Cyclone separators are well known for their efficiency in separating air-solid mixture. Cyclones are often used for the removal of particles of about 10 µm or more diameters from air streams and also used for separating particles from liquids and for separating liquid droplets from gases. Cyclones can be used for heating solid particles where direct contact with gas is permitted. Since it has potential applications as heat exchangers in fertilizer, polymer powder, pharmaceutical and other industries, study of cyclone as heat exchanger is gaining attention. In present study, experiments are conducted in a cyclone heat exchanger of 160 mm diameter, using sand. The effects of solid feed rate (0.01-0.025 kg/s), cyclone inlet air velocity (5.44-9.1m/s), and particle sizes (196-725 µm) on heat transfer rate, exit solid temperature, heat transfer area and heat transfer coefficient were studied. An empirical correlation was proposed for the prediction of heat transfer coefficients based on experimental data. The heat transfer coefficients obtained by correlation in the present study were compared with literature values and it was within an error band of +10% to —8%.