1. What is External Reflux Flowrate?

Definition: The External Reflux Flowrate to Distillation Column is the number of moles of condensed top product flowing back into the column as reflux per unit time.

Purpose: It helps in determining the amount of liquid that needs to be returned to the distillation column to achieve the desired separation efficiency.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( L_0 \) — External Reflux Flowrate (mol/s)
• \( R \) — External Reflux Ratio (dimensionless)
• \( D \) — Distillate Flowrate from Distillation Column (mol/s)

Explanation: The external reflux flowrate is calculated by multiplying the external reflux ratio by the distillate flowrate.

3. Importance of Reflux Flowrate Calculation

Details: Proper reflux flowrate estimation is crucial for maintaining the mass balance in distillation columns and achieving the desired product purity.

4. Using the Calculator

Tips: Enter the external reflux ratio (typically between 1.0 and 10.0) and the distillate flowrate in mol/s. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical reflux ratio value?
A: The reflux ratio typically ranges from 1.0 to 10.0 depending on the separation difficulty and desired product purity.

Q2: How is distillate flowrate determined?
A: Distillate flowrate is usually set based on production requirements and column capacity.

Q3: What units should be used for this calculation?
A: The calculator uses mol/s for flowrates, but the same formula works with any consistent units.

Q4: What's the difference between internal and external reflux ratio?
A: External reflux ratio is based on the liquid returned to the column, while internal reflux ratio accounts for vapor condensation inside the column.

Q5: How does reflux ratio affect column operation?
A: Higher reflux ratios generally improve separation but increase energy consumption and column size requirements.