PERFORMANCE ANALYSIS ON SCREW CONVEYOR DRYER (SCD) WITH HEATER FLUID INSIDE SHEATH THROUGH MATHEMATICAL MODELING

• Main Author: Rizan Abdalla, Adams
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/52297
• Institution: Institut Teknologi Bandung

Nowadays, the coal drying process still uses the rotary dryer method, where in the drying process there is a risk of coal dust formation and also a direct contact process between the drying air and the coal dust that may create explotion. This challenge in drying coal can be solved through the method using a Screw Conveyor Dryer (SCD). SCD has the advantages of being able to minimize the formation of coal dust due to collisions in the drying chamber and also to minimize contact between coal dust and oxygen in the drying chamber. Reseach from Waje et.al (2007) regarding horizontal SCD still has a small drying capacity, making it difficult to apply on a larger scale for drying coal. In this study, the SCD configuration was modified to be inclined at an angle of 20o. The result of the analysis and mathematical modeling simulation show that the degree of fullness increases to 83.07% with a drying capacity to 660.26 kg/hour at 5 rpm rotation of the shaft. The SMER (Specific Moisture Extraction Ratio) value on the inclined SCD shows a value of 1.61 kg water vapor/kWh and overall heat transfer coefficient (U) of 72.26 W/m2.K. The length requirements for heater and dryer are 8.2 meters and 85.4 meters, respectively, with a drying time of 212.60 minutes for drying coal from initial moisture content at 45% to 13.3% moisture content wet basis. The power requirement to drive the SCD was 167.53 W. This value indicates that modification of SCD from horizontal to inclined configuration can increase drying capacity and can be used as a reference for the application of SCD on a larger scale for drying coal in the mining industry.