| 摘要 |
<p>The element is the type which is extruded in tubular form with outer, circumferential wall contg. longitudinal partitions which intersect to make longitudinal passages. Holes are made through the outer wall and at least some of the partitions so that a pressurised fluid surrounding the element would flow into the passages. Holes through the outer wall are pref. an axes radial to the axis of the extrusion. This facilitates entry of nozzles to deliver a cooling fluid, e.g. compressed air or gas. The extrusion is pref. subjected to torsion which orientates the passages helicapply w.r.t. the longitudinal axis of the element. The biological filter element is used for purificn. of waste water. The element can also be used as packing for mass transfer operations. The holes facilitate uniform air cooling of walls and partitions during extrusion. This overcomes the current problems of uneven cooling which can lead to stresses deforming the thin walls and partitions. Walls and partitions can safely be made even thinner to reduce wt. and save material.</p> |
