Concentrated Membrane for fermentation broth
The internal pressure type polyvinylidene fluoride hollow fiber microporous membrane module with a diameter of 90mm×1000 mm and a membrane area of 40m² is used to assemble a two-way flow process. Reverse the fermentation broth flow in a cycle of 20 minutes, that is, after the fermentation broth flows in the usual bottom-in-up-out mode for 20 minutes, switch the valve to reverse the fermentation broth flow direction to the top-in and bottom-out mode. After running for 20 minutes Reversing again, repeating in turn, the inlet pressure of the membrane device is 0.1 MPa, and the outlet pressure is 0.0 MPa. Using this two-way feed membrane filtration method, the same concentration of 1.2 t fermentation broth can be completed in only 1 h, and the average filtration rate is 150 L/h·branch, which is much higher than that of the usual membrane process. the way. This is because when the fermentation liquid flows in the bottom-in and top-out mode, the hollow fiber membrane in the lower half of the membrane module is in a filtering state, and the hollow fiber membrane in the upper half is in an isobaric cleaning state due to almost no pressure difference; After that, the upper half of the hollow fiber membrane that has just been cleaned enters the working state, and the lower half of the hollow fiber membrane that has just been cleaned enters the isobaric cleaning state. Such cycles alternate, the same hollow fiber membrane module is always in an efficient working and cleaning state.
The characteristic of two-way flow process is that the same hollow fiber membrane module is in the working state and cleaning state at the same time during the filtering process, so as to maintain high separation efficiency. This process is especially suitable for the filtration and refining of viscous liquids such as fermentation broth. It changes the situation that hollow fiber membranes cannot be used for the filtration and separation of viscous liquids in the past, expands the application fields of hollow fiber membranes, and has a small equipment footprint, The advantages of low cost and high recovery rate of concentrated liquid are especially suitable for the treatment of large-scale fermentation liquid.