Measurement of Friction Coefficient on a Powder Layer and Fluid Dynamic Study

Discussion 3 ~ Dynamic pressure model (2)

Figure 25 shows the critical speeds of floatation estimated from the dynamic pressure model and the experimental results. In this figure, the bulk density of  flour and starch are 0.5´103 kg/m3 and 0.65´103 kg/m3,  respectively.

 The theoretical values give a minimum boundary for the experimental values. Since the theoretical values are estimated from maximum dynamic pressure for a certain speed, and since the density of the fluidized powder could be smaller than the normal bulk density, the theoretical values are consistent with the experimental values. 

 


Fig. 25. Theoretical and experimental values of the floating critical speed.
:experimental values on flour layer 
: experimental values on dogtooth violet starch layer
_ :theoretical values on flour layer 
_ :theoretical without flour layer

Measurement of Friction Coefficient on a Powder Layer and Fluid Dynamic Study