Design, Fabrication and Performance Evaluation of a Convective Coal Moisture Remover System

Abstract

Abstract: Moisture in run-of-mine coal significantly reduces its calorific value, increases transportation cost, and causes operational difficulties in furnace systems. This paper presents the design, fabrication, and experimental evaluation of a laboratory-scale Coal moisture remover that employs forced convective thermal drying. The system integrates four core sub-assemblies: a motorised conveyor belt for continuous coal feeding, nichrome/FeCrAl alloy electric resistance heating coils as the heat source, a suction fan running at 2900 RPM to drive heated airflow through the coal bed, and three temperature sensors positioned at the inlet duct, drying zone, and outlet to monitor the real-time thermal profile. The prototype was designed with low-cost, locally procurable components and standard workshop fabrication processes, keeping total outlay well below commercially available industrial dryers. Experimental trials conducted at varying coil power settings and belt feed rates indicate an expected moisture reduction of 50% to 70% relative to initial moisture content, with a corresponding improvement of 10%–20% in effective calorific value. This work demonstrates a practical, affordable, and fully instrumented drying platform suitable for laboratory research, small industrial units, and educational settings.

Introduction

Coal is the primary fuel for thermal power generation in India, but its high moisture content reduces efficiency, increases transport costs, destabilizes combustion, raises emissions, and creates handling problems. While industrial coal dryers exist, they are expensive and impractical for small-scale use.

To address this, the paper presents the design and development of a compact, low-cost coal moisture removal system using forced hot-air drying. The system includes key components such as heating coils, a suction fan, a conveyor belt for continuous feeding, and temperature sensors to monitor the drying process. It operates by passing heated air through coal, evaporating moisture, and expelling it through airflow.

The study aims to reduce moisture content, improve calorific value, and evaluate performance using metrics like moisture reduction, energy consumption, and thermal efficiency. It draws on established principles of heat and mass transfer and prior research showing that controlled hot-air drying is effective and energy-efficient.

Overall, the system offers an affordable and scalable solution for improving coal quality and power plant efficiency, particularly for small-scale applications and research settings.

Conclusion

This paper has presented the complete design rationale, component selection, fabrication approach, and expected performance of a laboratory-scale Coal moisture remover based on suction-driven forced convective thermal drying. The four-component architecture — motorised conveyor belt, nichrome/FeCrAl alloy resistance heating coils, 2900 RPM suction fan, and three-point temperature sensing — forms a fully integrated and instrumented drying platform that is simple to fabricate, easy to operate, and within the budget and resource constraints of a seventh-semester undergraduate engineering project. The system is expected to deliver 50%–70% moisture reduction relative to initial coal moisture content, with a corresponding 10%–20% improvement in effective calorific value at the optimum coil power setting. Specific energy consumption estimated at 3,000–6,000 kJ per kilogram of water evaporated places the design within the performance range reported for comparable small-scale dryers in the literature. Three-point temperature sensing enables real-time monitoring of the axial thermal gradient, providing both operational safety oversight and data for performance characterisation. The project demonstrates that a practical, affordable, and fully instrumented coal drying unit can be successfully designed and constructed from locally available materials and components, making the technology accessible to small industrial operators and academic research groups who cannot justify the capital expenditure associated with commercial industrial-scale dryers.

References

[1] Mujumdar, A. S. (Ed.), Handbook of Industrial Drying, 4th Edition, CRC Press, Boca Raton, 2014. [2] Rao, Z., Zhao, Y., Huang, C., Duan, C. and He, J., Recent developments in drying and dewatering for low rank coals, Progress in Energy and Combustion Science, Vol. 46, pp. 1–11, 2015. [3] Incropera, F. P., DeWitt, D. P., Bergman, T. L. and Lavine, A. S., Fundamentals of Heat and Mass Transfer, 7th Edition, John Wiley and Sons, Hoboken, 2011. [4] Bureau of Indian Standards, IS 1350 (Part I) — Methods of Test for Coal and Coke: Proximate Analysis, BIS, New Delhi. [5] Central Electricity Authority, Growth of Electricity Sector in India from 1947–2023, Government of India, New Delhi, 2023. [6] Tahmasebi, A., Yu, J., Han, Y., Yin, F., Bhattacharya, S. and Stokie, D., Study of chemical structure changes of Chinese lignite upon drying in superheated steam, microwave and hot air, Energy and Fuels, Vol. 26, No. 6, pp. 3651–3660, 2012.

Copyright

Copyright © 2026 Mr. Khushal Dhumne, Mr. Kunal Mule, Mr. Harshvardhan Zilpe, Mr. Aman Turkar, Mr. Shantanu Mathankar, Dr. M. S. Dhande. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.