Continuous sampling device for pollution gas

Abstract

The invention discloses a continuous sampling device for pollution gas. The device comprises a sampling system, an undisturbed sampling and blowing device and a continuous on-line gas analysis cabinet, wherein the sampling system comprise a sampling filter, a sampling rod and a sampler; the sampling filter is communicated with the sampler through the sampling rod; the undisturbed sampling and blowing device comprises a gas collecting filter, a gas collecting rod and a gas collecting and blowing device; the gas collecting filter is communicated with the gas collecting and blowing device throughthe gas collecting rod; the sampler is communicated with the continuous on-line gas analysis cabinet through a sampling tube; the sampler is communicated with the gas collecting and blowing device through a blowing tube, a sampling filter blowing valve is arranged between the sampler and the gas collecting and blowing device, and the gas collecting and blowing device is communicated with a compressed air source pipe through a gas pipe; a gas collecting filter blowing valve is arranged between the gas collecting and blowing device and an external compressed air source. According to the continuous sampling device for the pollution gas, the blowing performance is effectively improved, the availability rate of equipment is improved to a greater extent, and control process accuracy and measurement accuracy are improved.

Description

Technical field: [0001] The invention relates to a continuous sampling device for polluted gas, and relates to the technical field of polluted gas sampling and monitoring. Background technique: [0002] At present, the CEMS system, that is, the automatic flue gas monitoring system, is mainly used on the market to carry out real-time automatic monitoring of the gas, and it is usually necessary to connect the CEMS system to the sampling device for sampling, and then perform gas sampling and detection, and the flue gas sampler is a sampling device The important components inside are the equipment used for the detection of gaseous pollution sources in the flue gas of fixed pollution sources. At present, the flue gas samplers on the market generally include probe rods, pre-filters, blowback devices, and samplers with built-in electric heating and constant temperature devices. Since the flue gas contains solid particles and colloidal particles, they will accumulate on the pre-filt...

AI Technical Summary

Problems solved by technology

When the current purging device purging, first close the sampling valve, stop the sampling pump pumping work, then open the purge gas source, purge from the sampler to the pre-filter through the heating device, and close the purge gas source after the purge is completed. , open the sampling valve and start the sampling pump, and the purging step is completed, and this process takes about 3 minutes. During this period, the sample gas analyzed in the continuous online gas monitoring instrument is still and does not flow, so the output data maintains purging Then continue to sample gas to the instrument for analysis. At this time, the pipeline between the sampling valve and the pre-filter and the purger is filled with purge gas, which comes from compressed air and has the same composition as the atmosphere. , and the temperature is low, a certain clean gas with impurities removed, the pressure is 0.5MPa, and when these compressed air is sent to the analyzer for testing, it will affect the detection and measurement of the instrument, which affects the measurement time and the time left in the sampling system The volume of the air is proportional to the flow rate of the sampling pump, and the time is 3-17 minutes. In addition, due to the low temperature of the compressed air, the temperature has a great impact on the detection of the denitrification system, because the sample gas is more than 300°C higher than the air, resulting in partial sampling. Condensed water dew and acid dew in the pipeline, SO2 gas is easily soluble in water, causing the output SO2 concentration of the instrument to be small, and it takes several minutes to return to normal; especially in the measurement system for measuring ammonia escape by catalytic reduction method, the sampler has a built-in denitrification catalyst If it is cooled, it will affect the denitrification efficiency, and it will take more than 15 minutes for the ammonia concentration to return to normal measurement.

Therefore, the pollutant concentration detected by the instrument is discontinuous, and this discontinuous detection data is fatal in process control, causing control interruption, during which the disturbance of the process system cannot be adjusted. In addition, In the measurement of pollutant concentration and total amount, the interruption will be missing, which will affect the accuracy of measurement

Images