Removal Rates of Explosive Particles From a Surface by Impingement of a Gas Jet

Figures & data

FIG. 1 Diagram of the air jet interrogation experimental setup.

FIG. 2 Ceramic microsphere removal for jet bursts of different durations (2.5 mm nozzle diameter, 276 kPa reservoir pressure, 152 mm standoff distance). (Color figure available online.)

FIG. 3 Volume of air ejected from a 4.5 mm diameter nozzle as a function of reservoir pressure and pulse duration.

FIG. 4 Microscope images of ceramic microspheres on glass, both before and after interrogation, by an air jet pulse (2.5 mm diameter nozzle, 207 kPa reservoir pressure, 152 mm standoff distance).

FIG. 5 Ceramic microsphere removal for jet bursts with varying reservoir pressures (2.5 mm diameter nozzle, 152 mm standoff distance). (Color figure available online.)

FIG. 6 Microscopic images of TNT before and after transfer. (a) Solid TNT nugget (5 μg) resulting from desiccation. (b) TNT particles after transfer. (Color figure available online.)

FIG. 7 Microscopic images of TNT on glass, both before and after interrogation, by an air jet pulse (4.75 mm diameter nozzle, 655 kPa reservoir pressure, 47 mm standoff distance). (a) TNT before air jet interrogation. (b) TNT after air jet interrogation. (Color figure available online.)

FIG. 8 Histograms of particle size for the 4 types of particles in our study. (Color figure available online.)

TABLE 1 Particle size distribution properties

	Zeeospheres^TM	TNT	C-4	RDX
Median dp (μm)	16	12	13	12
D 10 (μm)	18	16	18	15
σ d (μm)	9	13	16	11
D 20 (μm)	20	21	24	18

FIG. 9 Diagram of dimensions used for analysis.

FIG. 10 Plot of experimental data for ceramic microsphere particle diameter experiencing 50% removal at various ζ; data are fit with the curve from Equation (11),

. (Color figure available online.)

FIG. 11 Plot of removal versus ζ for 3 explosives and ceramic microspheres [experimental results as points; curve fits from Equation (15) as lines]. (Color figure available online.)