Sand dewatering device and method

{
  "publication_number": "US2009057204A1",
  "country": "US",
  "kind": "A1",
  "title": "Sand dewatering device and method",
  "abstract": "A dewatering device for aggregate products such as sand and gravel to allow dewatering to a moisture within the range of 8% by weight. This energy efficient dewatering system uses an inclined rotatably mounted dewatering screw to initially dewater, followed by an associated vibratory dewatering screen to achieve combined results that neither an inclined dewatering screw or a vibratory screen can achieve separately.",
  "claims": [
    "1. A dewatering device for aggregate product, comprising: a housing having an entrance end and an exit and; an inclined dewatering screw rotatably mounted with said housing, and positioned below said entrance end; and a vibrator dewatering screen having an entrance and mounted with said housing adjacent said exit end of said housing for receipt of aggregate product that has passed through said dewatering screw; and a vibrator motor or motors, mounted to linearly and horizontally move said dewatering screen.",
    "2. The dewatering device of claim 1 which includes a recycle system to recycle fines that have passed through the vibratory dewatering screen back to the dewatering screw.",
    "3. The device of claim 2 wherein the vibratory dewatering screen includes an inclined section and a horizontal section.",
    "4. The device of claim 1 which includes an exit and associated with said vibrator dewatering screen for exit of dewatered aggregate.",
    "5. The device of claim 1 wherein the dewatering screen is a two directional screen so that the initial pass through material can be reintroduced to the dewatering screw.",
    "6. The device of claim 1 wherein the aggregate product that leaves said dewatering screw is sand and has a moisture content of 15% by weight to 25% by weight.",
    "7. The device of claim 6 wherein the aggregate product leaving the dewatering screen has a moisture content of from about 8% by weight to about 13% by weight.",
    "8. The dewatering device of claim 7 wherein the dewatering screw is from about 20 feet in length to about 35 feet in length.",
    "9. The dewatering device of claim 7 wherein the dewatering screen is from about 6 foot in length to about 12 foot in length.",
    "10. The dewatering device of claim 1 wherein the dewatering screw is mounted at an angle of from 15° to 25° above horizontal.",
    "11. The dewatering device of claim 10 wherein the dewatering screw is mounted at 18° above horizontal.",
    "12. The device of claim 1 which uses 30 horsepower to dewater 100 tons of aggregate/hour to a moisture level of from about 8% by weight to about 13% by weight.",
    "13. A method of dewatering aggregate, said method comprising: providing an inclined dewatering screw rotatably mounted within a housing, said housing having an entrance end and an exit end, and said dewatering screw being positioned below said entrance end; feeding aggregate product into said rotatable dewatering screw while said dewatering screw is rotating to partially dewater said aggregate; feeding said partially dewatered aggregate from onto a vibrating dewatering screen to further dewater said partially dewatered aggregate; and discharging said aggregate from said vibrating dewatering screen to provide commercial grade dewatered aggregate.",
    "14. The process of claim 13 which includes recycling fines that have passed through the vibratory dewatering screen back to the dewatering screw.",
    "15. The method of claim 14 wherein the commercial grade dewatered aggregate has a moisture content of from about 8% by weight to about 13% by weight.",
    "16. The method of claim 13 wherein the dewatering screen is a two direction screen.",
    "17. The method of claim 16 wherein the dewatering process includes a recycle system to recycle material associated with the water from dewatering screw for follow up recycle dewatering by the dewatering screw.",
    "18. The method of claim 14 wherein the power consumed in said method is 30 horsepower per hour to dewater 100 tons of aggregate per hour to a moisture level of from about 8% by weight to about 13% by weight.",
    "19. The method of claim 17 wherein the power consumed in said method is 30 horsepower per hour to dewater 100 tons of aggregate per hour to a moisture level of from about 8% by weight to about 13% by weight."
  ],
  "cpc": [
    "B30B 9/128",
    "B01D 2201/287",
    "B01D 29/035",
    "B01D 29/56",
    "B01D 29/6476",
    "B01D 33/0346"
  ],
  "assignees": [
    "GREYSTONE INC"
  ],
  "filing_date": "2007-09-04",
  "publication_date": "2009-03-05",
  "priority_date": "2007-09-04",
  "application_number": "US-84962607-A",
  "family_id": "39535430",
  "citations": [
    "US3398676A",
    "US3970549A",
    "US4100248A",
    "US4113626A",
    "US5516427A",
    "US5552044A",
    "US6168102B1",
    "US6325311B1"
  ]
}