Effect of a Horizontal Inlet on the Collection Efficiency of a Rectangular-Slit-Nozzle Impactor

Figures & data

FIG. 1 Schematic of rectangular-slit-nozzle impactors with a: (a) typical inlet; (b) horizontal inlet.

FIG. 2 Schematic of the experimental setup.

FIG. 3 Comparison of the collection efficiency in the experimental results and the numerical simulation results for a rectangular-slit-nozzle impactor with either a typical inlet or a horizontal inlet.

FIG. 4 Particle trajectories in a horizontal inlet impactor with a PM_2.5 nozzle (Q = 12.5 L/min, W = 1 mm, A/W = 1, B/W = 3, and T/W = 4): (a) Stk^1/2 = 0.17, d_p = 0.5 μm; (b) Stk^1/2 = 0.71, d_p = 2.3 μm; (c) Stk^1/2 = 0.80, d_p = 2.6 μm; (d) Stk^1/2 = 1.36, d_p = 4.5 μm.

FIG. 5 Comparison of spanwise flow-velocity profile at the end of a PM_2.5 nozzle (Q = 12.5 L/min, W = 1 mm, A/W = 1, B/W = 3, and T/W = 4).

FIG. 6 The effect of B/W on (Stk₅₀)^1/2 for a rectangular-slit-nozzle impactor with a horizontal inlet.

FIG. 7 The effect of A/W on (Stk₅₀)^1/2 for a rectangular-slit-nozzle impactor with a horizontal inlet.

FIG. 8 Comparison of the collection efficiency of a typical inlet impactor and a horizontal inlet impactor.

Table 1 Comparison of the pressure drop between the typical inlet impactor and the horizontal inlet impactor

			Pressure drop (Pa)
			Typical	Horizontal
Cutoff			inlet	inlet
size	W (mm)	Q (L/min)	impactor	impactor
PM1	0.3	1.94	660	750
	0.42	5.33	1157	1382
	0.54	11.33	1811	2243
PM2.5	0.7	4.29	109	126
	1	12.52	199	237
	1.3	27.50	315	395
PM10	2.8	17.96	7.0	8.7
	3.9	48.52	13.1	15.5
	5	102.25	20.1	25.5