Flash Vapor Liquid Split Calculator
Solve an ideal isothermal flash phase fraction from feed weights and supplied component equilibrium K values.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Normalize the feed and bracket the Rachford–Rice root between all-liquid and all-vapor limits.
Σ zi(Ki−1)/(1+β(Ki−1))=0; xi=zi/(1+β(Ki−1)); yi=Ki xi
Worked example
Equal feed fractions with K values 2 and 0.5 give vapor fraction 0.5, liquid composition (1/3,2/3) and vapor composition (2/3,1/3).
Assumptions and input details
K values must apply at one common temperature/pressure and be supplied. This solves component balances, not K-value thermodynamics or energy balance. In a single-phase case the absent phase composition is undefined and not invented. Near-unit K values for every present species leave the phase amount unresolved and are rejected.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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