How to select an appropriate instrument control system for a process

Provide the process operation procedures and requirements to the automatic control designers, who will determine them.

So, on what basis do those in charge of control make their choices? Is there any standard or is it based on experience?

This is a very common real-world problem: due to a lack of professionalism and experience, people are unable to formulate questions or make requests accurately. Last month, I encountered a very similar problem. I have been working in the gas industry; previously, one of the powder materials I used was synthesized by my own team in the laboratory. When there was a large-order placement for this powder, it was assigned to my department to handle. Since I have not done this before, I lacked an understanding of the quality requirements for production processes with larger batch sizes, which led to many problems. Although we have a technical department to back us up, the approach to collaboration is that if you have any questions, they’re more than willing to help answer them. But when you lack experience and the problems haven’t yet arisen at that stage, it’s difficult to come up with specific questions, which is problematic. Fortunately, by working hard for a month and avoiding many detours, I finally managed to finish it

It is determined by various factors; currently, the DCS+SIS system is mostly used. Technical aspects such as process level, operational control requirements, detection and control response speed, number of signal points, etc ； In terms of management, this includes whether there are follow-up projects (Phase 2, Phase 3, etc.), whether capacity expansion is planned, the situation regarding project financing and investment, and the amount invested in instrumentation projects ； The technical skills of operators and instrument technicians, etc. How to control it (single-loop, cascade, feedforward, uniform, split-range, etc.), taking full account of the operational requirements in the production process, the difficulty of control, and an analysis of the interference factors that affect stable production.

It’s the process that depends on the characteristics and requirements of the workflow; I need to achieve a certain outcome, and I figure out how to use control (adjustment) methods to do that, so I choose that control approach. The instrumentation field is used to achieve the objectives of the process. With the new production process, control issues are inevitable; continuous improvements are made based on the problems that arise during operation.