Industrial drying: principles and calculation of machines

In articles [J 2 451] and [J 2 452] we presented "Hot-air drying", its industrial applications and energy-saving techniques for this drying mode, where it is the hot air that brings the energy of water vaporization to the product, via convective transfers between the air and the product. The articles [J 2 453] and [J 2 454] are devoted to "Other drying modes than hot air drying", where it is no longer the hot air circulating around the product that provides (mainly) the heat useful for vaporizing the water, but other heating modes, with specific advantages and disadvantages described in the text. In particular, it has been shown at [J 2 453] that energy consumption can be reduced by a factor of 2 to 15 in some cases, compared with hot-air drying, by using boiling drying, either by conduction or by superheated steam. The following techniques are either "boiling" or "entrainment", depending on the type of heat input.

This article [J 2 454] presents four types of "other than hot air" drying, in addition to conduction and VES drying described in [J 2 453] :

• Radiation drying: the supply of energy to the product by radiation corresponds to infrared, microwave and high-frequency heating, as well as direct...