The significance of underreporting the taphole pressure difference
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For a 3-meter-square furnace with four nozzles, the pressure difference at the slag outlet is generally between 20-50 kPa. Setting an alarm threshold of 15 kPa for low pressure difference – what is the purpose of this? What does a low pressure difference indicate? Has the slag hole become larger?
I’m not sure how long your refractory bricks have been in use; it’s possible that the refractory bricks at the slag outlet may have fallen off or become severely worn. Once they fall off, the temperature of the backing plate will increase to varying degrees. Additionally, this situation is very detrimental to the quenching ring, as liquid slag can easily splash onto it and cause erosion.
The taphole brick suffers severe erosion, causing the taphole to enlarge; as a result, the pressure difference at the taphole decreases. Air leakage in the downcomer or cooling ring can also lead to a decrease in pressure difference, as the air flow takes a shortcut. Other factors such as an increase in system pressure or a reduction in load can likewise cause a decrease in pressure difference, but this is considered normal
We previously had a gasification furnace in which the pressure difference at the slag outlet was very high before it stopped operating, reaching 480 kPa; this pressure couldn’t be reduced. Later, that same gasification furnace had to be shut down due to extremely high temperatures on the support plates. I wonder if there is a connection between these two situations
It seems that when the size of the slag outlet changes during the early and later stages of operation, the pressure difference at the slag outlet doesn’t change significantly either