Particle Collection Efficiency for Nylon Mesh Screens.

Area of Science:

• Materials Science
• Aerosol Science
• Analytical Chemistry

Background:

• Nylon mesh screens offer advantages for nanoparticle collection due to minimal ash and spectral interference during spectrometric analysis.
• Previous theoretical models for wire-mesh screens were adapted to evaluate nylon mesh screens for submicrometer particle collection.

Purpose of the Study:

• To assess the suitability of nylon mesh screens as a collection substrate for nanoparticles.
• To experimentally evaluate the collection efficiency, pressure drop, and single-fiber efficiency of nylon mesh screens for submicrometer particles.
• To refine a theoretical model for predicting nanoparticle collection efficiency on nylon mesh screens.

Main Methods:

• Experimental evaluation of pressure drop and collection efficiency for nylon mesh screens (60, 100, 180 microm pores) at varying flow rates (2.5, 4, 6 Lpm).
• Investigation of particle morphology effects (spherical vs. fractal) on collection efficiency.
• Comparison of experimental single-fiber efficiency data with theoretical predictions and development of modified model coefficients.

Main Results:

• Pressure drop across nylon mesh screens increased linearly with superficial velocity.
• Collection efficiency showed minimal variation (<4%) irrespective of particle morphology.
• Experimental single-fiber efficiency agreed with theory for 40-150 nm particles but deviated for others.
• A modified theoretical model significantly reduced the sum of square error (SSE) compared to the original theory.

Conclusions:

• Nylon mesh screens are a viable and effective substrate for nanoparticle collection in spectrometric analysis.
• The refined theoretical model provides improved accuracy in predicting nanoparticle collection efficiency on nylon mesh screens.
• The study offers enhanced understanding of aerosol-particle interactions with mesh screens for improved sampling and analysis techniques.