Calculate Total Drying Time - Online Calculator, Examples - Chemical Engineering

Drying is an important unit operation in chemical industries to remove excess moisture content from a product. Drying time plays a significant role to decide production rate and drying time depends on the several factors such as area exposed to air (A), moisture content of drying material and more. In this online calculator , you can calculate required total drying time to dry the material from a higher moisture level to a lower moisture level.

Online Calculator to calculate Drying time

Enter values for each parameter. If you need furthermore clarifications regarding parameters, please scroll down this page.

Total Weight of Dry Material (kg)
Fraction of Initial Moisture Content in Dry Basis (Example 0.40)
Drying Rate (kg m^-2 s^-1) during Constant Drying Period
Fraction of Critical Moisture Content in Dry Basis (Example 0.20)
Fraction of Final Moisture Content to be Dried in Dry Basis (Example 0.15)
Fraction of Equilibrium Moisture Content (Example 0.15)
Area of Drying Material Exposing to Air Stream (m²)

Explanation and parameters of drying time equation

Usually, there are two periods (some times three periods) of drying as constant drying rate period and falling drying rate period.

drying curve - moisture content and drying rate

Total drying time = drying time for constant drying rate period + drying time for falling drying rate period

t_total = t_constant + t_falling

Total weight of dry material (kg)

There are two different weight contributors for drying material. There are dry solid and water. Only weight of dry solid should be used in the calculation because calculations are done on dry basis.

Drying Rate (kg m^-2 s^-1) during Constant Drying Period

Drying rate is uniform until water content fraction reaches up to critical water content fraction. It's called constant drying rate (R_c).

Drying Rate (kg m^-2 s^-1) during falling drying period

When water content reduced than critical water content fraction, drying rate also reduces and become zero when water content reaches to the equilibrium water content fraction. So, this drying rate is vary with available free moisture content and define as falling drying rate (R_falling).

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