关键词: 折板絮凝器, FLUENT, 流场, 絮凝, 薄荷水提液

Abstract: As a part of the excellent culture of the Chinese nation, traditional Chinese medicine have been favored by more and more people in recent years due to its high safety and low side effects. At present, most of the researches on impurity removal of traditional Chinese medicine by flocculation were based on the flocculation operating conditions, such as flocculation temperature, pH value of the traditional Chinese medicine solution and different flocculants. In order to optimize the structure of the folded-plate flocculator and enhance the flocculation effect of the Chinese medicine liquid. Vortex distribution and vorticity in the flow field of the same wave folded-plate flocculator and the opposite wave folded-plate flocculator were simulated and analyzed by FLUENT. Taking the peppermint water-extraction solution as the research object, using chitosan as a flocculant, flocculating the peppermint water-extraction solution by different folded-plate flocculators, let clear layer height, sedimentation velocity, total flavonoid retention rate, flocculation rate, absorbance and fractal dimension of flocs index, the influence of different inlet flow rates on flocculation for the effect of flocculant by different folded-plate flocculators were discussed. Results showed that the vortex positions of the same wave folded-plate flocculator were respectively unilateral vortex, and the vortex position of the opposite wave folded-plate was distributed on the two sides of the folded plate, under the same inlet flow rate, the vorticity generated by the same wave folded-plate flocculator was smaller than that of the opposite wave folded-plate flocculator. The flocculation effect of the same wave and the opposite wave folded-plate flocculator on the mint water extract showed a trend of first increasing and then decreasing, the optimal flocculation inlet flow rate of the same wave folded-plate flocculator was 0.068 m/s, the total flavonoid retention rate of the peppermint water-extraction solution was 91.2% , the flocculation rate was 85.3%, the optimal flocculation inlet flow rate of the opposite wave folded-plate flocculator was 0.051 m/s, the total flavonoid retention rate of the peppermint water-extraction solution was 91.8%, the flocculation rate was 85.4%.

Key words: folded-plate flocculator, FLUENT, flow field, flocculant, peppermint water-extraction solution