The collection and reuse of white water in paper and board making processes reduces fresh water usage, sewer losses and loads, and energy usage. The primary white water circulation loop, or short circulation loop, quickly returns white water removed from the stock on the former to the thin stock system and headbox. The secondary white water loop, or long circulation loop, collects the excess white water, clarifies it, and supplies dilution, shower, and make-down water back to the process. This module will identify and describe the components and main functions of the primary and secondary white water circulation loops.
•Define the terms "white water" and "closed system"
•Describe the benefits of collecting and reusing white water in paper and board production processes
•Identify the components and two main functions of the primary white water circulation loop
•Identify and describe the components of the secondary white water circulation loop
•Identify the uses of secondary white water
•Identify and describe the primary process flows
