Patent ID: 8021559
Filing Date: 2011-09-20
Classification: B01D

Abstract:
1. A thickening apparatus for a feed liquid carrying suspended particles, the thickening apparatus comprising: a tank in which settling of solids takes place, whereby pulp of higher relative density settles towards the bottom of the tank, forming a bed of thickened pulp, and dilute liquid of lower relative density is thereby displaced towards the top of the tank, a feedwell disposed within the tank, the feedwell defining a chamber and having an inlet for receiving feed liquid and delivering the feed liquid tangentially into the chamber and an outlet in fluid communication with the tank for discharging liquid from the chamber into the tank, wherein the feedwell comprises an outer wall that bounds the chamber outwardly, a horizontal structure within the feedwell and dividing said chamber into an upper mixing space and a lower outlet space, and an inner bounding element that bounds at least the upper mixing space inwardly, whereby the upper mixing space is substantially annular, and a feed pipe for delivering feed liquid to the inlet of the feedwell, and wherein the inlet of the feedwell is located above the horizontal structure, whereby the inlet delivers the feed liquid into the upper mixing space, and the horizontal structure is a baffle structure that restricts downward flow of liquid from the upper mixing space to the lower outlet space and defines passages that allow downward flow of liquid from the upper mixing space to the lower outlet space.