Patent · US Expired

Sludge thickening device

US7828961B2 · kind B2 · utility

2Cited by
11References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 20, 2005
Grant dateNov 9, 2010
Priority date
Expiry dateMay 27, 2026

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC02F2209/006
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A differential rate rotary thickener; a power detector which is disposed in a sludge receiver tank for thickened sludge thickened in the differential rate rotary thickener; a discriminator which receives an electric signal for a thickened sludge concentration (X) detected by the power detector and which calculates and discriminate the data; a first controller which receives an instruction signal being a discriminated result in the discriminator and which operates an outer cylinder driving machine and a screw driving machine; a ratio setter which receives a discriminated signal of the discriminator and which increases or decreases a chemical feed rate (α) of flocculant stepwise; and a second controller which receives an instruction signal from the ratio setter and which operates a flocculant-feeding pump are provided. Thickening of sludge is performed by controlling the chemical feed rate (α), a rotational speed (S) of a screw, and a rotational speed (C) of an outer cylinder screen.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.