CFW offers drying solutions for seed processing at any scale. We take the requirements of the customer as well as the humidity and temperature conditions of the site into account when engineering a system, rather than prescribing a standard unit.

Seed drying has two chief goals: one is to extend the shelf life of edible seeds by preventing germination and mould growth, the other is to preserve seed viability for future planting or research. Seed longevity is influenced by various factors, but reducing the moisture content to the correct level is often regarded as the most important. High moisture levels encourage the growth of harmful microorganisms and insect infestation, and promote higher seed respiration rates. In some instances, increased temperatures that result from higher respiration rates can create a fire hazard.

In order to dry seeds safely and reliably on a large scale, the correct drying technique must be used. Sun-drying can be slow, is dependent on the weather and can harm viability, particularly with darker seeds, as temperature control is difficult. Faster and more even drying techniques are needed to ensure product quality.

For this reason, forced-air drying with careful flow control, taking account of both volumes and turbulence, is often preferred and can yield consistently good results. Hot-air drying can provide higher production rates provided that it is even enough to prevent localised overheating that will damage the seeds. Case hardening can occur when the surface dries out quickly and becomes less permeable. The interior of the seed then retains too much moisture. In these circumstances, Moisture content testing can yield inaccurate results, and seed degradation may occur more quickly than anticipated.

A number of different convection drying designs are used. Continuous dryers may be suitable for larger production runs but typically require more (or more powerful) fans. In many cases, the fans continue to run after the appropriate moisture content has been reached, in order to cool the product and prevent moisture from condensing onto surfaces.