Hydrodynamic characteristics of a two-dimensional jetting fluidized bed with binary mixtures

摘要

A cold model of a two-dimensional jetting fluidized bed with a cross section 300 mm X 50 mm was employed to study the jet penetration depth and flow regime transitions. Four types of particles and four kinds of binary mixtures were used as bed materials in the test, In addition, a new multi-channel pitot tube system was developed to investigate the penetration depth. Experimental results indicate that the penetration depth decreases when the annular gas flow rate is increased from 1.0_(mf) to 2.5Q_(mf), while it remains constant for annular gas flow rate ranging from 2.5Q_(mf) to 3.0Q_(mf) (annular gas flow rate including fluidization air from the plenum chamber and the V type gas distributor). A new correlation is presented for predicting the penetration depth for different annular gas flow rate. The effects of particulate density, particulate diameter, jet velocity, static bed height, nozzle diameter, and annular gas flow rate on flow regime transition, i.e. jet, transition flow regime and spout, were systematically examined. A correlation to predict flow regime transition was also developed, which was in good agreement with the experimental data from the present study and other references.