Blower exhaust backflow damper

• US 20070207723A1
• Filed: 03/06/2006
• Published: 09/06/2007
• Est. Priority Date: 03/06/2006
• Status: Active Grant

• Current Assignee: Lenovo International Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Jensen, David, Lewis, Seth, Henry, Matthew, Baker, Bruce
• Granted Patent: US 7,416,481 B2
• Time in Patent Office: Days
• US Class Current: 454/229
• CPC Class Codes: F04D 25/14 and having shutters, e.g. automatically closed when not in use
• CPC Class Codes: F04D 29/663 Sound attenuation
• CPC Class Codes: F24F 7/007 with forced flow using ducting systems F24F7/06
• CPC Class Codes: H05K 7/20172 Fan mounting or fan specifications

Abstract

A system, method, and apparatus for preventing exhaust backflow into a blower are disclosed. Embodiments may include a blower system with an invertible blower chassis having a blower exhaust to direct airflow from the blower chassis at an airflow angle. The system may also include a backflow damper frame attached to the blower chassis and positioned to receive airflow from the blower chassis and one or more vertical damper vanes rotatably attached to the backflow damper frame. Each damper vane may freely rotate between a first, closed position and a second, open position. The damper vanes may block airflow into the blower exhaust when in the closed position and may freely rotate to a position where the damper vanes are substantially parallel to the airflow from the blower exhaust. The damper vanes may each include a vane pin to rotatably attach to frame holes of the backflow damper frame.

Claims

1. A blower system, the system comprising:

an invertible blower chassis having a blower exhaust to direct an airflow from the blower chassis at an airflow angle from an axis perpendicular to the chassis, the blower chassis being adapted to be used with both a first side and a second, opposite side being substantially perpendicular to a vertical axis aligned with a gravitational force;

a backflow damper frame attached to the blower chassis and positioned to receive airflow from the blower chassis;

one or more damper vanes rotatably attached to the backflow damper frame, each damper vane having a vane body with a long axis, wherein the long axes of the one or more vane bodies are substantially parallel to the chassis vertical axis, and wherein the one or more damper vanes are adapted to freely rotate between a first, closed position and a second, open position; and

wherein the one or more damper vanes block airflow into the blower exhaust when the one or more damper vanes are in the closed position, and wherein further the one or more damper vanes freely rotate to a position where the one or more vane bodies are substantially parallel to the airflow from the blower exhaust.

2. The system of claim 1, further comprising a blower intake fan to draw air into the blower chassis.

3. The system of claim 1, wherein the backflow damper frame further comprises a pair of opposing frame holes for each of the one or more damper vanes.

4. The system of claim 3, wherein at least one of each pair of opposing frame holes comprises a notch to restrain a keyed end of a damper vane.

5. The system of claim 1, wherein the one or more damper vanes comprise four damper vanes.

6. The system of claim 1, wherein the one or more damper vanes comprise two or more damper vanes.

7. The system of claim 1, wherein the one or more damper vanes are constrained to rotate within approximately ninety (90) degrees or less from the closed position.

8. The system of claim 1, wherein the one or more damper vanes each further comprise a vane pin to rotatably attach to frame holes of the backflow damper frame.

9. The system of claim 8, wherein at least one vane pin for each damper vane comprises a keyed end.

10. A backflow damper apparatus for a blower, comprising:

a backflow damper frame having a perimeter defining an airflow area, the backflow damper frame being adapted to receive and pass an airflow from a blower exhaust through the airflow area where the blower exhaust airflow flows substantially at an airflow angle from an axis perpendicular to the airflow area;

one or more damper vanes rotatably attached to the perimeter of the backflow damper frame, each damper vane having a vane body with a long axis, wherein the long axes of the one or more vane bodies are adapted to be vertically oriented when the backflow damper is attached to the blower, and wherein the one or more damper vanes are adapted to freely rotate between a first, closed position and a second, open position; and

wherein the one or more damper vanes block airflow into the blower exhaust when the one or more damper vanes are in the closed position, and wherein further the one or more damper vanes rotate to a position where the one or more vane bodies are substantially parallel to the airflow from the blower exhaust during blower operation.

11. The apparatus of claim 10, wherein the backflow damper frame further comprises a pair of opposing frame holes for each of the one or more damper vanes.

12. The apparatus of claim 11, wherein at least one of each pair of opposing frame holes comprises a notch to restrain a keyed end of a damper vane.

13. The apparatus of claim 10, wherein the one or more damper vanes comprise four or more damper vanes.

14. The apparatus of claim 10, wherein the one or more damper vanes are constrained to rotate within approximately ninety (90) degrees or less from the closed position.

15. The apparatus of claim 10, wherein the one or more damper vanes each further comprise a vane pin to rotatably attach to frame holes of the backflow damper frame.

16. The apparatus of claim 15, wherein at least one vane pin for each damper vane comprises a keyed end.

17. A method for preventing exhaust backflow from a blower, the method comprising:

receiving angled exhaust airflow from a blower exhaust, the blower exhaust airflow being angled less than ninety (90) degrees from perpendicular to the blower;

rotating one or more damper vanes freely in the blower exhaust during operation of the blower; and

in the event of failure of the blower, rotating the damper vanes to a closed position via a pressure force applied to the damper vanes resulting from a lower pressure inside the blower than ambient pressure outside the blower.

18. The method of claim 17, further comprising blocking rotation of the one or more damper vanes past a vane centerline.

19. The method of claim 17, wherein rotating the one or more damper vanes freely in the blower exhaust airflow comprises rotating the one or more damper vanes freely about a vertical axis substantially parallel to the gravitational axis.

20. The method of claim 17, wherein rotating the one or more damper vanes freely in the blower exhaust comprises allowing the one or more damper vanes to rotate to an angle parallel with the angle blower exhaust airflow.