Method for passive mixing

摘要

An improved method that requires no electricity or moving parts to increase lime utilization where pebble quicklime (CaO) and/or hydrated lime (Ca(OH)2) is used for mine drainage treatment. Lime utilization at such facilities has been historically poor due to the low solubility, high density, and large particle size of pebble quicklime. This invention takes two passive technologies, a diversion well-inspired MixWell system followed by a TROMPE-driven, air lift mixer for enhancing lime dissolution. It showed an estimated 40 to 57 percent reduction in lime usage.

主权项

1. A method for improving lime utilization rates at a water treatment facility, said method comprising:
(a) providing a holding well adjacent a reagent feed source, said holding well having a pipe extending vertically through a middle region of said holding well, said pipe having a plurality of apertures near a base of the pipe, said base situated near a bottom of said holding well; (b) adding flush water into the holding well at or near the bottom of the holding well; (c) continuously adding a reagent consisting of pebble quicklime or hydrated lime from a feed source and into the holding well; (d) providing a source of water consisting of raw water or mine drainage water down the pipe extending vertically through the middle region of the holding well and out its apertures for causing larger particles of the reagent nearby to collide with one another and be ground to finer particle sizes; and (e) allowing the finer particle sizes to rise inside the holding well before passing out of said holding well.