Method and device for measuring SOx in fire coal fume

Abstract

The invention discloses a method and a device for measuring SOx in fire coal fume. The method comprises the following steps of: a. sampling fire coal fumes, wherein the temperature for sampling is kept the same as that of the fire coal fume in a flue during the process; b. cooling by using a condenser and absorbing SO3 in the fumes, wherein the temperature is controlled within 75-85 DEG C during the process; c. carrying out the oxidation absorption on the fumes, eliminating the moisture in the fumes, and simultaneously controlling to ensure a stable fume flow; and d. respectively detecting the content of SO3 absorbed by the condenser during the cooling and the content of SO2 after the oxidation absorption. According to the method, the temperature while the fume is sampled is kept the same as that in the fume constantly, so the secondary reaction of SO3 is avoided; and meanwhile the fly ash in the fume is isolated, and the accuracy of the flow, temperature and pressure for the fume sampling can be ensured; and moreover a high precision iron chromatography method is adopted for the measurement, so that the method is higher in measuring precision, and the error is reduced.

Description

[0001] technical field [0002] The invention belongs to the technical field of energy saving and environmental protection engineering, and in particular relates to a method and a device for testing SOx in coal-fired flue gas. Background technique [0003] Currently thermal power plant SO 2 A large amount of emissions have caused serious air pollution and acid rain problems. Although the emission of SO3 is very small, SO3 is easily combined with water vapor in the flue gas to form sulfuric acid vapor, which condenses on the heating surface whose wall temperature is lower than the acid dew point, causing acid dew point corrosion. The more SO3 content in the flue gas, the higher the acid dew point temperature, and the wider and more serious the corrosion range. At the same time, the corrosion problem also seriously restricts the recovery of low-temperature waste heat. The sampling test of SOx is of great significance to the understanding of acid corrosion and the developmen...

AI Technical Summary

Problems solved by technology

[0004] At present, the sampling and testing method of SO3 is mainly the controlled condensation method, which has two problems in operation. 1) Since the temperature of the sampling pipe is generally set above 260°C, which is inconsistent with the temperature in the actual sampling flue, SO 2 and O 2 , SO3 and fly ash inevitably react in the flue, resulting in discrepancies between the measured SO3 and the SO3 at the actual sampling location; 2), SO3 in the flue gas is easily deposited on the fly ash when it passes through the fly ash filter , resulting in the concentration of SO3 measured by the condensation method is often lower than the real concentration

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