This TAPPI Technical Information Paper provides practical guidelines for designing and sizing suction boxes, also known as Uhle boxes, used in paper machine press fabric dewatering and conditioning. It covers dwell time and slot-width calculations, vacuum factor selection, airflow and vacuum capacity estimation, suction box sizing, piping velocity limits, air/liquid separator arrangements, and vacuum system design considerations.
The document includes conversion factors, calculation formulas, worked examples, recommended design values, sizing tables, and guidance for both conventional Uhle box dewatering and nip dewatering applications. It is a focused reference for engineers and technical professionals responsible for paper machine performance, press fabric conditioning, vacuum equipment, and process optimization.
Application Scope: Intended for paper and tissue machine engineers, press fabric specialists, maintenance and process professionals, equipment designers, and technical teams evaluating Uhle boxes, vacuum pumps, piping, separators, and press dewatering systems.
