Patent DE-102004055981-A1 (DE)
Title: Sludge-scraping and -collecting system, especially for a sewage plant, comprises a reversible slide running on a rail on the bottom of the processing tank and fitted with scraper arms which are raised when the slide returns
Inventor: FUJIWARA MICHIHIRO
IPC: C02F11/00
Filed: 2004-11-19
Abstract: A sludge-scraping and collecting system with a central guide rail on the bottom of processing pond with a cavity at one end for collecting sludge, comprises a slide running on the rail and fitted with scraper arms on each side, a system for raising the scrapers for reversal and lowering them for the next pass, a reversible drive above the pond and a slide-pulling mechanism. A device (D1) for scraping up and collecting sludge, comprises: (a) a guide rail running through a central section (between the sides) on the bottom of a rectangular processing pond having front, back and side walls and a cavity at one end; (b) a slide with wheels, running backwards and forwards along the rail and fitted with a scraper which scrapes off the sludge on either side of the rail and gathers it towards the cavity, after which the scraper can be rotated vertically from the scraping/collecting position to a higher return position and then reversed; (c) a drive section above the pond which turns a drive wheel continuously in a direction of rotation which can be switched over from normal to reverse; and (d) a pulling and winding system which is wound round the drive wheel and a direction-changing wheel in the pond so as to turn the scraper to its upper or lower position and pull the slide forward or back. Independent claims are also included for: (1) a sludge scraper (D2), e.g. for a sedimentation pond, with: (a) a slide as above; (b) a common shaft projecting from each side of the slide and carrying running wheels on each side so as to be rotated and rolled along the bottom of the pond; (c) a scraper round the common shaft (with the wheels arranged round the scraper) and designed to be lowered into the scraping position (moving forwards) and raised into the return position (moving backwards); (d) a device to stop the slide moving to the left or right when it is moves forwards or backwards; and (e) a drive section and a pulling/winding system as in D1; (2) a sludge scraper (D3) with a rotatable arm carrying a scraper which scrapes off the sludge from the bottom of a round sedimentation pond and gathers it so that it falls into a central cavity, in which the arm is turned by a driven wheel on the arm, which rolls round the bottom of the pond when actuated by a drive; (3) a sludge scraper (D4) for a round pond (see D3), which: (a) is aligned on the bottom so as to rotate above the water and move the floating foam in a radial direction towards the outside of the pond for elimination by a suitable system; and (b) is fitted with a gathering/guiding element to take the floating foam to the outside as above and then return to the inside; and (4) a sludge scraper (D5) in which: (a) there is a main air supply at the top of a wall of a rectangular processing pond and parallel to the sides; (b) there is a means of removing the scraped and collected deposits at a longitudinal end of the pond; (c) an air distributor tube projects from the main air line and crosses it so as to run along the side in contact with the main line; (d) the device scrapes off deposits from the bottom of the pond (e.g. an oxygen enrichment pond) and moves them towards the means provided (see (b)); (e) there is a guide rail on the bottom; (f) the guide rail has an upper section with a frame which runs backwards and forwards, a fixed feed scraper and another scraper of the vertically reversible type, the fixed scraper being aligned so as to scrape the deposits which have collected under the distributor tube towards the outside while the other is lowered so as to gather and move onward deposits from the bottom together with those scraped off by the feed scraper, and then raised to move it back again without any scraping action.