High-Frequency Flow Reversal
Aquamarijn microsieves offer unrivaled fluxes, compared to other microfiltration techniques. To maintain these fluxes it is important to apply High-Frequency Flow Reversal in order to stabilize the high filtration performance of microsieves. This removes non-permeable substances concentrating on the membrane surface very effectively.
Aquamarijn developed a unique system which combines cross-flow and flow-reversal for fouling control with microsieve filtration. The microsieves are mounted on a rotating hollow disk inside a filtration vessel chamber through which the feed solution flows. During filtration the disk rotates at frequencies between 5 to 25 Hz. The flow reversal is achieved by reversing the flow through the microsieve with a vacuum device, placed close to the surface of the rotating disk with the microsieve. This device creates locally a negative pressure drop because of the high flow and close proximity to the microsieve surface. The microsieve will pass the vacuum device every rotation and the pressure drop will reverse the flow through the microsieve. This results in local flow reversal through the microsieve and minimizes filtrate loss. Due to the continuous rotation the whole microsieve gets cleaned with a high frequency.
Micro filtration of beer
For beer filtration there is still no match for the fluxes obtained with Aquamarijn microsieves. In addition, the low internal surface area of the membrane avoids adhesion of valuable proteins that characterize the beer. Furthermore, the smooth surface and the chemical inertness of the membranes make them less sensitive to fouling leading to longer intervals between cleaning. When operated with High-Frequency Flow Reversal technologies, the membrane is kept clean during filtration by breaking up the fouling deposit layer on the membrane. This results in an even longer filtration cycle without the use of cleaning chemicals at very low power consumption. Moreover, the outstanding flux performance, yields extremely high fluxes at low-pressure operation. This reduces energy consumption and thus production costs. Contact us if you want to learn more about filtration or other microsieve applications.
Dairy filtration
Removal of bacteria, spores and yeast for increasing shelf life of milk or improving cheese milk, requires a membrane with a very sharp pore definition, in order to separate the unwanted part from the wanted cut of cheese brine. The well-defined pores make especially the microsieve well suited for this type of separation. And because the membrane is very thin, the milk proteins and casein micelles, will easily be transported through the membrane. This results in high throughput of your filtration. Contact us if you want to learn more about milk filtration or other microsieve applications.
High volume micro filtration requires large scale filtration plants. Aquamarijn works together with preferred system builders and integrators to deliver you an advanced filtration system based on microsieve membrane technology. Aquamarijn has designed and manufactured pilot systems for the beverage and dairy industry. For example, the company MST Microsieve Technologies GmbH is currently running a pilot line to filter beverages in Asia.
Further Reading
- Verwijst, T.; Baggerman, J.; Liebermann, F.; van Rijn, C. J. M., High-frequency flow reversal for continuous microfiltration of milk with microsieves. Journal of Membrane Science 2015, 494, 121-129.
- van Rijn, C. J. M., MicroFiltration. In: Nano and Micro Engineered Membrane Technology. Elsevier: Amsterdam, 2004; pp 169-253
- Kuiper, S.; van Rijn, C.; Nijdam, W.; Raspe, O.; van Wolferen, H.; Krijnen, G.; Elwenspoek, M., Filtration of lager beer with microsieves: flux, permeate haze and in-line microscope observations. Journal of Membrane Science 2002, 196, 159-170.
- Kuiper, S.; van Rijn, C. J. M.; Nijdam, W.; Elwenspoek, M. C., Development and applications of very high flux microfiltration membranes. Journal of Membrane Science 1998, 150, 1-8.