๐ฌ๏ธ Drying Rate Calculator
Estimate total drying time and rate curve for constant-rate and falling-rate periods using critical and equilibrium moisture contents.
๐จ Drying Period Schematic
๐ Configuration
Key Equations:
Constant-rate time: tc = Ms(XโโXc)/(A Nc)
Falling-rate model: dX/dt = โkf(XโXe)
Falling-rate time: tf = ln[(XstartโXe)/(XfโXe)]/kf
Constant-rate time: tc = Ms(XโโXc)/(A Nc)
Falling-rate model: dX/dt = โkf(XโXe)
Falling-rate time: tf = ln[(XstartโXe)/(XfโXe)]/kf
๐ Results & Visualization
Configure inputs and click Calculate to view results.
๐ Calculation Methodology
Mathematical Model
The drying process is split into a constant-rate period down to the critical moisture content and a falling-rate period where the drying rate decreases approximately with free moisture XโXe.
Worked Example
For a 10 kg dry solid with Xโ=1.2, Xc=0.45, Xe=0.08 and Xf=0.15, the calculator first computes constant-rate time, then integrates the falling-rate equation to obtain total drying time and rate curve.
Assumptions
- Moisture contents are on dry basis.
- Constant area and constant air conditions.
- Falling-rate period follows first-order free-moisture behavior.
- Heat-up period and shrinkage are not included.