dD

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droplet
particle
dD
xS
Stream lines
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Single droplet collection efficiency (Calvert
Equation)
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Photo courtesy of Fisher-Klosterman, Inc .
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QL
QG
L
?Z
G
Flux from gas to liquid Flux into liquid phase

(volume swept/time) x Concentration x Efficiency
-QG dC
Volume swept per time Number of drops swept x
Drop residence time x volumetric flux
Thus
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Solve equation to get the overall efficiency of
the scrubber
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Spray tower collection efficiency
Collection efficiency as function of droplet and
particle size adapted from Wark Warner
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Cyclone Spray Chamber Impingement Scrubber
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Cyclonic Spray Tower
Venturi Scrubber
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Venturi Scrubber
High efficiency even for small particles.
QL/QG 0.001 - 0.003 VG 60 - 120 m/s
Handbook of Air Pollution Control Engineering
Technology, Mycock, McKenna Theodore, CRC Inc.,
1995.
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Calvert Equation for Venturi Scrubber
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Figure 5.24 (page 245) in the textbook provides a
nomograph for dimensionless throat length (?)
with ln (Pt)/B.
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Contacting Power Approach When compared at the
same power consumption, all scrubbers give the
same degree of collection of a given dispersed
dust, regardless of the mechanisms involved and
regardless of whether the pressure drop is
obtained by high gas flow rate or high water
flow rate
Venturi scrubber collecting a metallurgical fume
Contacting power, hp/1000 cfm
Nt Number of transfer unit (unitless)
(PT in hp / 1000 acfm)
(1 inch of water 0.1575 hp/1000 cfm)
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