# What parameters should one consider for designing a cyclone separator for removing solids from gas?

I want to design a cyclone separator for cleaning the product gases of a steam gasification process. The gases will exit the reactor at around 850degC.

## Popular Answers

Zach raymond-becker· Shannon and Wilson, Seattle, United StatesDesign parameters to remove solids from gas using a cyclone separator.

Input Data:

- Diameter of Separator

- Flow

- Target Efficiency

- Max Pressure Drop

- Particle Density

- Gas Density

- Gas Viscosity

- Number of Turns Inside the Cyclone

- Diameter of Particle Collected with 50% Efficiency

Preliminary Calculations to Determine Overall Size of Separator:

- Height

- Width

- Volume

- Diameter of Exit

- Length of Body

- Length of Cone

Other Important Considerations:

- Overall Collection Efficiency Calculation

- Pressure Drop Calculation

Hope this helps!

## All Answers (18)

Łukasz Wieczorek· Lodz University of Technology1. Expertise or assume some granulometric range, (Diameter of dust vs Mass fraction of dust), as well as density of dust, and the gas parameters such as density, viscosity (transport parameters)

2. Calculate the minimum efficiency for separation you need (You can use an air pollution standards)

3. Assume some dimensions

4. Use Leicht and Licht set of equations for design (They're best as far as i know)

5. Check if calculated efficiency is greater than minimum (if not, change the assumptions, back to 3)

6. Calculate the pressure losses. Check if pressure losses are lower than maximum (if not, back to point 3 and change assumptions). Pressure loses should be up to about 20kPa max. for industry

Ad.4 You can assume those dimensions according to some of the following hints:

- Find out the correlation for critical velosity in cyclone. Critical means this at which dust is being carried away with gas. Find out the ratio beetween the inlet velo and critical velo. Those two combined together will give you the external diameter vs lineal dimensions of inlet correlation

- If u're designing it for industry, it is recommended to have square-shaped inlet (easier to pipe) a=b

- Calculate the natural lenght of cyclone, what means the lenght needed to drop out the dust (ideally)

- Assume the dust outlet dimension, usually its diameter stands between 0,3-0,4 of external diameter

- Assume the cylindrical height of cyclone, which should be greater than height of the gas inlet

Rest of dimensions could be calculated by the geometry of cyclone, if not, assume and go straight ahead.

More precise calculations demand optimalization (cost balance).

Good luck.

Lucas

Yu-Fen Chang· University of BergenThere are many things to be considered. As a start if we take a look at the book "Gas Cyclones and Swirl Tubes"

http://books.google.no/books?id=DjreNh9CqioC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false

in Chap. 15 Design Aspects, for "Cylinder-on-Cone Cyclones with Tangential Inlet" there are

- Some Standard Cyclone Designs

- Design of the Inlet

- Design of the Cone Section

- Solids Outlet Configurations

- Vortex Finder Geometries

- Cyclone Length

- Cyclone Roof

- Cyclone Operating Conditions.

Then we know what aspects we need to consider and take this chapter as a guideline.

Zach raymond-becker· Shannon and Wilson, Seattle, United StatesDesign parameters to remove solids from gas using a cyclone separator.

Input Data:

- Diameter of Separator

- Flow

- Target Efficiency

- Max Pressure Drop

- Particle Density

- Gas Density

- Gas Viscosity

- Number of Turns Inside the Cyclone

- Diameter of Particle Collected with 50% Efficiency

Preliminary Calculations to Determine Overall Size of Separator:

- Height

- Width

- Volume

- Diameter of Exit

- Length of Body

- Length of Cone

Other Important Considerations:

- Overall Collection Efficiency Calculation

- Pressure Drop Calculation

Hope this helps!

Leon Prentice· The Commonwealth Scientific and Industrial Research OrganisationReeshab Goenka· Indian Institute of Technology BombayThe cyclone is not industrial scale and neither is my work very strange sir, just the high temperature is a parameter to take care of.

Bruce Fraser· Health CanadaJoao F Gomes· Instituto Politécnico de LisboaYou can make estimates using the Deutsch equation.

N.C. Markatos· National Technical University of AthensJon Makibar· IkerlanQaiser Khan· Technische Universität DortmundKeith D. Patch· Joule Unlimited, Inc.My comments on important factors:

1. Be extremely careful on seleting your design conditions. Cyclones are extremely sensitive to changes in hydrodynamic flow conditions (actual cubic meters per second); if you vary from the design conditions by 50% (up or down), the collection efficiency drops quite significantly. So make sure you know the temperature/pressure/composition/mass flow rate of your gasification process.

2. If you commercialize this gasificaiton process, do not believe the efficiency numbers of the cyclone vendor. They will tell you that the efficiency is 99.5% over an extremely wide turndown range. But when you try to verify their performance after you star up the full-scale plant and see poor performance, they will tell you that since you are not at the exact specified design conditions, the warranty does not apply.

Anybody, feel free to tweet me if you have any questions.

Best regards,

@KeithDPatch ,

http://www.keithdpatch.com ,

http://blog.fuelcellnation.com

Davide Papurello· Politecnico di TorinoResuming: the geometry and flow rate define the cut point of the cyclone. This cut point is the size of particles that will be removed from the stream with a 50% efficiency. Particles larger than the cut point will be removed with a greater efficiency, and smaller particles with a lower efficiency.

Zakaria Al-Qodah· Taibah University, Madina , Saudi ArabiaTim C. Keener· University of CincinnatiSumeth Wongkiew· Asian Institute of TechnologySometimes, criteria were designed for a range of specific data.

Is it cyclone the better than bag house? Can 850oC be heat exchanger for another system?

Christian Hanisch· Technische Universität Braunschweigmaybe these will help:

Zhao, B.

Prediction of gas-particle separation efficiency for cyclones: A time-of-flight model

(2012) Separation and Purification Technology, 85, pp. 171-177.

School of Energy and Power Engineering, University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093, China

Staub, Reinhaltung der Luft

Volume 30, Issue 5, May 1970, Pages 187-195

TECHNICAL PRACTICE IN CYCLONE SEPARATOR DESIGN,

[AUSLEGUNG VON ZYKLONABSCHEIDERN IN DER TECHNISCHEN PRAXIS]

MUSCHELKNAUTZ E

Chemical Engineering and Technology

Volume 35, Issue 12, December 2012, Pages 2099-2106

Analytical Approach for Calculating the Separation Efficiency of Uniflow Cyclones

Muschelknautz, U.

MK Engineering, Innsbruck, Austria

Filtration and Separation

Volume 26, Issue 4, July 1989, Pages 272-274

Cyclone optimisation

Iozia, D.L., Leith, D.

Univ of North Carolina, United States

Have fun,

Christian

Romualdo L. Salcedo· University of PortoCan you help by adding an answer?