管式超滤膜浓缩牛乳的研究

CONCENTRATION OF WHOLE MILK BY TUBULR ULTRAFILTRATION

采用ＰＡＮ管式超滤膜进行牛乳的浓缩试验，探讨了膜孔径、压力对透液通量和截留率的影响。结果表明，超滤膜孔径对牛乳透液通量和截留率有较大的影响，压力仅显著影响透液通量。选用聚丙烯腈（ＰＡＮ）３万膜，在０．２０ＭＰａ，４５℃条件下超滤，浓缩倍数可达２．４０，平均透液通量为９．３４ｋｇ／ｍ２ｈ，蛋白质截留率在９１．１０％以上，钙、磷等矿质元素也有较高的截留率，乳糖截留率在１３．３０％以下。

Whole milk was concentrated by polyacrylonitrile tubular UF membranes, and the effects of membrane pore size and pressure on flux and retention were investigated. The pore size of UF membrane had a great effect on flux and retention, while pressure had a great effect on the flux only. Best UF results were obtained at 0.20 MPa and 45℃ with polyacrylonitrile membrane of 30000 dalton pore size. Concentration factor and average flux of milk were up to 2.40×and 9.34 kg/m 2·h respectively. Protein retention was more than 91.10%; mineral (Ca,P) retention was also comparatively high, and retention of lactose was less than 13.30%.