Vertical screen is a compact and simple unit used for separation and handling of screenings in sewage treatment plants as well as industrial sites. The vertical screen combines sieving, washing and pressing functions in one unit.
Waste water is screened through the lower sieve part of the unit installed inside a channel or a tank. The separation can be done with a perforated plate or with a wedge wire. The sieving element is shaped as a trough equipped with a spiral inside, conveying the captured separated screenings. The spiral is fitted with a brush inside the sieving through to prevent clogging.
The enclosure contributes to a good working environment and it gives a good conveying ability. Inside the conveying section the screenings are washed and conveyed to the discharge end on top. The washing water, used to wash out the organics from the screenings, is added in the opposite direction to the spiral movement. The screenings are shredded into pieces at the discharge in order to eliminate large compact screenings that can cause problems at incineration.
The conveyed screenings are dewatered up to 45% before being shredded into smaller pieces and finally discharged.