RECIRCULATING PNEUMATIC SEPARATOR

• US 3,608,716 A
• Filed: 01/27/1969
• Issued: 09/28/1971
• Est. Priority Date: 01/27/1969
• Status: Expired due to Term

• Current Assignee: Lorne A. Rowell, Peter A. Tillich
• Original Assignee: Lorne A. Rowell, Peter A. Tillich
• Inventors: Rowell, Lorne A., Tillich, Peter A.
• Primary Examiner(s): Lutter, Frank W.
• Assistant Examiner(s): Hill, Ralph J.
• Application Number:
  US04/794,000
• Time in Patent Office: 974 Days
• Field of Search: 209/133,133T,134,135,138,139,502,140,141,154,143,380,153 131/146
• US Class Current: 209/139.1
• CPC Class Codes: A24B 5/10 by crushing the leaves with subsequent separating
• CPC Class Codes: B07B 4/025 the material being slingered or fled out horizontally before falling, e.g. by dispersing elements

Abstract

This invention relates to a recirculating pneumatic separator which is particularly designed for separating threshed tobacco leaves form the heavier tobacco parts. The lighter tobacco fraction is carried up by air which is recirculated through the separator and the heavier tobacco function falls to an endless belt and is separately conveyed out of the separator. Means is provided for accurately controlling the air velocity in the separation chamber and for ensuring complete separation of the tobacco fractions by means of an air jet impeller.

Claims

1. A pneumatic separator for separating lighter particles from heavier particles comprising, a separating chamber, means for circulating air upwardly through said chamber, inlet impeller means mounted on one side of said separating chamber for thrusting particles to be separated into and across the chamber, an air jet impeller means mounted on the side of said separating chamber opposite to said inlet impeller means for thrusting the particles across the chamber in a direction opposite to the direction in which said inlet impeller means thrusts the particles, means for separating the lighter particles from the upwardly circulating air and means for collecting and carrying the heavier particles from the chamber.

2. A pneumatic separator according to claim 1 and further including means for recirculating the air from the upper end of the separating chamber to the lower end thereof and bypass means in the recirculating air means to cause a portion of the air recirculated to bypass the separating chamber.

3. A pneumatic separator according to claim 2 and further including a diffuser disposed adjacent the lower end portion of the separating chamber for equalizing the velocity of the air across the separating chamber.

4. A pneumatic separator according to claim 1 wherein the means for separating the lighter particles from the upwardly circulating air includes a rotating screen.

5. A pneumatic separator accordiNg to claim 1 wherein the means for separating the lighter particles from the upwardly circulating air includes a rotating screen and further including means for recirculating the air from the upper end of the separating chamber to the lower end thereof and bypass means in the recirculating air means to cause a portion of the air recirculated to bypass the separating chamber and pass to the rotating screen.

6. A pneumatic separator according to claim 1 and further including a diffuser in said separating chamber whereby the upwardly moving air has a substantially uniform velocity across the separating chamber.

7. A pneumatic separator according to claim 1 wherein said means for carrying the heavier particles from the chamber includes an endless foraminous belt extending across the separating chamber.

8. A pneumatic separator according to claim 7 wherein said means for carrying the heavier particles from the chamber further includes an air conveyor means and a damper in said air conveyor means for diverting a portion of the air passing therethrough.

9. A pneumatic separator according to claim 8 and further including a makeup air inlet into the separating chamber to replace the air diverted from said air conveyor means.

10. A pneumatic separator for separating lighter particles from heavier particles comprising, a separating chamber, means for circulating air upwardly through said chamber, inlet impeller means mounted on one side of said separating chamber for thrusting particles to be separated into and across the chamber, means for collecting and carrying the heavier particles from the chamber, means for recirculating the air from the upper end of the separating chamber to the lower end thereof, screen means for separating the lighter particles from the circulating air, a bypass means in the recirculating air means to supply additional recirculated air to said screen means to remove lighter particles from said screen means and means for adjusting the airflow through said bypass means to vary the velocity of the air circulating upwardly in the separating chamber.

11. A pneumatic separator according to claim 10 and further including an air jet impeller means mounted on the side of the separating chamber opposite to said inlet impeller means for thrusting the particles to be separated across the chamber in a direction opposite to the direction in which said inlet impeller means thrusts the particles.