【JST-113】One-on-one Q&A on Chemical Process Instruments and Automation 【Updated on 20.9.16】
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This post was last edited by Xiāoyáo Ténglóng on 2020-9-16 at 17:57. I wish to join the Haichuan technology team; in accordance with the forum’s rules, I am posting this thread for one-on-one inquiries. First, let me briefly introduce myself. I graduated in July 2013 from Hebei University of Science and Technology with a degree in Measurement and Control Technology and Instruments. After graduation, I joined a fine chemicals company in Dalian. In November 2014, I was transferred to the Wuhai project team, where I worked in the engineering department of another fine chemicals company for 1 year and 2 months. In January 2015, I returned to a production department of a fine chemicals company in Dalian. I worked in the field of industrial control instruments; I left that job after 18 years and went to... Well, that doesn’t prevent me from discussing issues with everyone else. Specialization: Chemical process control and instrumentation. My responsibilities in this field include the maintenance of field instruments, the maintenance of DCS systems (mainly Zhejiang University Zhongkong JX-300XP; alternatively, Yokogawa VP and ABB 800F), measurement management, instrument selection and design, as well as control algorithm development. Regarding low-voltage electronics: I participated in the \"National College Students’ Electronic Design Competition\" during my university years, so I have some basic knowledge of programming and hardware related to low-voltage controllers such as microcontrollers and ARM (with a focus on hardware). I welcome discussions with others on this topic. Explanation as follows: 1) This post welcomes marine enthusiasts to discuss various issues, but the focus is mainly on industrial control and instrumentation, with the aim of exchanging ideas and improving together. 2) This post is not intended solely for one-on-one discussions between the person seeking help and me; other users are also welcome to participate in the discussions. If you are not satisfied with the responses, please create a new thread in the Control or Instrumentation forum. Thank you! 3) Any personal attacks are prohibited; let’s work together to create a harmonious society. 4) I log in at least once a week to reply to various questions from fellow sailors; if there are questions I don’t know the answer to, feel free to discuss them together. I sincerely hope that all participants will be able to make progress and achieve greater heights through communication, and I also hope that together we will leave our own remarkable mark in the field of control instruments! ! Postscript, March 8, 2017: I’ve been working in the field of instruments for almost 4 years now, and I’m still going strong… Postscript, November 23, 2017: A sharp sword is forged through grinding, and the fragrance of plum blossoms comes from harsh winters. The leadership isn’t confident enough in me; it’s because I haven’t done my job well enough. I need to keep working harder! Diligence + Learning * = Success. Postscript, March 20, 2018: I’ve been working for five years now, but in my manager’s eyes I’m still considered an apprentice-level engineer. Should I consider changing jobs? ****(Hidden) My salary isn’t enough to support myself, let alone cover the mortgage… Are there any factories in Dalian that are looking for instrument engineers, automation engineers, electrical engineers, etc.? Please hire me… Does Haichuan consider establishing a design firm or something? Hire me please… I even heard that there’s a big demand in the southern region – is anyone hiring? Please get in touch with me as soon as possible for further discussion. Postscript, May 12, 2018: I changed jobs during Labor Day… I joined an environmental protection company and work as an electrical automation engineer. Learn PLC. Postscript, October 10, 2018: I left the fine chemicals industry and entered the environmental protection sector to work in electrical automation design. It’s been over 5 months now; most of my working time is spent in front of the computer, or I’m on site carrying out installations. Only now do I realize how difficult it is to be a designer. I’ve been assigned a project related to DCS systems, and I’m still working hard to master that technology. I hope that once I do, I’ll have a brighter future ahead. After all, my junior colleagues now all earn over 9,000 per month, while I only make around 6,000. While there are regional factors at play, opportunities and skills play a bigger role as well. Keep it up; I hope all fellow sailors can encourage each other. November 20, 2018: Postscript: Design is truly a tough profession. Engineers who can work on operation and maintenance would rather not be designers – they’d definitely die 20 years earlier… This post has been around for so long now, yet it still hasn’t even received a technical post identifier; I’m quite frustrated about that~~ January 3, 2019: Postscript: A new year, new job, new opportunities – maybe things will really be different this time. I hope to have a good exchange with the experts from Luoyang Institute this year. Improve myself! ! Postscript, March 12, 2019: Today is Arbor Day, but my workplace didn’t organize any tree-planting activities; maybe Dalian doesn’t need to plant trees after all… (A light opening joke.) At the beginning of the year, I changed jobs again, this time to a company that deals with petrochemical-related services, where I work on instrument design, selection, and technical support. The first task for the new company was to design the instruments for hydrogen recovery in Tianjin Petrochemical; however, more than two months have passed now yet the process parameters have not been determined. For many of the instruments, I have already completed the specification sheets, but the process itself has not yet been finalized. Some time ago I went to Liaoyang Petrochemical to provide technical support for their facilities… It was my first time entering such a large petrochemical plant, and it felt really different; there’s a big difference compared to fine chemical industries. I think I should study harder for another two to four years, then move into the petrochemical or coal chemical sector to build up my knowledge and skills. I want to take advantage of this golden period around the age of 40 to achieve something significant in my career. May 16, 2019. P.S.: Today I established a small group for those working in the field of instrumentation – it’s a WeChat group that brings together experts in SEI and CEI, as well as experienced instrumentation engineers from various chemical industries. I invite all those who are determined to make a name for themselves in this field to join us, so we can discuss issues together and brainstorm ideas! If you really want to join the WeChat group, feel free to leave a message and I’ll send you the QR code~! ! Postscript, September 16, 2020: I changed jobs again at the end of June this year... It’s a company involved in coal chemistry; I won’t mention its name. It’s located by the Yellow River in Tuoketuo County, Hohhot, Inner Mongolia. The location is quite remote, and the project is still in the construction phase. I’m currently involved in the installation of instruments for the water system; my main responsibility at the moment is related to demineralized water (chemical water, boiler water). What will happen in the future is unknown… I won’t go into details about WeChat groups or anything like that. That’s all for now. This situation isn’t very good indeed; if anyone has any questions, feel free to leave a message in this post by HaiChuan. Perhaps as I get older and become more busy with work, I really don’t have much time to pay attention to this post about Hai Chuan. Of course, if I see it, I’ll reply to you right away. Also, those who really want to be friends with me are welcome to send me a private message. I hope that by using coal chemical processing as a stepping stone, I’ll be able to enter the large-scale petrochemical industry in the future and take charge of the instrumentation for some facilities… But that’s still three years away. As a technical discussion thread, it’s pointless to say too much; everyone is welcome to contribute their ideas. Finally, congratulations that this post has returned to the dashboard…… Automatic control dashboard
Thank you! Thank you! Thank you to the technical staff for their support!
How can the seismic issues of instrument pipelines be analyzed and resolved, and are there any appropriate practices?
To be honest, I’ve really never heard of this before – seismic resistance for instrument pipelines? ? Do you mean conduit and cable trays when you talk about instrumentation piping? It seems that the process pipelines have seismic resistance requirements, and there are installation standards for conduit pipes and cable trays; following these standards should meet the seismic resistance needs. But if the building collapses... then seismic resistance of the conduit pipes becomes meaningless. Do you mean small earthquakes, during which the building doesn’t collapse, but you’re worried that the conduit pipes might fall? As long as the bridge frame is designed according to the standard assumptions, it definitely won’t fall down. Besides, even if it falls off, well, it just fell off – just attach it again……
The instrument pipelines referred to consist of two parts: process connection pipelines, and gas signal and gas supply pipelines. Process connection pipelines are installed using the appropriate installation diagrams based on different measurement requirements. It mainly involves conditions such as the temperature of the medium under test, its pressure, and its physical properties. Welding is generally used for this purpose, with butt welding and socket welding being the two main types of welding ； Some also use threaded connections. Gas signals and gas supply pipelines are mainly connected to pneumatic control valves; Φ6 copper tubes are generally used, while nylon 66 tubes are used in some cases. When installed in accordance with the specifications, there are almost no seismic issues.
Special media, such as toxic ones, must not be leaked. However, the instrument pipes are fixed to buildings or structures using clamps, brackets, and similar devices; under vibrations such as those caused by earthquakes or equipment shaking, if the pipes remain rigid as a whole, they are prone to breaking or cracking. The question is how to maintain a certain degree of flexibility in the pipeline, how to choose the clamps and supports, what spacing to use, and so on; how to analyze and design this is something I have been thinking about recently.
Hehe, the original poster is so young and already participating in 1v1 competitions – that’s really admirable. Well, I’ll ask you a question as well, related to control algorithm design: among the devices you’ve seen, can you give an example of an intelligent control algorithm that has been successfully applied in practice? At least something like fuzzy PID or similar
Please leave your contact information; we’re in the same industry, haha.
You make a good point; the gas supply pipe should also be considered part of the instrumentation piping. In our company, we use quarter-inch galvanized iron pipes with threaded connections for gas supply pipes. After leaving the air supply ball valve, it generally comes in various forms: the first is a φ8 air supply hose, the second is a φ8 stainless steel pipe, and the third is a φ8 copper pipe. All connection methods are threaded or snap-fit. (The same goes for φ6.) But I’m not sure what connection this has to vibration protection; as long as it’s installed according to the standards, there should be no problems. I’ve only heard of devices exploding, but not anything related to instrument cables – after all, there’s a safety barrier in place first……
Your question relates to aspects that should be taken into consideration in the manufacturing process. I’m not quite sure what you mean, but based on my understanding, I’ll share my own perspective: 1. If it’s the instrument itself that is damaged, such as a pressure transducer with flanges. Or it could be a flow meter, installed on **chemical pipelines. In the event of vibrations, flange failure, or breakage in the middle of the flow meter, this is unlikely to happen; as reputable manufacturers, when selecting components, will choose PN4.0MPa flanges for pipelines with a pressure rating of PN1.6MPa. The strength of these flanges is greater than that of the flanges used on the process pipelines, which means that the process pipelines will break first, followed by the instrument pipelines. 2. If a strong earthquake causes the process pipelines to break, flammable and explosive gases may escape; subsequently, the instrument trays may break as well as the instrument cables, leading to arcing. In such a case, there will be no explosion from the instrument itself either, as there is a safety barrier in place that limits the energy to a very low level, preventing it from reaching the energy threshold required for an explosion. However, in the case of such an earthquake, an explosion is certainly likely to occur, as there are also electrical cable trays and significant electrical arcing… 3. The instrument pipelines are used for instrument air or instrument cables, and do not contain any toxic substances. As for the installation specifications, I’m not a professional in installation work, but I have reviewed the approval documents, and any company with the necessary qualifications carries out the installation in accordance with the standards. All pipelines must be fixed and installed securely; cable trays require brackets, and there must be crossbeams every 1.5 to 2 meters. All instrument pipelines shall be connected using threading or clamping methods, and welding shall not be used for fixation. There are specifications for pipeline installation; I’m uploading them for your reference.