Rotary plasma reactor

Patent metadata

Field	Value
Publication number	US-11545343-B2
Application number	US-202016743091-A
Country	US
Kind code	B2
Filing date	Jan 15, 2020
Priority date	Apr 22, 2019
Publication date	Jan 3, 2023
Grant date	Jan 3, 2023

Abstract

A rotary plasma reactor system is provided. In another aspect, a plasma reactor is rotatable about a generally horizontal axis within a vacuum chamber. A further aspect employs a plasma reactor, a vacuum chamber, and an elongated electrode internally extending within a central area of the reactor. Yet another aspect employs a plasma reactor for use in activating, etching and/or coating tumbling workpiece material.

First claim

The invention claimed is:

1. A plasma reactor system comprising:
a vacuum chamber;
a plasma reactor located inside the vacuum chamber;
the plasma reactor being rotatable about a substantially horizontal and longitudinal axis;
a workpiece material feed inlet located adjacent a first end of the plasma reactor;
a workpiece material feed outlet located adjacent a second end of the plasma reactor, the inlet and the outlet being longitudinally spaced away from each other;
the plasma reactor including internally projecting structures configured to tumble workpiece material and transport the workpiece material in a longitudinal direction between the inlet and the outlet;
the structures including a portion inwardly projecting from a curved inner surface of the plasma reactor in a radial direction substantially toward the horizontal and longitudinal axis, and a geometric line intersecting the internally projecting structures having a substantially spiral shape;
a central electrode located inside the plasma reactor along the longitudinal axis;
at least a majority of the internally projecting structures being longitudinally and radially adjacent to the central electrode internally located therein, and the electrode being stationary while the projecting structures rotate about the longitudinal axis of the plasma reactor;
a radio frequency power source electrically connected to a proximal end of the central electrode adjacent to an electrically grounded vacuum flange which is electrically connected with the vacuum chamber; and
the vacuum chamber being metallic and serving as a surrounding anode electrode.

2. The plasma reactor system of claim 1 , wherein the central electrode is at least five times longitudinally longer than its diameter within the vacuum chamber, the central electrode including a solid conductive metal rod.

3. The plasma reactor system of claim 1 , further comprising:
a distal end of the central electrode spaced away from an end plate of the vacuum chamber which is adjacent the feed inlet.

4. The plasma reactor system of claim 1 , further comprising magnets fastened to the central electrode, which is hollow, with North-South of the magnets alternating with South-North of the magnets, and each of the magnets including a longitudinally elongated middle section substantially parallel to the longitudinal axis of the plasma reactor.

5. The plasma reactor system of claim 1 , further comprising:
the plasma reactor being horizontally elongated between the ends;
a reactive gas inlet coupled to the plasma reactor;
the central electrode creating a plasma in the plasma reactor with the reactive gas;
the reactive gas inlet being spaced away from the central electrode and the surrounding anode electrode; and
the workpiece material including carbon or powder which is horizontally moved from the workpiece material inlet to the outlet while being tumbled within the plasma.

6. The plasma reactor system of claim 5 , wherein the workpiece material includes a pharmaceutical powder.

7. The plasma reactor system of claim 5 , wherein the workpiece material includes biochar.

8. The plasma reactor system of claim 5 , wherein the workpiece material includes fossil carbon.

9. The plasma reactor system of claim 1 , wherein the structures include spaced apart fins radially projecting inwardly from a cylindrical inside surface of the plasma reactor, the fins being circumferentially and longitudinally spaced apart from each other.

10. The plasma reactor system of claim 1 , wherein the internally projecting structures each include perpendicular walls.

11. The plasma reactor system of claim 1 , further comprising:
the central electrode located within the plasma reactor; and
a sputter target located within the plasma reactor.

12. The plasma reactor system of claim 1 , further comprising an electrical field vector direction, between the vacuum chamber and the central electrode, being oriented substantially perpendicular to the horizontal axis, and a magnetic field strength is 100-2,000 Gauss.

13. A plasma reactor system comprising:
a vacuum pump;
a vacuum chamber coupled to the vacuum pump;
a plasma reactor located within the vacuum chamber;
the plasma reactor being rotatable about a substantially horizontal axis;
a material inlet located adjacent a first end of the plasma reactor;
a material outlet located adjacent an opposite second end of the plasma reactor;
a reactive gas inlet coupled to the plasma reactor;
electrodes being configured to create a plasma in the plasma reactor with the reactive gas;
the reactive gas inlet being spaced away from the electrodes;
carbon or powder being horizontally movable from the material inlet to the material outlet while being tumbled within the plasma reactor;
one of the electrodes being a central electrode located inside the plasma reactor along the substantially horizontal axis;
the central electrode being at least five times longitudinally longer than its diameter within the vacuum chamber;
an electrically grounded flange; and
a radio frequency power source electrically connected to the central electrode which is adjacent to the electrically grounded flange, the flange being electrically connected with the vacuum chamber to serve as a surrounding anode electrode.

14. The plasma reactor system of claim 13 , wherein the central electrode includes a solid conductive metal rod.

15. The plasma reactor system of claim 13 , further comprising:
a distal end of the central electrode being spaced away from the first end of the vacuum chamber which is adjacent the material inlet.

16. The plasma reactor system of claim 13 , further comprising magnets fastened to the central electrode, which is hollow, with North-South of the magnets alternating with South-North of the magnets, and each of the magnets including a longitudinally elongated middle section substantially parallel to the substantially horizontal axis of the plasma reactor.

17. The plasma reactor system of claim 13 , further comprising:
at least one internally projecting structure located adjacent to at least one of the electrodes;
the structure being rotatable to tumble the carbon or powder through the plasma; and
a geometric line, intersecting innermost points along the at least one internally projecting structure, having a substantially spiral shape.

18. A plasma reactor system comprising:
a vacuum chamber serving as a surrounding electrode;
a plasma reactor, located inside the vacuum chamber, rotatable about a substantially horizontal axis;
a central electrode located inside the plasma reactor;
the central electrode being at least five times longer than its diameter within the plasma reactor;
a radio frequency power source connected to the central electrode;
at least one internally projecting fin rotating with the plasma reactor around the central electrode which is stationary; and
a geometric line, intersecting innermost points along the at least one internally projecting fin, having a substantially spiral shape;
a workpiece material outlet aperture;
a workpiece material inlet aperture being located adjacent an opposite longitudinal end of the plasma reactor from the outlet aperture;
an electrically grounded flange located adjacent a proximal end of the central electrode and adjacent the workpiece material outlet aperture;
the radio frequency power source being electrically connected to the central electrode;
the flange being electrically connected with the vacuum chamber to serve as a surrounding anode electrode; and
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Assignees

• Univ Michigan State

Inventors

• Fan Qi Hua
• Toomajian Martin E

Classifications

• H01J37/32669

  Particular magnets or magnet arrangements for controlling the discharge · CPC title

• H05H1/466

  using capacitive coupling means, e.g. electrodes · CPC title

• C23C16/4417

  Methods specially adapted for coating powder · CPC title

• C23C16/509

  using internal electrodes · CPC title

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title