Humidity adjusting device and method of aerosol collection sample feeding gas flow and measurement instrument

Abstract

The invention provides a humidity adjusting device of an aerosol collection sample feeding gas flow. The humidity adjusting device comprises a drying unit (3) and a control system (4), wherein the drying unit comprises at least two drying pipes; each drying pipe comprises an inner pipe for the sample feeding gas flow to pass through, a unidirectional vapor transmission film which covers on an outer wall of the inner pipe and is used for water vapor in the sample feeding gas flow to pass, and an outer pipe which is located at the outsides of the inner pipe and the unidirectional vapor transmission film and forms a space with the inner pipe, wherein the space is filled with a drying agent; and the control system (4) is used for controlling the sample feeding gas flow to enter the other at least one drying pipe when the drying agent in a certain drying agent is inactive. The device is provided with the vapor transmission osmosis film and excessive water vapor is removed by utilizing a water vapor pressure difference principle, so that the loss of volatile matters in particles, caused by heating, is avoided, and the accuracy and reliability of measurement results of subsequent physicochemical and optical properties of the particles are guaranteed.

Description

technical field [0001] The present invention relates to a measurement method and device, and further relates to a humidity adjustment device for aerosol collection and sampling airflow, an adjustment method using the humidity adjustment device, and an atmospheric particle measuring instrument including the humidity adjustment device. Background technique [0002] Atmospheric particulate matter refers to solid or liquid particulate matter uniformly dispersed in the air, and can be divided into total suspended particulate matter (TSP) and inhalable particulate matter (PM) according to its particle size. 10 ). Among them, the inhalable particulate matter can be subdivided into fine particulate matter (PM 2.5 ) and coarse particles. Atmospheric particles directly affect the Earth's atmospheric radiation balance by scattering and absorbing radiation, and indirectly affect the Earth's atmospheric radiation balance by affecting the optical properties of clouds and the cloud's lif...

AI Technical Summary

Problems solved by technology

[0006] (1) The constant temperature heating process only increases the temperature, correspondingly reduces the relative humidity of the air, but does not remove the excess moisture of the sample gas

At the same time, part of the semi-volatile substances (such as semi-volatile organic compounds and nitrates, etc.) are volatilized and lost due to the increase of temperature, and the measurement of particulate matter containing high concentrations of these components is even more inaccurate;

[0007] (2) Although the drying tube method can effectively remove the moisture in the sample gas, when the air humidity is high, the desiccant will quickly deactivate after absorbing excess moisture, and the desiccant in the drying tube needs to be replaced frequently to maintain dehumidification Efficiency, not only requires a lot of manpower and material resources, but also affects the online observation of the instrument;

[0008] (3) The one-way osmotic membrane method is the method with the highest efficiency in removing moisture from the sample gas among the three types of methods. However, in case of polluted weather, high-concentration atmospheric particles are easy to adhere to the surface of the osmotic membrane, thereby reducing the dehumidification efficiency of the osmotic membrane and even causing its dehumidification. Inactivation;

[0009] (4) For the method of installing a condensation pipe outside the sampling gas transmission pipe, on the one hand, this method cannot deal with the excess water vapor in the air below 5°C, and the condensation and dehumidification effect is not ideal when the air temperature is 5-15°C

At the same time, due to the presence of condensed water droplets and water films on the air pipe wall in this method, these water droplets and water films will capture air particles, and the condensed and discharged water will take away these captured particles, resulting in low monitoring results.

Images