Method and apparatus for cleaning surfaces with plasma

• US 5,236,512 A
• Filed: 08/14/1991
• Issued: 08/17/1993
• Est. Priority Date: 08/14/1991
• Status: Expired due to Fees

• Current Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Original Assignee: Thiokol Corporation (Howmet Aerospace, Inc.)
• Inventors: Frandsen, Blaine A., Hislop, C. Lamont, Rogers, Ernest E.
• Primary Examiner(s): Morris, Theodore
• Assistant Examiner(s): Chaudhry, Saeed T.
• Application Number:
  US07/745,457
• Time in Patent Office: 734 Days
• Field of Search: 134/1, 134/21, 15/1.5 R, 15/320, 156/345
• US Class Current: 134/1
• CPC Class Codes: A47L 11/00 Machines for cleaning floors, carpets, furniture, walls, or wall coverings
• CPC Class Codes: A47L 11/4013 Contaminants collecting devices, i.e. hoppers, tanks or the like
• CPC Class Codes: A47L 11/4036 Parts or details of the surface treating tools
• CPC Class Codes: A47L 11/4044 Vacuuming or pick-up tools; Squeegees
• CPC Class Codes: A47L 11/405 Machines using UV-lamps, IR-lamps, ultrasound or plasma cleaning
• CPC Class Codes: C23G 5/00 Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
• CPC Class Codes: H01J 2237/162 Open vessel, i.e. one end sealed by object or workpiece
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32366 Localised processing

Abstract

A device is provided for cleaning a surface by introducing a highly reactive gas mixture to the surface. The highly reactive gas mixture may include excited species such as ozone and relate excited ions, atoms, and electrons. The excited gas mixture then oxidizes undesirable materials on the surface. The device includes a structure which defines an enclosed space when placed against the surface to be cleaned. A set of one or more electrodes are positioned within the device such that an electrical discharge across the electrodes excites the selected gases species. The electrodes are attached to a power supply capable of generating a high frequency, high voltage discharge. A tube is provided for transporting selected gases, such as air or oxygen, to the enclosed space. Another tube is provide for removing reaction products from the enclosed space. This tube is place in communication with a source of suction for establishing a flow of gases into and out of the enclosed space.

Claims

1. A device for cleaning a surface comprising:

means for defining an enclosed chamber wherein at least a portion of the surface to be cleaned defines at least a portion of the interior surface of the chamber;

means for activating a selected gas;

means for introducing the activated gas into the chamber such that the portion of the surface which forms a portion of the chamber is capable of reacting with the activated gas;

means for removing reaction products from the chamber; and

a handle such that the device is capable of being manipulated over the surface by said handle.

2. A device for cleaning a surface as defined in claim 1 wherein said means for activating the gas comprises at least one electrode capable of activating the gas within the chamber.

3. A device for cleaning a surface as defined in claim 1 wherein said means for activating the gas within the chamber comprises two electrodes capable of activating the gas within the chamber.

4. A device for cleaning a surface as defined in claim 3 wherein the discharge of said electrodes is capable of producing an excited gaseous mixture within the chamber which includes ozone.

5. A device for cleaning a surface as defined in claim 4 wherein said means for activating the gas further comprises a power supply capable of producing a high voltage and high frequency discharge.

6. A device for cleaning a surface as defined in claim 1 wherein said means for introducing a gas into the chamber comprises a tube capable of carrying a gas.

7. A device for cleaning a surface as defined in claim 1 wherein said means for removing reaction products from the chamber comprises a tube capable of carrying said reaction products.

8. A device for cleaning a surface as defined in claim 7 wherein said means for removing reaction products further comprises a suction source in communication with said tube.

9. A device for cleaning a surface as defined in claim 2 wherein said means for activating the gas comprises means for causing a discharge between said at least one electrode and the surface to be cleaned.

10. A device for treating a surface, comprising:

a head configured such that when the head is placed against a surface to be treated, the head and the surface together define an enclosed chamber;

electrical means for exciting selected gases such that the excited gases are capable of reacting with selected materials on the surface;

means for introducing said excited gases into the chamber;

means for manipulating the chamber such that the device can be moved over a selected area of the surface to be treated; and

means for transporting reaction products away from the chamber.

11. A device for treating a surface as defined in claim 10 wherein said means for manipulating the chamber comprises a handle attached to the device.

12. A device for treating a surface as defined in claim 10 wherein said means for exciting the gases within the chamber comprises a pair of electrodes capable of producing a sufficient electrical discharge to activate the gases within the chamber.

13. A device for treating a surface as defined in claim 10 wherein said means for exciting gases is capable of producing a mixture of ions, atoms, and electrons, which mixture includes ozone.

14. A device for treating a surface as defined in claim 12 wherein said means for exciting gases further comprises a power supply attached to the electrodes, which power supply is capable of producing a high frequency and high voltage discharge across said electrodes.

15. A device for treating a surface as defined in claim 14 wherein said high voltage discharge is in the range of from about 50,000 volts to approximately 1,000,000 volts.

16. A device for treating a surface as defined in claim 10 wherein said means for exciting gases within said chamber comprises an electrode and means for producing an electrical discharge between said electrode and said surface.

17. A method of cleaning a surface comprising the steps of:

a. obtaining a device comprising

a cleaning head configured such that when the cleaning head is placed against a surface to be cleaned, the cleaning head and the surface define an enclosed chamber;

means for introducing a gas into the chamber;

means for manipulating the chamber such that the device can be moved over a selected area of the surface to be cleaned;

electrical means for exciting the gases within the chamber such that the excited gases are capable of oxidizing selected materials on the surface; and

means for transporting reaction products away from the chamber;

b. positioning the device adjacent to the surface to be clean such that a chamber is formed;

c. introducing a gas into the chamber;

d. activating said electrical means such that said gas is excited; and

e. transporting reaction products from the chamber by said transporting means.