Regarding fluctuations in burner pressure difference
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The burner pressure difference is the outlet pressure PA1031 of the slurry pump minus the pressure PA1304 in the gasifier; the burner pressure difference for the furnaces in our plant is generally around 0. 5—0. Between 7, the LL value is 0. 15, its fluctuations were observed on the DCS, dropping as low as 0. Around 3. Personally, I think this is directly related to coarse ions entering the slurry pump. Some people say it’s due to a blockage in the burner ring system, but I don’t think that’s the cause. I hope everyone can share their opinions
Is it coarse ions or coarse particles? If coarse particles continuously make their way into the slurry pump, it can cause problems with the gland packing of the high-pressure slurry pump, as well as lead to fluctuations in the slurry level. It’s necessary to remove the slurry from the bottom of the slurry tank in a timely manner. In my opinion, both of these possibilities exist. Additionally, the outlet of the syngas from the gasifier might be blocked, and high load levels can also result in high pressure differences. The question posed by the original poster is quite strange; at first, I thought it was referring to the circulation water of the burner. Perhaps in your case, this type of pressure difference is referred to as the burner pressure difference
Fluctuations in the burner pressure difference can be used to determine the quality of the burner and whether there are any abnormalities in production. The burner pressure difference is indeed an important indicator in production, as its fluctuations can help identify many issues
Check whether the outlet pressure of your slurry pump is fluctuating
We are considering whether to implement a burner pressure differential. Indeed, the burner pressure differential can reflect many issues in production. However, since we have a multi-nozzle system, if such a differential is introduced, many instrument pipelines would need to be connected at the pressure measurement points in the gasification furnace (at least 6: four for burner pressures, one for the slag outlet pressure, and one for the pressure inside the furnace). The approach suggested by the design team is to directly measure the pressure in the gasification furnace and the pressure at the outlet of the slurry pump, and then compare these values
What size of particles does the poster think can cause a semi-blocking condition in the check valve of the slurry pump? The expansion coefficient of liquids is very low; therefore, if a check valve gets stuck, it will result in one cylinder not functioning properly. There won’t be a situation of partial blockage, and it will only affect the pressure difference across the burner. Fluctuations in the burner pressure difference generally occur toward the end of the gasifier’s operation; therefore, it can be inferred that wear on the burners is responsible for an increased local clearance, which in turn affects the pressure at the outlet of the slurry pump.
Your words make me think that our production systems are not quite the same. The pressure fluctuations at the outlet of the gasifier, as you mentioned, can cause fluctuations in the pressure difference within the gasifier. That refers to the pressure PA1304 – the outlet pressure PA1307; it’s something different. As for the pressure difference in our burners, I meant the difference between the outlet pressure of the slurry pump and the pressure inside the gasifier
However, our factory’s experience shows that although it was thought the burner was worn out, inspections after shutting down the equipment revealed that the burner was in good condition with no signs of wear. While burner wear can affect the pressure difference across the burner, it is not the sole cause
We have also encountered this situation, and we agree that it is caused by the sticking of the check ball valves at the inlet and outlet of the slurry pump, which leads to a decrease in the pumping capacity of the slurry pump. This in turn results in a lower pressure difference at the burner, manifesting as an increase in oxygen consumption and an elevation in furnace temperature. The reason is that after fluctuations in the burner pressure difference, it can recover over time; therefore, it cannot be attributed to burner wear, as burner wear is not reversible. The ball valves we import and export are double-ball valves, so the impact is not particularly significant.
Since the burner is in good condition, and if there is no problem with the instruments that are giving incorrect readings, then it must be that one of the cylinders in your high-pressure coal slurry pump is not functioning properly, or there might be a problem with the cylinder gaskets. It could also be caused by large particles in the coal slurry
Burner wear or a reduction in the burner gap due to heating can both cause fluctuations in the burner pressure difference. If the annular gap decreases and the pressure difference increases, the pressure difference can be reduced by reducing the load on the burner.
1. Coarse particle blockages can cause an increase in pressure difference; a high pressure difference is unfavorable for the vaporization reaction. Many coal particles reach the quenching chamber without participating in the reaction, which reduces the vaporization efficiency. Wear on the cone-shaped bricks is also significant. 2. If wear occurs in the internal gaps of the coal slurry, it leads to a decrease in pressure difference. The atomization angle increases, resulting in poor reaction efficiency, and the hot zone moves upward, causing wear on the refractory bricks in the upper part of the vaporization furnace
Check the pressure in the buffer tank at the outlet of the slurry pump again. Fluctuations in the pump outlet pressure can also be caused by insufficient nitrogen pressure in the buffer tank. Slurry pump outlet pressure – gasifier pressure? ? ? Burner pressure difference: Generally, we consider the pressure of the coal slurry entering the furnace minus the pressure in the gasifier to be the burner pressure difference, which is a relatively accurate representation.
Excuse me, on the 11th floor, what do you mean by a cushion cylinder? Could some expert please tell me?
I think this is a question that is easy to determine. First, check whether the pressure difference is fluctuating or stable; if it remains stable at a level as low as 0.3, then it’s likely that the gap around the burner is too large, and replacing the burner might be an option. If it is fluctuating, then it is possible to determine whether it is a problem with the slurry pump by considering other parameters of the furnace. The reason some facilities implement this interlock is for safety reasons, to prevent similar tragedies to those that occurred at Nanhua from happening again due to failures in the slurry pumps.