Wash-out prevention

For waterworks applications, decanters normally will be operated with polymer addition facilities, at alternative admission points. They will need full erosion protection for the flights, using tiles. They will have some kind of cake baffle, possibly a cone, and a variable speed back-drive, with good differential and torque control. They will be operated with deep neutral ponds, with axial flow (i.e. with flight windows, such that the liquid flows parallel to the axis, rather than around the helical space), and with provision for wash-out prevention at start-up. 

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