Apparatus for discharge of sediment from a tank

{
  "publication_number": "US5676827A",
  "country": "US",
  "kind": "A",
  "title": "Apparatus for discharge of sediment from a tank",
  "abstract": "A device for displacing sediment, for example sand, from the bottom of a liquid-filled container (20) to a receptacle device (29) in which first conveyor (22) is disposed in the edge region (21) of the container (20) near the bottom of the container to receive sediment which accumulates at the bottom. The first conveyer (22) has a rotating screw thread (24) located in a casing (23) and includes a discharge portion (27). A second conveyor (40) consisting of a rotary screw thread (44) in a casing (41) has an infeed opening (43) located at the lower portion of the container, preferably below its bottom, and a discharge portion (42) located above the maximum filling level of the container (20). A mechanical device (50) displaces the sediment from the discharge portion (27) of the first conveyor (22) to the infeed opening (43) of the second conveyor (40). The discharge portion (42) of the second conveyor (40) discharges sediment to a receptacle (29) either directly via a transport device (60).",
  "claims": [
    "1. Apparatus for displacement of sediment from the bottom of a container filled with liquid to a receptacle comprising: a first conveyor disposed in a region near the bottom of said container, said first container including an upwardly open casing into which said sediment falls and a screw in said casing to transport said sediment therein to a discharge portion of the casing, a second conveyor having an inlet portion for receiving sediment from said first conveyor and including a casing and a screw in said casing to transport the sediment from said inlet portion of the casing of the second conveyor to a discharge portion of the casing of the second conveyor located above a maximum filling level of the liquid in the container, and transfer means disposed in said container for conveying the sediment from said discharge portion of the casing of the first conveyor to the inlet portion of the casing of the second conveyor, said transfer means comprising a third conveyor including a screw.",
    "2. Apparatus as claimed in claim 1, wherein said screw of the transfer means is located at a level below the screw of the first conveyor.",
    "3. Apparatus as claimed in claim 2, wherein the screw of the first conveyor and of the transfer means are rotatable about parallel axes.",
    "4. Apparatus as claimed in claim 3, wherein the screw of the first conveyor and the screw of the transfer means transport the sediment in respectively opposite directions.",
    "5. Apparatus as claimed in claim 2, wherein said transfer means further includes an inclined plate extending between said screw of the first conveyor and said screw of the transfer means.",
    "6. Apparatus as claimed in claim 5, wherein said plate extends at least partially around said screw of the first conveyor and said screw of the transfer means.",
    "7. Apparatus as claimed in claim 2, wherein the screw of the first conveyor and the screw of the transfer means are rotatable about perpendicular axes.",
    "8. Apparatus as claimed in claim 2, wherein said transfer means includes a second said screw located parallel to the first said screw of the transfer means, and a casing in which said first and second screws rotate, said casing defining passages for conveying the sediment from the screw of the first conveyor to the two screws of the transfer means.",
    "9. Apparatus as claimed in claim 8, wherein said casing of the transfer means includes a plate of inverted V-shape bounding said passages.",
    "10. Apparatus as claimed in claim 1, wherein said first conveyor extends transversely in said container, said discharge portion of the casing of the first conveyor being located near a side wall of the container, said second conveyor extending upwardly between opposite side walls of the container at a transversely spaced location from the discharge portion of the casing of the first conveyor, said second conveyor extending transversely in said container between said discharge portion of the casing of the first conveyor and the inlet portion of the casing of the second conveyor.",
    "11. Apparatus as claimed in claim 1, wherein said casing of the second conveyor extends upwardly from the container to a level above the liquid filled in the container, said casing of the second conveyor being provided with drainage openings, above the liquid level in the container, through which liquid conveyed by said second conveyor can directly drop back into said container.",
    "12. Apparatus as claimed in claim 1, wherein said transfer means includes an upwardly opening casing in which said screw of the transfer means is rotatable.",
    "13. Apparatus as claimed in claim 1, wherein at least one of the screws of said first and second conveyors and of said transfer means comprises a spiral without a mechanical shaft.",
    "14. Apparatus as claimed in claim 1, comprising sensor means in said transfer means for sensing level of sediment at an inlet portion of the transfer means which receives sediment from the discharge portion of the casing of the first conveyor.",
    "15. Apparatus as claimed in claim 14, wherein the screws of the first and second conveyors and of the transfer means are driven by respective drive means, said sensor means being connected to said drive means to control operation thereof and drive of the respective screws based on the level of sediment sensed by said sensor means."
  ],
  "description_excerpt": "The present invention relates to a device for displacing sediment, for example sand, from the bottom of a container filled with liquid to a receptacle device.\n\nIn many technical applications, liquid is allowed to rest in basins, pools (containers) for varying lengths of time in order that particles located (suspended) in the liquid be allowed to sink to the bottom and there form a sediment. In such contexts, it is often desirable that this sediment be removed from the bottom of the container at the same time as the container is filled with liquid. For example, such needs exist in treatment plants for waste water.\n\nIt is previously known to employ for this purpose scraper devices which displace the sediment to an edge region of the bottom of the pool, normally the short side of the pool or container, which is often between 15 and 20 meters long. In order to remove the sediment which has been scraped together in this edge region, use is generally made of an arrangement comprising a pump which depends from a gantry above the pool. The pump includes a pump pipe whose intake opening is located close to the sediment strand. The pump, with its suction pipe is intended to be displaced along the strand of accumulated sediment.\n\nThe pump equipment, with its suspension construction, is expensive and wear on the pump is extreme, since sediment of the type under contemplation here contains considerable quantities of sand.",
  "cpc": [
    "B01D 21/2461"
  ],
  "ipc": [
    "B01D 21/24"
  ],
  "assignees": [
    "Spirac Engineering AB"
  ],
  "inventors": [
    "Richard L. Bruke"
  ],
  "filing_date": "1994-05-10",
  "publication_date": "1997-10-14",
  "grant_date": "1997-10-14",
  "priority_date": "1993-05-10",
  "application_number": "US-54585295-A",
  "family_id": "20389918",
  "cited_by_count": 20,
  "citations": [
    "DE174003C",
    "US1716228A",
    "GB405314A",
    "US2935931A",
    "US3285415A",
    "US3865727A",
    "US3910775A",
    "US3923655A",
    "GB2024032A",
    "US4364831A",
    "SU1057067A1",
    "SE464080B",
    "US5000307A",
    "US5368153A",
    "US5078861A",
    "SU1645220A1",
    "US5092453A",
    "SE468589B"
  ]
}