Problems encountered with refractory bricks in water-coal slurry gasifiers
Thread Content
After the original furnace or refractory bricks have been in use for a period of time, problems arise in the refractory bricks of coal water slurry gasifiers, such as minor cracks that cause gas leakage, localized temperature increases, and accelerated local wear. It turns out that after I encountered the original drying furnace, the refractory fibers at the top of the burner bricks were drawn away.
Minor cracks generally do not cause issues such as gas leakage, localized temperature increases, or rapid localized wear. The situation where the refractory fibers at the top of the burner bricks are drawn away after initial furnace heating. The occurrence of these phenomena is largely due to construction and furnace heating! During construction, if the grout joints are uneven, the mortar is not sufficiently filled, or if the heating rate is too fast during furnace drying with large temperature fluctuations, all of these factors can have a significant impact on the refractory materials!
The local temperature rises, and the wear rate in those areas is high. The cause of this is not related to the refractory bricks, but rather to the burner; it is likely that the burner is spraying unevenly, or the coal slurry is not atomized properly, resulting in localized excess oxygen levels. This leads to excessively high temperatures or severe erosion in those areas, thereby causing significant damage to the refractory bricks and giving rise to the aforementioned problems.
This mainly involves monitoring the outer wall temperature; if it exceeds the limit, attention is needed. This is especially true for newly installed furnace bricks, in which case care must be taken regarding the quality of the furnace construction
20140729-2: It is necessary to review the temperature rise curve during furnace drying; if there are no issues during this process, then it is a problem related to the quality of construction. The relevant persons are responsible
The quality of bricklaying is one aspect; there is a limit to the number of layers that can be built per day. For the cylinder section, 5–7 layers are constructed, while for the arch top, inspection is carried out after 3 layers have been built, in order to assess the quality of the construction. During furnace heating, it is essential to maintain the low temperature and constant temperature as specified, and the speed must not exceed the set limits. If there is uneven spraying during operation, the surface temperature will change rapidly; if parts of the surface are affected by spraying, it is necessary to stop the furnace and replace the burner. Under no circumstances should one try to continue operating in such conditions, as this will lead to serious problems