Fluidized bed peanut sorter

• US 5,087,351 A
• Filed: 08/02/1990
• Issued: 02/11/1992
• Est. Priority Date: 08/02/1990
• Status: Expired due to Fees

• Current Assignee: Golden Peanut Company A Georgia General Partnership
• Original Assignee: Golden Peanut Company A Georgia General Partnership
• Inventors: Valentine, Howard E. Sr.
• Primary Examiner(s): Huppert, Michael S.
• Assistant Examiner(s): WACYRA, EDWARD MICHAEL
• Application Number:
  US07/561,566
• Time in Patent Office: 558 Days
• Field of Search: 209/20, 209/44.2, 209/466, 209/467, 209/468, 209/469, 209/474, 209/475, 209/476, 209/486, 209/488, 209/490, 209/492, 209/502, 209/504, 209/506, 209/508
• US Class Current: 209/20
• CPC Class Codes: B03B 4/02 using swinging or shaking tables

Abstract

A modified fluidized bed separates materials differing in weight by as little as one percent. A fluidized bed is formed by directing air through vanes on an underside of a screen. Products, such as peanuts, delivered to a central portion of the screen are initially separated so that lighter weight products float on the fluidized bed and are drawn by gravity toward a lower end where a second separation takes place. The lightest products at this second end are listed over an exit weir by a controllable air jet. Desired products are not ejected and are collected.

Claims

1. An apparatus for sorting peanuts, comprising:

a finely perforated screen having a first end and a second end, the screen being inclined so that the first end is lower than the second end;

means for delivering peanuts to the screen;

means for forming a fluidized bed upon the screen, so that lighter peanuts float on the fluidized bed while heavier peanuts fall toward an upper surface of the screen;

means, located at said first end, for selectively separating lighter weight peanuts from the fluidized bed, the selective separating means comprising a raised barrier extending across all but an exit portion of the first end;

an exit weir at the exit portion; and

a first compressed air means for delivering continuous air pressure at the exit portion, the air pressure being directed at an angle to the exit weir whereby lighter ones of the peanuts are selectively removed from the fluidized bed as the air pressure delivered to the exit end lifts the lighter ones of the peanuts over the exit weir.

2. The apparatus according to claim 1, wherein the raised barrier extends vertically higher above the screen than the exit weir.

3. The apparatus of claim 1, wherein the screen has perforations and the means for forming the fluidized bed comprises fans in communication with an underside of the screen.

4. The apparatus recited in claim 3 wherein the fans produce different air pressure in chambers under the screen.

5. The apparatus recited in claim 4, further comprising vanes directing a portion of the air from the fans toward the exit weir.

6. The apparatus recited in claim 4, further comprising a plurality of riffles on the screen, the screen being oscillated to cause heavier peanuts to move toward the second end.

7. The apparatus recited in claim 1, wherein said first compressed air means is adjustable and comprises at least one compression jet and pressure regulator, whereby adjustment of said first compressed air means precisely controls separation of lighter peanuts.

8. The apparatus recited in claim 1 wherein said means for delivering peanuts is located to delivery said peanuts to a delivery location remote from either end of said screen and further comprising a second compressed air means for delivering air pressure from beneath said delivery location, thereby preventing trapping of lighter weight peanuts under heavier peanuts.

9. A method of sorting peanuts, the method comprising the steps of:

delivering peanuts to an inclined screen having a first end lower than a second end;

forming a fluidized bed upon the screen, so that lighter weight peanuts floating on the fluidized bed are drawn by gravity down toward a barrier at the first end while heavier peanuts move along the screen surface toward the second end of the screen;

further separating the lighter weight peanuts at an exit portion of the first end, the separating step comprising delivering continuous pressurized air at an angle to the exit portion, thereby lifting lighter peanuts over an exit weir.

10. The method recited in claim 9, wherein the heavier peanuts are directed toward the second end by oscillating the screen.

11. The method recited in claim 9, wherein the screen is formed with perforations and the step of forming the fluidized bed comprises:

directing air flow in two separate air chambers to an underside of the screen to produce different air pressures at first and second portions of the screen.

12. The method recited in claim 9, wherein the barrier at the first end is extended across all of the first end and is used in controlling depth of the fluidized bed in conjunction with a speed of a fan communicating with an underside of the screen and a speed of an oscillating deck moving the screen.

13. The method recited in claim 12, wherein an adjustable portion of the exit weir can be vertically and horizontally extended to remove peanuts of various specific gravity over the exit weir.

14. The method recited in claim 9, wherein the screen is tilted in a transverse direction toward the exit weir.