For a fundamental study of solid-gas mixing feeders, the compressed air was introduced into a bed of particles packed in a cylindrical vessel, and the flow rate of the solid particles through the orifice at the end of the vessel was measured. In the range of low air pressure, the weight-flow rate of the particles was proportional to square root of the corrected air pressure and inversely proportional to square root of the height of the bed of the particles in the vessel. The effect of all the variables upon the flow rate is expressed in the following equations:
and
where w=weight flow rate of particles (gw/s)
C=discharge coefficient (-)
A
0=cross-sectional area of the orifice=(π/4)D02
g=gravitational acceleration (cm/s2)
γ=apparent specific weight of particles (gw/cc)
p=air pressure difference (gw/cm2)
p
0=fictious pressure corresponding to the gravitational flow rate:
D
0=orifice diameter (cm)
L=bed height in the vessel (cm)
Dp=average particle size (cm)
D
T=inner diameter of the cylindrical vessel (cm)
(gw means gram-weight)
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