Ultraviolet passthrough sterilization device

• US 5,446,289 A
• Filed: 04/15/1994
• Issued: 08/29/1995
• Est. Priority Date: 04/15/1994
• Status: Expired due to Term

• Current Assignee: Despatch Industries, Inc. (Illinois Tool Works Inc.)
• Original Assignee: Despatch Industries, Inc. (Illinois Tool Works Inc.)
• Inventors: Davenport, Stewart, Shodeen, Keith, Melgaard, Hans L.
• Primary Examiner(s): Dzierzynski, Paul M.
• Assistant Examiner(s): NGUYEN, KIET TUAN
• Application Number:
  US08/227,959
• Time in Patent Office: 501 Days
• Field of Search: 250/455.11, 250/454.11, 250/453.11, 422/24, 422/25
• US Class Current: 250/455.11
• CPC Class Codes: A61L 2/10 Ultraviolet radiation

Abstract

An ultraviolet sterilization and decontamination system which is particularly useful in ultraviolet passthrough applications. The system includes a shell having a reflective inner surface and a barrier positioned within the shell and spaced inwardly of the inner surface of the shell, the barrier being formed of a material which will transmit at least about 70% of the desired wavelength of ultraviolet light. The space between the shell and the barrier defines a lamp cell for holding one or more ultraviolet lamps and the interior of the barrier defines a sterilization cell wherein items can be sterilized or decontaminated. The barrier is supported within the shell by supports and reflective endwalls substantially seal the lamp cell from the sterilization cell, as well as substantially sealing the sterilization cell and lamp cell from communication with the external environment. The system can be placed for use in sterilizing or decontaminating an item being introduced from a non-sterile environment to a substantially sterile, "clean" environment. In such an application, the endwalls should both include doors permitting operator access to the sterilization zone, with one of the doors being accessible from the "clean" environment and the other door should be accessible from the non-sterile environment.

Claims

1. An ultraviolet sterilization device comprising:

an external shell extending along a center line and having at first and second ends, the shell having an inner surface defining a chamber extending from the first end to the second end;

a transmissive barrier extending along the center line of the shell and having first and second ends, the barrier being spaced inwardly of the shell to define a lamp cell therebetween, the inner surface of the barrier defining a sterilization cell, the barrier being formed of a material which transmits at least about 70% of light having a wavelength of about 253.7 nm;

supports adapted for positioning the barrier within the shell;

a lamp contained within the lamp cell; and

reflective endwalls including a first reflective endwall sealingly engaging the first ends of the shell and barrier respectively and a second reflective endwall sealingly engaging the second ends of the shell and barrier respectively, the reflective endwalls substantially sealing the lamp cell from the sterilization cell and an outside environment.

2. The ultraviolet sterilization device of claim 1, wherein at least one endwall includes a reflective door, the door having an open position wherein an operator may access the sterilization cell and a closed position wherein it substantially seals the sterilization cell from an outside environment.

3. The ultraviolet sterilization device of claim 2, wherein the endwalls each include a reflective door, a first door sealingly engaging the first end of the barrier and a second door sealingly engaging the second end of the barrier, one of the doors being accessible from a non-sterile environment and the other of the doors being accessible from a substantially sterile environment.

4. The ultraviolet sterilization device of claim 3 further comprising a fused silica shelf positioned within and extending substantially throughout the length of the sterilization cell, the doors being positioned so that each inner surface of the doors lies in substantially the same plane as the shelf when the doors are opened.

5. The ultraviolet sterilization device of claim 1, wherein the shell is generally cylindrical in shape.

6. The ultraviolet sterilization device of claim 5, wherein both the shell and the barrier are generally cylindrical in shape and have center lines, the center line of the shell substantially coinciding with the center line of the barrier so that the shell and the barrier together define generally concentric cylinders.

7. The ultraviolet sterilization device of claim 5 further comprising a plurality of lamps sources spaced generally equiangularly about the generally cylindrical inner surface of the shell.

8. The ultraviolet sterilization device of claim 1, wherein the barrier is generally cylindrical in shape and is formed of a fused silica.

9. The ultraviolet sterilization device of claim 1 further comprising a plurality of lamps equally spaced circumferentially around the inner surface of the shell.

10. The ultraviolet sterilization device of claim 9 further comprising means for remotely verifying the operability of a lamp without visually inspecting the lamp.

11. The ultraviolet sterilization device of claim 10 further comprising an alarm indicating a failure of a lamp.

12. The ultraviolet sterilization device of claim 1 further comprising a transmissive shelf positioned within and extending substantially throughout the length of the sterilization cell.

13. The ultraviolet sterilization device of claim 12, wherein the shelf is formed of fused silica.

14. The ultraviolet sterilization device of claim 1, wherein the transmissive barrier is formed of fused silica and transmits at least about 80% of light having a wavelength of about 253.7 nm.

15. The ultraviolet sterilization device of claim 1 further comprising a reflective liner positioned between the inner surface of the shell and the lamp.

16. The ultraviolet sterilization device of claim 15, wherein the reflective surface is a reflective Solarbrite film.

18. The ultraviolet sterilization device of claim 12, wherein the reflective inner surface is Solarbrite.

19. The ultraviolet sterilization device of claim 12 further comprising a means for verifying the intensity of the lamps without removal thereof.

20. The ultraviolet sterilization device of claim 12 wherein the barrier is adapted to transmit at least about 70% of light having a wavelength of about 253.7 nm.

17. An ultraviolet passthrough sterilization device for passing items from a non-sterile environment to a substantially sterile environment comprising:

a generally cylindrical external shell extending along a center line and having a first end accessible from the non-sterile environment and a second end accessible from the substantially sterile environment, the shell having a reflective inner surface which defines a chamber extending from the first end to the second end;

a generally cylindrical fused quartz barrier extending along the center line of the shell and having a first end accessible from the non-sterile environment and a second end accessible from the substantially sterile environment, the barrier being positioned generally concentrically within the shell and spaced radially inwardly of the inner surface of the shell to define a lamp cell therebetween, an inner surface of the barrier defining a generally cylindrical sterilization cell;

supports adapted for positioning the barrier within the shell;

a plurality of lamps spaced generally equiangularly about the inner surface of the shell and contained within the lamp cell;

a fused quartz shelf positioned horizontally within and extending along substantially the entire length of the sterilization cell;

reflective endwalls having openings for receiving reflective doors and including a first reflective endwall sealingly engaging the first ends of the shell and barrier respectively and a second reflective endwall sealingly engaging the second ends of the shell and barrier respectively, whereby the first and second endwalls substantially seal the lamp cell from the sterilization cell, the sterile environment, and the non-sterile environment; and

the reflective doors including a first door positioned in the opening through the first endwall and sealingly engaging the first end of the barrier, and a second door positioned in the opening through the second endwall and sealingly engaging the second end of the barrier.