Why capacity is not a fixed figure
The same dryer processing a different material, a different initial moisture content or a different target final moisture will produce a different actual capacity. A figure in a manual can therefore only be treated as an order of magnitude.
Dry basis versus wet basis
Dry basis refers to the mass of bone-dry material; wet basis includes the moisture in the material. The two produce very different numbers, so failing to state which one is used creates ambiguity. In practice, figures are expected to state the basis explicitly.
Why a trial run is required
Until the operating parameters are fixed, any capacity figure is an estimate. Official capacity data has to come from a trial run, which is why we recommend arranging a small trial before signing.
Which parameters can be stated precisely
Air volume can be stated precisely. It is fixed by the machine size and does not change with the material, so it can be given at the selection stage. The drying tube diameter and the model number (for example JYD-400 for Ø400 mm) are also fixed.
What to provide for a more accurate selection
The material name and its properties, the initial moisture content and the target final moisture. The clearer these three items are, the closer the recommendation will be to your actual process.
References and Standards
- GB/T 6284—2006 Chemical products for industrial use — General method for determination of water content — The loss of mass on drying method[S]. Beijing: Standards Press of China, 2006.
- Mujumdar A S. Handbook of Industrial Drying[M]. 4th ed. Boca Raton: CRC Press, 2014.
- Tan T E, Dou M. Principles of Chemical Engineering[M]. 4th ed. Beijing: Chemical Industry Press, 2013. (in Chinese)
- Pan Y K, Wang X Z, Liu X D. Modern Drying Technology[M]. 2nd ed. Beijing: Chemical Industry Press, 2007. (in Chinese)
- Liu X D, Li Z Y. Modern Drying Technology[M]. 3rd ed. Beijing: Chemical Industry Press, 2022. (in Chinese)