The coarse screen forms the first stage of mechanical water treatment for pump protection. It removes the largest, bulky contamination.
The spacing between the screen prongs is regularly selected between 80 – 100 mm.
Depending on the expected level of contamination, the coarse screen can be cleaned either manually or automatically using a movable cleaning machine.
Coarse screens which can be cleaned manually are placed as an alternative to stoplogs in the same guide frames used for holding the stoplogs. For cleaning purposes, the screens are raised with lifting beams and the contamination removed manually at an appropriate place.
For automatic cleaning, cleaning machines are used in the same way as the description for the fine screen.