1. What is Condensation Rate?

Condensation Rate represents the mass flux of vapor condensing on a surface per unit area per unit time. It quantifies how quickly vapor transforms into liquid on a surface due to temperature differences and concentration gradients.

2. How Does the Calculator Work?

The calculator uses the condensation rate formula:

Where:

• \( h_m \) — Mass transfer coefficient (m/s)
• \( \rho_{v,s} \) — Vapor density at the surface (kg/m³)
• \( \rho_{v,\infty} \) — Bulk vapor density away from the surface (kg/m³)

Explanation: The equation calculates the mass transfer rate based on the concentration difference between the surface and bulk fluid, scaled by the mass transfer coefficient.

3. Importance of Condensation Rate Calculation

Details: Accurate condensation rate calculation is crucial for designing heat exchangers, refrigeration systems, distillation columns, and understanding phase change phenomena in various engineering applications.

4. Using the Calculator

Tips: Enter mass transfer coefficient in m/s, vapor densities in kg/m³. All values must be positive, with surface vapor density typically higher than bulk density for condensation to occur.

5. Frequently Asked Questions (FAQ)

Q1: What factors affect the mass transfer coefficient?
A: Flow velocity, fluid properties, surface geometry, and temperature gradients all influence the mass transfer coefficient value.

Q2: When is condensation rate negative?
A: Condensation rate becomes negative when bulk vapor density exceeds surface vapor density, indicating evaporation rather than condensation.

Q3: How is vapor density determined?
A: Vapor density can be calculated from ideal gas law using temperature and pressure, or measured experimentally.

Q4: What are typical values for condensation rates?
A: Condensation rates vary widely depending on conditions, typically ranging from 0.001 to 0.1 kg/m²s in industrial applications.

Q5: How does temperature affect condensation rate?
A: Temperature directly affects vapor density and mass transfer coefficients, with lower surface temperatures generally increasing condensation rates.