Thin-Layer Drying Of Yeast Fermented Liquor On Carriers

Fermented liquor, the large and concentrated by-product of the beet sugar industry process, contains much organics such as BOD5, CODcr, SS, etc., whose direct discharge would severely pollutes the water resources by eutrophication and leads to water hypoxia, the extinction of aquatic animals and river stink.Using the fermented liquor as a feed additive, this paper aims to reclaim its helpful substances so as to produce rumination feed by the thin layer drying technology, through which realize the economic circulation of resources. It is also expected to offer a new solution for the drying of viscous materials with the research of viscous materials adsorption-thin layer drying technology represented by fermented liquor.With a cylindrical solid bed, whose diameter is110mm, the experiment studies the influence of air temperature, air velocity, bed height, mixing ratio, and standing time to the adsorption-thin layer drying rate and the reasons of the material agglomeration, particle sticking on the wall, and finally comes up with an appropriate mixing ratio and the extension of the materials’standing time.The results show that air temperature exerts a significant effect on the absorption-thin layer drying rate. In particular, when the air temperature exceeds100℃,the drying rate increases apparently. The higher the temperature reaches and the higher the drying rate becomes, accordingly, the more effect the air temperature exerts on the drying rate. Furthermore, bed height also has a remarkable effect on the drying rate. It is shown in this research that the least energy consumption happens in the bed’s height of30mm.The drying rate decreases with the increase of the mixing ratio of material. And the drying rate accelarates with the extension of the materials’standing time.In the absorption-thin layer drying, as the repose angle of viscous materials and adsorption carriers becomes larger, the probability of the material particle agglomeration is greater, the agglomeration diameter is bigger and the phenomenon of material sticking on the wall becomes more serious. Contrarily, that probability decreases even disappears, and it is the same with the material sticking on the wall.The repose angle value is greatly influenced by the mixing ratio and the standing time of the materials. It grows in a decreasing rate with the increase of the mixing ratio until the latter is over1/0.6, and declines gradually in a decreasing rate with the extension of the standing time.