Ultra-low wall loss submicron terminal virtual impactor

Abstract

The invention relates to an ultra-low wall loss submicron terminal virtual impactor. The impactor comprises an inflow inlet, positioning double-screw bolts, a lateral flow cavity, an accelerating nozzle, a small-particle-size particle collecting cavity and a large-particle-size particle collecting cavity; the inner flow inlet is fixedly connected with the top wall of the lateral flow cavity through the positioning double-screw bolts; the bottom wall of the lateral flow cavity is fixedly connected with the acceleration nozzle; the upper end of the acceleration nozzle is located inside the lateral flow cavity; the lower end of the acceleration nozzle is fixedly connected with the upper end of the small-particle-size particle collecting cavity; the lower end of the small-particle-size particle collecting cavity is fixedly connected with the large-particle-size particle collecting cavity; and the upper part of the large-particle-size particle collecting cavity is located in the small-particle-size particle collecting cavity. The ultra-low wall loss submicron terminal virtual impactor of the invention can be adopted as a terminal device so as to be directly exposed to a sample environment, and can separate aerosol particles at the beginning of collection; a transverse-ring-shaped sample collection inlet design for submicron particles is realized, so that the pre-separation of the particles is realized, and separation precision can be improved; and pure gas flow is added, so that direct contact of the aerosol particles with an inner wall surface can be avoided, so that the wall surface loss of the particles is extremely low.

Description

Technical field [0001] The invention relates to a radioactive aerosol monitoring equipment, in particular to a submicron terminal virtual impactor with ultra-low wall loss. Background technique [0002] In radioactive aerosol monitoring, it is usually necessary to use a virtual impactor to separate aerosol particles of different particle sizes according to their particle size characteristics using the action of inertial force. The current virtual impactor structure design generally has the following shortcomings: (1) Insufficient separation accuracy, the large-diameter branch channel contains a large content of small-sized particles, and it is impossible to separate sub-micron particles; (2) Due to the aerosol particles and virtual The inner wall of the impactor is in direct contact, and the wall loss of aerosol particles is too large. Summary of the invention [0003] The purpose of the present invention is to provide an ultra-low wall loss submicron terminal virtual impactor, w...

AI Technical Summary

Problems solved by technology

The structural design of the currently used virtual impactor generally has the following disadvantages: (1) The separation accuracy is insufficient, and the small particle size particles in the large particle size shunt channel are relatively large, and submicron particles cannot be separated; (2) Due to the aerosol particles and the virtual The inner wall of the impactor is in direct contact, and the wall loss of aerosol particles is too large

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