Cyclone Calculator

Effective turns equals pi over inlet height times 2 times cylinder length plus cone length

Solution

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How It Works

A cyclone separator spins dirty gas at high speed so that centrifugal force pushes heavier particles outward against the wall while clean gas exits through a central vortex. The number of effective turns the gas makes inside the body and the cut diameter (the smallest particle size collected at 50% efficiency) are the two main design parameters.

Effective turns depend on cyclone geometry -- specifically the inlet height, cylinder length, and cone length. The cut diameter also factors in gas viscosity, inlet width, inlet velocity, and the density difference between particles and gas.

Example Problem

A cyclone has an inlet height of 0.5 m, cylinder length of 1.5 m, and cone length of 2.5 m. How many effective turns does the gas make?

  1. N = π / h × (2Lcyl + Lcone)
  2. N = 3.1416 / 0.5 × (2 × 1.5 + 2.5) = 6.283 × 5.5
  3. N ≈ 34.6 turns

Frequently Asked Questions

What is the cut diameter of a cyclone separator?

The cut diameter is the particle size at which the cyclone achieves 50% collection efficiency. Particles larger than the cut diameter are mostly captured; smaller ones pass through. Typical cyclones have cut diameters of 5–25 μm.

How does inlet velocity affect cyclone performance?

Higher inlet velocity increases centrifugal force and improves collection efficiency, but also raises the pressure drop and energy cost. Typical inlet velocities range from 15 to 25 m/s for standard designs.

Can cyclones remove PM2.5 particles?

Standard cyclones are not efficient at removing particles below about 5 μm. For PM2.5 removal, you need high-efficiency cyclones, multi-cyclone arrangements, or downstream devices like electrostatic precipitators or baghouses.

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