| Abstract: | The aim of this study was to measure the pressure drops of a solid-liquid food model and to compare pressure drop estimations obtained from proposed correlations for asymmetric distributed suspensions in a horizontal pipe. The model food suspension consisted of alginate spheres suspended in a Newtonian sugar syrup of medium viscosity. The suspension was pumped into a horizontal pipe and measurements for three different sphere diameters and solid-phase concentrations were carried out. Particle velocity, necessary for pressure drop estimations, was predicted using the Eulerian approach, which assumed solid and liquid phases as continuous. Considerations taken were: one dimensional flow of fluid and particles, drag force acting on the particles and constant pressure drop. The momentum equations were solved by the fourth order Runge-Kutta method. Predicted particle velocities showed a retarded parabolic profile compared to the fluid. Drag expressions used, considerably influenced the predicted particle velocities. Estimated pressure drops for the suspensions using the predicted particle velocities agreed with the experimental pressure drops when the tube-particle diameter ratio was higher than 5.8. |
