Ion Exchange Softener simulation

1 inlet -> 1 outlet (water passes through thermodynamically; the hardness balance rides alongside it as mg/L as CaCO3)

Governing equations

The exact equations the solver works for a ion exchange softener — the same math shown in the app's "Theory" panel, not a black box.

$C_{resin}$

resin operating capacity [eq/m^3]

$V_{resin}$

resin volume in the bed [m^3]

$H_{in}, H_{out}$

inlet and treated hardness [mg/L as CaCO3]

$V_{throughput}$

water treated per service run [m^3]

$t_{service}$

time between regenerations [s]

$m_{NaCl}$

salt per regeneration [kg]

$\eta_{salt}$

regenerant utilisation [-]

Parameters

resin_volume [m^3, REQUIRED], inlet_hardness [mg/L as CaCO3], outlet_hardness [mg/L, default 5 — typical sodium-cycle leakage], resin_capacity [eq/m^3, default 1800 = 1.8 eq/L operating capacity for a strong-acid cation resin], salt_efficiency [0..1, default 0.6], pressure_drop [Pa, default 50000]. Reports the service run between regenerations, the salt each one costs, and the sodium released (one equivalent per equivalent of hardness — softening swaps divalent for monovalent rather than reducing total dissolved solids).

Example flowsheets that use it