The Study On Clarification Of Vinegar By Ultrafiltration

The vinegar is one of the oldest and most popular flavors in the world. It is made in most of countries and regions. But the turbidity in some vinegar brewed affects straight on their quality. Presently, there are various methods to clarify the vinegar, including to natural clarification, filtration, composite defecates clarification, ultrafiltration and so on. Ultrafiltration is considered a method that it is not only economical but also effective technique in various methods.Ultrafiltration is one of membrane separation technology. It can be described as the following: the raw liquid acted by a pressure difference flows through the surface of dissymmetrical structure ultrafiltration membrane are separated. The membrane has different tiny holes for realization separation of different sizes molecular. The process of ultrafiltration is a simple physical separation. No matter is added, and without phrase changing also. Ultrafiltration to treat vinegar can remove bigger size matter to bring turbidity and keep effective component. This technique improves product quality. At the same time, no pollution is brought into the product.In our experiments, the raw material was produced by Nanning Sauce Factory. The experimental equipment was purchased from Shanghai Yadong Nuclear Grade Resins Co. Ltd. The experimental results were achieved bysingle-factor and orthogonal experiments. Firstly, the relation between membrane flux and operation time is concluded in different operation pressure and different feed rate. Secondly, two regression equations are set up. The relationship between the membrane flux and the operation pressure and the time is obtained. Another relationship is between the membrane flux and the feed rate as well as the operation time. Thirdly, after some physical and chemical characteristics of vinegar were analyzed. The results show that the characteristics have no changes significantly except for the content of protein. And the relationship between the physical and chemical standard of vinegar and the operation conditions were studied also. Finally, the orthogonal experimental analysis was conducted on the single factor results. The third regression equation that related the membrane flux and the feed rate as well as the pressure was obtained. At the same time, the optimum operation parameters of the experiment were found to be: O.lMPa for the operation pressure and 48L/h for the feed rate. In addition, the influence factors of the working conditions on membrane pollution were investigated also. From some comparable experiments, the suitable cleaner and the cleaning technique were chosen, which can regain the membrane flux soon. In conclusion, the optimum method and cleaning programs for the experiments is to clean for 30 to 40 minutes with H2O2(0.2%), and then continue with NaOH(0.2%) for 20 to 30 minutes.