Mini-Encyclopedia of Papermaking Wet-End
Part Three: Equipment & Unit Operations
The function of a save-all is to remove fiber fines and other solids from white water. The clarified white water can then be used for showers, for stock dilution, and for make-down of certain types of chemical product. Also it can be stored with a much-reduced chance of materials becoming settled as deposits. Clarified white water from a save-all also may be discharged to wastewater treatment, minimizing the loss of solids from the process. The most widely used types of save-alls use disk screens or drum screens. Some long fiber or broke usually is added to aid in the filtration of fines. Dissolved-air-flotation (DAF) equipment is also used for flotation save-alls in many mills. Such processes are designed so that fiber fines and other solids rise to the top of a shallow chest where they can be skimmed off and recovered.
Request from the webmaster: Our goals include brevity and accuracy. Hopefully we have succeeded with the first goal without sacrificing the second. Please let us know right away if you find an error or omition. Also, please indicate points that need a clearer description.
RETURN TO INDEX PAGE OF ENCYCLOPEDIA
This page is maintained by Martin hubbe, Associate Professor of Wood and Paper Science, NC State University, firstname.lastname@example.org .