What are the reasons for the increased fouling resistance in the coarse coal gas pipeline at the outlet of the gasifier?

Partial blockage of the downcomer, blockage or breakage of the upcomer, accumulation due to the detachment of defoaming strips, dust accumulation in the syngas outlet pipeline of the quench chamber, etc

In the case of boilers using water-coal slurry, the reason for this issue is the significant amount of ash present in the raw gas exiting the boiler. However, there are many factors that can lead to such high levels of ash in the raw gas; for example, the coal used may have a high ash content, the gasification furnace may operate at high or even excessive loads for extended periods. Additionally, under high load conditions, water accumulation in the gasification furnace becomes severe, the liquid level in the quenching chamber remains low for long periods, the water circulation rate in the quenching chamber is insufficient, and the water contains a high amount of solids. All these factors result in poor washing efficiency of the gas exiting the combustion chamber within the quenching chamber. Generally speaking, this situation occurs quite often. In the original process package for water-coal slurry gasification, a flushing water pipeline was designed at the large tee at the gas outlet of the gasifier; the flushing water came from the shift condensate, and this was done to address this issue. However, it seems that most manufacturers have removed this pipeline.