초록 ▼

A preassembled unit for a sewage nitrification field has minimum outward dimensions of loose, lightweight plastic aggregate material enveloped and bound by a plastic sleeve around a horizontal conduit. In one embodiment, the unit takes a bag form with an aggregate-filled netting sleeve concentricall

A preassembled unit for a sewage nitrification field has minimum outward dimensions of loose, lightweight plastic aggregate material enveloped and bound by a plastic sleeve around a horizontal conduit. In one embodiment, the unit takes a bag form with an aggregate-filled netting sleeve concentrically surrounding and fastened to the ends of corrugated plastic vent pipe. In another form, the sleeve is a plastic extrusion of rectangular cross-section and the conduit can be formed integrally with the sleeve. Cross-webbing is added for strength. In ground installation, conduitless units make up insufficiency of aggregate dimension. Mating male and female end caps are used to interconnect the conduit of adjacent units end-to-end. Apparatus for manufacturing the concentric netting sleeve/vent pipe version has a hopper that discharges aggregate into the top of a mandrel and an annular disc or helical auger blade that pushes the aggregate forward into the sleeve.

대표청구항 ▼

In a drainage field employed in a sewage treatment and disposal system for delivering fluid from a source of sewage effluent for absorption into the ground, a preassembled drainage line unit, comprising: a horizontally extending perforated conduit connected to deliver fluid from said source; a loose

In a drainage field employed in a sewage treatment and disposal system for delivering fluid from a source of sewage effluent for absorption into the ground, a preassembled drainage line unit, comprising: a horizontally extending perforated conduit connected to deliver fluid from said source; a loose aggregation of discrete, crush resistant, lightweight elements surrounding said conduit; a perforated sleeve member enveloping said aggregation and bounding the same relative to said conduit to define an aggregate-filled drainage cavity in fluid communication with the ground and with the perforations of said conduit; said drainage cavity having predetermined minimum dimensions in directions outwardly of said conduit, and providing drainage characteristics similar to those of a cavity of the same dimensions constituted by an aggregation of rock or crushed stone; and a male end cap mounted over one end of said conduit and a female end cap mounted over the other end of said conduit; said end caps being dimensioned and configured so that the male end cap of one such unit will mate in conduit interconnecting relationship with the female end cap of another such unit brought into end-to-end alignment therewith.