Crossflow filtration is a method for filtering liquids which is used in the beverage industry, the foodstuffs industry, the pharmaceutical and bio-industry and in the field of environmental protection when it comes to the filtration or diafiltration of suspensions. Static crossflow filtration as well as dynamic crossflow filtration (rotation filtration) each have their specific advantages. Please contact us for your application.

In contrast to dynamic crossflow filtration, static crossflow filtration involves a tangential flow over the filter surface.

This also creates a turbulent flow on the membrane surface. The shear forces during the overflow of the membrane surface prevent the separated material from forming a coating (cake) on the filter surface. The surface is cleaned in the process so that the flow rate remains as constant as possible.

In addition to the product properties (density, viscosity, solids content) and ingredients, the flux rate is primarily determined by the filter layer pore size, the product temperature, the differential pressure and the circulation speed. In the case of preferential recirculation filtration via a receiver tank, the concentration of the retained solids (retentate) increases on the unfiltrate side. The permeate is fed into a sterile or hygienic filtrate tank by means of the system pressure.

Filtration base
By means of a circulation pump, the medium to be filtered is passed over the membrane (ceramic, hollow fibre, etc.), while a booster pump generates the required filtration pressure in the membrane. The unfiltered product is fed into the circuit in proportion to the permeate rate. The retentate is continuously discharged into the receiver tank. As a result, the proportion of solids and colloids in the receiver tank increases continuously. The cyclical backwashing with permeate prevents blocking of the membrane and maintains the flux rate.