Particle Collection Efficiency for Nylon Mesh Screens

Figures & data

TABLE 1 Physical specifications of the nylon mesh screens

Screen model	Pore size (μm)	Open area (%)	Thickness, h (μm)	Fiber diameter, df (μm)	Mass (SD) (mg)	Packing density, α
NY60	60	41	50	33	31.9 (0.5)*	0.32
NY1H	100	44	80	51	45.5 (0.2)*	0.29
NY8H	180	47	135	83	83.4 (0.3)**	0.31
SS635	∼60	n/a	50***	20***	n/a	0.35***
*From Yamamoto et al. (2005).
**Weighed by microbalance (n = 8).
***From Cheng et al. (1985).
n/a—not available.

FIG. 1 Scanning electron microscopy image of NY60 nylon mesh screen with insert showing fluorescein loading (white spots) on a single fiber.

FIG. 2 Experimental setup for particles collection efficiency tests.

FIG. 3 Experimental setup for evaluation of particle morphology on collection efficiency (adapted from Ku and Maynard 2006).

FIG. 4 Transmission electron microscopy images of (a) highly fractal Ag nanoparticles (no sintering) and (b) spherical Ag nanoparticles (600°C sintering).

FIG. 5 Pressure drop per screen as a function of superficial velocity. Solid line is a linear regression through data points.

FIG. 6 Experimental data with comparison of original and modified single-fiber efficiency theory for NY60 screens at 6 Lpm. Error bars represent 95% confidence intervals.

TABLE 2 Effects of particle morphology on collection efficiency of NY60 screens

		Collection efficiency (SD) (%)
Particle diameter (nm)	Number of screens	Spherical	Highly fractal-like
15	5	37.9 (0.6)	34.3 (0.7)
40	20	43.9 (0.1)	45.6 (0.5)
100	20	23.4 (0.3)	24.0 (0.2)

TABLE 3 Sum of squares error between experimental single-fiber efficiency values and theoretical models (original and modified)

		Sum of squares error
Screen type	Flow rate (Lpm)	Original theory (Equation (3))	Modified theory (Equation (4))
NY60	2.5	8.65 × 10^−3	2.43 × 10^−3
	4	3.08 × 10^−3	5.59 × 10^−4
	6	4.86 × 10^−4	3.83 × 10^−5
NY1H	2.5	9.50 × 10^−4	5.07 × 10^−5
	4	6.53 × 10^−4	5.57 × 10^−5
	6	1.77 × 10^−4	5.25 × 10^−5
NY8H	2.5	8.43 × 10^−4	5.87 × 10^−5
	4	4.41 × 10^−4	2.39 × 10^−5
	6	2.11 × 10^−4	4.46 × 10^−6
SS635	2.5	1.32 × 10^−2	3.76 × 10^−3
	4	2.95 × 10^−3	2.23 × 10^−4
	6	3.54 × 10^−3	8.58 × 10^−4

FIG. 7 Theoretical (Equation (4)) and experimental single-fiber efficiency of (a) NY60 screens, (b) NY1H screens, and (c) NY8H screens. Error bars represent 95% confidence intervals.

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