Reward Discussion: Downcomer Clogging and Solutions
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This post was last edited by lflsedin on 2014-12-21 at 21:31. Recent discussions on the issue of downcomer blockage in the forum have been quite intense, indicating that downcomers play a crucial role in ensuring long-term stable operation in gasification technologies such as Texaco and four-nozzle types. Take this opportunity to post more information about accident phenomena, analyze their causes, and propose solutions. 1. For dry coal powder gasifiers with a quenching process, many no longer use downcomers, such as GSP and space furnaces; therefore, what are the advantages and disadvantages of eliminating them? 2. East China University of Science and Technology also developed a type of foam-breaking strip, but its performance is not very good; it’s difficult to disassemble and clean as well. Everyone can share any other better optimization ideas that would allow us to avoid frequent deformation and blockages in the downcomer, while still keeping the downcomer and upcomer in place
I once read an article that said (original text): Through this, we have another basis for making judgments. As long as the pressure difference increases, and the trends in the gas composition and the blockage at the slag outlet are similar, along with large fluctuations in the liquid level of the gasification furnace, we can conclude that it must be the downcomer that is blocked. The vehicle must be stopped to prevent more serious consequences. It has been suggested that changing the temperature of the quench water could resolve this issue, but whether this is feasible remains to be verified. I don’t know what to do if the downcomer gets blocked; it seems the only option is to find ways to prevent such blockages. Looking forward to better answers.
Why does the presentation on space furnaces still mention a downcomer? Please have the moderator verify it
The blockage of the downcomer does not occur suddenly; it happens gradually as slag accumulates there. The best solution is to use direct discharge through the lockhopper. We have a sophisticated lockhopper direct discharge technology that effectively addresses the issue of slag accumulation in the gasifier’s downcomer, preventing blockages that could lead to shutdowns. The approach involves maintaining a high liquid level in the gasifier, setting all lockhopper valves to manual mode, and proceeding step by step. By opening and closing the pressure relief valve of the lockhopper, high-temperature gas and ash can be used to repeatedly flush out the slag accumulated in the downcomer, thereby removing it or preventing further accumulation.
I’ve seen a lot of discussion recently about the problem of clogged downcomers. Could that senior expert please clarify whether the downcomers in question are those used for slag discharge? It’s that type of furnace; I wonder if a BGL furnace will be available
I have discussed this issue with the user unit; I have some ideas similar to those mentioned on the 4th floor – namely, by eliminating slag accumulation, the problem of blockage caused by slag can be resolved.
Friend on the 4th floor, it seems you have a lot of experience. But I would like to add that although this method works, it should be used with caution when other alternatives are available. It’s best to use this method cautiously by those who don’t have much experience – it can be quite dangerous. Of course, if it can be controlled properly, then this method is quite useful. Hehe, many issues have two sides to them
Using the slag discharge port to clear slag blockages is quite dangerous; we have even had to remove the refractory bricks in such situations.
Is the blockage of the downcomer related to the quality of the coal? Hehe
Recently, many manufacturers have encountered problems with their downcomers, mostly due to issues with the coal. Attention should be paid to the quality inspection of coal.
The method on the 4th floor is practical in real life, but it is mostly carried out by experienced operators. Our factory also uses this approach frequently; however, there have been instances where other pipelines were damaged or blocked as a result