Cement industries have kilns of length varying from 70 to 80 m where clinker generation occurs. Typical Rotary Kiln surface temperature in a cement industry varies from 150 deg C to 400 deg C. The energy from the rotary kiln at temperatures around 150-400 deg Celsius presently is being radiated into the atmosphere. Similarly, in the paper and pulp industry, the kiln temperature is around 200 deg Celsius. There is a continuous loss of heat from such kilns to the ambient which can be converted into useful work.
A part of this heat can be captured through our waste heat recovery system and converted into useful work such as space cooling or power generation.
By using Oorja Waste Heat Recovery System
1. The waste heat recovery system solves two purposes – generating power at cheap costs and offsetting carbon footprint at once.
2. The hot water generated can be integrated into VAM and chilled water produced can be used to cool spaces.
3. The recovered heat also can be used to preheat water for captive power plant.
4. To increase calorific value, limestone, lignite or coal can be dried.
Figure 1 Cement Kiln Thermograph
The proposed system will have heat recovery panels, i.e. aluminium panels with copper tube embedded in it will be placed around the kiln preferably where temperatures are higher. The panels have water at ambient temperature circulated through them. Through radiation, the temperature of the water is raised to 90-95 deg Celsius. In this way, from a cement kiln of length 70-80 m, 3-4 Kw/sq.mt of power can be captured.