The air drying process is an expensive business; this applies not only to condensation and adsorption dryers, but also to the hybrid dryers of energetic interest (combined condensation and adsorption drying). It is not economical to place an air dryer at every drying installation. Continuous drying does not take place at all installations, and dried air is not required constantly.
On the right: Central hybrid air dryer
During the seed drying process, a lot of moisture can be discharged using heated up outside air. Unfortunately the conditions of the outside air are not always suitable to reach the desired equilibrium moisture content at the end. Especially now that more seed companies want to receive, store and package the seed with a lower moisture content. To be able to dry the seed quickly and successfully, dried air is needed in the last phase.