Particulate control devices – Working principle of a cyclone separator: The operating principle of a cyclone dust collector is primarily based on which action exerted on the particles?

Introduction / Context:
Cyclone separators are rugged, low-maintenance devices used to remove medium-to-coarse particles from gas streams in boilers, kilns, and process exhausts. Knowing their governing mechanism guides selection and performance prediction.

Given Data / Assumptions:

• Swirling gas flow is generated tangentially in a conical/cylindrical body.
• Particles have inertia relative to the carrier gas.

Concept / Approach:
As gas swirls, particles experience an outward radial force proportional to mass, tangential velocity squared, and inversely to radius (centrifugal force). Particles migrate to the wall, lose momentum, and drop into a hopper, while cleaned gas exits near the centerline.

Step-by-Step Solution:
Induce tangential entry → create vortex flow.Centrifugal force drives particles radially outward to the wall.Axial flow carries the gas upward through a vortex finder; particles fall by gravity into the dust leg.

Verification / Alternative check:
Empirical grade-efficiency curves show improved capture with higher inlet velocity and larger particle size, consistent with centrifugal separation physics.

Why Other Options Are Wrong:

• Diffusion/Brownian motion: dominate for ultrafines, not the cyclone’s main mechanism.
• Gravitational settling only: gravity helps once at wall, but the key separation is centrifugal.
• Electrostatic attraction: principle of ESPs, not cyclones.

Common Pitfalls:
Using cyclones for submicron particles expecting high efficiency—electrostatic precipitators or fabric filters are better for very fine dust.

Final Answer:
Centrifugal force