Characterization of particle collection efficiency in an ionizing wet scrubber

The primary objectives of this study were to characterize and quantify the particle collection efficiency of an ionizing wet scrubber (IWS). The system tested consisted of a cross-flow packed bed pre-scrubber, an ionizer, and a second cross-flow packed bed scrubber in series. The penetration of the system was studied as a function of particle diameter, gas flowrate, and packing media used in the scrubbers. Studies were conducted at gas flowrates of 500, 900 and 1100 ft³/min (specific collector areas of 62.6, 34.8 and 28.5 respectively), for particle diameters ranging from 0.118 - 5.0 microns. Three types of packing were studied. Three equations were developed as a function of specific collector area to describe the behavior of the IWS, which consists of an ionizer and a packed bed in series. The models have the following forms:

IWS: 62.6 SCA (For d_p= 0.075 - 3.2μ: d_a=0.12 - 5.0μ)

Pt_(62.6)IWS= exp [- (-0.48 d_p² + 3.07 d_p + 2.02)]

X [0.006199 d_a³ - 0.060103 d_a² + 0.011302 d_a + 0.77037]^(L/8)

IWS: 34.8 SCA (For d_p= 0.075 - 3.2μ: d_a=0.12 - 5.0μ)

Pt_(34.8)IWS = exp [- (-0.43 d_p² + 2.60 d_p + 1.20)]

X [0.006199 d_a³ - 0.060103 d_a² + 0.011302 d_a + 0.77037]^(L/8)

IWS: 28.5 SCA (For d_p= 0.075 - 3.2μ: d_a=0.12 - 5.0μ)

Pt_(28.5)IWS = exp [- (-0-66 d_p² + 2.93 d_p + 0.74)]

X [0.006199 d_a³ - 0.060103 d_a² + 0.011302 d_a + 0.77037]^(L/8) where Pt is the fractional penetration, d_p is the physical diameter of the particle in microns, d_a is the aerodynamic diameter of the particle in microns, and L is the depth of wetted packing in the direction of gas flow in feet.