THE ROTARY PRESS VS THE SCREW PRESS

Lower polymer and maintenance costs, less water usage

ITEM	ROTARY PRESS	SCREW PRESS
Spare requirements	Low footprint	Much larger footprint and installation is two stories high. This results in higher initial capital investment in building space.

Maintenance cost	Maintenance is less frequent, simple and easy.	Maintenance is frequent and troublesome.
	Most maintenance can be performed by one person.	Maintenance cannot be performed by only one person.
	Screens are long-lasting (over 10 years)	Screens need to be changed every 2-3 years.

Wash water	No continuous wash water is required.	Continuous wash water is required

Capture Rate	A high capture rate is intrinsic in the Rotary Press design and frequent adjustments are not required to maintain it high: 95% av.	Capture rate is low (less than 90%), and sometimes less than 65%. Capture rate evaluation needs to take into account both filtrate and wash water.

Operation	Adjustments to variations in sludge solids content and dewaterability are automated.	Manual adjustments are required.

Partial operations	For a multi-channel machine, one or more channel(s) may be removed for maintenance purposes, while the machine with the remaining channel(s) may still be operated.	Maintenance requires total machine shut-down, generating operations down time.

Shut down procedure	5-min system flush.	The whole machine needs to be flushed.