Liquid Flowrate Formula:
From: | To: |
Definition: This calculator determines the molar flowrate of liquid in the rectifying section of a distillation column based on the stripping section flowrate, feed quality, and feed flowrate.
Purpose: It helps chemical engineers design and analyze distillation columns by calculating the liquid flow in the upper (rectifying) section.
The calculator uses the formula:
Where:
Explanation: The liquid flow in the rectifying section equals the stripping section flow minus the product of feed quality and feed flowrate.
Details: Accurate flowrate calculations are essential for determining column diameter, tray design, and separation efficiency in distillation processes.
Tips: Enter the liquid flowrate in the stripping section (mol/s), feed quality (dimensionless), and feed flowrate (mol/s). The feed quality can be positive or negative depending on feed condition.
Q1: What does feed quality (q) represent?
A: Feed quality indicates the thermal condition of the feed - q = 1 for subcooled liquid, 0 for saturated vapor, and between 0-1 for mixed phase.
Q2: Can the liquid flowrate be negative?
A: No, if the calculation yields a negative value, it suggests an error in input parameters as flowrates cannot be negative.
Q3: How does feed quality affect the flowrate?
A: Higher q values (more liquid-like feed) will result in lower rectifying section liquid flowrates.
Q4: What units should I use?
A: Flowrates should be in consistent molar units (typically mol/s), and feed quality is dimensionless.
Q5: Does this apply to all distillation columns?
A: This formula applies to conventional distillation columns operating under steady-state conditions.