What Is the Rachford-Rice Flash Vaporization Calculator?
The Rachford-Rice algorithm solves for the molar split between vapor and liquid in an isothermal, isobaric flash drum.
How Does the Rachford-Rice Flash Vaporization Calculator Work?
Combines component mass balance with phase equilibrium definition Ki = yi / xi, yielding a strictly monotonic function bounded between 0 and 1.
Rachford-Rice Flash Vaporization Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
f(psi) = sum_{i=1}^N rac{z_i (K_i - 1)}{1 + psi (K_i - 1)} = 0, quad psi = rac{V}{F}
Rachford-Rice objective function for vapor-liquid flash equilibrium.
How to Use the Rachford-Rice Flash Vaporization Calculator
- Specify feed mole fractions zi and equilibrium K-values Ki for each chemical component.
Step-by-Step Example Calculation
3-Component Hydrocarbon Flash Separator
Input Values:
z1:0.3
k1:3.2
z2:0.4
k2:1.1
z3:0.3
k3:0.25
Worked Steps: Vapor fraction V/F = 43.1%, Liquid fraction L/F = 56.9%.
Understanding Your Result
Displays the equilibrium vapor fraction V/F (psi) and liquid fraction L/F.
Factors That Affect the Result
- Temperature and pressure dictate component K-values via thermodynamic equations of state (Peng-Robinson, SRK).
When Should You Use This Calculator?
- Designing crude oil separation trains, LNG fractionation columns, and distillation flash drums.
Assumptions & Limitations
- Assumes two-phase vapor-liquid thermodynamic equilibrium without liquid-liquid phase splitting.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard chemical engineering VLE formulation.