MetPro
Size hydrocyclones with the published Plitt (1976) model: corrected cut size d50c, pressure drop, flow split, sharpness of separation and number of cyclones for the duty.
This calculator sizes hydrocyclones with the published Plitt (1976) model, using all four of Plitt’s equations: corrected cut size D50c, pressure drop, volumetric flow split S between underflow and overflow, and sharpness of separation m. The corrected efficiency curve is y(d) = 1 − exp(−0.693·(d/D50c)^m), so y(D50c) = 0.5 by construction. The engine carries the Flintoff, Plitt & Turak (1987) viscosity term (µ^0.5). This page fixes viscosity at 1 cP (water), where the term equals 1.
Plitt’s D50c constant is 50.5 with dimensions in cm and flow in L/min. With flow in m³/h, the same equation takes the constant 50.5 / (1000/60)^0.45 = 14.24. The free vortex height h enters at the exponent 0.38 (Plitt 1976). Inputs here are mm and m³/h and are converted internally.
Pressure enters the cut size only through the flow term Q^0.45, exactly as published. The pressure drop is an output of Eq. 2, so the page has no pressure input. The number of cyclones for a duty comes from matching per-unit flow against a table of standard cyclone sizes. The implementation is a single authoritative transcription of the four equations, verified against an independent hand evaluation (15-inch cyclone: D50c = 99.75 µm, ΔP = 170.3 kPa, S = 0.177, m = 2.74).
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