System for simultaneously sampling and detecting flue gas NO and mercury

Abstract

The invention relates to a system for simultaneously sampling and detecting flue gas NO and mercury. The method comprises an off-line mercury detection apparatus and a sampling probe gun used for stretching into a flue, a flue gas pipeline of the sampling probe gun is several independently arranged quartz pipelines, an outlet of the quartz pipeline is communicated to a flue gas dedusting, acid-removal and dehumidifying apparatus, a flow control apparatus and a NO detector, the flow control apparatus and the NO detector are connected to a computer; a heating layer used for keeping the sampling probe gun at temperature of more than 120 DEG C is arranged on an inner wall of a housing of the sampling probe gun, an active carbon adsorption pipe is arranged on each quartz pipeline, and the active carbon adsorption pipe is filled by an adsorbent, the adsorbent is divided into the adsorbent which is a mercuric oxide capture layer of KCl and a simple substance mercury adsorption layer of mercury-removal active carbon according to a flue gas passing sequence. The system can simultaneously realize sampling and detection of NO and mercury pollutants at a same sampling point in the flue gas, and can realize flow parallel sampling and constant current sampling, the detection results can be mutually calibrated.

Description

technical field [0001] The invention relates to an environment detection and sampling device, in particular to a system for simultaneous sampling and detection of flue gas NO and mercury in a thermal power plant. Background technique [0002] Mercury emitted from coal combustion is a highly toxic pollutant. When mercury is released into the atmosphere, it will cause serious harm. Mercury is a neurotoxin that can accumulate in brain tissue, causing movement disorders, language barriers, etc. Flue gas from thermal power plants can have a synergistic effect on mercury removal while denitrification, dust removal and desulfurization. The European Union's "Best Available Technology Reference Document for Large-Scale Combustion Plants" recommends that mercury removal be prioritized by adopting the technical route of high-efficiency dust removal, flue gas desulfurization and denitrification coordinated control. [0003] Selective catalytic reduction technology (SCR process) has be...

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Problems solved by technology

[0007] However, in the prior art, there is only a separate sampling and detection system for NO or mercury in the flue gas, and no system capable of simultaneously sampling and detecting NO and mercury has been developed, resulting in high sampling and detection costs

At the same time, because it is impossible to detect NO and mercury at the same sampling point at the same time, the obtained mercury and NO concentration values ​​are not at the same sampling point, which seriously affects the representativeness, repeatability and efficiency of NO and mercury sampling and detection.

In addition, the adsorbent used to collect mercury in flue gas is activated carbon, and those skilled in the art believe that activated carbon has an adsorption effect on NO, which also greatly restricts the simultaneous sampling and detection of NO and mercury in flue gas. system development

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