Residence time distribution of food and simulated particles in a holding tube

摘要: Abstract Residence time distribution (RTD) was determined for food and simulated particles flowing in a holding tube, as affected by particle shape (cube, cylinder, sphere), concentration (10, 20, 30% w/v), type (potato, carrot, turkey, green peas, polystyrene), fluid viscosity (0.0% CMC, 0.5% 1.0% CMC), bulk flow rate (5.81, 7.28, 8.71 × 10 −4 m 3 /s) SSHE shaft speed (30, 60, 90 rpm). times of tracer were recorded video camera equipped with timer. Cylindrical remained the tube longer than cubic particles. Increasing tended to decrease mean normalized residence (MNPRT). decreased MNPRT significantly, apparently due strong lift action on Although turkey denser other particles, they had smaller carrot potato The peas found be significantly higher that polystyrene spheres. Swept-surface heat exchanger did not influence tube. curves narrowed decreasing increasing rate, using high fluids longest 5.3 average time. fastest exceed 1.8 velocity. This finding is within conservative value 2.0 considered safe sizing tubes aseptic processing systems.