Cyclone separators utilize centrifugal force to separate solid or liquid particles from gases. They have no moving parts and are available in various sizes. Gas enters tangentially, creating a spiral that forces particles to the inner walls. Particles exit through an underflow pipe while gas reverses direction and exits the vortex finder. Key design parameters include inlet dimensions and vortex finder diameter, with larger finders and inlets improving efficiency but also increasing pressure drop. Cyclones are commonly used in industrial applications like power plants and mineral processing due to their low cost and maintenance requirements.

1. Cyclone Separator
Presented By:
Rahil Goel (13112070)
Rajat Verma (13112071)
Rakesh Lahre (13112072)
Ramlal (13112073)
Ranjan Tak (13112074)
Group No. 28

2. Overview
• Basic Definition
• Objectives
• Working Principle
• Design Procedure
• Types
• Advantages/Disadvantages
• Industrial Usage

3. A centrifugal separator
stationary mechanical device that utilizes centrifugal force to separate
solid or liquid particles from a carrier gas
What it is…
Cyclones have no moving parts and available in many shapes and sizes, for example from the small 1
and 2 cm diameter source sampling cyclones which are used for particle size analysis to the large 5 m
diameter cyclone separators used after wet scrubbers.

4. Classification of the
dust collectors…

5. The flow enters near the top
through the tangential inlet, which gives rise to an axially descending spiral
of gas and a centrifugal force field that causes the incoming particles
to concentrate along, and spiral down, the inner walls of the cyclone separator.
Working principle
The collected particulates are allowed to exit out an underflow pipe while the
gas phase reverses its axial direction of flow and exits out
through the vortex finder (gas outlet tube) .

6. Lets make things a bit
clear… Vortex Finder
Tangential inlet duct
Barrel
Cone
Dust Collector

7. Design procedures

8. Vertical cyclone separator
Horizontal cyclone separator
Multiple cyclone separator Single cyclone separator
TYPES

9. Design Parameters
a = inlet height
b = inlet width
Dx = vortex finder diameter
Ht = total height of cyclone
h = cylinder height
S = Vortex finder diameter
Bc = cone tip diameter

10. Design of experiment (DOE)
The statistical analysis is performed through three main steps.
1) Construct a table of runs with combination of values of the independent variables via the commercial
statistical software STATGRAPHICS centurion XV by giving the minimum and maximum values of the seven
geometrical factors under investigation as input.
Table depicts the parameters ranges selected for the seven geometrical parameters. The study was planned using
Box–Behnken design, with 64 combinations. A significant level of P<0.05 (95% confidence) was used in all tests.
Analysis of variance (ANOVA) was followed by an F-test of the individual factors and interactions
http://www.sciencedirect.com/science/article/pii/S0009250910005245

11. Analysis of variance (ANOVA) showed that the resultant quadric polynomial models adequately
represented the experimental data with the coefficient of multiple determination R2 being 0.92848. This
indicates that the quadric polynomial model obtained was adequate to describe the influence of the
independent variables studied . Analysis of variance (ANOVA) was used to evaluate the significance of the
coefficients of the quadric polynomial models .For any of the terms in the models, a large F-value (small P-
value) would indicate a more significant effect on the respective response variables.
2) Perform the runs by estimating the pressure drop
(Euler number).

13.  Based on the ANOVA results presented in above table , the variable with the largest effect on the
pressure drop (Euler number) was the linear term of vortex finder diameter, followed by the
linear term of inlet width and inlet height (P<0.05); the other four linear terms (barrel height,
vortex finder length, cyclone total height and cone tip diameter) did not show a significant
effect (P>0.05). The quadric term of vortex finder diameter also had a significant
effect (P<0.05) on the pressure drop; however, the effect of the other six quadric terms was
insignificant (P>0.05). Furthermore, the interaction between the inlet dimensions and vortex
finder diameters (P<0.05) also had a significant effect on the pressure drop, while the effect of
the remaining terms was insignificant (P>0.05).

14. Most significant factor on the Euler number are
 The vortex finder diameter, with a second-order curve with a wide range of inverse relation and a narrow
range of direct relation,
 Direct relation with inlet dimensions,
 Inverse relation with cyclone total height and insignificant effects for the other factors.
3) fill in the values of pressure drop in the STATGRAPHICS worksheet and obtain the response surface
equation with main effect plot, interaction plots, Pareto chart and response surface plots beside the
optimum settings for the new cyclone design.

15. Cyclone collector design consideration
• Particle size ( particles with larger mass being subjected to greater force),
• Force exerted on the dust particles
• Time that the force is exerted on the particles

16. Mathematical models and equations
 fluid mechanics and particle transport equation
 air into the cyclone with an inlet velocity Vin.
 Assuming that the particle is spherical, a simple analysis to calculate critical separation particle sizes.
 considers an isolated particle circling in the upper cylindrical component of the cyclone at a rotational
radius of r from the cyclone's central axis,
the particle is therefore subjected to drag, centrifugal, and buoyant forces.
 The fluid velocity is moving in a spiral the gas velocity.
 Velocity can be broken into two component velocities:
 a tangential component, Vt, and an outward radial velocity component Vr

18.  Assuming Stokes' law,
the drag force in the outward radial direction that is opposing the outward
velocity on any particle in the inlet stream is:
 Using ρp as the particles density, the centrifugal component in the outward radial direction is:
 . Using ρf for the density of the fluid, the buoyant force is:
• Optimization of the cyclone separator geometry for minimum
pressure drop using mathematical
• Models and CFD simulations, Vrije Universiteit Brussel,
Department of Mechanical Engineering, Research Group Fluid
Mechanics and Thermodynamics, Pleinlaan 2, B-1050 Brussels,
Belgium
Source

19.  Vp is equal to the volume of the particle (as opposed to the velocity).
 Outward radial motion of each particle is found by setting Newton's second law of motion equal
to the sum of these forces:
 To simplify this, we can assume the particle under consideration has reached "terminal velocity",
i.e., that its acceleration dVr/dt is zero.
 This occurs when the radial velocity has caused enough drag force to counter the centrifugal and
buoyancy forces. This simplification changes our equation to:

20.  Which expands to:
 Solving for Vr we have
 density of the fluid > the density of the particle, the motion is (-), toward the center of rotation
 density of the fluid <the density of the particle, the motion is (+), away from the center.
 In non-equilibrium conditions when radial acceleration is not zero, the general equation from
above rearrange to

21. • Since Vr is distance per time, this is a 2nd order differential equation of the form :
 Experimentally it is found that the velocity component of rotational flow is proportional to r2 ,

22. Limitations and Alternate models
 the geometry of the separator is not considered, the particles are assumed to achieve a steady
state.
 A major limitation of any fluid mechanics model for cyclone separators is the inability to predict
the agglomeration of fine particles with larger particles, which has a great impact on cyclone
collection efficiency.
 computational fluid dynamics (CFD) is a conventional method of predicting the flow field and the
collection efficiency of a cyclone .
 Three models in cyclone simulation: k–ε model, algebraic stress model (ASM) and RSM.
 The k–ε model adopts the assumption of isotropic turbulence, so it is not suitable for the flow in a
cyclone which has anisotropic turbulence.
 ASM cannot predict the recirculation zone and Rankine vortex in strongly swirling flow.
 RSM forgoes the assumption of isotropic turbulence and solves a transport equation for each
component of the Reynolds stress. It is regarded as the most applicable turbulent model for
cyclone flow.
 To predict the mean particle diffusion in turbulent flow, both Lagrangian and Eulerian techniques
can be used.

23. Advantages of cyclones are
• the collected product remains dry and, normally useful.
• low capital investment and maintenance costs in most
applications.
• very compact in most applications.
• can be used under extreme processing conditions
• can be fabricated from plate metal or, in the case of smaller
units,
• can, in some processes, handle sticky or tacky solids with
proper liquid irrigation.
• can separate either solids or liquid particulates; sometimes
both.
• no moving parts.
• very robust.

24. Some disadvantages of cyclones are
 low efficiency for particle sizes below their ‘cut-off diameter when operated under low solids-
loading conditions.
 usually higher pressure loss than other separator types, including bag filters and low pressure drop
scrubbers.
 subject to erosive wear and fouling if solids being processed are abrasive or ‘sticky.

25. • ship unloading installations
• power stations
• spray dryers
• fluidized bed and reactor riser systems (such as catalytic crackers
and cockers)
• synthetic detergent production units
• food processing plants
• crushing, separation, grinding and calcining operations in the mineral and chemical
industries
• fossil and wood-waste fired combustion units
• vacuum cleaning machines
• dust sampling equipment
Industrial usage

26. Cyclone efficiency
The efficiency of a cyclone has direct effect on the pressure drop.
Higher efficiency cyclones have highest pressure drops
Different levels of collection efficiency and operation are achieved by
varying the standard cyclone dimensions.
The collection efficiency of cyclones varies as a function of density,
particle size and cyclone design. Cyclone efficiency will generally
increase with increases in particle size and/or density; inlet duct
velocity; cyclone body length; number of gas revolutions in the cyclone;
ratio of cyclone body diameter to gas exit diameter; inlet dust loading;
smoothness of the cyclone inner wall.
Similarly, cyclone efficiency will decrease with increases in the
parameters such as gas viscosity; cyclone body diameter; gas
exit diameter; gas inlet duct area; gas density; leakage of air
into the dust outlet.

27. What we plan to do in the coming month
We know that a smaller and compact cyclone has more efficiency than a bigger cyclone.
A lot of industries would be functioning on larger cyclones and therefore would have a large scope of cost reduction
as the efficiency of the system could be increased.
We will take up full data from the industry of the TAC and the efficiency of the cyclone and will try to provide a better model
with greater efficiency in the same cost.
We plan to do this…
Increasing Efficiency on the way

28. In final presentation we will use computational fluid dynamics, response surface
methodology and Reynolds stress model for determining the behavior of cyclone
separator.
According to patent:
“The separating efficiency of a cyclone separator can be increased by
retarding the partices before they arrive at the cyclone and then
accelerating them over the short distance before they enter the
cyclone.
In this way the larger particles will have lower speed than small
particles when
entering the cyclone and hence the separation of the fine particles is
improved.”

29. An Example…
Avg. Particle size in range Wt percentage
1 03
5 20
10 15
20 20
30 16
40 10
50 06
60 03
>60 07
Estimating cut diameter and the overall efficiency of the cyclone
Given data:
Gas viscosity = 0.02 Cp
Specific Gravity of the
particle = 3.0
Inlet gas velocity of
cyclone = 48 ft/sec
Effective number of
turns within cyclone = 5
Cyclone diameter = 8 ft
Cyclone inlet width = 2 ft

30. Cut Diameter
First We will calculate ρp –ρ = 3(62.4)=187.2 lb/ft3
Then we will calculate the cut diameter:

31. Collector efficiency can be calculated as:
Dp.(um) wi Dp/Dpc Ei,% WiEi.%
1 .03 .11 0 0.0
5 .20 .55 23 4.6
10 .15 1.11 55 8.25
20 .20 2.22 83 16.6
30 .16 3.33 91 14.56
40 .10 4.44 95 9.5
50 .06 5.55 96 5.7
60 .03 6.66 98 2.94
>60 .07 - 100 7.0

32. References
• PhD_thesis_Khairy_Elsayed
• Nptel
• http://www.sciencedirect.com/science/article/pii/S0009250910005245
• https://en.wikipedia.org/wiki/Cyclonic_separation
• Optimization of the cyclone separator geometry for minimum pressure drop using mathematical
models and CFD simulations, Vrije Universiteit Brussel, Department of
Mechanical Engineering, Research Group Fluid Mechanics and Thermodynamics,
Pleinlaan 2, B-1050 Brussels, Belgium
• Numerical study of gas–solid flow in a cyclone separator, Center for Simulation and Modelling of Particulate Systems
and School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia

33. Thank You…