Solid-liquid suspension in a stirred tank driven by an eccentric-shaft: Electrical resistance tomography measurement

Abstract

Aiming at improving particle suspension performance in the stirred tank, the eccentric-shaft agitation and two-half-pitched-blade (THPB) impeller were proposed. The power consumption and suspension characteristics of THPB impellers under the eccentric-shaft, concentric and eccentric agitation schemes were experimentally studied. Effects of solid loadings and impeller rotation speeds were discussed. Results were compared with their counterparts of the two-flat-blade (TFB) impeller. It was found that, when running at the same rotation speed, although power consumption of eccentric-shaft agitation is large, its suspension performance is the best. When operated under the equal-power condition, for the eccentric-shaft agitation scheme, TFB has the best suspension performance. For the concentric and eccentric agitation schemes, THPB impellers behave better than TFB. Under the lower-than- N js condition, increasing rotation speed can improve the suspension performance. Given the simple design and good suspension performance of eccentric-shaft agitation, it is promising to be applied in the industries. • Development of the eccentric-shaft agitation scheme. • Electrical resistance tomography (ERT) measurements of solid-liquid suspension performance. • Comparison of performances among the concentric, eccentric and eccentric-shaft agitation schemes. • Discussion on the effect of impeller type, rotation speed and solid loading.