Problem: The burner cooling water cut-off valve cannot be closed properly
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This post was last edited by jensse on 2015-9-12 at 11:53. The inlet and outlet shut-off valves for the burner cooling water serve as an important safety interlock mechanism in the gasification furnace; they isolate the furnace in case the cooling water coils are punctured, thereby preventing the leakage of hot raw gas. However, several plants have found that when this interlock is triggered, the inlet and outlet valves for the burner cooling water fail to close completely due to factors such as high back pressure. As a result, raw gas leaks into the burner cooling water pipelines, causing them to overheat or even get punctured and lead to leaks. Should any tests be conducted before installing these shut-off valves to ensure that they can close completely and accurately in the event of a leak or high pressure difference, thus ensuring the safety of the gasification furnace? What measures should be taken, and what kind of testing should be conducted prior to installation, to ensure that the burner cooling water shut-off valve can still close properly under the most severe operating conditions. For example, methods such as increasing the instrument air pressure of the cut-off valve or enlarging the cylinder of the cut-off valve to increase torque! I hope everyone can discuss this and share any good experiences that others might find useful to learn from*.
The newcomer doesn’t have enough qualifications; such issues need to be asked of the master: L
The inlet and outlet valves for the burner cooling water cannot be closed properly – how can the raw gas get into the pipes? ?
It’s a furnace made of refractory bricks, right? In a furnace with water-cooled walls, the pressure of the cooling water is higher than that in the combustion chamber; if the tubes crack, the cooling water will flow into the furnace, so this situation does not occur.
Generally, in Texaco’s gasifier burner cooling water systems, there is a pipeline branch that includes a manual valve, a check valve, and a shut-off valve. The check valve in this branch needs to be regularly inspected to ensure its sealing performance. The water used for cooling the burners is soft water, so the valves generally do not get stuck. Could it be that the screws inside the check valve have fallen out and are stuck inside the valve? We have also encountered issues with the shut-off valves during calibration; these problems were caused by screws falling out of the check valves
The probability of the internal component screws jamming the valve is very low. The fact that VW shut-off valves cannot be fully closed poses a significant safety risk; we have encountered this issue once here as well, with process gas leaking out and causing the burner’s cooling water return pipes as well as the separator to overheat (in that case, the check valve played a role in preventing this). To avoid such potential hazards, on the one hand, attention must be paid to the quality of the valves chosen; on the other hand, the valves should be adjusted using instruments as part of the process prior to starting operation, thereby minimizing the likelihood of such hazards.
Contact the manufacturer to handle it; if it cannot be turned off, it is a quality issue.
This post was last edited by jensse on 2015-9-12 at 11:54. The valve doesn’t work properly; there’s no other solution. There is a safety valve designed to release pressure when it exceeds a certain level, and there’s also a CO alarm. If the alarm activates and the instrument is functioning correctly, it’s better to stop the machine early and replace the burner.
This is worth learning about*; it indeed represents a serious risk, as the purpose of the interlock settings is not fulfilled at all.
This issue relates to valve selection; for example, in the case of an oxygen cut-off valve, I need it to open at a pressure of 120 kilograms during material feeding, and the valve manufacturer will certainly be able to meet the pressure requirements you specified. Therefore, the pressure relief design ensures a stable and reliable valve. Such problems can be avoided in this way.
There was definitely no problem with the valve selection; it was determined during the design phase. The accident was mainly caused by the valve, but no accident report was issued after the incident