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03_chap_wang.qxd 05/05/2004 12:48 pm Page 114
114 José Renato Coury et al.

d = 0.096 m
c
Z = 1.057 m
c
v tmax = 23.6 m s
×
−
D = 3.7 10 m = 3.7 m
µ
6
50
β= 2.89
The collection efficiency is
η = 1 with D in micrometers.
i [ 1+ (3.7 D i ) 2.89 ] i

For v = 20 m/s
i
d = 0.096 m
c
Z = 1.057 m
c
v tmax = 31.5 m s
−
µ
6
D = 3.2 × 10 m = 3.2 m
50
β= 3.28
and the efficiency is
1
η = [ 1+ (3.2 D i ) 3.28 ] with D in micrometers.
i
i

Figure 6 shows the efficiency curves obtained with the Iozia and Leith model compared to
the experimental results of Dirgo and Leith (17), for the same operating conditions.
By looking at Figs. 4–6, it can be verified that the Iozia and Leith model provided the best
prediction in the studied conditions. However, it is worth noting that the model underesti-
mated the collection efficiency of the larger particles (see Fig. 6). The Barth model provid-
ed an efficiency curve with an adequate slope, but displaced to the right of the experimen-
tal points, as can be seen in Fig. 4. This is probably the result of the calculated values of
v , underestimated by Eq. (5). The Leith and Licht model provided the worst prediction
tmax
of the three, overestimating the efficiency of the smaller particles and underestimating the
larger ones (see Fig. 5).

2.5.1. Pressure Drop and Power Consumption
The pressure drop in the cyclone can be estimated by Eq. (31), with ∆H given by Eq.
(32), (33), or (34). Note that, in SI units, the resulting ∆P is in Pascals (Pa).
The power, W , consumed by the fan in order to maintain the required volumetric flow
c
rate in the cyclone can be estimated by a correlation given by Cooper and Alley (30):
∆
W = QP (43)
c
E f
where E is the fan efficiency.
f