Coarse screening removes knots, larger stones and junk. Valmet recommends coarse screening directly after cooking to reduce the wearing of the washing equipment. It is beneficial to install the coarse screening immediately after the digester blow tank. Coarse screening solutions can also be used to protect various types of capital equipment throughout the pulp mill, and to help achieve efficiency goals. Valmet’s wide installed base extends across the globe with its Delta and HI-Q series coarse screening portfolio that includes knotters, knot washers, liquor filters and protection screens.
Valmet Knotter Delta is a highly effective coarse screening system. Previously known as the DeltaKnotter™, it can handle high pulp consistencies and it ensures reliable performance at all cooking conditions. Advantages of Valmet Knotter Delta include:
Valmet Knotter HI-Q is a stable, inward flow coarse screen specifically designed to separate knots from chemical pulps following the blow tank. Unlike other knotting equipment, the screen cylinder of the HI-Q® series knotter is stationary and smooth for minimal wear. Valmet Knotter HI-Q was previously known as the HI-Q® Knotter.
Advantages of Valmet Knotter HI-Q include:
Valmet Knot Washer HI-Q is secondary knotter for chemical pulps that provides very low good fiber losses. Available in one, compact size, it is an effective piece of equipment for most screening applications. The knot washer’s unique design features a rotating screen cylinder concept, and discharges nearly fiber-free knots while consuming minimal energy. Valmet Knot Washer HI-Q was previously known as the HI-Q® Rejects Separator.
Advantages of Valmet Knot Washer HI-Q include:
Valmet Fiber Filter HI-Q is a high-efficiency liquor filter used to recover fiber from weak black liquor, bleach plant effluent or white water streams. It is a versatile machine (with five separate models based upon capacity), that is available in several grades of stainless steel for application flexibility. Valmet Fiber Saver HI-Q was previously known as the HI-Q® Fibresaver Fibre Filter.
Advantages of Valmet Fiber Filter HI-Q include:
Valmet Protection Screen DX removes larger foreign objects or tramp material from a pulp stream at up to 4% to 6% consistency. Previously known as the DualXCluder® protection screen, Valmet Protection Screen DX is best suited to removing heavier materials but can be used for removal of lighter contaminants in certain applications. It is a simple device with the capability for flexible installations and many different applications. Featuring a small, integral gear motor and two-valve junk trap, it consumes much lower power than a conventional screen or high density cleaner.
Advantages of Valmet Protection Screen DX include: