What are the main limiting factors of the gasifier’s operating cycle?
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What are the main limiting factors of the gasifier’s operating cycle? What are the main factors that determine the operating cycle of a water-coal slurry gasifier? Is it a burner? For example, assuming that the burner can operate continuously for 6 months, can the gasifier generally operate continuously for the same amount of time? Those domestic manufacturers that have statistical data can share it with us. Our company has newly installed a gasification furnace with dimensions of 3200mm, operating at 6.5 Mpa and with a capacity of 1500 tons; it is equipped with imported burners. There are no obvious changes in terms of structure or materials, and its service life is difficult to predict. Could it become a bottleneck for the long-term operation of the gasification facility? Additionally, what is the approximate economic loss resulting from one switch of the gasification furnace?
The GE coal-water slurry gasifier has an operating cycle that is primarily limited by the burners; generally, the gasifier needs to be replaced after about 45 days, which is why a backup unit must be available.
Now, burners are not the main influencing factor in water-coal slurry gasification units; on the contrary, some factors that were previously thought to have no impact on operation have instead become the key factors! For example: the quality of operation of the flash vaporization system ； Service life of cone-bottom bricks ； The water quality of graywater, and so on
“For example, assuming that the burner can operate continuously for 6 months, can the gasifier generally operate continuously for the same amount of time? ” Answer: No, it is necessary to replace the refractory bricks; the lifespan of these bricks varies in different parts of the furnace.
Currently, the operating cycle of burners in domestic water-coal slurry plants is generally around 70 days
Based on the actual operation of our unit, its operating cycle is primarily limited by the burners; generally, these burners become unusable after just one month due to excessive wear. This is manifested as fluctuations in the pressure difference across the burners, as well as variations in the composition of the useful gas, leading to unstable production conditions and the need to replace the burners ! ! In our facility, there have also been instances where the burner coils burned through, leading to an automatic shutdown of the plant (imported burners are not necessarily better than domestic ones). In comparison, refractory bricks and cone-bottom bricks have a much longer lifespan than burners. Usually, when a burner stops working, the plant is shut down and allowed to cool down naturally before entering the furnace to check the condition of the refractory bricks and cone-bottom bricks; if any damage is found, they are replaced! ! ! As mentioned by the colleague on the 3rd floor, it relates to the quality of operation of the flash vaporization system and the quality of the graywater! ! Personally, I think the operating cycle of the vaporizer shouldn’t be restricted by this! ! ! I’m not sure how many flash systems your company has; there should be 2, right? ! ! If the flash evaporation system isn’t working properly, simply switch to another flash evaporation system – there’s no need to cause a shutdown of the gasification process! Moreover, the flash evaporation system can generally operate without problems for three to four months, but the burners certainly cannot last that long! ! !
Mid-last year, our company carried out maintenance on the gasifier; it had been in operation for a year without a single refractory brick needing to be replaced, and the damage was not severe.
Could you specify the exact area where the wear is occurring? For example, is it a conical tube section or the straight edge of the nozzle? The outer surfaces of the straight pipe section and the central oxygen cone tube are generally fine, right?
There are many factors that affect the long-term operation of gasifiers! Refractory materials are one aspect of it! For Texaco’s furnaces, the lifespan of the cone-bottom bricks might be shorter! For multi-nozzle types, the dome is relatively short! The impact of other devices is also significant! Burner!
What a great post; I’ll learn from it. I’m also upvoting it, hoping more people will join the discussion
Our burners generally last for 2 months, at most a little over 3 months. The main issue that limits long-term operation is the cooling water. The volume of this cooling water gradually decreases, and eventually it can no longer meet the production requirements, forcing us to shut down the furnace. It might be due to our limited design capabilities – 200,000 tons.
The burner is the main factor that has an impact; burners generally need to be replaced every 2–3 months. If process control is not proper, it is possible for the coil to be burned through in a very short period of time. Cone-bottom bricks should also be replaced regularly depending on their condition of use. Additionally, the issue of cooling water mentioned earlier can cause the gasification process to stop, forcing a shutdown of the furnace.