Hurricane lines of cyclones can reduce emissions from the clinker cooler to under legal emission limits in several situations and avoiding the use of bag filters. Depending on the chosen Hurricane line of cyclones, emissions from the cooler can be reduced in 99.8% to 99.9%, from 50g/Nm3 to under 100mg/Nm3 or 25mg/Nm3.
For this application, the cyclones have to be inner lined with ceramic based cement to overcome the high abrasiveness of the process.
For the pre-heater tower, Hurricane lines of cyclones are a good solution for the gas cleaning before a coal mill. Given that the particulates are very small, regular cyclones have efficiencies between 60 and 75%, while Hurricane cyclones achieve above 90% for the same pressure drop.
The control of clinker fines emissions after the heatexchanger, placed downstream of the clinkercooler, is usually a problem for cementplant managers.
The process is characterized by high material abrasiveness, high loads and variable flow rate in normal and maximum conditions.
The usual dedustingarrangement includes a bag filter as a finalstage deduster, which is typically associated with high maintenance costs anddowntime in production due to frequent replacements of filter elements.
Reducing fineparticulates from the exhaust stream ofthe pre-heater tower is also an objective in order to purify the air used for energy recovery, such as heating a petroleum coke or coal mill, thereby increasing the value of thegrinded product. A high efficiency cyclone system is often used for this purpose.
Clinker cooler: A bag filter is typically the final stage deduster downstream of a heat exchanger.
The Median Volume Diameter (MVD) of the particles coming from the exhaust gases from the clinker cooler is relatively coarse, ranging from 100µm to 150µm.
Pre-heater tower: A bag filter is usually the final stage deduster. High efficiency cyclones are used upstream to purify the exhaust stream used for energy recovery purposes in applications such as the grinding of coal or pet coke.
The Median Volume Diameter (MVD) of the particles coming from the pre-heater is typically very small, ranging from 2.4µm to 3µm.