It has the goal to separate coarse and medium-fine solids at the inlet, avoiding thus their sedimentation in next stages and clogging in machineries (pumps, mixers etc.).
There are several models of screens, depending on the type of plant: rotary drum, arch with brushes, arch with comb, static, cascade, disk, step, cochlea etc.
In all cases the screen is made of stainless steel or, however, in material suitable to be constantly in contact with water without suffering corrosion.
The solids are separated from the water and forwarded to special containers that must be periodically emptied.
The cleaning of the screening surface is automatic and continuous and occurs by brushes, combs or counter current pressured water jets. The screening equipment is controlled by pre-set time switches or level sensors.
In the case of a static screen cleaning occurs manually.