Gas-Solid Cyclone Efficiency (Leith-Licht) Calculator
Model reverse-flow industrial dust collection cyclones: Leith-Licht fractional grade efficiency, d50 cut size, overall recovery %, inlet velocity, and pressure drop.
1. Cyclone Dimensions & Geometry
2. Dust Particle & Gas Properties
Collection & Aerodynamic Results
Stairmand Cyclone Profile & Grade Efficiency Curve
5 Fatal Engineering Traps in Cyclone Dust Collection
1. Dust Hopper Air Leakage & Vortex Tornado Re-Entrainment
Because static pressure at the bottom cone apex is negative (-100 to -250 mmWC), any air leak through a worn rotary valve vane or drum clamp creates a high-velocity upward air jet. This parasitic draft sucks separated dust particles off the cone walls and flings them straight into the vortex finder, collapsing collection efficiency from 94% down to 45%.
2. Excessive Inlet Velocity & Centrifugal Particle Shattering
Operating inlet gas velocity above 22 m/s to force higher efficiency backfires catastrophically. Friable particles (e.g. spray-dried detergent, coal, sugar) shatter into sub-micron dust fragments upon high-speed tangential wall impact. Furthermore, high turbulence strips collected boundary-layer dust off the wall, accelerating abrasive metal erosion.
3. Acid Gas Dew Point Condensation & Sticky Wall Cake Glazing
In combustion or smelting flue gas streams containing SOx or HCl, allowing gas temperatures to drop below 135°C condenses micro-droplets of sulfuric acid. Acid droplets wet the collected dust, forming an impenetrable, rock-hard glazed concrete-like cake that chokes the cone taper and plugs the apex hopper solid.
4. Hopper Ash Level Overfilling & Apex Choking Catastrophe
Allowing accumulated dust inside the hopper to rise above the cone apex flange completely submerges the bottom vortex reversal point. The upward spinning tornado drills directly into the ash bed, fluidizing tons of stored dust and spewing a continuous black dust cloud out the clean gas exhaust stack.
5. Vortex Finder Dip Tube Abrasion Pinhole Bypassing
Abrasive silica particles circulating in the top annulus scour the external metal face of the vortex finder dip tube. Once a pinhole or slot wears through the tube wall, raw dust-laden gas short-circuits directly into the clean gas exhaust, bypassing the cyclone body without separation.
Aerodynamic Equations & Leith-Licht Formulation
The vortex exponent n governs centrifugal velocity distribution via the Alexander correlation:
n = 1 - (1 - 0.67 · D0.14) · (TK / 283)0.3
Modified inertia centrifugal parameter ψ for particle diameter dp:
ψ = [ ρp · dp² · vi · (n + 1) ] / [ 18 · μg · D ]
Leith-Licht fractional collection grade efficiency η(dp):
η(dp) = 1 - exp[ - 2 · (C · ψ)1 / (2n + 2) ]
Cyclone pressure drop (ΔP) and fan shaft power:
ΔP = 0.5 · ρg · vi² · NH, Pfan = (Qgas · ΔP) / ηfan
where NH ≈ 16 · (a · b / De²) is the number of inlet velocity heads (NH ≈ 6.4 for Stairmand).