Content uploaded by Ferit Ficici

Author content

All content in this area was uploaded by Ferit Ficici

Content may be subject to copyright.

International Journal of the Physical Sciences Vol. 5 (6), pp. 804-813, June, 2010

Available online at http://www.academicjournals.org/IJPS

ISSN 1992 - 1950 ©2010 Academic Journals

Full Length Research Paper

The effects of vortex finder on the pressure drop in

cyclone separators

Ferit Ficici*, Vedat Ari and Murat Kapsiz

Technical Education Faculty, Sakarya University, Sakarya, Turkey.

Accepted 25 May, 2010

In this study, three cylinder-shaped vortex finders with diameters of 80, 120 and 160 mm were designed

and manufactured to find out the pressure drop of the cyclones by experimentally investigating the

effects of gas inlet velocity, the vortex finder diameter and length on the cyclone performance at

different gas concentration. As a result of this experimental analysis, a critical diameter of vortex finder

is obtained as 120 mm. Furthermore, analyzing the experimental findings with a statistical regression

method indicated that there was a linear relationship between length of vortex finder and pressure loss.

Then, according to the analysis results, relevance values were obtained as 98.87, 98.37 and 97.59% for

these vortex finders (with diameters of 80, 120 and 160 mm), respectively.

Key words: Cyclone, vortex finder, pressure drop.

INTRODUCTION

Cyclones are devices that employ a centrifugal force

generated by a spinning gas stream to separate particles

from the carrier gas (Gimbun et al., 2005). Cyclone

separators operate under the action of centrifugal forces.

Fluid mixture enters the cyclone and makes a swirl

motion and, due to centrifugal forces, the dense phase of

the mixture gains a relative motion in the radial direction

and is separated from main flow (Avci and Karagoz,

2003). In this design, particle-laden gas enters the

cyclone at the top of the cylinder and makes several

revolutions due to the shape of the entry forming a vortex

with a high tangential velocity which accelerates particles

outward to the wall for collection. Below the bottom of the

gas exit tube, the spinning gas gradually migrates inward,

to a “central core” axially along the cylinder centerline,

and from there up, finally out exit tube (Zhu and Lee,

1999). Their simple design, low capital cost and nearly

maintenance-free operation make them ideal for use as

pre-cleaners for more expensive final control devices

such as baghouses or electrostatic precipitators.

Cyclones are particularly well suited for high temperature

and pressure conditions because of their rugged design

and flexible components materials. Cyclone collection

efficiencies can reach 99 % for particles bigger than 5 µm,

*Corresponding author. E-mail: fficici@sakarya.edu.tr.

and can be operated very high dust loading. Cyclones

are used for the removal of large particles for both air

pollution control and process use (Silva et al.,2003).

Application in extreme condition includes the removing of

coal dust in power plant, and the use as a spray dryer or

gasification reactor (Gimbun, 2005).

Engineers are generally interested in two parameters in

order to carry out an assessment of the design and

performance of a cyclone. These parameters are the

collection efficiency of particle and pressure drop through

the cyclone (Dirgo and Leith, 1985). An accurate predict-

tion of cyclone pressure drop is very important because it

relates directly to operating costs. Higher inlet velocities

give higher collection efficiencies for a given cyclone, but

this also increases the pressure drop across the cyclone.

Therefore, a trade off must be made between higher

collection efficiency and low pressure drop across the

cyclone (Griffiths and Boysan, 1996).

The vortex finder size is an especially important

dimension, which significantly affects the cyclone

performance as its size plays a critical role in defining the

flow field inside the cyclone, including the pattern of the

outer and inner spiral flows. The vortex finder affected the

collection efficiency and pressure drop of cyclones, and

proposed an energy-effective cyclone design (Lim et al.,

2003).

The purpose of this study is to help in understanding of

the pressure drop of cyclones by experimentally exploring

Ficici et al. 805

Figure 1. Reverse flow cyclone.

Table 1. Dimensions of the Tests Cyclone.

Sizes (m)

Dc 0.340 h1 0.272

Dw 0.126 h2 0.374

Dp 0.068 h3 0.05

Hc 0.647 be 0.075

ht 0.0961 hi 0.550

the effects of gas inlet velocity, the vortex finder diameter

and length, at different gas concentration, on the cyclone

performance. The pressure drop of cyclones with 3

different vortex finders diameters have been evaluated

and compared. This study focused on the effects of the

vortex finder diameter on the pressure drop as little work

has been performed on cyclones in relation to this

dimension.

EXPERIMENT

Cyclone geometry

There are a number of different forms of cyclone but the reverse

flow cyclone represented in Figure 1 is the most co mmon design

used in the industry. The cyclone consists of four main parts: the

inlet, the separation chamber, the dust chamber and the vortex

finder. Tangential inlets are preferred for the separation of solid

particles from gases (Atmeyer et al., 2004). Cyclone dimension

used in this simulation are as shown in Table 1. Cyclone tests were

performed on the system as shown in Figure 2.

Definition and composition of the pressure drop

Generally, the pressure drop over a cyclone is the difference of

static pressure between the inlet and outlet, which can be written

as:

si so

P P P

∆ = −

The static pressure at the inlet cross-section is uniformly distributed

because there is no swirling motion. It can be easily measured with

a pressure tapping in the wall. But the static pressure at the outlet

wall is quite different from its cross- sectional average due to the

strong swirling flow. The dynamic pressure stored in the swirling

motion can be significant. The determination of the static pressure

downstream of a cyclone, hence the pressure drop, becomes more

complicated and difficult (Chen and Shi, 2006).

The total pressure drop consists of four partial pressure drops

(Equation 1) pressure drop due to gas expansion at the separators

entrance; (Equation 2) pressure drop due to wall friction within the

separator; (Equation 3) pressure drop due to swirling motion of the

gas (Equation 4); pressure drop due to gas flow through the outlet

pipe (Zhao,2004).

806 Int. J. Phys. Sci.

Figure 2. Schematic diagram of experimental set-up.

Pressure drop due to gas expansion at the separator entrance

Pressure drop due to gas expansion at the separator inlet was

determined as follows:

1

( )

2

in in g in

P v

ξ ρ

∆ = (1)

This pressure drop was calculated for the case of uniform flow from

the right pipe to the limited space, and was expressed as:

1

( )

Rw

ev

w e re

v v dr

R r

θ θ

=−

2

1( )

in

w e

ab

R r H

ξ

= − − (2)

Pressure drop due to wall friction within the separator

Pressure drop due to wall friction within the separator can be

described under static equilibrium in the cyclone separators:

2 2

1

1

( ) ( )

4eev

fr

P D d c DL

θ

π τ π

∆ − = (3)

1

c

is a swirling flow correction factor related to the uniform flow at

the wall in the cyclone separator. According to Stepherd and

Lapple’s method:

1

D

c

a

π

= (4)

ev

θ

τ

is the mean shear stress of the gas in the external vortex, and

can be calculated in terms of Fanning’s equation as:

1

( ).

2

g

ev ev

f v DL

θ θ

τ ρ π

= (5)

where

0.0055

f

=

.

w

v

θ

is the mean tangential velocity in the external vortex, and can

be obtained from:

1

( )

Rw

ev

w e re

v v dr

R r

θ θ

=−

(6)

Combining the above equations gives:

2

2

2 2

( / )( ) 1 1

( )

1/4 ( ) ( ) 2

Rw

g in

fr

e w e in re

D a DL f

P v dr v

D d R r v

θ

π π ρ

π

∆ = − − (7)

Pressure drop due to swirling motion of the gas

From the Navier-Stokes equation in cylindrical coordinates, the

relationship between pressure and 3D velocity can be simplified by

neglecting the axial effects:

2

g

v

dp

dr r

θ

ρ

= (8)

According to Mothes and Loffler (1988) the circumferential flow

pattern or velocity profile including the wall roughness is expressed

as follows:

( / ) 1 (1 / )

w

w w

v

vr R P r R

θ

θ

=+ − (9)

1 1

( . )

4 2

.

d w

w

d

vv

v h v

h

θ

θ

ξ

ξ

∗

∗

∗

= + −

(10)

2

0.204( / ) 0.889

w

wd

w

R

v v ab b R

θ

π

∗

=− + (11)

2

d

w

Q

v

R

π

= (12)

2

2 arccos( / 1)

2

w

w w

b R

a h

h

R R

π

π

∗

− −

= + (13)

( )

sin

w

d

v

Pv

θ

ζ

ζ

ε

= + (14)

( )

in

Q ab v

=

(15)

Where

0.0065 0.0075

ζ

= −

Although the expression for

v

θ

looks complicated, the result

agrees very well with the typical velocity profile based on the power-

law correlation of Alexander (1949). The advantage of this

expression is that it presents a quantitative value of the tangential

velocity at the edge of the core,

w

v

θ

∗

, which has sometimes been

assumed equal to the inlet velocity.

Combining and transforming the above equations gives:

2 2

2

2 2

2( / ) ( / ) 1

( )

( / ) (1 / ) 2

Rw

w

wd

g in

Pvf

w r w

re

v v ab R

dr v

r r R P P R

θ

πρ

∆ = + −

(16)

Pressure drop due to gas flow through the outlet pipe

This pressure drop includes the local pressure drop and the friction

Ficici et al. 807

pressure drop within outlet pipe.

out

ol of

p p p

∆ = ∆ + ∆

(17)

The local pressure drop was handled as gas flow contraction loss

from the cyclone body to the outlet pipe:

2 2 2

2

1 1

( ) 1 ( ) ( )

2 2

e

g in

ol

e

r

ab

v

r Rw

ξ ρ

π

= − (18)

Because of the strong swirling flow in the outlet pipe, this pressure

drop was calculated in an analogous way to the pressure drop due

to wall frictions within the separator:

2

2

1

( ) . ( )

4

e e

iv

ol

p d c d s s

θ

π τ π

′

∆ = + ∆

(19)

'

2

e

e

d

c

d

π

= (20)

2

1

( )

2

g

iv iv

f v

θ θ

τ ρ

= (21)

Where

iv

θ

τ

is the mean shear stress of gas in the internal vortex,

and

iv

v

θ

is the mean tangential velocity in the internal vortex, and

can be obtained by assuming it to be equal to the tangential velocity

at

e

r r

=

:

( / )(1 Pr / )

w

iv

e w e w

v

v

r R P R

θ

θ

=+ − (22)

Combining and transforming the above equations yields:

2

2

2

/

( )

1/4 ( / )(1 Pr / )

wd

of

e e w e w w

v v

S S f ab

d r R P R R

θ

π

ξπ π

+∆

=+ − (23)

Total pressure drop

Su mming up, the equation for total pressure drop can be

expressed as:

in out

fr vf

p p p p p

∆ = ∆ + ∆ + ∆ + ∆

(24)

The pressure drop across a cyclone is co mmonly expressed as the

number of gas inlet velocity heads

ξ

, named the pressure drop

coefficient (PDC), which is just a function of the cyclone geometrical

dimensions. It is accordingly defined as:

2

1/ 2 g

in

p

v

ξρ

∆

= (25)

808 Int. J. Phys. Sci.

Figure 3. Cyclone vortex finder adjusting mechanism

Test procedure

In the experiment (Figure 2), chimney gas of 1100°C is produced

with a diesel oil burner (1). Cyclone inlet flow is measured with a

pitot tube. The necessary gas flow is adapted by tuning the cycle

number of the exiting ventilator. Desired amount of far is supplied

into the system by a loading unit (2) before the entrance of the

testing cyclone (6) and after regime is established, the measures

are recorded. These measuring results recorded as analog signals

are evaluated at Data collecting and Controlling System which is

conducted by a PC. In the experiment, the temperature is

measured at seven different places beginning from the entrance up

to the existence as TG, 1, 2, 3, 4, 5, C with the help of a

thermocouple. Moreover, pressures at the entrance and existence

of cyclones are measured and their difference is calculated as

pressure drop (Ari, 2000).

In the experiments, pressure decrease, change at vent depth of

cyclone vortex finder, cyclone entrance velocity, entrance

temperature and entrance concentration are chosen as varying

parameters and pressure drop are investigating according to these

parameters.

The mechanism designed for investigation of the powder

suppression efficiency and pressure drop according to cyclone

vortex finder insert depth are shown in Figure3. The depth of vortex

finder insert depth, here is denoted as h4 and varies from 10 up to

220 mm in length. Experimental program consists of 3 main groups.

First, cyclone, vortex finder diameter of which is changed, is

adapted to experiment set-up. For finding the pressure drop and

powder suppression efficiencies according to change in depth of

vent of the vortex finder, ventilator cycle is stabilized as the flow

velocity would be 12.44 m/s for each vent length and regime of the

system is waited for. Then, 0.566 kg/ m3 farin is loaded to system.

After loading, the decrease of the system entrance temperature to a

constant value is waited for. After that process, other test data,

cyclone entrance temperature, flow measure temperature, cyclone

temperature of conic section, cyclone temperature of cylindrical

section, storing temperature of farin, cyclone entrance and existing

temperatures are recorded by taking the correct values from Control

Unit. Stopping the test, farin, which is and preheated raw material of

cement (limestone kalker+clay) and taken from cyclone powder

reservoir, is carefully collected and weighed out.

At second group of tests, cyclone characteristics for changing

velocities are measured which is increased from 9.5 m/s up to

10.18 m/s. Here, the powder concentration is fixed.

At third and final group of tests, tests are repeated for increasing

behavior of particle concentration.

At each experiments with particles and without particles,

measured values are recorded (Ficici, 2006).

RESULTS AND DISCUSSION

Dependencies at pressure drop according to length of

vortex finder, inlet velocity and concentration for three

different types of vortex finders with different vortex finder

diameters are investigated at the experiments. These

diameters are taken as 80,120 and 160 mm.

Effects of length of vortex finder

The cyclone pressure drops for the different vortex finder

are compared at different length of vortex finder in

Figure4 and Fig5. Figure 5 shows that pressure drop

increases as vortex finder length increases. This situation

is observed for all cyclones. Under these conditions there

is, however, poor separation of coarse particles. The

main reason is that large quantities of coarse particles

bypass the separation process via the short circuit flow

under the top cover and report to the overflow. Extension

of the vortex finder, however, shortens the natural vortex

in the cyclone body and reduces the opportunity of the

fine particles to separate from the vortex. This has been

confirmed for cyclones (Fuping et al., 2006; Martinez et

al., 2008).

In these experiments, pressure drop measured betw-

een entrance and exit points of cyclone are displayed

graphically. According to these results, an increase at

pressure drops is determined depending on the dia-

meters of vortex finder. When we increase the diameter

of vortex finder to 120 mm in the test cyclone with a

diameter of 80 mm, this pressure drop is increased while

a further decrease in diameter to 160 mm causes the

pressure drop to approach to the measured values of the

case with 80 mm diameter. This situation tells us that up

to a critical diameter of vortex finder, pressure drop shows

Ficici et al. 809

y = 7.726x + 11.60

R² = 0.988 y = 7.571x + 0.678

R² = 0.983

y = 6.595x - 3.678

R² = 0.975

0

10

20

30

40

50

60

70

80

10 50 90 96 130 170 210 220

Pressure Drop (Pa)

Length of Vortex Finder (mm)

80 mm

120 mm

160 mm

Figure 4. The effect of length of vortex finder on pressure drop.

Figure 5. Effect of length of vortex finder on pressure drop.

shows a climbing behavior and for further increasing

diameters after that absolute diameter value (120 mm), a

sinking behavior is observed. This finding is verified in

other studies of literature (lim et al., 2003; Cullivan et al.,

2004).

In addition, experimental results were also analyzed

with statistical regression method. As a result of

analyzing the experimental results with such a statistical

method, it was observed that there was a linear

relationship between length of vortex finder and pressure

loss. According to the analysis results, relevance values

were obtained as 98.87, 98.37 and 97.59% for lengths of

vortex finder considered as 80, 120 and 160 mm,

respectively. Table 2 shows the using regression

equations.

Effects of inlet velocity

Measurement of the cyclone pressure drop was carried

out for average inlet velocity ranging from 4.62 to 14.16

m/s by Bohnet (Bohnet, 1995) and from 5.1 to 25 m/s by

Griffiths and Boysan (1996). In this study, measurement

of the cyclone pressure drop was carried out for inlet

velocity ranging from 9.56 to 10.18 m/s. The cyclone

pressure drops for the different vortex finder are compar-

810 Int. J. Phys. Sci.

Table 2. Static analysis of length of vortex finder

Regression R2 F Sigf

0

1

80 mm 0.9887 1184.11 0.00 7.7262 11.607

120 mm 0.9837 1124.90 0.00 7.5714 0.6786

160 mm 0.9759 1555.20 0.00 6.5952 3.6786

y = 16.65x + 19.53

R² = 0.948

y = 16.31x + 36.4

R² = 0.959

y = 16.65x + 56.53

R² = 0.948

0

20

40

60

80

100

120

140

160

180

9.56 9.73 9.81 9.98 10.02 10.18

Pressure Drop (Pa)

Average of Inlet Velocity (m/s)

80 mm

120 mm

160 mm

Figure 6. Pressure drops of the cyclone separator with different vortex finder diameter.

Figure 7. Effect of average inlet velocity on pressure drop.

ed at different inlet velocities in Figures 6 and 7. These

Figures show that the cyclone pressure drop is increased

with the all vortex finder diameter. At a low inlet velocity,

the pressure drop increases slowly, and at a higher inlet

velocity, the pressure drop increases greatly (Gimbun et

al., 2005).

Additionally, in this experiment when the velocity of gas

with particles is increased, pressure drops at each

cyclone with three vortex finder diameters differ from

each other. With this fact, it is observed that the diffe-

rence of this pressure drop is decreasing when diameter

of vortex finder value is changed from 80 to 120 mm. A

Ficici et al. 811

Table 3. Static analysis of inlet velocity

Regression R2 F Sigf

0

1

80 mm 0.9482 74.44 0.01 16.657 56.533

120 mm 0.9593 54.80 0.02 16.314 36.400

160 mm 0.9482 54.80 0.02 16.657 19.533

y = 22.5x + 12

R² = 0.810

y = 15.7x +

59

R² = 0.

983

y = 24.7x + 60.5

R² = 0.975

0

20

40

60

80

100

120

140

160

180

0.23

0.38

0

.

52

0

.

67

Pressure Drop (Pa)

Figure 8. The effect of inlet farin concentration on pressure drop.

Table 4. Static analysis of inlet farin concentration

Regression R

2

F Sigf

0

1

80 mm 0.8106 74.44 0,096 16.657 56.533

120 mm 0.9838 54.80 0,007 16.314 36.400

160 mm 0.975 54.80 0,011 16.657 19.533

further increase up to 160 mm, again these differences of

losses become lower. The increase of entrance velocity

is very much related with cycle number of swirl. Since the

swirl cycle number will be much for smaller diameters of

vortex finder, pressure drop is higher than losses at

greater diameters. The conclusion presented in this study

is consistent with the literature (Fuping and Yanpeng,

2009). In addition, According to the regression analysis

results, relevance values were obtained as 94.82, 95.93

and 94.82 % for length of vortex finder considered as 80,

120 and 160 mm, respectively. Table 3 shows the using

regression equations.

Effects of inlet farin concentration

The cyclone pressure drops for the different vortex finder

are compared at different inlet farin concentration in

Figures 8 and 9. In this study, experiments are carried on

with cyclone concentrations are varied between 0.19

kg/m3–0.55 kg/m3. As the farin concentration is increas-

ed, the pressure drop, as expected, also increases. This

finding has been observed by many researchers (Kim

and Lee, 1990; Saltzman and Hochstrasser, 1983; Dirgo

and Leith, 1985; Dirgo and Leith, 1985; Moore and

Mcfarland, 1993).

Furthermore, Pressure loss is highest at cyclone with

160 mm diameter. The reason is that, number of swirls is

less at this diameter. Thus, higher pressure loss is seen

at 160 mm. Table 4 shows that relevant values were

obtained as 81.06, 98.38, and 97.5% for length of vortex

finder considered as 80, 120 and 160 mm, respectively.

Conclusions

As a result of this experimental research and data from it,

a critical diameter of vortex finder is obtained. This is

812 Int. J. Phys. Sci.

Figure 9. Effect of inlet farin concentration on pressure drop.

determined as 120 mm. A desired result has not been

obtained according to cyclone collection efficiency

despite the fact that further increase in diameter lowered

the pressure drops. That means that pressure drop can

be lowered with increasing diameter, however efficiency

of collection is lost then. In this research, the theoretical

argument of critical vortex finder is experimentally

proved.

ACKNOWLEDGEMENT

The authors would like to thank the Nuh Cement A.S for

financial and technical supports.

NOMENCLATURE

a [m] inlet height

b [m] inlet width

B [m] particle outlet diameter

c [-] swirling flow correction factor

D [m] cyclone body diameter

de [m] gas outlet diameter

h [m] cyclone cylinder height

H [m] cyclone height

L [m] natural length of cyclone

p [Pa] pressure

P [-] parameter of momentum

exchange between gas at the

wall

Q [m3/s] volumetric gas flow rate

r [m] radial dimension

Rw [m] cyclone body radius

re [m] vortex finder radius

S [m] gas outlet duct deep length

S [m] gas outlet duct extend length

Greek symbols

e [rad] the cone slope

g [kg/m3] gas density

t [Pa] shear stress

[m/s] gas velocity

[-] the pressure drop coefficient

[-] the wall friction coefficient

Subscripts

d cyclone body

g gas

e near the exit or vortex finder

fr friction

in cyclone inlet

iv internal vortex

ol outlet local loss

of outlet friction loss

out cyclone outlet

vf vortex flow

tangential coordinate directions

r radial coordinate directions

w near the wall

REFERENCES

Alexander RM (1949). Fundamentals of cyclone design and operation,

Proc. Aust. Inst. Min. Met. 152: 203.

Altmeyer S, Mathieu V, Jullemier S, Contal P, Midoux N, Rode S,

Leclerc JP (2004). Comparison of different models of cyclone

prediction performance for various operating conditions using a

general software. Chem. Eng. Process., 43: 511-522.

Ari V (2000). An Experimental investigation on the pre-heater cyclone

reactors utilizing in cement industry. Ph.D Thesis, Sakarya

University.

Avci A, Karagoz I (2003). Effects of flow and geometrical parameters on

the collection efficiency in cyclone separators. J. Aerosol Sci. 34:

937-955.

Bohnet M (1995). Influence of the gas temperature on the separation

efficiency of aerocyclones., Chem. Eng. Process, 34: 151–156.

Chen J, Shi M (2006). A Universal Model to Calculate Cyclone Pressure

Drop., Powder Technol. 171: 184-191.

Cullivan JC, Williams RA, Dyakowski T, Cross CR (2004). New

understanding of a hydrocyclone flow field and separation mecha-

nism from computational fluid dynamics. Minerals Eng. 17: 651-660.

Dirgo J, Leith D (1985). Performance of theoretically optimized

cyclones, Filtration & Separation. pp. 119.

Dirgo J, Leith D (1985). Performance of theoretically optimized

cyclones”, Aerosol Sci. Technol. 12: 673-685.

Dirgo J, Leith D (1985). Cyclone collection efficiency: Comparison of

experimental results with theoretical predictions., Aerosol Sci.

Technol. 4: 401-411.

Ficici F (2006). An experimental investigation on the effect of vortex

finder diameter change in cyclones to the flow parameters.,Ms.C

Thesis, Sakarya University.

Fuping Q, Yanpeng W (2009). Effects of the inlet section angle on the

separation performance of a cyclone. Chem. Eng. Res. Design, 87:

1567-1572.

FupingQ, Jiguang Z, Mingyao Z (2006). Effects of the prolonged vertical

tube on the separation performance of a cyclone. J. Hazard. Mater.

B, 136: 822-829.

Gimbun J, Chuah TG, Choong TSY, Fakhr’ul-Razi A (2005). Prediction

of the effects of cone tip diameter on the cyclone performance. J.

Aerosol Sci. 36: 1056-1065.

Gimbun J, Chuah TG, Fakhr’ul-Razi A, Choong TSY (2005). The

influence of temperature and inlet velocity on cyclone pressure drop:

a CFD study” Chem. Eng. Process. 44: 7-12.

Ficici et al. 813

Griffiths WD, Boysan F (1996). Computational fluid dynamics (CFD) and

empirical modelling of the performance of a number of cyclone

samplers. J. Aerosol Sci. 27: 281-304.

Kim JC, Lee KW (1990). Experimental-study of particle collection by

small cyclones, Aerosol Sci. Technol., 12: 1003-1015.

Lim KS, Kwon SB, Lee KW (2003). Characteristics of the collection

efficiency for a double inlet cyclone with clean air, J. Aerosol Sci. 34:

1085-1095.

Martinez LF, Lavin AG, Mahamud MM, Bueno JL (2008). Vortex finder

optimum length in hydrocyclone separation., Chem. Eng. Process.

47: 192–199.

Moore ME, Mcfarland AR (1993). Performance modeling single-inlet

aerosol sampling cyclone.” Environ. Sci. Technol. 27: 1842-1848.

Mothes H, Löffler F (1988). Int. Chem. Eng. 28:231.

Saltzman BE, Hochstrasser JM (1983). Design and performance of

miniature cyclone for respirable aerosol sampling, Environ. Sci.

Technol. 17: 418-424.

Silva PD, Briens C, Bernis A (2003). Development of a new rapid

method to measure erosion rates in laboratory and pilot plant

cyclones. Powder Technol. 131: 111-119.

Zhao B (2004). A Theoretical Approach to Pressure Drop across

Cyclone Separators, Chem. Eng. Technol. 27: 10.

Zhu Y, Lee KW (1999). Experimental Study On Small Cyclones

Operating at High Flowrates” J. Aerosol Sci. 30: 1303-1315.