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03_chap_wang.qxd 05/05/2004 12:48 pm Page 118
118 José Renato Coury et al.

Table 6
Results from the Calculation of the Particle Size Distribution in the Cyclone Exit.
Range (µm) D (µm) η (20 m/s) η x (20 m/s) m (kg/s) x (in mass)
i i i i oi oi
0–1 0.5 0.00226 0.0000226 3.6158E-05 0.138877
1–2 1.5 0.07690 0.0015380 6.6906E-05 0.256976
2–4 3 0.44728 0.0178910 8.0123E-05 0.307739
4–6 5 0.81212 0.0487270 4.0853E-05 0.156911
6–8 7 0.92874 0.0742990 2.0661E-05 0.079354
8–10 9 0.96745 0.0967446 1.1798E-05 0.045312
10–20 15 0.99374 0.1291862 2.9493E-06 0.011328
20–30 25 0.99882 0.1498233 6.4035E-07 0.002459
30–40 35 0.99961 0.1199531 1.7004E-07 0.000653
40–50 45 0.99983 0.0999828 6.2154E-08 0.000239
50–60 55 0.99991 0.0699938 2.2529E-08 8.65E-05
60–70 65 0.99995 0.0499974 9.3040E-09 3.57E-05
70–80 75 0.99997 0.0399987 4.6551E-09 1.79E-05
80–90 85 0.99998 0.0199996 1.5439E-09 5.93E-06
90–100 95 0.99998 0.0099999 5.3597E-10 2.06E-06
Σ η x = 0.93 Σ m = 2.604E-4 Σ x = 1.0
i i oi oi

From Example 1, the pressure drop in cyclone operating with a particle-free gas at 20 m/s
was estimated using
∆P at c in 0 = 1510 Pa
=
Therefore, Eq. (35) gives

∆P
at c in . 0 013 8 ( .7) . 05
= 1 −
1510 Pa
∆P at c in = 1452 Pa

3. COSTS OF CYCLONE AND AUXILIARY EQUIPMENT*
3.1. Cyclone Purchase Cost
Cyclones are used upstream (60) of particulate control devices (e.g., fabric filters,
ESPs) to remove larger particles entrained in a gas stream. Equation (44) yields the cost
of a carbon steel cyclone with support stand, fan, and motor, and a hopper or drum to
collect the dust:
0.9031
P cyc = 6250A cyc (44)

*This subject is also presented in the chapter “Technical, Energy and Cost Evaluation of Air Pollution
Control Technologies”, by L. K. Wang et al. in Volume 2 of the Handbook of Environmental Engineering
series. The examples given here were taken from that chapter.