Design and Characterization of an Improved Screw-Assisted Rotary Feeding System for Aerosolization of Ultra-Small Quantities of Particulate Solids

Figures & data

FIG. 1 Design of the screw-assisted rotary feeding system: (a) front view, (b) side view.

FIG. 2 Experimental setup. MFC, mass flow controller; SS, stainless steel.

FIG. 3 Effects of the screw at the tip of the stirrer for the 12-grooved rotor at a speed of 3 rpm.

FIG. 4 Number concentrations at various rotational speeds: (a) 4-grooved rotor and (b) 12-grooved rotor.

FIG. 5 Comparison of the number concentrations for the 4- and 12-grooved rotors at a speed of 6 rpm.

TABLE 1 Average number concentration and calculated COV of the 4- and 12-grooved rotors at various rotational speeds

	Rotational speed (rpm)	3	6	9	18	27
4-grooved rotor	Average number concentration (× 10^5 particles/cm^3)	1.275	6.455	11.02	13.52	15.95
	COV^a	0.358	0.176	0.127	0.075	0.082
12-grooved rotor	Average number concentration (× 10^5 particles/cm^3)	2.849	7.363	6.115	6.039	3.949
	COV	0.127	0.088	0.075	0.069	0.312

FIG. 6 Size distribution of aerosolized sorbent particles using the 12-grooved rotor at various rotational speeds, measured by (a) APS and (b) SMPS.

FIG. 7 GMD and GSD for (a) the 12-grooved rotor at various rotational speeds and (b) the 4-, 8-, and 12-grooved rotors at 27 rpm.

FIG. 8 Scanning electron microscopy image of the discharged sorbent particles.

FIG. 9 Verified stability region for the 4-, 8-, and 12-grooved rotors at various rotational speeds.