Pulping is used to break down raw wood into separate fibers for use in paper-making. There are several pulping methods, including mechanical (RMP), thermo mechanical (TMP), chemithermomechanical (CTMP), and chemical (Sulfite, Kraft). Each variation of the pulping process yields fibers of different lengths and strengths for use in various grades of paper. RMP, TMP, and CTMP processes are all mechanically based and rely on a refiner for the final separation of fibers. The pulp produced and the chemicals used in the pulping process require special consideration when selecting valves and instrumentation for each application. High solids content, corrosive nature, and the level of accuracy required must be evaluated at each stage to ensure the most suitable equipment is selected.
The Fisher Vee-Ball control valve is designed for handling pulp stock of all consistencies in even the most demanding installations such as MC pump discharge, and blow valve applications. Accurate and reliable chemical handling can be achieved through the use of high precision Rosemount flowmeters and Fisher special alloy control valves with FieldVue positioners. Selecting precise and reliable devices for chemical addition applications can result in significant cost savings.