GIFSQ Tools · Module 17 — Food Processing, Thermal Engineering & Utilities · Tool 328 of 500
Work out the drying rate of a batch from the mass lost, the drying area and the time — the basic rate used to size dryers and compare drying runs.
Try sample values — fills the form with the worked example below.
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Water removed (kg)
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Drying rate (kg/m²·h)
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Removal rate (kg/h)
Equation: Water removed = starting mass − ending mass; drying rate = water removed ÷ (drying area × time); removal rate = water removed ÷ time.
Method: Standard mass-balance drying rate used in food process engineering (Heldman and Singh); the rate is the average over the stated period, not an instantaneous rate.
Assumptions: all mass lost is water; the drying area stays constant; the rate is averaged over the whole period.
Limitations: the drying rate falls as moisture drops, so one average rate cannot describe the whole curve — see the Drying Curve Analyzer for the two-period model.
Rounding: water removed and removal rate to 2 decimal places, drying rate to 3; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: Standard mass-balance drying rate used in food process engineering (Heldman and Singh); the rate is the average over the stated period, not an instantaneous rate.
Assumptions: all mass lost is water; the drying area stays constant; the rate is averaged over the whole period.
Limitations: the drying rate falls as moisture drops, so one average rate cannot describe the whole curve — see the Drying Curve Analyzer for the two-period model.
Rounding: water removed and removal rate to 2 decimal places, drying rate to 3; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: 100 kg drying to 60 kg over 10 m² in 5 h: water removed = 40.00 kg, drying rate = 0.800 kg/m²·h, removal rate = 8.00 kg/h.
Enter values above to see results.
Constant-rate drying typically runs at 0.5–2 kg/m²·h for tray drying; falling-rate values are much lower. Tool 328 of 500 — GIFSQ
