FILTER Russian patent published in 2003 - IPC

FIELD: water supply and drainage systems; manufacture of filters for waterwells and unwatering wells. SUBSTANCE: filters may be metal or nonmetallic; filter is provided with wire spiral; filter element is provided with radial rows of longitudinal slots with through holes; their length is determined form the following relationship: l≤кD, where D - is diameter of framework and k is coefficient preset by radial load on framework; filter is provided grooves on projections of framework between slots; diameter of wire, depth of groove and slots are related by the following relationship: d<h_gr<h_cl, where d-, where d is diameter of wire, h_gr and h_cl is depth of groove and slots, respectively; through holes in slots are so located that radial section of framework does not intersect holes in adjacent rows. EFFECT: enhanced strength of filter framework; improved filtration capacity. 2 cl, 3 dwg