A New Thermophoretic Precipitator for Off-Line Particle Analysis

Abstract

A new thermophoretic particle precipitator has been developed for representative and efficient collection of aerosol particles from the ambient air and technological pipelines. The device consists of hot and cold plates (5?׿5?cm2) capable of operation at temperature gradients ranging from 20?000 to 100?000?K/m. A gas sample is made to pass through a 1-mm slot between the plates at a flow rate of up to 1.5?L/min, which makes the device suitable for operation in conjunction with common aerosol instruments including DMA and diffusion batteries with similar operational flow rates. It was shown that the efficiency of the device was highest for the lowest gas flow rate used (0.3?L/min) reaching a level of above 99%. The efficiency was decreased reaching its minimal values at the highest flow rate investigated (1.5?L/min). However, even for highest flow rate, the average efficiency for removal of particle smaller than 60?nm was around 50%.