New membrane module
Toray Industries, Inc. (Tokyo, Japan; www.toray.com) has developed an exceptionally robust hollow-fiber ultrafiltration-membrane module that is suitable for purification and concentration processes in the food-and-beverage and biotechnology sectors. The module operates in steam (125°C) and hot water (90°C) environments, and can be steam sterilized.
Toray leveraged its high-strength polyvinylidene fluoride hollow-fiber membrane technology, which is already used in water-treatment applications, to develop a new module that employs an “outside-in” type crossflow-filtration design. Crossflow filtration is a common technique, whereby feed passes parallel to the membrane surface and prevents turbidity from accumulating. Pressure losses from this design are just one-third those of “inside-out” type that is normally used by food companies, says Toray. With the new design, it is possible to filter and concentrate highly turbid or viscous liquids, which is challenging with conventional membranes.
The new module has a large membrane area, which reduces the number of modules needed, reduces the space requirements by 50% and can potentially lower cleaning and equipment costs by more than 20%, Toray says.