This paper presents a simplified drainage model applicable to twin wire and top wire formers. Therndesign model presented here is predicated on twin wire models previously published in the literature. Thernmodel is applicable to formers that employ multi-blade and counter-blade dewatering elements. The modelrnpredicts wire deflections, pressure pulses, mat thicknesses and dewatering rates. One unique feature of thisrndesign model is that it includes variable fiber mat resistance coefficients.rnResults are presented for three design configurations of blades used industrially on twin wire formers.rnThe pressure pulses and drainage rates predicted by the model compare favorably with previously publishedrnwork. The inclusion of counter-blades in the design of top wire units increases the magnitude of the pressurernpulse emanating from the blades. The model also suggests that as the fibrous mat builds on the wire, thernmagnitude of the pressure pulse in the vicinity of the blades increase and this increase can lead to mat disruption.
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