Agitation of bulk materials with low flowability in mixer - by using two stirrers rotating in opposite directions, esp in mfg. dextrin and similar prods.

摘要

The materials possess a large specific surface; and are fed downwards into a gap between two long stirrer shafts, each provided with rows of arms ending in stirrer blades. Shafts are rotated in opposite directions so streams of the material are driven towards each other; and a liq. is pref. added to wet the material. The pref. mixer consists of a long chamber formed by two half cylinders so the cross-section of the chamber resembles a figure-8. Each half cylinder contains an axial shaft; and the space between the shafts exceeds twice the radius of the stirrer arms on the shafts. The peripheral speed of the stirrers is pref. 10-40 m/s. For example in mixing starch with a catalyst acid to make a prod. during dextrin mfr.; or for agglomerating a prod. obtd. by the hydrolysis of starch; or for granulating dextrin.