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Acoustic particle focusing (Technion)

总结

Particle analyzers utilize particle 'focusing' by establishing high particle concentrations within a thin stream of gas. Most specimens for analysis, like gunpowder residue in ambient air, do not show these properties. Aerodynamic lens arrays which consist of many tubes which reshape the particle flow into a very thin line serve as the conventional solution to this problem. However, for the lens to operate properly without mixing, the gas flow inside them must be free of turbulence. This is achieved by reducing the pressure inside the tubes to a near-vacuum, which requires costly high powered vacuum pumps.Our technology enables focusing of gas-suspended particles without a reduction of pressure. Focusing is achieved by means of a pressure field which is generated inside an X-shaped channel (Fig. 1). The channel is comprised of four resonating hyperbolic walls. Each wall emits a sound wave towards the center of the channel. These quadrupole waves interact to create a pressure field rising towards the channel's walls (Fig. 2). As gas flows through the channel, particles are drawn towards the axis by viscous forces.
The particle flow can then be directed into an aerodynamic lens for further focusing. Since the flow is not turbulent, particle mixing and residue in the tubes are reduced which also leads to higher sensor sensitivity since more particles reach the end of the tube for subsequent analysis.

技术优势

• Higher sensitivity than aerodynamic lens vacuum-pump-based focusing devices
• Fewer readout errors due to less particle residue in the aerodynamic lens
• Lower cost and higher reliability due to replacement of vacuum pumps with transducers
• Larger maintenance intervals for aerodynamic lens due to reduced mixing
• Much smaller volume and lower noise levels compared to vacuum-pump based devices

技术应用

• Gas preprocessing for particle analyzers used for bomb sniffing and toxin detection in air, engine exhaust analysis
• Numerous processes in the chemical and pharmaceutical industries

ID号码

MAE-1038

国家/地区

以色列