The wastewater enter the cylindrical internal ring, the form of which makes the fluid circulate. The centrifugal force and weight makes the sand and solid bodies of high specific weight drop down to the conical collection chamber bottom, to the collection hopper. Thanks to the fine-bubble aeration fat and other flotate is kept within sand trap internal ring, from where they are removed periodically with flotate filtration system. Filtrated wastewater is removed outside with outlet stub pipe.
The sand-water pulp from the collection chamber is transferred to the sand separator with the air pump. In the separator, the pulp flows into wash and sedimentation chamber. The organic contamination is washed away from the mineral matter with air provided to the chamber. Cleaned sand drops down to the bottom and the fluid surplus with organic suspension flows through the overflow back to the external ring, form where it is transferred outside with worm conveyor.