Dual fan hepa filtration system

• US 5,358,443 A
• Filed: 04/14/1993
• Issued: 10/25/1994
• Est. Priority Date: 04/14/1993
• Status: Expired due to Fees

• Current Assignee: C Core, Inc.
• Original Assignee: CenterCore Group, Inc. (MITY Holdings of Delaware, Inc.)
• Inventors: Havrilla, George, Mitchell, Robert G.
• Primary Examiner(s): Joyce, Harold
• Application Number:
  US08/047,597
• Time in Patent Office: 559 Days
• Field of Search: 55/487, 55/470, 55/473, 55/498, 55/502, 55/521, 454/230, 454/231, 454/233, 454/310
• US Class Current: 454/230
• CPC Class Codes: F24F 8/10 by separation, e.g. by filtering
• CPC Class Codes: F24F 8/108 using dry filter elements
• CPC Class Codes: F24F 8/158 using active carbon
• CPC Class Codes: F24F 8/80 Self-contained air purifiers
• CPC Class Codes: F24F 8/97 for removing tobacco smoke

Abstract

A device for use with at least one workspace, to produce an umbrella of clean room air for a distance of one meter from the device and 98% fewer particles than the air in the area three meters from the device. The device has a chamber defined by an outer wall, end walls and a filter as the inner wall. The filter functions as tile sole outlet of air. A motor with an axially extending drive shaft is mounted inside said filter. The shaft has an intake fan mounted on one end to define a sealed path which is the sole air inlet to the chamber. An exhaust fan is mounted on the other end of the shaft to define a path from the sole outlet. Air is exhausted in an axial direction is then deflected from the axial direction to the radial direction onto a baffle to reduce the velocity of the air to laminar flow. The baffle includes an upper terminal lid and a plurality of annular stepped vanes that divide the axially exhausted air into turbulent air streams and converts the turbulent air streams into radial laminar flow.

Claims

1. A device for use with at least one workspace, comprising:

a chamber including an outer wall and end walls forming the chamber;

filter means defining an inner wall of said chamber and being the sole outlet of air entering said chamber;

a fan motor mounted inside said filter means and including a drive shaft extending axially out from motor in two directions;

an intake fan mounted on one end of the shaft, including first path defining means for defining a sealed path which is the sole air inlet to said chamber;

an exhaust fan mounted on the other end of shaft, including second path defining means for defining a path from said sole outlet to said exhaust fan for exhausting air in a generally axial direction; and

baffle means for deflecting air in said axial direction to a radial direction while reducing the velocity of said air to laminar flow.

2. The device of claim 1, wherein said baffle means include an upper terminal lid of the chamber and a plurality of annular stepped vanes for dividing axially exhausted air into turbulent air streams and converting said turbulent air streams into radial laminar flow.

3. The device of claim 2, wherein said plurality of stepped vanes comprises two annular stepped vanes spaced axially in from said lid and having decreasing inner radii in the direction from said exhaust fan to said lid.

4. The device of claim 1, wherein said motor is rated at less than 2 amp and said device produces at least 150 CFM of exhaust air.

5. The device of claim 1, wherein said filter is a HEPA filter requiring about 150 CFM for optimum filtration efficiency.

6. The device of claim 1, which further includes means for mounting said device on a divider wall of a work station.

7. The device of claim 1, wherein said first path defining means includes seal means for preventing air flow to said shaft.

8. A device for use with at least one workspace, comprising:

a chamber including an outer wall and end walls forming the chamber;

HEPA filter means requiring about 150 CFM for optimum filtration efficiency and defining an inner wall of said chamber and being the sole outlet of air entering said chamber;

a fan motor mounted inside said inner wall of the chamber and including a drive shaft extending axially out from motor in two directions, said motor being rated at less than 2 amp and producing at least 150 CFM of exhaust air;

an intake fan mounted on one end of the shaft, including first path defining means for defining a sealed path which is the sole air inlet to said chamber including seal means for preventing air flow to said shaft;

an exhaust fan mounted on the other end of shaft, including second path defining means for defining a path from said sole outlet to said exhaust fan for exhausting air in an axial direction; and

baffle means for deflecting air in said axial direction to a radial direction while reducing the velocity of said air to laminar flow comprising an upper terminal lid and a plurality of annular stepped vanes for dividing axially exhausted air into turbulent air streams and converting said turbulent air streams into radial laminar flow to thereby produce noise proximate thereto of less than 47 decibels in an umbrella of clean room air for a distance of at least one meter from said device and having 98% fewer particles than the air in the area at least three meters from said device.

9. The device of claim 8, wherein said plurality of vanes comprises two annular stepped vanes spaced axially out from said exhaust fan and having decreasing inner radii in the direction from said exhaust fan to said lid.

10. The device of claim 8, wherein said device further includes means for mounting said device on a divider wall of a work station.

11. A method of providing an umbrella of clean room air in at least one workspace for a distance of at least one meter within said workspace and having 98% fewer particles than the air in the area at least three meters from said workspace, comprising the steps of:

providing a chamber proximate a workspace, said chamber having an outer wall, end walls and an inner wall defined by filter means to form a sealed chamber in which said filter means is the sole outlet of air entering said chamber;

said air being drawn into said chamber by a fan motor mounted proximate the center of the filter means and including a drive shaft extending axially out from motor in two directions;

drawing air into said chamber using an intake fan mounted on one end of the shaft along a first path defining means for defining a sealed path which is the sole air inlet to said chamber;

exhausting air in an axial direction using an exhaust fan mounted on the other end of shaft, by defining a second path from said sole outlet to said exhaust fan; and

deflecting air in said axial direction to a radial direction with baffle means including an upper terminal lid for said device and a plurality of annular stepped vanes to divide axially exhausted air into turbulent air streams and convert said turbulent air streams into radial laminar flow with reduced velocity of deflected air to have laminar flow.

12. The method of claim 11, including the step of dividing said exhaust air with two annular stepped vanes spaced axially out from said exhaust fan and having decreasing inner radii in the direction from said exhaust fan to said lid.

13. The method of claim 11, wherein said motor is rated at less than 2 amp and produces at least 150 CFM of exhaust air, said filter is a HEPA filter requiring about 150 CFM for optimum filtration efficiency, and said device produces noise proximate thereto of less than 47 decibels.

14. The method of claim 11, which further includes the step of mounting said device on a divider wall of a work station.