Analysis of the reasons for steam emission from the chimney
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Our plant has 4 20T and 1 35T circulating fluidized bed boilers, and steam has been coming out of the chimneys recently. However, the furnace still cannot be stopped; it’s not possible to shut it down for inspection at the moment. I would like to ask fellow users to analyze the possible reasons and solutions.
This post was last edited by zgj2405 on 2011-12-29 at 20:51. The temperature in winter is too low, causing the smoke to condense and form steam. The boiler exhaust temperature can be appropriately increased to prevent condensation in the flue gases.
It is normal for flue gas to contain a certain amount of water vapor, as coal contains some moisture, and the combustion products of hydrogen in coal are also water. In summer, when temperatures are high, the water vapor is not condensed before it is released from the chimney, so no white vapor can be seen. In winter, when temperatures are low, the water vapor condenses into small water droplets, and thus it can be observed. In fact, water vapor is an invisible substance; what is visible are actually tiny water droplets in the form of fog. Of course, the possibility of tube leakage cannot be completely ruled out. It is not scientific to determine whether the tubes are leaking based on the boiler’s flue gas; rather, this should be determined from the operating conditions, such as whether the feedwater and steam flows are balanced, as well as any changes in the negative pressure in the furnace and flues, among other factors.
This post was last edited by dongjiang1001 on 2012-1-11 at 19:23. If the possibility of a leak in the boiler is ruled out, it is due to the moisture content in the coal.
This post was last edited by dongjiang1001 on 2012-1-11 19:23. Two possibilities: the boiler is leaking； The raw material has a high moisture content.
This post was last edited by zgj2405 on 2012-1-2 at 13:01; it’s likely caused by too low a smoke exhaust temperature. When the exhaust temperature of our boiler is low (around 60 degrees, with a low load), white smoke is emitted; however, this phenomenon disappears once the load is increased and the exhaust temperature rises. If the furnace tube ruptures, it is absolutely impossible to maintain continuous operation.
In winter, water vapor tends to condense, so it’s easy to notice. As long as the furnace tube is not damaged, that’s fine. Besides, there is also water vapor in coal.
It is caused by a low flue gas temperature; adjusting the ratio of the primary and secondary air appropriately can resolve the issue.
It’s not a big issue; just pay attention to the exhaust temperature.
It’s probably due to the low ambient temperature; just pay attention to the exhaust gas temperature :)
This post was last edited by dongjiang1001 on 2012-3-22 at 17:48. It’s probably white smoke or water vapor; maybe the temperature is too low. Making sure to control the temperature properly should solve the issue!