Paolo Bergadano, Mechanical Maintenance Engineer at Smurfit-Kappa Verzuolo, often encountered problems with the extraction of the coarse screen basket. If the basket was not extracted perfectly parallel, (which is unfortunately impossible, given the length and weight of the basket), the inner diameter of the pumping ring clashed against the bottom of the stator foils. As a result, the pumping ring could be deformed and distorted when trying to pull the basket out.
The customer's suggestion for improvement was to machine a chamfer at the inner edge of the pumping ring.
At this point Valmet's experts were consulted, to ensure that there was no weakening of the pumping ring.
These problems in the foil-end clashing with the shoulder of the ring had been experienced in other applications. It was also remarked that on occasions the basket was fouled in the mid area. The fouling of the basket and foil was caused due to the basket not being aligned with the foils when removing it.
The customer’s proposal was appreciated and taken into account for other sizes.
Walter Morniroli, Product Sales Manager, Stock Preparation in Italy and Jarno Heikkila, Technical Product Manager, Screening, were enthusiastic about the proposed improvement and, subject to further inspection, Valmet will extend this modification to all coarse screen sizes.
Valmet is grateful to Paolo Bergadano for the excellent proposal received: the mutual cooperation and trust developed over years of working in constant contact led to this successful solution that will benefit both the Customer and Valmet.