Fluidization Calculator

• •Use the Fluidization Calculator when solving homework or exam problems that require quick numerical verification of your hand calculations — instant feedback helps identify arithmetic errors before they propagate.
• •Use it during the early design phase to rapidly iterate on parameters and narrow down feasible configurations before committing time to detailed finite element simulations or full design packages.
• •Use it when reviewing a colleague's calculation or checking a vendor's data sheet for plausibility — a quick sanity check can prevent costly downstream errors.
• •Use it to generate reference data for a technical report or presentation without manual computation, ensuring consistent, reproducible numbers throughout the document.
• •Use it in the field when a quick estimate is needed and a full engineering software package is not available.

The Fluidization Calculator is a precision engineering calculation tool designed for students, engineers, and technical professionals. Minimum fluidization velocity from Ergun equation, terminal velocity (Haider-Levenspiel), Archimedes number, and operating regime classification All calculations are performed using established engineering formulas from the relevant scientific literature and standards. Inputs support both metric (SI) and imperial unit systems, with unit conversion handled automatically — simply select your preferred unit from the dropdown next to each field. Results are computed instantly in the browser without sending data to a server, ensuring both speed and privacy. This calculator is intended as a supplementary tool for learning and design exploration; always verify results against authoritative references for safety-critical applications.

Fluidization occurs when upward gas flow through a particle bed is high enough to lift the particles, creating fluid-like behavior. The minimum fluidization velocity u_mf is found from Ergun's equation with ΔP equal to the bed weight per unit area (the gas must support the particles): 150·μ·(1−ε_mf)·u_mf/(ε_mf³·φ²·d_p²) + 1.75·ρ_g·u_mf²/(ε_mf³·φ·d_p) = (ρ_s − ρ_g)·g, where ε_mf is void fraction at incipient fluidization (typically ~0.4), φ is sphericity, and ρ_s and ρ_g are solid and gas densities. For the Wen and Yu simplification applicable to many practical cases: Re_mf = (33.7² + 0.0408·Ar)^0.5 − 33.7, where Ar = ρ_g·(ρ_s−ρ_g)·g·d_p³/μ² is the Archimedes number. Terminal velocity u_t is the velocity at which a particle falls at steady state in still gas — gas flow above u_t blows particles out of the bed (elutriation). Haider and Levenspiel correlation for terminal velocity handles particles of any shape. Fluidization regimes: fixed bed (u < u_mf), bubbling (u_mf < u < u_mb), slugging, turbulent, and dilute phase (u > u_t). Each regime has different mixing, heat transfer, and mass transfer characteristics. Fluidized beds offer excellent solid-gas contacting, temperature uniformity, and continuous solids handling. Applications include catalytic cracking (FCC), combustion (CFBC power plants), roasting and drying, and coal gasification.

• •Fluid catalytic cracking (FCC): the largest industrial fluidized bed application, converting heavy crude oil fractions into gasoline and lighter products using a fluidized catalyst.
• •Fluidized bed combustion (CFBC): coal, biomass, or waste is combusted in a fluidized bed of limestone or sand for efficient heat transfer and low emissions.
• •Drying of particulate materials: fluidized bed dryers for food products, pharmaceuticals, and minerals provide uniform temperature and fast drying.
• •Coating and granulation: pharmaceutical tablets and granules are coated or agglomerated in fluidized beds with sprayed coating solutions.
• •Biomass gasification: fluidized beds provide high heat and mass transfer for biomass-to-syngas conversion at 700-900°C.