The effect of tangential lubrication by bridge liquid on the behavior of agglomerating fluidized beds

Cohesiveness due to particle wetting often causes significant troubles in many industrial fluidized processes. There are two contributions for liquid bridge force, i.e. static force and dynamic force. The dynamic force due to viscosity in the tangential direction is called hydrodynamic lubrication. Lubrication is the reduction of intra-particle friction force by switching from solid-solid Coulomb friction to the fluid shear resistance of the liquid bridges between particles. In the present paper, simulations of a fluidized bed were carried out by taking into account the tangential lubrication effect. Experiments were carried out by using a 200-mm diameter three-dimensional bed of glass beads. Results are compared in terms of pressure fluctuation and bubbling behavior. With the lubrication effect, particles moved more actively in the whole region of the bed and became less adhesive to the wall, but pressure fluctuation did not change much. (C) 2000 Elsevier Science S.A. All rights reserved.