Temperature rise issue after the gasifier is shut down!
Thread Content
I heard that after the gasification furnace is shut down, its temperature drops; when it is started up again to raise the temperature, it should not be too high. Is that correct? Why? This post was last edited by snowdfr on 2009-3-21 19:23]
Could those who are experts in refractory bricks please explain the reasons? !
From personal experience, and considering refractory materials, they cannot withstand sudden changes in temperature, especially below 600°C; therefore, the heating process must be carried out according to a strict heating curve. Going a step further, there is the issue of hot standby, that is, a backup furnace. After the gasification furnace stops operating, it is kept at a temperature that allows it to reach the minimum feeding temperature again after some time.
As long as it follows the curve provided by the refractory brick manufacturer, there should be no problems. As for what the original poster mentioned – that \"it is said that after the gasification furnace is shut down and its temperature drops, when it is restarted and the temperature rises again, it should not exceed a certain level\" – I’m not sure where this information came from. We have been driving for over 3 years and have replaced the refractory bricks once; the temperature does not reach over 1000°C every time during the heating process.
There is only the issue of controlling the heating rate; no mention is made of high-temperature control. There are requirements regarding the temperature at which coal should be added. Moreover, increasing the temperature and pressure generally occurs simultaneously; as long as there is no pressure buildup in the subsequent systems, the temperature is easy to control.
In refractory materials, there is a property called thermal shock stability! If the fluctuations are severe, such as sudden rises or drops, it will damage the refractory materials, leading to their peeling or breaking! It is generally required to operate according to the provided curve!
While driving, we generally recommend using standard units, maintaining a stable operating procedure, and minimizing the number of starts and stops in order to ensure continuous operation and thus extend the lifespan of the materials used!
From our experience, the temperature should not be increased too quickly; this process of raising the temperature is essentially baking the bricks, and it must be carried out strictly in accordance with the designed baking curve. If the temperature is increased too fast, the bricks are likely to break, which would lead to more serious consequences. Although bricks aren’t very expensive at the moment, it’s not easy to obtain a batch of good quality bricks, and this approach is quite time-consuming.
I haven’t heard such news in any of the units in my country! It is sufficient to raise the heating curve until it reaches the specified feeding temperature.
Under normal circumstances, the temperature is raised to around 1100 degrees, over a period of about 24 hours