Coal fired hot blast furnace flue gas online monitoring analyzer

1、 Product Overview

The continuous online monitoring system for flue gas utilizes extraction condensation sampling, backscattering smoke concentration measurement, pitot tube flue gas flow velocity measurement, and computer network communication technology to achieve online continuous monitoring of pollutant emission concentration and total emissions from fixed pollution sources. At the same time, technical improvements have been made in response to the situation where domestic coal types are relatively diverse, coal quality changes greatly, pollutant emission concentrations are high, and flue gas humidity is high. and

Coal fired hot blast furnace flue gas online monitoring analyzer

3.2 The dilution air flow on both sides of A/B increases from small to large: it is possible that the ammonia spray grille pipeline has been worn and worn through by fly ash for a long time, resulting in poor ammonia spray adjustment performance and a significant increase in ammonia spray unevenness, leading to an increase in local ammonia escape. It is difficult to expect the ammonia injection control valve to control the total ammonia injection amount and reduce ammonia escape, as the serious wear and tear has already formed.

3.3 The ammonia spraying grille arranged in the horizontal flue has a problem of burying small holes due to the deposition of fly ash at the bottom of the corridor. In this case, the dilution airflow will decrease, and the ammonia spraying amount will also decrease accordingly, resulting in insufficient denitrification ability. Through the negative feedback of the system, the ammonia spraying flow control valve will be opened to increase the ammonia spraying amount, which will lead to excessive ammonia spraying and subsequently cause the problem of excessive ammonia escape.

4. Monitoring of flue gas temperature, pressure difference, and flow rate

4.1 Pay attention to the variation of inter layer pressure difference in SCR: This pressure difference indirectly reflects the degree of dust pollution and fly ash blockage of the catalyst in the reactor. If the catalyst is contaminated, poisoned or blocked, the reduction ability will decrease, and there will be more ammonia escape. So it is necessary to strengthen soot blowing during the operation phase to reduce interlayer pressure difference. If necessary, increase the frequency of soot blowing.

4.4 Strengthen boiler combustion adjustment: adjust the flue gas volume on both sides of A/B to maintain basic balance and symmetry; When the flue gas flow is severely unbalanced, it may induce fly ash to enter the ammonia spray grille and form a blockage in the grille; Additionally, efforts should be made to reduce the generation of combustion type NOx and decrease the NOx concentration at the SCR inlet.

4.5 Strengthen ammonia injection control under smoke temperature conditions below 320 ℃ and above 420 ℃: If it takes 4-5 hours, apply to the overall control to adjust the unit load to improve smoke temperature conditions and prevent catalyst damage

Coal fired hot blast furnace flue gas online monitoring analyzer