Sampling method and device for testing concentration of SO3 acid mist in wet desulfuration flue gas

Abstract

The invention discloses a sampling method and device for testing concentration of SO3 acid mist in wet desulfuration flue gas. The device is composed of a heating sampling gun, a spiral condenser pipe, a membrane device and a flue gas sampler. The method comprises the steps that desulfuration flue gas is collected at a constant speed, the heating temperature is controlled to be above the acid dew point, SO3 condensed on the surface of particulate matter and tiny SO3 acid mist in the flue gas are converted to gas-state SO3, and the particulate matter in the flue gas is removed through a filter drum arranged in the sampling gun; the SO3 enters the follow-up spiral condenser pipe along with the flue gas, the flue temperature is decreased to be below the acid dew point, the gas-state SO3 is condensed and converted into SO3 acid mist drops, most of the SO3 acid mist drops are gathered by the spiral condenser pipe, and small part of the SO3 acid mist drops enter the follow-up membrane device along with the flue gas to conduct gathering; the SO3 acid mist gathered through the spiral condenser pipe and the membrane device is washed and collected through an alkaline solution and converted into SO4<2-> for follow-up assay determination. According to the sampling method and device for testing the concentration of the SO3 acid mist in the wet desulfuration flue gas, efficient gathering of the SO3 acid mist can be achieved, and interference of the particulate matter and the SO2 in the flue gas can be eliminated.

Description

1. Technical field [0001] The invention relates to SO in coal-fired flue gas 3 The separation and capture of the desulfurization net flue gas is specifically related to the use of separation membranes to efficiently separate SO in the flue gas after heating and condensation 3 Acid mist condensate, use 0.5 ~ 1% NaOH solution to wash SO 3 Acid mist is converted into stable SO in the liquid phase 4 2- Analytical determination of SO in desulfurized net flue gas 3 Acid fog method and apparatus. 2. Background technology [0002] SO in desulfurized flue gas 3 to SO 3 The form of acid mist is discharged through the chimney, which causes corrosion of pipelines, equipment and chimneys and decreases the transparency of exhaust smoke. 3 The content of acid mist is the basic condition to control its discharge. [0003] The controlled condensation method is currently considered to measure low concentration SO in power plants. 3 / H 2 SO 4 The most accurate method: use a heating ...

AI Technical Summary

Problems solved by technology

[0004] Purpose of the invention: the present invention aims at collecting SO in the desulfurized net flue gas by the existing controlled condensation method and the isopropanol absorption method. 3 The collection efficiency of acid mist is difficult to control and SO 2 Interference and other problems, providing a method for the determination of SO in desulfurization net flue gas 3 Method and device for acid mist, using separation membrane to efficiently capture SO in desulfurized flue gas 3 Acid mist, accurate determination of SO in flue gas 3 Acid mist concentration

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