An experimental investigation of the concurrent cogravity flow of particulate solids and water in a 1-in. diameter vertical column is reported. Measurements were made of the particle concentration, or holdup, existing in the column as a function of the fluid and particle flow rates for two particle sizes, 0.0184- and 0.00396-in. diameter glass spheres. The experimental results form the basis for a prediction of the generalized characteristics of concurrent cogravity fluidization.

The data for each particle size are correlated in terms of the slip velocity and the holdup. The slip velocity is demonstrated to be the same unique function of the holdup for concurrent cogravity flow and for batch fluidization. Therefore the holdup and the conditions of limiting operation for concurrent cogravity flow can be accurately predicted from the batch fluidization curve.