Closed-Circuit Granulation by a Single Horizontal Rotating Conical Vessel -Effect of Circulating Load Ratio on the Properties of Products - by

Closed-Circuit Granulation by a Single Horizontal Rotating Conical Vessel -Effect of Circulating Load Ratio on the Properties of Products by Masunori SUGIMOTO* and Hideki NAKAZAWA** In order to investigate the effect of the circulating load ratio CL on the properties of granule products in a closed-circuit granulation system, the relationship between CL and the residence time distribution of particles passing through a closed-circuit process was discussed with a few assumptions. Furthermore, the openand closed-circuit granulation experiments were carried out in a single horizontal rotating conical vessel with a rotary lifter. CaCO3-powder and water were used as powder and binder, respectively. The results are summarized as follows. (1) It is expected that the uniform size and spherical products can be obtained by a closed-circuit granulation process having an effective separating system, although the theoretical consideration showed that the large CL makes the residence time distribution of particles wide in the process. (2) It was experimentally confirmed that more spherical, more uniform size and harder products were obtained in the closed-circuit granulation than that in the open-circuit granulation under the optimum circulating load ratio, CL<1.3 which satisfies the optimum separating condition in the present granulator, which has the functions of both granulation and separation.