# US 2014/0197117 A1 · System and method for sludge removal in a circular settling tank > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197117 A1 - Document ID: US20140197117A1 - Status: Published application - Kind: A1 - Application number: 14/238,786 - Filed: 2012-08-16 - Published: 2014-07-17 - Earliest claimed: 2011-08-23 - Assignees: Nordic Water Products AB - Inventors: Bertil Ljungberg - Web page: https://patentgrep.com/patent/US20140197117A1 ## CPC - B01D 21/06: with rotating scrapers - B01D 21/18: Construction of the scrapers or the driving mechanisms for settling tanks - B01D 21/20: Driving mechanisms - B01D 21/245: {Discharge mechanisms for the sediments} - F16H 55/10: Constructively simple tooth shapes, e.g. shaped as pins, as balls - F16H 55/17: Toothed wheels (worm wheels F16H55/22; chain wheels F16H55/30) - F16H 19/04: comprising a rack - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - F16H: GEARING ## Abstract A system for sludge removal in a circular settling tank having a side wall (106) comprises a rotatable drive ring (130) adapted to be interconnected to a scraper arm provided with scraper blades, wherein the drive ring having a plurality of engagement surfaces (134) A traction assembly (140) is fixedly attached to the side wall and comprises a drive wheel (142). By providing a drive wheel with a plurality of engagement rolls (148) adapted to engage the engagement surfaces of the drive ring during rotation of the drive wheel, the drive ring can be rotated essentially without exerting any radial forces on the drive ring. ## Claims ### Claim 1 A system for sludge removal in a circular settling tank having a side wall, the system comprising: a rotatable drive ring adapted to be connected to a scraper arm provided with scraper blades, the drive ring having a plurality of engagement surfaces, a traction assembly comprising a drive wheel, wherein the drive wheel is provided with a plurality of engagement rolls adapted to engage the engagement surfaces of the drive ring during rotation of the drive wheel. ### Claim 2 (depends on 1) The system according to claim 1, wherein the engagement surfaces are planar. ### Claim 3 (depends on 1) The system according to claim 1, wherein the engagement surfaces extend radially from the centre of the drive ring. ### Claim 4 (depends on 1) The system according to claim 1, wherein the drive wheel is star shaped. ### Claim 5 (depends on 1) The system according to claim 1, wherein six engagement rolls are provided at equal distance from the center of the drive wheel and spaced apart. ### Claim 6 (depends on 5) The system according to claim 5, wherein the equal mutual distance between adjacent engagement rolls is equal to the mutual distance between adjacent engagement surfaces of the drive ring. ### Claim 7 (depends on 1) The system according to claim 1, wherein the engagement rolls are journalled about a respective roll shaft extending between an upper star shaped plate and a lower star shaped plate of the drive wheel. ### Claim 8 (depends on 1) The system according to claim 1, wherein the drive ring comprises any of the following: a C-shaped profile with a plurality of engagement elements bolted to the C-shaped profile, two hollow profiles, preferably with circular cross-sectional shape, which are interconnected by a plurality of equidistant, preferably rectangular or square shaped, interconnecting hollow profiles providing the engagement surfaces, a bent metal strip cut to a radius corresponding to the radius of the settling tank, wherein flat steel is welded to the bent metal strip, and a plurality of equidistant bent and bolted or welded metal sheets, each having an essentially planar surface forming the respective engagement surface, a bent metal sheet having a cross-sectional shape with a bottom surface and two surfaces facing inward towards the center of the settling tank, and a plurality of equidistant elongated metal sheets which are attached to the two surfaces facing inward, and bent sheets which are attached to the bottom surface of the bent metal sheet and attached to the elongated metal sheets, and two essentially planar metal sheets with the appropriate ring radius, wherein the two essentially planar metal sheets are interconnected by equidistant metal sheets. ### Claim 9 A method of rotating a circular object, comprising the following steps: providing spaced apart engagement surfaces on the circular object, providing a drive wheel with a plurality of engagement rolls adapted to engage the engagement surfaces, and rotating the drive wheel. ### Claim 10 (depends on 9) The method according to claim 9, wherein the circular object is a rotatable drive ring of a circular settling tank.