Agricultural harvester and a dust extractor for the agricultural harvester

1. A dust collector for an agricultural harvester having a header for harvesting crop over the ground and a feeder housing receiving harvested crop from said header, said dust collector comprising:

a perforated tube extending between the outer walls of the feeder housing and having opposite ends;

exhaust plenum chambers connected to said opposite ends of said perforated tube, each of the exhaust plenum chambers having an outlet directed at least towards the ground;

a drive shaft extending longitudinally through said perforated tube and journaled for rotation therein, the drive shaft having ends;

impellers mounted on and adjacent the ends of said drive shaft for directing air flow out of said outlets upon rotation of said drive shaft; and

a drive mechanism connected to and selectively rotating said drive shaft to induce air flow and dust out of the feeder housing,

wherein said exhaust plenum chambers each further have a divergent section from said opposite ends of said perforated tube to a main chamber of said exhaust plenum chambers.

2. The dust collector as claimed in claim 1 , wherein said divergent section of each of said exhaust plenum chambers is a frustoconical component and a main portion of each of said exhaust plenum chambers has a cylindrical configuration.

3. The dust collector as claimed in claim 2 , wherein said impellers are axial flow fans in said cylindrical exhaust plenum chambers.

4. The dust collector as claimed in claim 3 , further comprising a deflector downstream of each of said fans and directed at least towards the ground.

5. The dust collector as claimed in claim 4 , wherein the deflector is a plate angled with respect to the longitudinal axis of said drive shaft.

6. The dust collector as claimed in claim 1 , wherein the drive shaft is journaled by bearings supported by the walls of said exhaust plenum chambers.

7. The dust collector as claimed in claim 6 , wherein the drive mechanism comprises a driven pulley and a tensioner adjacent said driven pulley and a drive pulley to rotate said drive shaft.

8. The dust collector as claimed in claim 1 , wherein an area of the perforations in said perforated tube range from about between 24.45% to 27.34% of an internal surface area of the tube.

9. The dust collector as claimed in claim 7 , wherein said drive and driven pulley have a step up ratio of approximately 3.7 to 1.

10. An agricultural harvester for harvesting agricultural crop over the ground and comprising:

a header for harvesting agricultural crop over the ground and directing it to a central location;

a feeder housing connected to a central portion of said header for receiving cut crop and directing it in a rearward direction;

a crop processing apparatus connected to and receiving cut crop from said feeder housing for processing the crop;

a dust collector comprising:

a perforated tube extending between the outer walls of the feeder housing and having opposite ends;

exhaust plenum chambers connected to said opposite ends of said perforated tube, each of the exhaust plenum chambers having an outlet directed at least towards the ground;

a drive shaft extending longitudinally through said perforated tube and journaled for rotation, the drive shaft having ends;

impellers mounted on and adjacent the ends of said drive shaft for directing air flow out of said outlets upon rotation of said drive shaft; and,

a drive mechanism connected to and selectively rotating said drive shaft to induce air flow and dust out of the feeder housing,

wherein said exhaust plenum chambers each have a substantially cylindrical shape and further a frustoconical section connecting the cylindrical shape to said opposite ends of said perforated tube forming a divergent flow area into said exhaust plenum chambers.

11. The agricultural harvester as claimed in claim 10 , wherein said impellers are axial flow fans positioned in said exhaust plenum chambers.

12. The agricultural harvester as claimed in claim 11 , further comprising an angled plate downstream of each of said axial flow fans, each said plate being angled with respect to the longitudinal axis of said drive shaft.

13. The agricultural harvester as claimed in claim 12 , wherein said drive shaft is journaled by bearings supported by walls of said exhaust plenums and said drive mechanism comprises a pulley affixed to one end of said drive shaft, a tensioner pulley engageable with the driven pulley, a drive pulley powered from said agricultural harvester and a drive belt interconnected between the driver pulley, tensioner and driven pulley.

14. The agricultural harvester as claimed in claim 10 , wherein the perforations in said perforated tube are approximately between 24.45% and 27.34% of the an internal surface area of said tube.

15. The agricultural harvester as claimed in claim 13 , wherein said drive and driven pulley have a step up ratio of approximately 3.7 to 1.