Filtering fluids esp. sludge water or oil - through helically wound wire bent to a radius

摘要

A filter for fluid. e.g. water, sewage, sea water or oil, comprises a helically wound object esp. of wire, which is treated to be corrosion-resistant and is of generally cylindrical form; this is bent round, esp. to a closed circle or the like, so that the distance between the turns on the inside is different from that on the outside; thus, as the liq. flows through it, circulation and convection automatically takes place which prevents clogging of the filter.