Coal water slurry is being fed in, and the temperature of the vaporizer is low!
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This post was last edited by Comrade Lao Li on 2009-5-20 at 21:17. What are the disadvantages of using water-coal slurry as a feed material when the temperature in the vaporizer is low? What are the risks?
The disadvantages of an inappropriate feed temperature for water-coal slurry can lead to unsuccessful feeding, which in turn may cause blockages at the slag outlet; heat shock can also occur, resulting in damage to the refractory bricks. What suggestions do everyone have?
May I ask what type of startup cooler is used in your coal-based methanol production plants? Is it tubular (tube-in-tube, U-type) or plate-type?
The main issue is that it may lead to unsuccessful material feeding
With a low feeding temperature, peroxides are the biggest concern. The reason is that a low feeding temperature does not mean that ignition is absolutely impossible; it’s merely a matter of how long it takes to ignite. During this time interval, how much oxygen gets into the gasification furnace? Therefore, when the feed temperature is low, the gasification furnace vibrates significantly during feeding. :)
We have fed materials at a temperature of at least 800 degrees; lower temperatures can lead to unsuccessful feeding, waste of coal, blockages in the slag outlet, and in cases where the furnace is not shut down in time, accidents such as explosions may occur
Thermal shock? Please explain on the second floor, and also why it has an impact on refractory bricks.
What is the feed temperature for water-coal slurry? ? ? ?
It generally needs to be above 1,000 degrees, with the temperature maintained at that level for 2–4 hours or more. It also depends on the type of furnace; if the furnace is smaller, it’s sufficient to reach 1,100 degrees before adding the material. Maintain a constant temperature for over 2 hours; if the furnace is of larger size, the temperature should be raised to 1400 and kept constant for 4 hours. This way, even when replacing the burner, the furnace temperature doesn’t drop much, which ensures a successful feeding process. After all, if feeding fails, it’s not only dangerous but also requires additional handling and temperature restoration, which is very troublesome. It’s better to get it right from the start!
That must be the reaction temperature in the gasifier; the gasification reaction rate in Texaco’s gasifiers is around 1400 degrees! ! ! 9# 49937790
Low temperatures, unsuccessful material feeding, or thermal shock are very dangerous and can easily lead to peroxide formation and explosions in subsequent processing stages!
The minimum feeding temperature for the Texaco gasifier is 800 degrees Celsius; when this temperature is not met, peroxides can form, feeding will fail, and there will be significant wear on the refractory bricks. Peroxides: The low temperature in the furnace prevents complete combustion of the coal slurry, resulting in a low carbon conversion rate. The slag cannot be brought to a liquid state for removal, which causes severe wear on the refractory bricks. Failed material feeding: Due to the low furnace temperature, when material is fed, the coal slurry first absorbs heat from within the furnace and burns to release heat, in order to maintain the furnace temperature. When the furnace temperature is low, the coal slurry cannot be completely burned; the carbon conversion rate is low, and the amount of heat generated is insufficient to maintain the operating temperature of the gasifier (around 1350 degrees Celsius). As a result, the coal slurry fails to burn, and feeding is unsuccessful.
1. Feeding at too low a temperature has a certain impact on the refractory bricks of the gasification furnace. 2. Excessively long feeding time results in too high an oxygen content in the gasification furnace. 3. The material will not burn fully, causing blockage at the slag outlet. 4. Feeding the material at a temperature of 800 is feasible, taking into account the heat storage capacity of the bricks; generally, during heating to 1200 degrees, this process should be carried out for 2 to 4 hours so that the bricks can accumulate sufficient heat and thus be protected from damage. 5. The normal furnace temperature is generally around 1350
It’s too dangerous; it’s absolutely not acceptable. If ignition fails once, there will be excessive oxygen present, and that’s definitely not feasible. Generally, the furnace needs to be heated to around 1100 degrees, and the gasification process must succeed on the first attempt!
If the feed temperature is too low, the coal slurry and oxygen enter the furnace at a low temperature, failing to provide the heat required for combustion and resulting in feeding failure. It also has an impact on refractory bricks.