Cyclone Separator Challenge
Topic
Perform an analysis of the cyclone separator and calculate the separation efficiency and pressure drop.
A project
Submitted in partial fulfillment of the requirement for the award of the certificate
Of
Master Program
(CFD Masters)
By
Nitesh Negi
(Enrolment ID:3081)
Under the supervision of
CFD Team Leader Director of product
Pritam Goel Sarangarajan Iyengar
5th floor, Bristol IT Park
Main Rd, South Phase, Sathya Nagar, Gandhi Nagar, Chennai, Tamil Nadu 600032,+918939850851
CANDIDATE'S UNDERTAKING
I, Nitesh Negi (Enrolment Id:3081) state that the contents and findings of the project entitled “Perform an analysis of the cyclone separator and calculate the separation efficiency and pressure drop using Ansys Fluent”, are original. To the best of my knowledge, the current project does not infringe upon anyone’s copyright nor violate any proprietary rights and that any ideas, techniques, quotations or any other material from the work of other people included in my project, published or otherwise, are fully acknowledged in accordance with the standard referencing practices. Even though later on in case of any complaint pertaining to plagiarism, I am solely responsible for the same and understand that as per norms.
ACKNOWLEDGEMENT
Primarily, I acknowledge this moment of time which has gone just forever but made up my mind to write the word for those who have been with me with their over-whelming gestures throughout this assignment. With deep gratitude, I express my earnest thanks to my respected guides Mr. Pritam Goel, CFD Team Leader, and Mr. Sarangarajan Iyengar, Director of product skilllync for his constant involvement, energetic efforts, and proficient guidance. Without his wise counsel and encouragement, it would have been impossible to complete the project work in this manner.
I would also thank to all the members of Ansys Fluent Skill-Lync what are app group members for support and express my gratitude.
ABSTRACT
Perform an analysis of the cyclone separator and calculate the separation efficiency and pressure drop. Moreover, the separation efficiency is of considerable interest, and numerous experimental studies and practical application have examined the question of optimal cyclone separator design. In this project, we discuss computer simulation of separator based on a three-dimensional flow code program utilizing the Viscous Model:- k-epsilon model - RNG - swirl mode on for turbulent flow. Comparison of the simulation results with different cases and appears to be a useful tool for predicting design. These mixtures consist of components that do not react chemically and have clearly visible boundaries of separation between the different phases. Components of such a mixture can be separated using one or more appropriate techniques. These separation processes include Gas-Liquid (vapor-liquid) separation, Gas-Solid separation (vapor-solid), Liquid-Liquid separation (immiscible), Liquid-Solid, and Solid-Solid separation etc. This separation can be done by exploiting the differences in density between the phases. Gravitational force or centrifugal force can be used to enhance the separation. The separation units can be either horizontal or vertical.
The computational fluid dynamics (CFD) package FLUENT as a fluid flow analysis tool to solve the governing equations, prominently equations of continuity, motion, and energy. Numerical results can be compared with experimental results and which was done by research scholar since due to model setup and lab constraints we will only compare the simulation results of different cases as per our objective. The mesh size is selected to do that the numerical solution is taken considering the computation time and simulation processing time.
Keywords: separation efficiency, numerical simulation, Fluent, CFD, k-epsilon,
CONTENTS
Candidate’s undertaking i
Acknowledgment ii
Abstract v
Contents vi
List of figures vii
List of table’s viii
Nomenclature viii
Contents
CHAPTER 1: INTRODUCTION
-Introduction
- What is a pre separator?
-History
-Application
CHAPTER 2: LITERATURE REVIEW
- Introduction
- Review of Literatures
- Objectives
CHAPTER 3: METHODOLOGY
-Flow chart for CFD simulation
-Procedure/Steps for the CFD simulation
CHAPTER 4: RESULT AND DISCUSSIONS
CHAPTER 5: CONCLUSIONS AND FUTURE SCOPE
REFERENCES
LIST OF FIGURES
Figure: Shows the pressure/velovity/eddy viscosity/time countor for the cyclone pre-seprator
LIST OF TABLES
Table :Shows the No. of particle trap, escape incomplete at diffrent particle size and velocity
NOMENCLATURE
Symbols Significance
mm/m millimeter/meter
D Bottom diameter of cyclone
CHAPTER 1
INTRODUCTION
What is a pre-separator?
CYCLONE(Pre Separator)
Cyclone Principle meaning that the inlet is mounted tangentially on the body and the airflow is thus forced against the inside of the cyclone. This principle is very effective in separating particles down to 1/100 mm.
Pre-Separators can be used in all applications where the extracted material is coarse or voluminous. These can be placed in the actual workplace for separate handling or recovery of the extracted material, or centrally. Pre-Separators separate material from the airflow using the action of a cyclone or with inertial separation. Inertial separators are generally configured as containers with the inlet and outlet in the same wall of the container. When the airflow changes direction abruptly, separation occurs for the particles with higher relative mass. When pre-separation is used to accommodate higher material volumes it is also important to consider the type of material discharge to be used.
Figure: Shows the cyclone design from design to the final stage(source: Generals and google search)
When a Pre-Separator is to be used the following should be considered:
- Type of dust to be handled.
- How the unit should be placed and how emptying will be performed.
- Expected airflow.
Pre-Separators should be used:
- for material recovery
- for material transportation
- to reduce the loading on the ducting system
- to relieve loading on the central filter
- to reduce the risk of filter clogging
- when fluids are to be separated
Cyclones are basically centrifugal separators. They simply transform the inertia force of gas-particle to a centrifugal force by means of a vortex generated in the cyclone body. The particle-laden gas enters tangentially at the upper part and passes through the body describing the vortex. Particles are driven to the walls by centrifugal forces, losing their momentum and falling down to the cyclone leg. In the lower section, the gas begins to flow radially inwards to the axis and spins upwards to the gas outlet duct.
The main variables describing the cyclone performance are pressure drop, efficiency, and cut diameter.
The collection or separation efficiency is most properly defined for given particle size. As mentioned, fractional efficiency is defined as the fraction of particles of a given size collected in the cyclone, compared to those of that size going into the cyclone. Experience shows that the collection efficiency of cyclone separator increases with increasing particle mean diameter and density; increasing gas tangential velocity; decreasing cyclone diameter; increasing cyclone length; extraction of gas along with solids through the cyclone legs. Several equations have been developed to predict the collection efficiency in cyclones through correlation equations. The following section describes two methods of calculating cyclone efficiency
Lapple Model
The particle that travels from inlet half-width to the wall in the cyclone is collected with 50% efficiency.
It is mostly based on the terminal velocity of particles in the cyclone.
Lapple assumed that a particle entering the cyclone is evenly distributed across the inlet
Lapple model was developed based on force balance without considering the flow resistance.
Iozia and Leith Model
Iozia and Leith logistic model is developed based on force balance
The model assumes that a particle carried by the vortex endures the influence of two forces: a centrifugal force, Z, and a flow resistance or drag force, W.
Koch and Leith Model
Koch and Licht collection theory recognized the inherently turbulent nature of cyclones and the distribution of gas residence times within the cyclone.
Koch and Licht described particle motion in the entry and collection regions with the additional following assumptions: The tangential velocity of a particle is equal to the tangential velocity of the gas flow, i.e.there is no slip in the tangential direction between the particle and the gas.
Li and Wang Model
The Li and Wang model include particle bounce or re-entrainment and turbulent diffusion at the cyclone wall.
A two-dimensional analytical expression of particle distribution in the cyclone is obtained. Li and Wang's model was developed based on the following assumptions:
The radial particle velocity and the radial concentration profile are not constant for uncollected particles within the cyclone.
Boundary conditions with the consideration of turbulent diffusion coefficient and particle bounce reentrainment on the cyclone wall where
DISCRETE PHASE MODELLING (DPM):-
Trajectories of particles, droplets or bubbles are computed in a Lagrangian frame. Particles can exchange heat, mass, and momentum with the continuous gas phase. Each trajectory represents a group of particles, all with the same initial conditions. DPM neglects collisions and other inter-particle interactions. Turbulent dispersion of particles can be modeled using either stochastic tracking (the most common method) or a particle cloud model. Many submodels are available – Heat transfer, vaporization/boiling, combustion, breakup/coalescence, erosion/accretion. Applicability of DPM Flow regime: Bubbly flow, droplet flow, particle-laden flow Volume loading: Must be dilute (volume fraction < 12%) Particulate Loading: Low to moderate Stokes Number: All ranges of Stokes number Application examples Cyclones Spray dryers Particle separation and classification Aerosol dispersion Liquid fuel Coal combustion
Discrete Phase Model (DPM) Setup
Define >Models >Discrete Phase>Define Injections>Display Particle Tracks
DPM Boundary Conditions[1]
Escape; Trap; Reflect;Wall-jet
Reflect:-The particle rebound off the boundary in question with a change in its momentum as defined by the coefficient of restitution.
Trap:-The trajectory calculation is terminated and the fate of the particle is recorded as " trapped ". In the case of the evaporating droplet, their entire mass instantaneously passes into the vapor phase and enters the cell adjacent to the boundary. In the case of a combusting particle, the remaining volatile mass is passed into the vapor phase.
Escape:-The particle is reported as having "escaped" when it encounters the boundary in question. Trajectory calculated are terminated.
Wall jet:-The direction and velocity of the droplet particle are given by the resulting momentum flux, which is a function of the impingement angle and weber number. The " wall jet" type boundary condition is appropriate for high-temperature walls where no significant liquid film is formed and in high Weber Number where the spray acts as jet.
Design considerations[1]
-Select either the high efficiency or high throughput design, depending on the performance required
-Obtain an estimate of the particle size distribution of the solids in the stream to be treated.
-Calculate the number of cyclones needed in parallel.
-Estimate the cyclone diameter for an inlet velocity of say 15 m/s. Then obtain the other cyclone dimensions from the graphs (refer to page 452, Sinnott, 2005)
-Then estimate the scale-up factor for the transposition of the figure. (refer to page 452 and 453, Sinnott, 2005) Estimate the cyclone performance and overall efficiency, if the results are not satisfactory try small diameter.
- Calculate the cyclone pressure drop and check if it is within the limit or else redesign.
-Estimate the cost of the system and optimize to make the best use of the pressure drop available (Sinnott, 2005).
History[2]
In the agricultural processing industry, 2D2D (Shepherd and Lapple, 1939) and 1D3D (Parnell and Davis, 1979) cyclone designs are the most commonly used abatement devices for
particulate matter control. The D’s in the 2D2D designation refers to the barrel diameter of the cyclone. The numbers preceding the D’s relate to the length of the barrel and cone sections, respectively. A 2D2D cyclone has barrel and cone lengths of two times the barrel diameter, whereas the 1D3D cyclone has a barrel length equal to the barrel diameter and a cone length of three times the barrel diameter. The configurations of these two cyclone designs are shown in figure 2. Previous research (Wang, 2000) indicated that, compared to other cyclone designs, 1D3D and 2D2D are the most efficient cyclone collectors for fine dust (particle diameters less
Application
Pre-separation normally takes place on particles > 5µm and is mostly used in:
- Wood and furniture industry;
- The building sector;
- Glass industry;
- The transport sector for storage and transfer;
- The foodstuffs industry;
- Waste combustion installations;
- The chemicals industry;
- Melting processes in metallurgy;
- Sintering processes;
- Coffee roasting industry.
CHAPTER 2:
LITERATURE REVIEW
- INTRODUCTION
To begin the proposed work it is required to make a review of research papers in order to discover what work has been done already about the related topic and which procedure or methodology has been adopted to perform the simulation/experiments and conclude the results.
A review of the various published literature on any specific topic is the first important step to be taken to get,
- Knowledge about the state of art.
- Familiarity with the established methods and procedures for conducting work.
- To stop duplication of work.
- LITERATURE REVIEW[3]
There are several numbers of studies conducted by researchers regarding the Perform an analysis of the cyclone separator and calculate the separation efficiency and pressure drop from the turbulence model using Ansys Fluent, some of them are discussed below:-
- Bashir, Kashan. (2015). Design and fabrication of cyclone separator. 10.13140/RG.2.2.20727.83368. To design a cyclone abatement system for particulate control, it is necessary to accurately estimate cyclone performance. In this cyclone study, new theoretical methods for computing travel distance, numbers of turns, and cyclone pressure drop have been developed. The flow pattern and cyclone dimensions determine the travel distance in a cyclone. The number of turns was calculated based on this travel distance. The new theoretical analysis of cyclone pressure drop was tested against measured data at different inlet velocities and gave excellent agreement. The results show that cyclone pressure drop varies with the inlet velocity, but not with cyclone diameter. Cyclone cut-points for different dusts were traced from measured cyclone overall collection efficiencies and the theoretical model for calculating cyclone overall efficiency. The cut-point correction models 2D2D cyclones were developed through regression fit from traced and theoretical cut-points Diameter. Experimental results indicate that optimal cyclone design velocities, which are for 2D2D cyclones, should be determined based on standard air density. It is important to consider the air density effect on cyclone performance in the design of cyclone abatement systems. The tangential inlet generates the
swirling motion of the gas stream, which forces particles toward the outer wall where they spiral in the downward direction. Eventually, the particles are collected in the dustbin located at the bottom of the conical section of the cyclone body. The cleaned gas leaves through the exit pipe at the top. - Wang-Li, Lingjuan & Parnell, Calvin & Shaw, Bryan & Lacey, Ronald. (2003). Analysis of Cyclone Collection Efficiency. 10.13031/2013.15040. Particle motion in the cyclone outer vortex was analyzed in this paper to establish the force balance differential equation. The Barth's "static particle" theory combined with the force balance equation was applied in the theoretical analyses for the models of cyclone cut-point and collection probability distribution in the cyclone outer vortex. Cyclone cut-points for different dusts were traced from measured cyclone overall collection efficiencies and the theoretical model for calculating cyclone overall efficiency. The traced cut- points indicate that Barth's d50 model needs to be corrected for particle size distribution (PSD). The cut-point correction factors (K) for 1D3D and 2D2D cyclones were developed through regression fit from traced cut- points The regression results also indicate that cut-points are more sensitive to mass median diameter (MMD) of PSD than to geometric standard deviation (GSD) of PSD. The theoretical overall efficiency model developed in this research can be used for cyclone total efficiency calculation with the corrected d50 and PSD.
-OBJECTIVE
Perform an analysis of the cyclone separator and calculate the separation efficiency and pressure drop.
PART-I
To perform an analysis of the given cyclone separator model by varying the particle diameter from 1 to 10 micron and calculate the separation efficiency in each case. The particle inlet velocity and the fluid inlet velocity was kept as 3m/s for this case
PART-II
To calculate the separation efficiency and the pressure drop between the inlet and outlet, In this case, the inlet velocity of the fluid and the injected particle is varied from 5m/s to 20m/s and the particle diameter is kept constant at 5 microns.
CHAPTER 3
-METHODOLOGY
The complete methodology that has been adopted to conduct the present project work is shown in the form of the flow chart in figure below
Figure: Flow Chart for Methodology
-Procedure for CFD simulation of Mixing Tee
Selection of material
The material property is not necessary for this simulation since we are not considering the heat transfer through the wall.For particles, we have considered the Anthracite which is used throughout the simulation at different cases.
Further, we will know that in this type of simulation we consider the wet volume and hat is extracted using the Space claim tool.
Cad Model Preparation
Step1: Open the workbench & double click open Flow Fluent
Step2: Double click on geometry to open space claim> open the file from saved location.
Step4: Go to prepare tab and select the volume generation tool and select the edges for complete volume generation from inlet to outlet.
Step5: Close space claim workbench and save files if required.
Preprocessing
Step6: Double click on Mesh from workbench>Generate Mesh by right-clicking the mesh icon and click generate mesh option and mesh will be generated; here you can change mesh size from element size option in the mesh tree.
Step7: Give a name to required parts by face section/edge selection>click update by right-clicking on the mesh>check the mesh metric matrix by select element quality should be not less than 5%.
Step8: Place the name section as inlet;outlet-1(top discharge);outlet-2(bottom discharge)
Setup/Processing
Step9: Double click on setup to open the workbench
Step10: select for Time -steady-state solution, Solver Type -pressure-based solvers, Velocity Formulation - Absolute and Physics-energy from the model.>select the Viscous Model -k-epsilon & model for turbulent flow based upon the condition.
Step11: setup the boundary condition as per the given data.
Model:-Viscous Model:- k-epsilon model - RNG - swirl mode on
DPM:-
caseI:
- Interaction - Interaction with continuous Phase
- Injection type:- Surface (inlet)
- Diameter(m) :- 1e-6;2e-6;3e-6;5e-6;7e-6;10e-5;
- Velocity inlet/particle velocity (m/s) :- 3/3 m/s:
- Total Mass flow rate:- 1e-20
caseII:
- Interaction - Interaction with continuous Phase
- Injection type:- Surface (inlet)
- Diameter(m) :-5e-6
- Velocity inlet/particle velocity (m/s) :- 5/5 m/s:10/10 m/s:20/20 m/s:
- Total Mass flow rate :- 1e-20
Material:-Air(Fluid);Anthracite(Particle)
Boundary Condition: Discrete Phase:- a) Reflect b)Trap c)Escape and d)wall
Numerical Schemes:Pressure Velocity Coupling:- Simple>Spatial discretization > Gradient:- Least square cell based> Pressure:- Second Order>Momentum :- Second-Order Upwind> Turbulent Kinetic energy :- Second Order>Upwind-Turbulent dissipation energy :- Second>Order Upwind-Solver:-Standard:- Initialization-Compute:- Inlet
Step12:Boundary conditions: Both the cases
Inlet & wall- Reflect
Outlet1(top discharge) - Escape
Outlet2(Bottom discharge)-Trap
Step13:Initialization: Standard initialization(computed from inlet)
All the cases were run for 300-600 iteration
Post-processing/Results
Step14: Open results workbench by double-clicking on the result option>Open the geometry by unchecking the named parameters>create XY plane to plot the contour of velocity and temperature>plot for temperature & velocity by drawn through the cyclone.
Step15: Extract animation/vortex flows/velocity countour etc.
CHAPTER 4:
RESULT AND DISCUSSIONS
The results of various Simulation tests conducted to Perform an analysis of the cyclone separator and calculate the separation efficiency and pressure drop by using Ansys Fluent & MS-Excel software. Comparisons of results are also done Case I and Case II. The compared results are summarized as the following:-
PART-I
To perform an analysis of the given cyclone separator model by varying the particle diameter from 1 to 10 and calculate the separation efficiency in each case. The particle inlet velocity and the fluid inlet velocity was kept as 3m/s for this case
Case 1:In this case 6 different analyses were performed by varying the particle diameter from 1 m to 10 m by applying different Boundary conditions on the inlet and wall, Outletbin (Bottom), and outlet discharge(Top).
Inlet & wall: Reflect
Outlet bin(Bottom): Trap-Outlet 2
Outlet discharge(Top): Escape-Outlet 1
The inlet velocity of both the particle and fluid are kept as 3m/s.
1) Particle diameter: 1e-6
Residual plot:
Pressure inlet plot
Pressure outlet-1 plot
Pressure outlet-2 plot
Eddy viscosity in vortex flow
Anthracite particle time
Anthracite particle velocity
Anthracite particle pressure
2) Particle diameter: 3e-6
Residual plot:
Pressure inlet plot
Pressure outlet-1 plot
Pressure outlet-2 plot
Anthracite particle ID
Eddy viscosity in vortex flow
Anthracite particle time
Anthracite particle velocity
Anthracite particle pressure
The inlet velocity of both the particle and fluid are kept as 3m/s.
3) Particle diameter: 5e-6
Residual plot:
Pressure inlet plot
Pressure outlet-1 plot
Pressure outlet-2 plot
Eddy viscosity in vortex flow
Anthracite particle time
Anthracite particle velocity
Anthracite particle pressure
The inlet velocity of both the particle and fluid are kept as 3m/s.
4) Particle diameter: 7e-6
Residual plot:
Eddy viscosity in vortex flow
Anthracite particle time
Anthracite particle velocity
Anthracite particle pressure
The inlet velocity of both the particle and fluid are kept as 3m/s.
1) Particle diameter: 10e-5
Residual plot:
Pressure inlet plot
Pressure outlet-1 plot
Pressure outlet-2 plot
Eddy viscosity in vortex flow
Anthracite particle time
Anthracite particle velocity
Anthracite particle pressure
Case 2: In this case, the analysis is done by varying the inlet velocity of both fluid and
particle from 5 to 20 m/s with the same Boundary conditions and keeping the
the diameter of the injections constant at 5e-6(5 m)
1) Inlet velocity of fluid- 5m/s;Inlet velocity of the particles - 5m/s
Residual plot:
Pressure inlet plot
Pressure outlet-1 plot
Pressure outlet-2 plot
Anthracite particle time
Anthracite particle velocity
Anthracite particle pressure
2) Inlet velocity of fluid- 10m/s;Inlet velocity of the particles -10m/s
Residual plot:
Pressure inlet plot
Pressure outlet-1 plot
Pressure outlet-2 plot
Eddy viscosity in vortex flow
Anthracite particle time
Anthracite particle velocity
Anthracite particle pressure
3) Inlet velocity of fluid- 20m/s;Inlet velocity of the particles - 20m/s
Residual plot:
Pressure inlet plot
Pressure outlet-1 plot
Pressure outlet-2 plot
Anthracite particle time
Anthracite particle velocity
Anthracite particle pressure
CHAPTER 5
CONCLUSIONS AND FUTURE SCOPE
In this chapter, we will discuss the outcome from a different Simulation performed i.e. Case I, Case II, and the graphs, plots. There are some results that support the previous outcome of research work and finds that increasing the length will archive the high separation efficiency. The influence of velocity, the diameter of a particle on the Average temperature value shows lower the difference better mixing archived. Based on observation, and analysis made in the study of Mixing Tee following conclusions are drawn:-
Table(1): Different boundary condition results are at the same velocity and different particle diameter
|
Particle NO. |
No. of particles trapped |
Escaped |
Trapped |
Aborted |
Incomplete |
Flow velocity/ Particle velocity |
Pressure Diff b/w 1-2 outlet |
|
1 micron |
364 |
58 |
281 |
0 |
25 |
3/3 |
4 [Pa] |
|
2 micron |
364 |
50 |
288 |
0 |
26 |
3/3 |
10 [Pa] |
|
3 Micron |
364 |
42 |
303 |
0 |
19 |
3/3 |
10[Pa] |
|
5 micron |
364 |
35 |
313 |
0 |
16 |
3/3 |
5 [Pa] |
|
7 micron |
364 |
15 |
337 |
0 |
12 |
3/3 |
4 [Pa] |
|
10 micron |
364 |
0 |
364 |
0 |
0 |
3/3 |
3 [Pa] |
Table(2): Different boundary condition results are at the same particle diameter and at a different velocity
|
Particle NO. |
No. of particles trapped |
Escaped |
Trapped |
Aborted |
Incomplete |
Flow velocity/ Particle velocity |
Pressure Diff b/w 1-2 outlet |
|
5 micron |
364 |
41 |
316 |
0 |
7 |
5/5 |
17 [Pa] |
|
5 micron |
364 |
26 |
338 |
0 |
0 |
10/10 |
51 [Pa] |
|
5 micron |
364 |
4 |
360 |
0 |
0 |
20/20 |
233 [Pa] |
|
5 micron |
364 |
8 |
356 |
0 |
0 |
20/15 |
233 [Pa] |
-We can see from the above table that with the increase in the inlet velocity of the fluid and the injected particle the pressure rises significantly at the inlet and drops at both the outlets.
-Smaller the particle higher is the chances of particle escape.
-The collection efficiency of cyclones varies as a function of density, particle size, and the design of the cyclone. From the above-tabulated data, it can be seen that the separation efficiency increases with an increase in particle size.
-For the same mesh size and different boundary conditions, it is observed that there is no variation in results
-Effect of Eddy viscosity:
-Another factor affecting the cyclone efficiency is gas viscosity. With a decrease in viscosity, efficiency increases. This is due to the reduction in drag force with a reduction in viscosity.
-For the different particle sizes, it is observed that when the mesh is refined the mass flow rate at Outlet 2 has increased, and at Outlet 1 has decreased as per particle size.
Effect of Velocity :
Shows velocity in a different direction for the particle size 3 micron in X-Y plane.
Shows velocity in a different direction for the particle size 3 micron in the Y-Z plane.
The above animation file shows the variation of velocity in different directions.
-Inlet velocity is a prime factor affecting the pressure drop and hence the cyclone efficiency. Efficiency increases with an increase in velocity as centrifugal force increases but this also increases the pressure drop which is not favorable. Also, decreasing the cyclone diameter increases centrifugal force and hence efficiency. The decrease in temperature will increase the gas density. One may be tempted to conclude that this will increase efficiency as viscosity decreases. But the increase in temperature also decreases the volumetric flow rate and thereby decreasing efficiency. Another important factor affecting efficiency is particle loading. With high loading, the particles collide with each other more and result in pushing of particle towards the wall. This, in turn, increases efficiency.
Figure 10 shows the relationship between efficiency and particle size for high-efficiency cyclone which slender and long, high throughput cyclone which is broad and creates less pressure drop and a conventional standard cyclone.
-Effect of pressure drop:
shows variations of pressure drop in x-y plane
shows variations of pressure drop in y-z plane
-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. The efficiency of a cyclone collector is related to the pressure drop across the collector. This is an indirect measure of the energy required to move the gas through the system. The pressure drop is a function of the inlet velocity and cyclone diameter. Form the above discussion it is clear that small cyclones are more efficient than large cyclones. Small cyclones, however, have a higher pressure drop and are limited with respect to volumetric flow rates. Another option is to arrange smaller cyclones in series and/or in parallel to substantially increase efficiency at lower pressure drops.
FUTURE SCOPE
Can utilize these steps to find the best design for the cyclone pre-separator, and can vary the dimension of the equipment with different diameter and length.
REFERENCES
[1] Wikipedia, google searches, etc
[2]Brownell, L. E., Young, E. H., 2004, Process Equipment Design, Wiley India Pvt. Ltd., New Delhi.
[3]Dawande, S.D., 1999. Process Design of Equipment, First Edition, Central Techno Publications, Nagpur, India.
[4]Hoffman, A. C., Stein, L. E., 2008, Gas Cyclones and Swirl Tubes, Second Edition, Springer Berlin Heidelberg, New York.
[5]Kuo, K. Y., Tsai, C. J., 2001, Aerosol Air Quality Research, 1, 47-56.
[6]McCabe, W.L., Smith, J. C., Harriott, P., 1987, Unit Operations of Chemical Engineering, Fourth Edition, McGraw-Hill Book Company, Singapore.
[7]Mahajani, V V., Umarji, S.B., 2009, Process Equipment Design, Fourth Edition, Mcmillan Publishers India Ltd., India.