1. What is the Water Evaporation Rate Equation?

The water evaporation rate equation calculates the mass transfer rate of water evaporating from a surface. It's fundamental in chemical engineering, environmental science, and HVAC system design.

2. How Does the Calculator Work?

The calculator uses the evaporation rate equation:

Where:

• \( E \) — Evaporation rate (kg/s)
• \( A \) — Surface area (m²)
• \( h \) — Mass transfer coefficient (m/s)
• \( x_s \) — Saturation humidity at surface temperature (kg/m³)
• \( x \) — Ambient air humidity (kg/m³)

Explanation: The equation quantifies how much water evaporates per second based on surface area, mass transfer efficiency, and humidity difference.

3. Importance of Evaporation Rate Calculation

Details: Accurate evaporation rate calculation is crucial for designing cooling towers, predicting water loss from reservoirs, industrial drying processes, and climate modeling.

4. Using the Calculator

Tips: Enter all values in correct units. Ensure saturation humidity is greater than ambient humidity for evaporation to occur. Values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What affects the mass transfer coefficient?
A: Air velocity, surface roughness, and temperature difference between surface and air all influence the mass transfer coefficient.

Q2: How to determine saturation humidity?
A: Saturation humidity depends on surface temperature and can be found in thermodynamic tables or calculated from temperature and pressure.

Q3: What are typical evaporation rates?
A: Rates vary widely - from 0.00001 kg/s for small surfaces to several kg/s for large industrial applications.

Q4: Does this equation work for other liquids?
A: The form is similar but coefficients and properties would differ for non-water liquids.

Q5: How accurate is this calculation?
A: It provides a good estimate but actual rates may vary due to factors like surface contamination or non-uniform airflow.