Lyophilizer (freeze dryer) simulation

liquid formulation -> cake + sublimed vapor

Governing equations

The exact equations the solver works for a lyophilizer (freeze dryer) — the same math shown in the app's "Theory" panel, not a black box.

$\dot m$

sublimation rate per vial [kg/s]

$p_{ice}$

ice vapour pressure at the sublimation front [Pa]

$p_{ch}$

chamber pressure [Pa]

$R_p$

cake resistance [m^2.Pa.s/kg]

$l$

dried-cake thickness [m]

$R_0, A_1, A_2$

cake-resistance parameters

$K_v$

vial heat-transfer coefficient [W/m^2/K]

$A_v$

vial outer area [m^2]

$T_{sh}$

shelf temperature [K]

$T_b$

vial-bottom temperature [K]

$\Delta H_{sub}$

heat of sublimation [J/kg]

Parameters

fill_depth [m], vial_inner_diameter [m], vial_outer_diameter [m], kv [W/m^2/K], r0 [m^2·Pa·s/kg] — all measured for your vial, dryer and formulation. Optional: a1/a2 (cake-resistance growth), shelf_temperature [K], chamber_pressure [Pa], collapse_temperature [K, enables the collapse check], max_sublimation_rate [kg/s per vial the dryer can carry], residual_moisture [default 0.02], batch_time [s].

Example flowsheets that use it