Ultrasound velocity profiling of wood chips flow in an industrial application

Abstract Ultrasound velocity profiling (UVP) was applied to an industrial impregnation vessel containing wood chips and liquid. The method could successfully determine the velocity of the wood chips by measuring through the 15 mm thick steel wall. The measuring depth is and covers 8% of the radius. Even though the measuring depth is limited this method is able to capture the normal production variations of the mill. The velocity profiles of the wood chips show a non‐zero velocity at the wall, a sharp gradient (a shear zone), and a plug flow, indicating that it is reasonable to assume that wood chips behave as a dense granular flow on industrial scale.