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The text discusses the second zone of dewatering on a paper machine wire, known as the Vacuum Dewatering zone. This zone occurs after the wet/dry line or around 5-7% consistency (solids content on total basis) and involves the use of suction boxes or flat boxes with suction couch rolls to dewater the paper mat. The vacuum applied in this zone is higher than in earlier stages, leading to two-phase flow (water and air) instead of just water flow. The mechanisms of dewatering include compression and consolidation of the compressible network, displacement of water by air, entrainment of water droplets, and convective heat and mass transfer associated with airflow. There has been limited research on the fundamental understanding of the vacuum dewatering process, with most work being empirical in nature and focusing on developing relationships between process parameters.