| 摘要 |
<p>1479656 Biological filtration element MONO PUMPS (ENG) Ltd 6 March 1975 [14 March 1974] 11518/74 Heading C1C A sewage biological filtration element comprises a bundle of polygonal cross-section tubes secured to one another, the element having a maximum axial dimension at least equal to its maximum transverse dimension, and the periphery of the element itself being polygonal. Preferably the element comprises a central hexagonal tube surrounded by six slightly shorter hexagonal tubes; a ring member or rib projects radially outward from the bundle at the centre of its axial length; and the ends of the element are chamfered. The elements may be moulded or extruded from polypropylene.</p> |
