Performance Evaluation of a Fiber Length Classifier

Details

• Personal Author:
  Baron, Paul A. ; Deye GJ ; Fernback, Joseph E. ; Gao, Peng-Fei
• Description:
  A performance evaluation was conducted on a differential mobility classifier that separates fibers according to length using dielectrophoresis. The classifier had been constructed and used for several applications in previous studies. The performance of the classifier was predicted using a two-dimensional axisymmetric model of the flow field and then calculating particle trajectories for a variety of conditions. Based on the flow calculations, several regions of the classifier were improved to reduce likelihood of turbulent losses. For a given total flow through the classifier and a maximum voltage across the electrodes, the performance of the classifier was found to depend on the ratios of the aerosol flow to the inner and the outer sheath flows. It was found that the minimum classifiable length, the minimum length distribution width, and the throughput of classified fibers can each be optimized, but not independently. Several approaches to testing the resolution of the classifier were tried. The first was to measure the length distribution of fibers passing through the classifier under different conditions using electron microscopy. However, this was a slow and imprecise measure of performance. Two approaches using monodisperse latex spheres were used; one operated the instrument as an electrical mobility (electrophoresis) analyzer and the other evaluated only the flow system accuracy. All measures indicate that the classifier operates close to theoretical performance, but improvements are still possible. Suggested improvements require redesign of the flow system and improved electrode alignment. [Description provided by NIOSH]
• Subjects:
  Air Movements Air Pollutants, Occupational Electricity Laboratories Occupational Health Particulate Matter Safety
• Keywords:
  Airborne Fibers Air Flow Analytical Instruments Electrical Fields Equipment Reliability Equipment Testing Fibers Force Laboratory Equipment Measurement Equipment Particle Aerodynamics Particle Size Analysis Performance Capability Performance Tests

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• ISSN:
  0278-6826
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Ohio ; OSHA Region 3 ; OSHA Region 5 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DPSE - Division of Physical Sciences and Engineering ; DRDS - Division of Respiratory Disease Studies
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  420-437
• Volume:
  30
• Issue:
  5
• NIOSHTIC Number:
  nn:20057094
• Citation:
  Aerosol Sci Technol 1999 May; 30(5):420-437
• Contact Point Address:
  G. J. Deye, National Institute for Occupational Safety and Health, Cincinnati, OH 45226 USA
• Federal Fiscal Year:
  1999
• Peer Reviewed:
  True
• Source Full Name:
  Aerosol Science and Technology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:49825f7a93c844497cf0436d103b614052b8be2a3967535395822d743f78c322c8b760ea8c2e1d4b0daaa4a17e9a3ebb8d998fc643e9f0dfb72ca720f3fbda61
• Download URL:
  https://stacks.cdc.gov/view/cdc/214552/cdc_214552_DS1.pdf
• File Type:
  [PDF - 493.50 KB ]