Fine screening

Pressure screens are today used in the main line of fine screening. The purpose of these screens is to transfer the impurities still contained in the pulp to reject treatment. Pressure screens are screens, which operate filled with liquid under pressure. Pulp is fed to the screen with a pump and the pressure is chosen in order to provide the correct pressure for the accepted fraction and the reject for the next step in the process. ***Centrifugal cleaners as bleached pulp screening operators have stepped aside; as a low feed consistency (0.5 - 0.6%) means that large pulp streams must be pumped.

Не совсем понимаю смысл последнего предложения:

stepped aside - перестали применяться?
и еще второе "as" в части "as a low feed consistency (0.5 - 0.6%) means that large pulp streams must be pumped. " не совсем понятно

Благодарю за помощь.

Centrifugal cleaners have stepped aside from the mainstream screening of unbleached pulp, as a low feed consistency (0.5 - 0.6%) means that large pulp streams must be pumped.