The groove is a common structure existing in pipeline components. In engineering applications, it often accumulates particles and thus may lead to component failure. The aim of this study is to investigate fluidization of these accumulated particles when subjected to an overhead airflow. Experiments were performed for five inflow velocities and five baffle heights. Particle surging is presented and analyzed for the first. The occurrence of particle surging depends on the non-dimensional crossing height and the Reynolds number of the flow. Moreover, the duration of surges is about 10%-20% of the whole fluidization period. A MATLAB program was also developed to obtain the number of particles in a monitoring window downstream of the groove. The results demonstrate that the number of monitored particles during a surge holds steady. The drop in particle number between the end and the beginning of the surge process increases exponentially with Stokes number. (c) 2020 Elsevier B.V. All rights reserved.