2013 Exhibitions
Maag has created tailor-made filtration units in close co-operation with Uhde Inventa-Fischer for an expansion project at a major facility in the Middle East.
With a total additional capacity of half a million tonnes of PET bottle grade resin per year, the plants have seen the deployment of the largest Melt-To-Resin (MTR) reactors in existence, with Maag also providing a complete range of melt pump equipment.
The reactors are now joined by a number of continuous screen changers, whose uniquely patent-pending arched filters maximise the filtration surface available, which guarantees a very low melt residence time, especially in high viscosity resin applications, yet they incorporate a compact footprint. Maag pioneered the production of supersized screen changers with a world-first delivery for virgin polymer production taking place no less than six years ago.
Those were equipped with candle filters and reduced the residence time of the resin to less than 30 seconds.
Arched filters are a logical development based on the same technology, but utilise “one way filters”, that can be disposed of after use. This in turn eliminates the entire process of cleaning the candle filter bundles, which normally involves vacuum ovens, acids, solvents and subsequent bubble point tests to determine if the filters are still useable.
“Though duplex and simplex filters are still widely used, piston-based screen-changers are a natural, cost effective addition to Maag’s portfolio, and they meet the increasingly technical demands of our customers. As for the adoption of arched screens it allows manufacturers to dedicate 75% of the surface of the cylinder to filtration. Finally, and contrary to traditional breaker plates facing each other, our very smart design also permits straight pump connections that reduce the investment further with no need for additional pipe work, “ Maag CEO Ueli Thürig, said.:
Changeovers now take less than 10 minutes, with only one operator, without requiring cranes or complex tools, thus guaranteeing constant operation of the system from process to process. Flexibility is also reflected in the fact that, depending on the melt contamination (solid or gel), the screens can be made out of Woven Wire Mesh (WWM) or Fibre Metal Melt (FMM).
(PRA)
