Filter and blower geometry for particle sampler

Patent metadata

Field	Value
Publication number	US-9631222-B2
Application number	US-201514645857-A
Country	US
Kind code	B2
Filing date	Mar 12, 2015
Priority date	Mar 14, 2014
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

The invention provides devices and methods for sampling, detecting and/or characterizing particles. Devices and methods of the invention, including particle samplers, impactors and counters, include a filter component for removing particles in the exhaust flow of the device, for example, to eliminate or minimize the potential for the device itself to provide source of particles in an environment undergoing particle monitoring. This aspect of the present devices and methods is particularly useful for monitoring particles in manufacturing environments requiring low levels of particles, such as cleanroom environments for electronics manufacturing and aseptic environments for manufacturing pharmaceutical and biological products.

First claim

We claim:

1. A sampler comprising:
one or more fluid inlets for sampling a fluid flow;
a particle analysis or collection region positioned in fluid communication with said one or more fluid inlets;
a fan or pump positioned in fluid communication with said particle analysis or collection region, said fan or pump for generating said fluid flow, wherein said fan or pump comprises a motor; and
a filter in fluid communication with said fan or pump and positioned around at least a portion of said motor, said filter for filtering said fluid flow exhausted from said fan or pump, wherein said filter has a toroid shape or cylindrical shape and said motor is positioned in a central region of said toroid shape or cylindrical shape.

2. The sampler of claim 1 , wherein said fan has a rotational axis and said filter has a cylindrical shape, wherein said cylindrical shape has a cylindrical axis and said rotational axis and said cylindrical axis are parallel.

3. The sampler of claim 1 , wherein said fluid flows through said one or more fluid inlets, through said particle analysis or collection region, into an intake of said fan or pump, to an exhaust of said fan or pump and through said filter, thereby filtering said fluid flow.

4. The sampler of claim 1 , further comprising an air intake manifold for independently drawing air samples from one or more locations into said one or more fluid inlets.

5. The sampler of claim 1 , wherein said filter removes at least 90% of particles having cross sectional dimensions greater than or equal to 0.5 μm.

6. The sampler of claim 1 , wherein said fan is a centrifugal blower, regenerative blower, radial blower, axial fan, high static pressure fan, or counter-rotating fan.

7. The sampler of claim 1 , wherein said pump is a reciprocating pump.

8. The sampler of claim 1 , wherein said fan or pump provides a flow rate selected from the range of 0.05 CFM to 10 CFM.

9. The sampler of claim 1 , wherein said filter is provided in a filter housing provided in thermal contact with said motor, wherein passage of said fluid flow exhausted from said fan or pump through said filter housing cools said motor.

10. The sampler of claim 1 , further comprising a filter housing positioned around said filter, said filter housing comprising a housing inlet in fluid communication with said fan or pump and a housing outlet in fluid communication with said housing inlet.

11. The sampler of claim 10 , wherein said fluid flow flows from said housing inlet through said filter to said housing outlet, thereby filtering said fluid flow.

12. The sampler of claim 1 , wherein said one or more fluid inlets comprise one or more air intake apertures and wherein said particle analysis or collection region comprises an impact plate positioned in fluid communication with said one or more air intake apertures for collecting particles from said fluid flow.

13. The sampler of claim 12 , comprising an active air impactor sampler or a slit-to-agar sampler.

14. The sampler of claim 12 , wherein said impact plate is positioned adjacent to said one or more air intake apertures in said particle analysis or collection region for collecting impacted particles from said fluid flow.

15. The sampler of claim 12 , wherein said impact plate comprises a petri dish for culturing impacted biological particles from said fluid flow.

16. The sampler of claim 15 , wherein said petri dish is removable or is integral to an impactor base.

17. The sampler of claim 12 , wherein said impact plate comprises a growth medium specific to one or more classes of biological organisms.

18. The sampler of claim 12 , wherein said impact plate comprises a rotatable impact plate.

19. The sampler of claim 12 , wherein a linear flow velocity of said fluid flow through said one or more air intake apertures is 5 to 50 meter/sec.

20. The sampler of claim 12 , wherein said fluid flow through said one or more air intake apertures is laminar.

21. The sampler of claim 12 , further comprising a plurality of air intake apertures, wherein said plurality of air intake apertures are arranged radially around a central point.

22. The sampler of claim 12 , further comprising a plurality of air intake apertures, wherein said plurality of air intake apertures allow for distinguishing whether particles present on said impact plate are impacted particles from said fluid flow or are not from said fluid flow.

23. The sampler of claim 12 , wherein each of said one or more air intake apertures corresponds to an impact area on said impact plate.

24. The sampler of claim 12 , wherein a flow direction of said fluid flow changes by 80° or more after as fluid flow passes through said one or more air intake apertures and past said impact plate, wherein particles present in said fluid flow are impacted onto said impact plate.

25. The sampler of claim 12 , wherein said one or more air intake apertures are located on a removable impactor sampling head.

26. The sampler of claim 1 , wherein said particle analysis or collection region comprises:
a source of electromagnetic radiation positioned to direct electromagnetic radiation through said fluid flow from said one or more fluid inlets, wherein electromagnetic from said source interacts with particles present in said fluid flow to generate scattered or emitted electromagnetic radiation;
an optical collection system positioned in optical communication with said fluid flow, said optical collection system for collecting at least a portion of said scattered or emitted electromagnetic radiation; and
a detector positioned in optical communication with said optical collection system, said detector for detecting a collected portion of said scattered or emitted electromagnetic radiation and for producing a signal characteristic of said particles present in said fluid flow.

Assignees

• Particle Measuring Syst

Inventors

• Ketcham Cliff
• Hartigan Paul B
• Adkins Ronald W

Classifications

• G01N2001/245

  Fans · CPC title

• G01N1/2205 Primary

  with filters · CPC title

• G01N1/2273

  Atmospheric sampling · CPC title

• G01N15/1434

  Optical arrangements · CPC title

• G01N2001/2223

  aerosol sampling devices · CPC title