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03_chap_wang.qxd 05/05/2004 12:48 pm Page 119
Cyclones 119

where P is the cost of the cyclone (August 1988 US$) and A is the cyclone inlet area (ft 2
cyc cyc
2
[0.200 ≤ A ≤ 2.64 ft ]).
cyc
The cost of a rotary air lock for hopper or drum is given by
P = 2730A 0.0985 (45)
ral cyc
where P is the cost of a rotary air lock (August 1988 US$) and A is the cyclone inlet
ral cyc
2
2
area (ft [0.350 ≤ A ≤ 2.64 ft ]).
cyc
The cost of the complete cyclone unit is given by the sum of P and P .
cyc ral
3.2. Fan Purchase Cost
In general, fan costs are most closely correlated with fan diameter (see Chapter 7 for a
detailed fan design). Equations (46)–(48) can be used to obtain fan prices. Costs for a car-
bon steel fan motor ranging in horsepower from 1 to 150 hp are provided in Eqs (49) and
(50). Equation (47) or (48) is used in conjunction with Eqs. (49) or (50), respectively.
The cost of a fan is largely a function of the fan wheel diameter, d , which, in turn,
fan
is related to the ductwork diameter. The fan wheel diameter can be obtained for a given
ductwork diameter by consulting the appropriate manufacturer’s multirating tables or
by calling the fan manufacturer.
For a centrifugal fan consisting of backward-curved blades including a belt-driven
motor and starter and a static pressure range between 0.5 and 8 in. of water, the cost as
a function of fan diameter (d ) in July 1988 dollars is provided by
fan
P fan = 42.3d 1.20 (46)
fan
where P is the cost of the fan system (July 1988 US$) and d is the fan diameter (in.
fan fan
[12.25 ≤ d ≤ 36.5 in.]).
fan
The cost of a fiber-reinforced plastic (FRP) fan, not including the cost of a motor or
starter, is provided by Eq. (47). The cost of a motor and starter as obtained in Eq. (49)
or (50) should be added to the fan cost obtained in Eq. (47):
P fan = 53.7d 1.38 (47)
fan
where P is the cost of the fan without motor or starter (April 1988 US$) and d is
fan fan
the fan diameter (in. [10.5 ≤ d ≤ 73 in.]).
fan
A correlation for a radial-tip fan with weld, carbon steel construction, and an operat-
ing temperature limit of 1000°F without a motor or starter is provided by Eq. (48). The
values for the parameters a and b are provided in Table 7.
f f
P = a d b f (48)
fan f fan
where P is the cost of the fan without motor or starter (July 1988 US$), a and b are
fan f f
obtained from Table 7, and d is the fan diameter (in.).
fan
The cost of fan motors and starters is given in Eq. (49) or (50) as a function of the
horsepower (hp) requirement (W ). The cost obtained from either of these equations
c
should be added to the fan cost obtained in Eq. (47) or (48). For low horsepower
requirements,
P = 235hp 0.256 (49)
motor