COAL MILL
When to use membrane filter bags:
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High-moisture present in fuel
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Reduce pressure drop, and increase the airflow
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Capacity enhancement with existing baghouse
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Reduce fuel cost by using low-cost low-calorific value coal
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Less maintenance and longer bag life
Two types of coal firing are used: 1. Direct Firing 2. Indirect Firing. Direct firing is when coal is milled and is directly fed to the kiln. In indirect firing system, coal is milled and stored and fed to the kiln as needed. Most new plants have indirect firing.
Operating Data
Case studies
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Nature of dust: Explosive, Free Flowing
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Dust Load: 30-500 g/Nm3
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Design Temperature: 127 deg C for Polyester and 135 deg C for Acrylic
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Surge Temperature: 140 deg C for Acrylic and 150 deg C for Polyester
Coal fineness has a direct relationship with its reactivity. Hence, in the cement plant, a special significance has been given to the milling behaviour of coal. It has been observed that low volatile matter in coal can be compensated by finer grinding. In order to reduce high fuel cost associated with cement production, many cement plants are using petcoke as their primary fuel. Depending upon fuel used dust can be very fine and sticky in nature. A higher percentage of sulphur in the fuel with moisture can accelerate corrosion in a bag-house. When using petcoke, the dust size is much finer and membrane filter bags are recommended.