Corn starch Drying: Equipment Selection

This is the same category as starch, with the same gelatinization limit, but corn starch normally arrives at a lower moisture than cassava starch, so the feed section is steadier and the bridging risk is smaller. Our configuration is the same flash airflow line, with two differences: the residence time can be a little shorter, because the gelatinization temperature of corn starch is slightly higher than cassava and the process window is comparatively wider; and the air volume can be more generous, because corn starch has a relatively narrow size distribution and pneumatic classification works cleanly, so a cyclone at the tail end can recover the fines separately and give both a dry powder and a reusable fine fraction.

This is the same category as starch, with the same gelatinization limit, but corn starch normally arrives at a lower moisture than cassava starch, so the feed section is steadier and the bridging risk is smaller. Our configuration is the same flash airflow line, with two differences: the residence time can be a little shorter, because the gelatinization temperature of corn starch is slightly higher than cassava and the process window is comparatively wider; and the air volume can be more generous, because corn starch has a relatively narrow size distribution and pneumatic classification works cleanly, so a cyclone at the tail end can recover the fines separately and give both a dry powder and a reusable fine fraction. Modified starch and pre-gelatinized starch are two different stories. Modified starch has been chemically treated and is more heat tolerant, so it can take a hotter process. Pre-gelatinized starch has already been gelatinized, so our approach is not to dry it at all but to spray dry it into granules — the route has to be confirmed with the supplier.

Can corn starch and cassava starch share one process?
The route can be shared, the parameters cannot. The gelatinization temperature of corn starch is slightly higher, so the process window is wider and the residence time can be a little shorter, and the lower incoming moisture makes the feed section steadier. The key difference is still the gelatinization temperature, which has to be set from the incoming batch.

What does the cyclone do in starch drying?
More than dust collection. Corn starch has a narrow size distribution, so pneumatic classification works cleanly: the main separator splits the product from the coarse fraction and the fines are captured separately, and they can be returned to the line or sold as a different grade. The dust system is doing classification and protecting the yield at the same time.

How are modified and pre-gelatinized starch handled?
Modified starch has been chemically treated and is more heat tolerant, so it can take a hotter process. Pre-gelatinized starch has already been gelatinized, so our approach is not to dry it at all but to spray dry it into granules. Both have to be confirmed with the supplier in advance rather than fitted to the ordinary starch route.