Abstract: In terms of the problems that exsit in the waste heat recovery of bulk solid particles,such as insufficient heat transfer,high gassolid flow resistance and low quality of the waste heat recovery,a cooling technology for high temperature particle using gas-solid crossflow moving bed was proposed in this study.The experimental study on particle flow characteristics under cold operating conditions was carried out with CFB boiler ash via a self-designed industrial experimental apparatus.Particle flow characteristics were measured by sampling and high-speed photography.The effects of the cross-sectional size of the particle flow on particle flow characteristics and cross-sectional gas speed on particle flow stability were analyzed and discussed.The results show that the downward velocity of particles in the central part of the straight flow section is basically constant. Neglecting the influence of the side walls,the calculated flow index M_(F1) of the front and side section of straight flow section exceed 0.3,which show that the particle flow was considered as a bulk flow under the experimental conditions.By sampling the particles at different locations,it is found that the maximum difference of particle mass ratio is about 14.4%,which could be considered that the particle flow in the enlarged section was uniform in practical engineering,while the particle size distribution at different locations is different.With increasing the transverse air velocity,the particle carrying rate increases.The air velocity in the downward moving bed can not exceed 1.45 m/s.