Lapple cyclone

Input data

Cyclone diameter

Particle density

Air flow

Air density

Air viscosity

Blower efficiency

Output data

Cut diameter

Head loss

Power

L1

L2

W

Dd

H

De

L3

Description

The Lapple cyclone is a widely used device for separating solid particles from gases through centrifugal force. It provides a simplified yet effective model to estimate separation efficiency, pressure drop, and power requirements in ventilation and exhaust systems.

Lapple CycloneLapple Cyclone

Available calculation methods:

  • Dimensions – computes main geometric parameters, cut diameter, pressure drop, and power.
  • Granulometric curve – generates the grade efficiency curve as a function of particle size.
  • Granulometry from the cyclone diameter – calculates the outlet granulometric distribution based on the cyclone diameter.
  • Granulometry from the diameter cut – estimates outlet granulometric distribution using a predefined cut diameter.

Inputs and outputs of the dimension calculation

Inputs

ParameterDefault unitsDescription
Cyclone diameter (dcdc)mMain dimension of the cyclone
Particle density (ρp\rho_p)kg/m³Solid particle density
Air flow (QQ)m³/sVolumetric airflow
Air density (ρ\rho)kg/m³Carrier fluid density
Air viscosity (μ\mu)Pa·sDynamic viscosity of air
Blower efficiency (η\eta)%Efficiency of the fan

Outputs

ParameterDefault unitsDescription
Cut diameter (dpd_p)mParticle diameter at 50% collection efficiency
Head loss (ΔP\Delta P)PaPressure drop across the cyclone
Power (PP)WPower required for operation
L1, L2, L3mCharacteristic heights of the cyclone
WmInlet width
DdmDischarge duct diameter
HmCylindrical body height
DemExit diameter

References

  • CIMBALA, J. M. Lesson 12B: Lapple Cyclone. A Practical Application of Inertial Separation.