Post-desulphurization flue gas moisture content determination method and apparatus

Abstract

The invention relates to a post-desulphurization flue gas moisture content determination method and apparatus. The apparatus comprises a sampling tube, a heat tracing ventilation pipe, a gas suction pump, a flow regulating valve, a flow meter, a three-way valve, a temperature measuring instrument, a pressure measuring instrument, and a Karl Fischer titrator, which are connected sequentially. The determination method comprises the steps that: (1) 100ml of anhydrous methanol is added into a titration cup, and the titrator is reset to a system blank value. (2) standard water is accurately measured, and is injected into the titration cup; and the concentration of a Karl Fischer reagent is measured by using the titrator; (3) the pipeline is washed by using flue gas for 10-15min; (4) a flue gas flow rate is controlled at 50-100mL / min, and a ventilation time is 2-5min; and titration is carried out by using the titrator; and (5) with the titrator, the post-desulphurization flue gas moisture content is automatically calculated. According to the post-desulphurization flue gas moisture content determination apparatus provided by the invention, a Karl Fischer titration method is used in flue gas moisture content determination, the analysis operation is simple and fast, and analysis result is accurate and reliable. Therefore, an instant and accurate basis can be provided for production operation adjustment and data calculation.

Description

technical field [0001] The invention belongs to the technical field of chemical analysis, and relates to a method and a device for measuring the moisture content of flue gas after desulfurization. Background technique [0002] The moisture content of the flue gas after desulfurization is an important parameter in the design, transformation and production operation of the wet desulfurization system. It is used to calculate the condensation temperature of the flue gas, the emission of flue gas pollutants and the water consumption of the desulfurization system. Traditionally, the moisture content of flue gas is determined by condensation method, wet and dry bulb method and gravimetric method. [0003] The condensation method is to pass the flue gas extracted from the flue gas pipeline through the condenser, and calculate the moisture content in the flue gas according to the sum of the condensed water amount and the water vapor content in the saturated gas removed by the condens...

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Problems solved by technology

Its disadvantages are: it is difficult to guarantee the condensation effect of the condenser; it is necessary to calculate the moisture content of saturated steam according to the relationship curve of saturated vapor pressure and temperature of water; the weighing of condensed water needs to be completed in the laboratory, and the moisture content cannot be obtained in real time results, and the accuracy of the measurement results is poor

The disadvantage of this method is that it is necessary to continuously add water to the water container to ensure that the gauze wrapping the wet bulb is soaked in water, otherwise the accuracy of the test cannot be guaranteed; during the calculation of the moisture content, it is necessary to check the saturated vapor pressure and temperature relationship curve of the water , since the calculation formula involves many parameters and many parameters are estimated based on empirical values, it is easy to produce large errors

The disadvantage of the gravimetric method is that the hygroscopic agent absorbs other substances in the flue gas while absorbing water vapor, causing large errors in the measurement results; the hygroscopic tube needs to be weighed in the laboratory before and after the measurement, and the measurement cannot be obtained in real time result

The above measurement method has large error, complicated measurement process and long measurement time

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