conveyors at the dust collector outlet and those leading to the surge bins, as well as the bins themselves.