Device and method for collecting airborne microorganisms

Patent metadata

Field	Value
Publication number	US-9433883-B2
Application number	US-201113985708-A
Country	US
Kind code	B2
Filing date	Feb 22, 2011
Priority date	Feb 22, 2011
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

The present invention provides an impaction-based microorganism collecting device in which microorganisms are captured by the capture surface of a collection plate. The microorganism collecting device is designed to reduce the influence of the lateral wind flowing over the perforated plate having multiple nozzles and also prevent warpage of the perforated plate.
Multiple air vents are formed around the circumference of the capture surface and through the capture surface so that air that has flowed through the nozzles of the perforated plate onto the capture surface can be discharged. This allows the air to flow in multiple directions over the capture surface, thereby reducing the speed of the air and increasing the microorganism capture rate.

First claim

The invention claimed is:

1. A microorganism collecting device comprising:
a perforated plate having a plurality of nozzles that allow passage of air containing microorganisms;
a collection plate facing the plurality of nozzles and having a capture surface for capturing the microorganisms;
a collection plate holder for holding the collection plate;
a fan for allowing the air to flow from the perforated plate toward the collection plate;
a housing for holding the perforated plate, the collection plate holder, and the fan; and
an air vent located in a space between the housing and circumferentially outer sections of the collection plate and the collection plate holder,
wherein the device further has a second air vent formed at circumferentially inner sections of the collection plate and the collection plate holder,
wherein ring-shaped convex portions are placed on the collection plate such that the convex portions are directly below the nozzles,
wherein the top surfaces of the convex portions act as capture surfaces of the collection plate, and
wherein the spaces between the convex portions communicate with the air vents.

2. The microorganism collecting device of claim 1 wherein the distance between the perforated plate and the collection plate is ⅓ to 15 times the diameter of the nozzles.

3. The microorganism collecting device of claim 1 wherein the perforated plate is a metal plate that is 0.01 to 2 mm in thickness and 5 to 200 mm in diameter, and wherein the nozzles of the perforated plate are 1,000 to 10,000 in number and each circular with the diameter of the nozzles being 50 to 200 μm.

4. The microorganism collecting device of claim 2 wherein the collection plate is formed from a solid medium selected from the group consisting of glass, quartz, resin (polypropylene, polyethylene terephthalate, polycarbonate, polystyrene, acrylonitrile-butadiene-styrene resin, polymethacrylic acid methyl ester or other acrylic resin, polydimethylsiloxane), metal (iron, aluminum, copper, tin, gold, silver, alloy steel, copper alloy, aluminum alloy, nickel alloy gelatin, and agar.

5. The microorganism collecting device of claim 1 wherein the collection plate includes concentric ring structures of different sizes whose top surfaces act as capture surfaces of the collection plate, and wherein the spaces between the concentric ring structures act as air vents.

6. The microorganism collecting device of claim 1 wherein the areas of the top surfaces of the convex portions are each about 1 to 4 times the area of each of the nozzles, and wherein the height of the convex portions is about 1 to 5 times the diameter of each of the convex portions.

7. The microorganism collecting device of claim 1 wherein one or more support columns are formed on the collection plate to support the perforated plate.

8. A method for collecting airborne microorganisms that involves the use of the microorganism collecting device of claim 1 , the method comprising the steps of:
causing the air to flow through the nozzles of the perforated plate toward the capture surface(s) of the collection plate;
causing the capture surface(s) to capture the microorganisms contained in the air; and
causing the air to flow toward both the air vent and the second air vent after flowing past the nozzles.

9. A microorganism collecting device comprising:
a perforated plate having a plurality of nozzles that allow passage of air containing microorganisms;
a collection plate facing the plurality of nozzles and having a capture surface for capturing the microorganisms;
a collection plate holder for holding the collection plate;
a fan for allowing the air to flow from the perforated plate toward the collection plate;
a housing for holding the perforated plate, the collection plate holder, and the fan; and
an air vent located in a space between the housing and circumferentially outer sections of the collection plate and the collection plate holder,
wherein the device further has a second air vent formed at circumferentially inner sections of the collection plate and the collection plate holder,
and wherein one or more support columns are formed on the collection plate to support the perforated plate.

10. The microorganism collecting device of claim 9 wherein the distance between the perforated plate and the collection plate is ⅓ to 15 times the diameter of the nozzles.

11. The microorganism collecting device of claim 9 wherein the perforated plate is a metal plate that is 0.01 to 2 mm in thickness and 5 to 200 mm in diameter, and wherein the nozzles of the perforated plate are 1,000 to 10,000 in number and each circular with the diameter of the nozzles being 50 to 200 μm.

12. The microorganism collecting device of claim 10 wherein the collection plate is formed from a solid medium whose primary materials include glass, quartz, resin (polypropylene, polyethylene terephthalate, polycarbonate, polystyrene, acrylonitrile-butadiene-styrene resin, polymethacrylic acid methyl ester or other acrylic resin, polydimethylsiloxane), metal (pure metals such as iron, aluminum, copper, tin, gold, silver, and the like and alloys such as alloy steel, copper alloy, aluminum alloy, nickel alloy, and the like), gelatin, and agar.

13. The microorganism collecting device of claim 9 wherein the collection plate includes concentric ring structures of different sizes whose top surfaces act as capture surfaces of the collection plate, and wherein the spaces between the concentric ring structures act as air vents.

14. A method for collecting airborne microorganisms that involves the use of the microorganism collecting device of claim 9 , the method comprising the steps of:
causing the air to flow through the nozzles of the perforated plate toward the capture surface(s) of the collection plate;
causing the capture surface(s) to capture the microorganisms contained in the air; and
causing the air to flow toward both the air vent and the second air vent after flowing past the nozzles.

Assignees

• Takenaka Kei
• Sasaki Yasuhiko
• Togashi Shigenori
• Hitachi Ltd

Inventors

• Takenaka Kei
• Sasaki Yasuhiko
• Togashi Shigenori

Classifications

• B01D45/08 Primary

  by impingement against baffle separators · CPC title

• G01N1/2273 Primary

  Atmospheric sampling · CPC title

• G01N1/2208

  with impactors · CPC title

• G01N2001/245

  Fans · CPC title