Study On Hydrokinetics Of Flocculation For Chinese Traditional Medicine Extracts

Compared with alcohol-precipitation method in clarification process of Chinese medicine extraction, flocculation can reduce the production cycle, lower the energy consumption, ensure the retention rate of available components as well as increase the clarity and stability of the pharmaceutical product. In this paper, by the way of flocculation substituting alcohol-precipitation, the Yangyingqingfei syrup produced by Lerentang is studied as a case. 7 kinds of natural macromolecule are selected as flocculants to treat Chinese medicine extraction. The jar test results show that, ZTC1+1 and chitosan can act as flocculants respectively in the process of clarification for water-extraction and alcohol-extraction. When under their optimum conditions in the process of flocculation for water-extraction and alcohol-extraction, the residue turbidity can reduce to 13.7NTU and 11.4NTU respectively, and the retention rate of avialible component can keep at 83.2%(glycyrrihizic acid) and 94%( paeonia radix). An experiment using centrifugal separation method as subsequent process after flocculation is carried out and the results indicate this method can further improve the clarity and stability of the pharmaceutical product with no effect on the available component of pharmaceutical product. Based on the analysis on flocs' dimention, morphosis and setting properties, flocculation mechanism including the effect of hydrodynamics on flocculation was also studied systematically. Stir velocity and time show weak influence to the retention rate of avialible component but strong influence to residue turbidity and setting properties of flocs. Through the test of amplifying flocculator, it is found that axial-radial flow can reinforce flocculation process compared with radial flow. Under the direction of theory and above experiments, a kind of new type gridding flocculator is designed and further verified its flocculation effect by experiment. The experiment results show that, under identical average energy dissipation, gridding reactor has better flocculation efficiency than that of no-gridding reactor in clarification process of Chinese medicine extraction.