Surface and air sterilization using ultraviolet light and ultrasonic waves

• US 6,171,548 B1
• Filed: 11/16/1998
• Issued: 01/09/2001
• Est. Priority Date: 12/29/1997
• Status: Expired due to Fees

• Current Assignee: Spectrum Environmental Technologies, Inc.
• Original Assignee: Spectrum Environmental Technologies, Inc.
• Inventors: Rose, Edward V., Clark, William E. Jr.
• Primary Examiner(s): Warden, Sr., Robert J.
• Assistant Examiner(s): Snider, Theresa T.
• Application Number:
  US09/193,330
• Time in Patent Office: 785 Days
• Field of Search: 422/20, 422/24, 422/128
• US Class Current: 422/20
• CPC Class Codes: A61L 2/02 using physical phenomena
• CPC Class Codes: A61L 2/10 Ultraviolet radiation
• CPC Class Codes: A61L 9/16 using physical phenomena
• CPC Class Codes: A61L 9/18 Radiation A61L9/22 takes precedence
• CPC Class Codes: A61L 9/20 Ultraviolet radiation

Abstract

A method and apparatus for sterilizing organic or inorganic matter through simultaneous exposure to ultraviolet light energy and ultrasonic wave energy in a non-aqueous environment such as air. The method is suitable for use in a chamber or in a mass production assembly line setting. Purification of air is similarly accomplished using simultaneous exposure to ultraviolet light and ultrasonic energy waves.

Claims

1. A method for sterilization of an organic or inorganic object, comprising the steps of:

(a) exposing an object to ultrasonic waves in a non-liquid environment to cause excitation and oscillation of exposed surface areas of the object and to cause a microorganism attached to the object to become dislodged from the object and airborne; and

(b) simultaneous with said step of exposing said object to ultrasonic waves, exposing said airborne microorganism to ultraviolet light, wherein said airborne microorganism experiences a greater surface area exposure to said ultraviolet light than it would experience if still attached to the surface of the object;

(c) wherein said simultaneous exposure to said ultraviolet light and said ultrasonic waves effects sterilization of said object.

2. A method as recited in claim 1, wherein said non-liquid environment comprises air.

3. A method as recited in claim 1, wherein said ultraviolet light is at a wavelength from approximately 180 nanometers to approximately 325 nanometers.

4. A method as recited in claim 1, wherein said ultrasonic waves are at a sweep frequency between approximately 20 KHz and approximately 52 KHz.

5. A method as recited in claim 1, wherein the sterilization is accomplished in a chamber.

6. A method as recited in claim 1, wherein the sterilization is accomplished on a conveyor belt.

7. A method as recited in claim 1, wherein said ultraviolet light is at a wavelength of approximately 250 to 260 nanometers for germicidal sterilization.

8. A method as recited in claim 1, wherein said ultrasonic waves are at a frequency of approximately 24 to 25 KHz for excitation of certain microorganisms.

9. An apparatus for sterilization of an organic or inorganic object, comprising:

(a) an ultrasound source configured to

(i) cause excitation and oscillation of exposed surface areas of the object in a non-liquid environment, and

(ii) cause a microorganism attached to the object to become dislodged from the object and airborne; and

(b) an ultraviolet light source configured to expose said microorganism to ultraviolet light simultaneously with exposure of said object to said ultrasonic waves, wherein said airborne microorganism experiences a greater surface area exposure to said ultraviolet light than it would experience if still attached to the surface of the object;

(c) wherein said simultaneous exposure to said ultraviolet light and said ultrasonic waves effects sterilization of said object.

10. An apparatus as recited in claim 9, wherein said non-liquid environment comprises air.

11. An apparatus as recited in claim 9, wherein said ultraviolet light source emits ultraviolet light at a wavelength from approximately 180 nanometers to approximately 325 nanometers.

12. An apparatus as recited in claim 9, wherein said ultrasound source emits ultrasonic waves at a sweep frequency between approximately 20 KHz and approximately 52 KHz.

13. An apparatus as recited in claim 9, wherein said ultraviolet light source and said ultrasound source are positioned within a chamber.

14. An apparatus as recited in claim 9, wherein said ultraviolet light source and said ultrasound source are positioned adjacent to a conveyor belt.