A study of heat transfer between horizontally-flowing air and a free-falling particle curtain was reported. A steady and uniformly distributed stream of cold particles was fed through a rectangular slit and allowed to fall to form a curtain across the entire width of a horizontal duct of cross-section of 0.15 x 0.60 m. Warm air at, velocities in the range of 0.9 m/s to 1.2 m/s and with a uniform velocity profile, flowed horizontally through the duct. A range of curtain thickness (4 cm to 10 cm) and Mass flow Fate (0.031 kg/s to 0.040 kg/s) were used to investigate the heat transfer characteristic of the free-falling particle curtain in a uniform cross-flowing gas. Particle temperatures within the curtain and air temperatures Outside the curtain were measured as a function of vertical position in the duct. A simple model based on single particle behaviour was developed. The predicted solid temperatures agreed well with the experimental results. However, the predictions for the gas temperatures were less satisfactory. (C) 2008 Elsevier B.V. All rights reserved.