Ceramic Membranes for the Future
Wednesday 20 December 2006New technology allows simpler, more efficient, and more economical separations for dairy, food and beverage, and biopharmaceutical applications.
New technology, now available from GEA Filtration, for cross-flow microfiltration separations that are sensitive to variations in trans-membrane pressure (TMP), are more efficient, more economical, and much easier to control than technologies used to date. The Isoflux® membrane, produced by a patented manufacturing technique, represents the third generation in membrane design and a real solution to the fouling and inefficiencies caused by gel layer formation.
In conventional microfiltration, as the product flows down the tubular element, there is a natural hydrodynamic pressure drop from the inlet to the outlet of the flow channel. The uneven permeate flux distribution along the length of the flow channel can be very significant due to the resulting concentration polarisation effect particularly at the higher pressure inlet, and decreasing toward the outlet end. This fouling interferes with the product transmission through the membrane, decreasing the quality of the separation, shortening running time, and increasing costs.
A second generation of membrane processes have attempted to solve this problem and create a uniform TMP over the length of the element by creating a pressure gradient on the permeate side of the membrane. This has been used in some dairy applications but suffers from significant problems such as: the requirement for extra piping and pumps; an increased risk of contamination; and a long residence time that affects the quality of the final product.