The ROTAMAT® Membrane Screen is a very fine screen with a low headloss and provides a large screening surface due to its drum-shaped screen basket and 35° installation angle. The screen uses a square mesh that provides, contrary to conventional slot screens, a defined separation size and ensures thus reliable separation of solids.
The twodimensional design and very fine apertures prevent that especially fibres and hairs are washed through the mesh before the screen basket surface is cleaned. Slot screens are not able to achieve the same efficiency due to their undefined separation size. In addition, square meshes have a very large free surface and are therefore able to cope with high hydraulic capacities despite their fine mesh.
The ROTAMAT® Membrane Screen is suitable for municipal and industrial wastewater flows of up to 3,500 m³/h and can be equipped with a square mesh size from 0.5 to 1.0 mm.
The low space requirement and high efficiency through a complete treatment by the combination of screening, transport, compaction, dewatering and discharge in one compact unit make the ROTAMAT® Membrane Screen an efficient and economical solution for removal of high solids concentrations. The screen can be installed either directly in the channel or in a separate tank.
Separation of hairs and fibres prior to membrane bioreactors
The selection of the mesh size depends on the applied membrane system. Membrane modules are divided into hollow fibre and plate modules. Separation of fibrous material is particularly important prior to hollow fibre membrane plants as fibres may lead to tressing or blocking of the membrane with the result of a reduced membrane permeability and membrane plant performance.
As a result, as fine as possible screening is required, in particular for hollow fibre membrane plants.
Reduction of COD/BOD5 in river and sea outfall applications
An as complete as possible reduction of the oxygenconsuming load that will be discharged into the receiving water course is particularly important in river and sea outfall applications as most of them do not have a mechanical treatment stage. An extensive reduction of COD/BOD in river and sea outfall applications can be achieved with 0.5 mm to 1.0 mm mesh size.
Treatment of industrial process wastewater
Due to new legislation concerning wastewater discharge into sewer systems, mechanical preliminary wastewater screening at source and treatment of the retained solids is required. The space-saving ROTAMAT® Membrane Screen is especially suitable for this purpose as it combines screenings separation, washing, transport and dewatering in one compact unit.