Semi-volatile organic matter sampling technique in exhaust emission pipe

Abstract

The invention relates to a technical method for taking samples of semi-volatile organic compounds (SVOC) in a waste gas discharge pipe, characterized by adopting an isokinetic sampling principle, collecting the SVOC samples in the waste gas discharge pipe by using an isokinetic sampling device; inserting the sampling device in the waste gas discharge pipe during the sample, calculating a flow velocity flow value of the gas in the waste gas discharge pipe by a microprocessor in a host (8) of the isokenetic sampling device based on the signals detected by a pitot tube (20), a temperature sensor, and a humidity sensor and the measured cross section area, comparing with flow signal values of a flowmeter detected in the host (8) of the isokinetic sampling device, controlling the rotation speed of an air pump (12), reaching the purpose of isokinetic sampling, after the SVOC samples enter the sampling device, collecting the particle samples in a filter cartridge (2), instantly cooling the gas when passing a condensation device (5), the steam state samples flowing in a liquid collection bottle (6) after condensation, and adsorbent (33) in an adsorption pot (7) collecting the SVOC steam state samples.

Description

technical field [0001] The invention relates to a method for sampling semi-volatile organic compounds in exhaust gas discharge pipes. Background technique [0002] Semi-volatile organic compounds (hereinafter referred to as SVOC) are contained in the exhaust gas discharged from flue, industrial waste gas discharge pipe, waste incinerator waste gas discharge pipe, etc. (hereinafter referred to as waste gas discharge pipe). These include polycyclic aromatic hydrocarbons (PAHs) organochlorine pesticides, organophosphorus pesticides, polychlorinated biphenyls, polychlorinated dibenzofurans, phthalic acid lipids, etc., which mainly exist in the form of gas, vapor, and particles. Among them, the 2-3 ring PAHs mainly exist in the gas phase, the 5-6 ring PAHs mainly exist in the particles (adsorbed on the surface of the particles), and the PAHs in between are distributed in both the gas phase and the solid phase. Mixture of gas phase and particulate matter. At present, the current...

AI Technical Summary

Problems solved by technology

However, due to the wide variety of SVOCs and their large distribution in the exhaust gas, studies have shown that the PAHs samples collected on the filter cartridge with a soot sampler are only 10% to 30% of the PAHs in the exhaust gas emissions, and the PAHs below the 4th ring are more than 10%. The gaseous form passes through the filter cartridge and cannot be collected by the filter cartridge. SVOC with a molecular weight greater than 252 can be collected on the filter cartridge. When the molecular weight is less than or equal to 252 or 3 rings, it only exists in a gaseous state and basically cannot be collected by the filter cartridge.

And when sampling, a small part of the SVOC sample adsorbed on the filter cartridge is also lost from the filter cartridge due to decomposition, adsorption and volatilization during the sampling process.

However, the gas phase SVOC in the exhaust gas has a small molecular weight and cannot be collected only by the filter cartridge. Therefore, only collecting and analyzing the SVOC samples in the particulate matter on the filter cartridge cannot truly reflect and understand the actual pollution emission of SVOC in the exhaust gas. quantity and condition

Images