Technology/quality

Ceramic membranes are so-called composite membranes, which means that a thin membrane is applied to a highly porous support. atech supports are characterized by high water permeability. The membrane is as thin as possible   thus presenting a small resistance - and at the same time thick enough to minimize imperfections.

Design and production of membrane elements

Membrane supports are made of high-purity alpha-aluminum oxide which ensures maximum permeability and fulfils high requirements regarding mechanical strength. The carriers supports  are produced by extrusion and are sintered at temperatures of up to 1,800°C. Only if pure materials and high temperatures are used, supports will be resistant even to very corrosive media liquids and will have a sufficient stability. Then, the filtration membrane is applied in layers, starting with the largest pores and continuing to finest pores having diameters of only a few nanometers (one thousand millionth of a meter, a hundred thousand times smaller than the diameter of a human hair). Depending on the application, membranes are available in alpha-aluminum oxide, titanium oxide or zirconium oxide.

Benefits

When compared to rival products, in particular to polymer membranes, ceramic membranes made by atech stand out due to their high chemical, thermal and mechanical strength, ensuring a long service life. Consequently, membranes are primarily used when polymer membranes are no longer able to meet the requirements. Due to their excellent material properties ceramic membranes ensure process stability, high availability levels, low pre-treatment requirements and minimum technical care. Compared to ceramic membranes made by other manufacturers the quality of atech membranes is significantly higher because they are produced without using any ceramic binders or other additives.

All in all, ceramic membranes made by atech provide the following benefits:

• High pressure resistance (bursting strength)
• Resistant to concentrated caustic solutions and acids
• Possibility of backpulsing
• Very high abrasion resistance
• Trouble-free cleaning
• Temperature stability
• High flux

Cross-flow filtration

During cross-flow filtration by means of ceramic membranes the liquids to be filtered flows through the channels of the membrane carrier. All particles whose size exceeds the pore diameter of the membrane are retained. The particles / molecules build up in the concentrate. The filtrate permeates through the pores and - depending on the procedure - is subjected to subsequent process stages.