Exhaust Filter Module Sampling Port for Room-Side Efficiency Testing
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Solution Overview
Problem
Testing exhaust filter modules in cleanroom applications is challenging due to inaccessible interstitial spaces and inaccurate sampling, especially when reverse flow direction testing may not reflect operational conditions, posing health and regulatory risks.
Innovation Solution
A filter module with a downstream sampling port and a shroud system that allows for room-side measurement of filter efficiency, including a flange for sealing, a collar for duct coupling, and aerosol injection ports to ensure accurate and uniform testing in the operational flow direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If reverse flow direction testing is performed to facilitate downstream sampling, then sampling accessibility is improved, but measurement accuracy deteriorates because the test conditions do not reflect operational flow direction
Solution Approach 1:
The patent inverts the conventional testing approach by providing a downstream sampling port on the cleanroom side of the filter, allowing sampling in the operational flow direction rather than reversing flow for accessibility
2Ease of operation
If sampling is performed within the interstitial space between housing and filter, then downstream sampling becomes possible, but measurement accuracy deteriorates due to poor air mixing in the interstitial space
Solution Approach 1:
The patent moves the sampling port from the difficult-to-access interstitial space to the cleanroom side of the filter housing, changing the spatial dimension of sampling accessibility while maintaining measurement accuracy
3Ease of operation
If filter testing is performed in reverse flow direction, then sampling accessibility is improved, but reliability deteriorates because pinhole leaks may be flow direction dependent
Solution Approach 1:
The patent inverts the testing approach by enabling sampling in the operational flow direction through the downstream sampling port on the cleanroom side, ensuring that leak detection reliability matches actual operational conditions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate and efficient testing of filter modules from the cleanroom side, ensuring filter integrity and compliance with regulations by allowing direct sampling and aerosol challenge in the operational flow direction, reducing the risk of contamination and health hazards.
Implementation Method 1
The aerosol injection port may be coupled to an aerosol dispersion device, such as a perforated tube
Implementation Method 2
Baffles or other mixing elements may be disposed in the shroud to mix the aerosol so that a uniform challenge is provided to the face of the filter element
Implementation Method 3
The shroud includes a flange for sealing against the face of the filter module
Implementation Method 4
a filter element having a face oriented toward the cleanroom and a downstream sampling port configured to allow a technician to sample flow, downstream of the filter module, from the cleanroom side
Data Source
AI summary
A filter module configured for exhaust application, and a method and apparatus for testing the same are provided. In one embodiment, the filter module includes a downstream sampling port configured to allow a technician to sample flow, downstream of the filter module, from the cleanroom side of a filter module. In another embodiment, a shroud adapted to sealing engage a filter module under test is provided and includes a tube, disposed in the shroud, that couples a port to a downstream sampling port of the filter module.