Average Convective Mass Transfer Coefficient Formula:
From: | To: |
Definition: This calculator estimates the average convective mass transfer coefficient based on the penetration theory, which considers the diffusion coefficient and contact time.
Purpose: It helps chemical engineers and researchers determine the mass transfer coefficient for fluid-fluid interfaces in absorption, distillation, and extraction processes.
The calculator uses the penetration theory formula:
Where:
Explanation: The formula shows that the mass transfer coefficient is proportional to the square root of the diffusion coefficient and inversely proportional to the square root of contact time.
Details: Accurate calculation of mass transfer coefficients is crucial for designing efficient separation processes and predicting mass transfer rates in chemical engineering applications.
Tips: Enter the diffusion coefficient (DAB) in m²/s and average contact time (tc) in seconds. Both values must be positive numbers.
Q1: What is penetration theory?
A: Penetration theory models mass transfer at fluid interfaces assuming unsteady-state diffusion into a semi-infinite medium during short contact times.
Q2: How do I determine the diffusion coefficient?
A: Diffusion coefficients can be found experimentally or estimated using empirical correlations based on the properties of the system.
Q3: What affects the contact time in mass transfer?
A: Contact time depends on fluid dynamics, system geometry, and operating conditions like flow rates and agitation.
Q4: Why is the coefficient proportional to √D?
A: This relationship comes from the fundamental solution to Fick's second law of diffusion for short contact times.
Q5: What are typical values for kL?
A: Values typically range from 10-5 to 10-3 m/s depending on the system and conditions.