Cyclone design workspace.
Size a cyclone for your process, estimate which dust escapes, and compare designs at the same flow.
Preliminary engineering calculation.
A saved draft is available in this browser. Restore it to continue, or discard it to use the current project.
Synthetic mineral dust demonstrates the workflow. These are teaching inputs, not measured material data or a previous project.
New to cyclone design? Start here
A cyclone makes dusty gas swirl. Particles that reach the wall fall into the dust outlet; the remaining dust leaves with the gas. This tool estimates that split and the pressure needed to move the gas through the cyclone.
- Explore the illustrative sample first. Open Collection & outlet dust to see where its dust goes.
- For your project, gather the actual gas flow, gas properties, particle density and an inlet particle size distribution. Add inlet dust loading to obtain kg/h and mg/m³.
- Choose a family and size in Geometry, then compare outlet dust and pressure. Use Add new design for another option, or Duplicate selected to change one dimension.
You can visit any step at any time. A dash means a result is unavailable; it does not mean zero. Leave unknown properties blank and obtain them from measurements, a laboratory or your process supplier.
01 · Process duty
Use actual gas volume at cyclone inlet conditions. Convert normal or standard volume before entering it.
What to enter
Design flow is the gas volume the process must handle each hour. Get it from your air balance, a measured flow or the process supplier. Nm³/h is a volume at reference conditions; ask for actual m³/h at the cyclone inlet before using it here.
Gas density means mass per gas volume. Viscosity describes resistance to flow. Obtain both at your operating temperature and pressure; copying room-temperature values into a hot-gas project changes the result.
Enter gas density and viscosity for the stated conditions. Temperature and pressure document that basis; they do not automatically calculate gas properties.
Inlet dust loading & targets
Loading is how much dust enters: kg/h is dust mass per hour; mg/m³ is dust mass in each cubic metre of gas. Use the concentration or mass-flow basis you know. Targets are your project requirements, not limits supplied by this tool.
Loading and targets are optional. Without loading, the tool can estimate the escaping fraction but cannot report kg/h or mg/m³.
02 · Material & inlet PSD
Describe the dust before it enters the cyclone
Particle density describes the particles themselves. Bulk density includes the air spaces in a pile and cannot replace particle density. Ask the material supplier or laboratory which density their result represents.
PSD means particle size distribution: how the incoming dust mass is shared between sizes. Enter mass percentages for separate size intervals, rather than particle counts or cumulative percentages. A laboratory sieve or particle-size report is a useful starting point.
Help with sizes, percentages and missing fractions
One micrometre (µm) is 0.001 mm. For example, 0.02 mm is 20 µm. Choose a representative diameter within each interval; use a measured representative size when available.
If a cumulative report says 10% is below 2 µm and 35% is below 5 µm, the 2–5 µm interval contains 25% by mass. Convert each interval this way before entering the table.
If you know only 90% of the inlet mass, enter the remaining 10% as unclassified. The tool cannot infer whether that missing dust is fine or coarse. Wide or open-ended intervals need a justified representative size.
Particle density is required for separation. Bulk density is recorded separately and is never substituted. A collected-dust PSD cannot represent the inlet without further evidence.
Inlet mass distribution
Import PSD from Excel or CSV
Copy cells from Excel and paste below, or open a CSV or TSV file. For an .xlsx workbook, copy its table or export that sheet as CSV. Files stay in this browser.
Use mass percentages, not particle counts or volume percentages. For cumulative data, map the sieve size to the size column. Open-ended fine and coarse tails remain unclassified. With bounds alone, the preview calculates representative sizes; check that these suit your material.
Enter non-overlapping size intervals, a representative diameter within each interval, and inlet mass percentages. For representative-size data alone, leave both bounds blank. Include fines and oversize; do not discard missing mass.
Classified and unclassified mass must total 100%. With unclassified mass, the tool gives overall bounds and withholds a single outlet prediction.
03 · Geometry
Choose a family to obtain an initial diameter, then adopt a practical size or enter an existing cyclone.
Choose how to size your design
Start with Size from design flow to get an initial body diameter, Dc. Choose Adopt a diameter to try a practical manufactured size. For an existing cyclone, use Existing cyclone and enter its measured dimensions under Geometry ratios and measured dimensions.
A family is a set of reference proportions and a sizing criterion. Names such as high efficiency describe the family, not guaranteed performance with your dust. Compare the calculated dust escape and pressure before choosing.
What do the drawing symbols mean?
- Dc
- Body diameter
- a, b
- Rectangular inlet height and width
- H, h
- Total body height and cylindrical height
- De
- Gas outlet diameter
- B
- Dust outlet diameter
- S
- Depth of the gas outlet tube inside the body
The drawing illustrates the entered dimensions. It is not a fabrication drawing.
Geometry ratios and measured dimensions
Each dimension uses ratio × Dc unless an override is entered. Clear an override to return to the ratio.
Cyclone dimensions · m
04 · Operating study
The baseline always uses the design flow. Enable a trial to evaluate another flow through exactly the same geometry.
Optional: check a change in process flow
Skip this step for a first design. Use a trial to investigate more or less gas through the same cyclone. To compare a larger and smaller cyclone at the same required flow, duplicate the design and change its diameter in Geometry instead.
Changing flow can change capture and pressure together. A trial result does not establish an allowable operating range or replace measured performance.
Flow and inlet velocity are linked by Q = 3600 × a × b × vi. A trial never resizes the body or inlet.
The entered dust-loading basis is held constant during a trial: concentration stays fixed in concentration mode; kg/h stays fixed in mass-flow mode.
Explore an operating-flow range
See how the selected cyclone responds to more or less gas. Its dimensions and gas properties stay fixed. Concentration stays constant in concentration mode; dust kg/h stays constant in mass-flow mode.
This is a sensitivity study, not an approved operating range. Dashed curves show bounds from unclassified dust. System power is omitted because other losses must be known at each flow.
Read flow-range values
05 · Collection & outlet dust
Baseline estimates from the Barth grade curve and the inlet mass distribution.
Read these results first
Escaping dust is the mass that leaves with the gas each hour. Outlet concentration is that dust mass per cubic metre of gas. Overall collection efficiency is the share of all incoming dust mass retained by the cyclone.
A high overall percentage can hide poor capture of fine particles if most inlet dust is coarse. Read the size-by-size chart as well as the overall result.
Where does the inlet dust go?
The full bar represents 100% of the original inlet dust mass. Gray mass is unclassified; its capture is unknown.
Grade efficiency
This curve answers: what share of dust at one particular size is captured? Moving right means larger particles; moving up means more capture. The horizontal scale is logarithmic: equal distances represent equal size ratios.
d50 is the size at which this model predicts 50% capture. It is not the overall efficiency and it is not the smallest particle that can be captured.
Each fraction uses its representative diameter. A broad interval may need more bins for a reliable mass-weighted estimate.
Dust balance by size
Each bar shows one size fraction of the original inlet mass, split into captured and escaping dust. A long escaping segment identifies a size range contributing strongly to emissions.
Read the detailed values
Outlet PSD describes the composition of the dust that remains: its percentages add to 100% of escaping dust. Escaped % of inlet uses the original inlet mass. These percentages have different denominators.
Barth is an empirical preliminary estimate with Stokes-regime and low gas-to-particle density assumptions. Fibrous pith, moisture and agglomeration need measured validation.
06 · Pressure & power
Connect dust collection to fan duty
Pressure loss is the resistance the fan must overcome. At the same flow and efficiencies, lower total pressure means less required fan shaft power. Compare it alongside dust escape, not in isolation.
Enter efficiencies as fractions: 65% is 0.65. Fan shaft power is the mechanical power delivered to the fan; motor electrical input also accounts for motor losses. The listed motor rating is a preliminary shaft-power reference.
Start with SL to inspect the available pressure estimate. RAM offers another correlation within its stated scope. These are estimates from different empirical models, not upper and lower guarantees.
Enter total losses along the critical path, excluding the cyclone. Enter zero for cyclone-only duty. The tool does not solve a duct network or fan curve.
These are clean-gas pressure correlations. RAM excludes half-scroll and unconfirmed entries. CB is unavailable because the source and worked example are inconsistent.
Motor rating is a direct-drive shaft-power reference without service allowance. Check the full operating range before equipment selection.
07 · Compare & select
Compare all candidates at the common design flow. Select one to review its dimensions and detailed dust balance.
Build a useful comparison
- Add new design to choose another family, or Duplicate selected to change only one dimension.
- Give alternatives clear names, such as Trial diameter 1.2 m and Trial diameter 1.4 m. Keep the required process flow and dust inputs common.
- Use Include to choose designs for the charts. Compare collection, outlet dust and pressure against your targets; the tool does not automatically declare one design best.
Selecting a design changes the detailed results and drawing. It does not change the common process or dust data.
Add missing reference families adds the available families you have not yet created, sized from the common design flow. It keeps your existing designs.
Which sizes does each design capture?
Higher curves predict more capture at the same particle size. Each curve uses the same design flow. Its effect on overall collection depends on how much dust you have at each size.
Overall collection comparison
More capture means less mass escaping. An outlined interval shows the possible range caused by unclassified inlet mass.
Cyclone pressure comparison
Lower pressure reduces the cyclone contribution to fan duty. Other system losses are not included in this chart.
Outlet dust comparison
Lower outlet concentration means less dust in each cubic metre of gas. Supply inlet loading to calculate this chart.
What differs between designs?
The selected design is the reference. Highlighted cells differ from it. Numerical differences are candidate minus reference; geometry values are the dimensions actually used, including overrides.
Show dimension and setting differences
Compare with measured performance
Enter one test record for the selected design. Predictions use its current geometry and the test flow and gas properties below. Confirm that the shared particle density and inlet PSD represent the tested material before comparing collection. Editing geometry changes the prediction against this same record.
Use cyclone-only pressure loss and the same actual-volume basis for inlet and outlet concentrations. Leave unmeasured quantities blank. A difference does not establish measurement accuracy or validate the model.
Efficiency differences are percentage points. Relative differences are unavailable when the measured value is zero. A prediction range has no single difference.
Methods & report
The calculation report records all inputs, adopted dimensions, baseline and trial results, outlet mass balances, target checks, assumptions and method version. Save a project to resume editing.
Coury, Pisani & Hung (2004) · Cyclones
Family sizing: Table 1. Barth separation: Eqs. 1–7. Pressure: Eqs. 31, 32 and 34. Mass balance: Eqs. 39–42. Sample data, interface text and drawing are original.
Results require project-specific validation and responsible engineering review before final equipment design.