Reasons for SHELL shutdown

Are the flame shield and water wall burn-throughs also problems with the instruments? Nonsense.

““The problems are all related to the equipment instruments; they have nothing to do with the manufacturing process,” that’s what your company has concluded – it probably isn’t the conclusion of the manufacturer who actually operates the equipment!

So, now I ask those manufacturers who already have vehicles in operation to tell me some reasons for downtime that are caused by manufacturing processes rather than equipment or instruments, so that I can counter their arguments. I really don’t have any strong practical evidence to refute it right now: handshake

Meters and equipment are only part of the reasons for shutdowns, and these issues were continuously resolved through subsequent modifications. I think what is troubling everyone at the moment is still the understanding of the shell processing technology itself. Only when everyone fully grasps the design principles of shells and carries out scientific process control can I believe that shell devices will be able to operate stably!

A device is just like a person; it is a unified whole that cannot be considered in isolation. For example, when a person catches a cold and has a runny nose, can we blame the nose alone for that?! In the case of vaporization devices, the process is akin to the faucet, the equipment forms the foundation, and the instruments serve as the eyes. These elements are interrelated and influence one another; it’s not possible to emphasize one aspect alone, nor can we blame just one element. In design and practice, it’s common for existing equipment to not fully meet the requirements of the process – this is true even when imported equipment is used. In such cases, the only solutions are to develop new types of equipment or to modify the process. As for the reasons that cause SHELL plants to stop operating, it seems obvious that they are caused by failures or malfunctions in the equipment and instruments. To analyze these causes, a comprehensive and thorough examination is necessary. But in reality, there are more important factors at play: the guidance provided by management and the operations carried out by workers! This is just my opinion; it’s meant for reference only.

Saying it’s due to the equipment or instruments is certainly a one-sided view; the analysis above is very insightful. The performance of a set of equipment ultimately depends on human factors.

There are also many reasons related to electricity.............

Things like the burn-through of the water wall are probably related to the instruments somehow~~ Control is the key here~~ Process defects themselves shouldn’t be the main issue

I also work in the field of instrumentation. Although I’m not familiar with the device mentioned by the original poster, when a piece of equipment stops working, it’s necessary to investigate possible causes such as those related to instrumentation, the manufacturing process, electrical issues, or problems with the equipment itself. Especially during the initial driving phase, there are potential problems in every aspect.

It’s not necessarily a problem with the instruments; on one hand, it is related to water quality. In normal production, one of the key factors is the burning through of pipes and blockages inside them, which result in low water flow rates. Of course, defects remaining from the manufacturing process can also occur in areas such as the quenching section and the thermal skirt. Some issues are not easy to distinguish clearly; actually, is it necessary to make such distinctions? For example, the issues of thinned slag layers in the pattern as mentioned on the forum some time ago, and the ablation of pins – do you think these are caused by coal quality problems, process operation issues, instrumentation problems, or even design flaws? After the incident occurred, everyone knew how to prevent it and deal with it. In fact, the topic raised by the original poster is meaningless and not very helpful for new factories. How about changing the topic to something like the reasons for the shutdown of shell gasification units and corresponding countermeasures? Of course, it might be difficult to post or reply to such a thread. Last edited by The purple bamboo is serene on 2008-1-23 12:37.]

1. Electrical reasons 2. Instrumentation reasons 3. Equipment reasons 4. Process reasons; among these, instrumentation, equipment, and process-related issues are more likely to be the cause. Last edited by Langtaosha on 2008-5-26 08:28]

This post was last edited by shanxg on 2009-7-20 09:00. There are currently 17 Shell gasifiers in use in China, and even the earliest ones installed by Shuanghuan Group have only been in operation for three years; thus, Shell’s presence in China is still relatively short, and many issues have not been thoroughly discussed. There are various reasons for the shutdown of these gasifiers, and tube failures in the water cooling walls are related to scaling, a problem that is not easy to resolve

There are many reasons for parking issues, which essentially fall within the categories mentioned by these speakers. But in my opinion, the reason for Shell’s shutdown is related to coal; issues such as those with the burners can already be resolved. The main problem was probably a lack of thorough planning at the initial stage – no consideration was given to our local coal resources.

On the surface, the reasons for SHELL’s shutdowns are obviously caused by failures or malfunctions of equipment and instruments. To analyze these causes, a comprehensive and thorough examination is necessary. In fact, there are more important factors at play: the supervision of management and the operations carried out by workers!

This post was last edited by shanxg on 2009-7-20 09:00. There should be no major issues with the process, as the relevant unit operations and design specifications are fairly well-established. It mainly depends on whether the supporting equipment and instruments can meet the process requirements. After all, none of us have any experience. Of course, the use of supporting equipment, instruments, etc. is closely related to whether the design principles and intentions are fully understood during the operation process. The problems that occur during the operation of the shell, such as damage to the burner covers, have been resolved to varying degrees (in my opinion, Sinopec has considerable strength in this regard). The main factors affecting its operational efficiency are: 1. Unstable coal quality – sometimes the coal type is changed two or three times a day, which is difficult even for ordinary boilers to handle; 2. Highly unstable supporting utility systems. After all, large-scale coal chemical projects are still in their infancy; even the design institutes lack experience. 3. They have not yet fully grasped and understood the design concepts and principles

I worked on instrument maintenance at Sinopec Zhijiang Gasification (using Shell technology). The operations did not proceed smoothly, with shutdowns occurring from time to time, but none of these issues were caused by the instruments! They were all due to process-related problems or issues with the power system, such as unstable steam from the power boilers, power outages, problems with supporting infrastructure, blockages in slag discharge caused by oversized slag particles in the water wall, and failures in the quenching gas compressors. It can be said that it is precisely because of the instruments that the equipment remains in a safe state. Therefore, it’s not right to blame the instruments for every problem that arises during operations. Process operators lack the necessary ability to adapt to new technologies and processes; lacking confidence, they tend to blame the instruments for various issues. Working on on-site instrument maintenance is extremely demanding – one needs to have a much deeper understanding of the processes involved. Sometimes, one has to repeatedly explain things to the process operators.

The performance of a device depends on various factors; if the responsibility is assigned solely to one department, it only indicates that the person in charge there is an incompetent leader. There may be various reasons for this during the operation of the equipment. Not to mention the reasons related to the device itself being thrown away. From a process operation perspective, it is entirely possible for equipment damage to occur due to improper process operations. On the surface, it seems that the shutdown was caused by equipment damage, but in fact it was due to improper process operation.

Hehe, good job – a salute to professional instrument technicians!

According to the information provided by Yihua Group’s Shuanghuan Chemical (the first SHELL powder gasification unit to be put into operation in China), the main problems that led to the shutdown of the system were as follows: 1. Burner cover burnout and leakage. 2. The issue with raw coal. 3. The ventilation device of the coal conveying system is damaged. 4. The internal components of the high-temperature and high-pressure filter (ceramic filter) are damaged. 5. The quenching compressor has failed. Through continuous technical upgrades, the process equipment of the facility has been successively improved, and some of the aforementioned problems have been effectively resolved. At present, the Shell gasification unit at Shuanghuan Company is operating in a relatively stable manner, having reached a new record of 73 consecutive days of operation.

Operational experience is extremely valuable; every plant that has been in operation has accumulated such experience and carried out numerous technical upgrades. This experience should be shared to prevent similar problems from arising in plants that start operating later.