System for mixing industrial waste water within a gravity settling tank

Abstract

A system for static mixing in a waste water settling tank to increase the percentage of recovery of entrained solids from the waste water comprising a settling tank having a hopper bottom defining a sludge hopper, a deflector dome centrally disposed within the space contained in the hopper bottom, and an inlet pipe for introduction of waste water containing second entrained solids into the settling tank and having a discharge outlet in proximity to the underside of the deflector dome. Influent waste water is directed vertically upward into the center of the deflector dome which distributes the influent radially into contact, preferably turbulent, with previously introduced waste water containing first entrained solids to cause coalescence of the first and second entrained solids to form larger particles having increased settling velocity.

What is claimed is: 
     
         1 . A system for static mixing in a waste water settling tank to increase the percentage of recovery of entrained solids from the waste water, comprising:
 a) a settling tank having a hopper bottom defining a sludge hopper;   b) a deflector dome disposed within the space contained in said hopper bottom; and   c) an inlet pipe for introduction of waste water into said settling tank, said inlet pipe having a discharge outlet in proximity to the underside of said deflector dome.   
     
     
         2 . A system in accordance with  claim 1  wherein said deflector dome is centrally disposed within said space. 
     
     
         3 . A system in accordance with  claim 1  further comprising a distribution cone centrally disposed within said dome. 
     
     
         4 . A system in accordance with  claim 3  wherein said deflector dome and said distribution cone define a deflector assembly. 
     
     
         5 . A system in accordance with  claim 3  wherein the diameter of said distribution cone is at least equal to the inner diameter of said discharge outlet. 
     
     
         7 . A system in accordance with  claim 3  wherein said discharge outlet is off-spaced vertically from said distribution cone by a distance equal to at least one-half the radius of said discharge outlet. 
     
     
         8 . A system in accordance with  claim 1  wherein said inlet pipe is arranged such that waste water discharged from said discharge outlet is directed upwards into said deflector dome. 
     
     
         9 . A system in accordance with  claim 1  wherein said settling tank is cylindrical and wherein said hopper bottom is conical. 
     
     
         10 . A system in accordance with  claim 9  wherein the included cone angle in said conical hopper bottom is 60°. 
     
     
         11 . A system in accordance with  claim 1  wherein the lower rim of said deflector dome is positioned about 12 inches from the bottom of said sludge hopper.