The Siemens specialist for proces optimization, advice and automation



The company
The Linde Group is a globally operating producer of gases. The production of among other things nitrogen and oxygen – and Linde’s specialisations – is based on the separation of air. The technique used is the so-called cryogenic separation technique developed more than a hundred years ago by Carl van der Linde. This technique collects, cleanses, and compresses air. After this, the compressed air is cooled and then compressed again, making it liquid and allowing it to be distilled into various components.

Linde develops, constructs and operates air separation plants in more than 100 countries. The gases produced by Linde are used in virtually all sectors of society, such as the chemical, metal and food industries, education and science, health care and the environment. For the Benelux market, the air gases are produced in Rotterdam and IJmuiden.

The contractor
Peter Wagenaar is head of the technical department at Linde Gas Benelux. He is, as such, responsible for the air separation plants in IJmuiden and Rotterdam. The plant in IJmuiden is located on the site of steel producer Tata Steel and produces mainly oxygen and nitrogen. The gaseous oxygen and nitrogen are used in the combustion process in the large steel furnaces of Tata Steel. Another major user of nitrogen is Gasunie, for mixing high calorific natural gas. The liquid oxygen goes, among other things, to hospitals.

In addition, various noble gases, such as argon, krypton and radon, are separated and used for different purposes.

“Linde Gas has experienced tremendous growth in recent years”, says Wagenaar. “About ten years ago, we were faced with the migration of one of the factories. The operating system we used at the time was from Hartmann & Braunn. We wanted to switch to PCS7 from Siemens and were alerted to CoNet by Siemens. As Siemens’ preferred supplier, CoNet was the right partner for us to manage migration. CoNet wrote the maintenance programme, among other things. An important starting point in this respect was availability and reliability. How can we work as safely as possible with as few failures as possible and as few failure costs as possible? That is why, throughout the process, we have worked hard with CoNet on standardisation. Not only in software, but also in hardware and in the procedures. Training our employees was, of course, key and we could also count on CoNet in that area.

The assignment
“It began with an assessment to determine which type of maintenance programme would best suit Linde Gas’s situation,” says John Koot of CoNet. However, this assignment was not only about writing and implementing the software. In order to safeguard the continuity of the production process, Linde Gas also concluded a maintenance contract with CoNet. First of all, this means that CoNet is ready to resolve any malfunctions 24/7. Secondly, CoNet can keep a close eye on what can be improved on site. Koot: “We make a customized maintenance contract for each company. In the case of Linde Gas, the migration of all the plants has been a process of years. In the first few years we developed a preventive and corrective total concept that we rolled out into parts. At present, three of the four air factories in IJmuiden have migrated to PSC 7. Meanwhile, all server platforms have been included in the system. In doing so, continuous improvements and savings have been made. We are now in the phase that a CoNet engineer is in IJmuiden one day a week to further identify the areas for improvement and to train the Linde Gas operators on site to further master the automation system. The possibilities with Siemens PCS 7 are so incredibly versatile; it takes time to get the people who work with it to know all facets of the system and make the most of it. What’s more, safety is always paramount and the production process must continue under all circumstances. It is then useful to have one of our specialists ‘at hand’ at set times.”

The cooperation
Linde Gas is a 24/7 continuous operation. All the gases produced by Linde Gas are used 24/7 by Tatasteel and Gasunie. The cooperation with CoNet enables Linde Gas to keep its agreements with these – and other – customers at all times. Wagenaar: “In this sense, CoNet is a kind of lifeline for our business. Of course, the intention is for our operators and employees to become increasingly self-reliant, and CoNet is helping us very well in this respect. But since CoNet now has as much process knowledge as we do, and we are constantly striving to optimise processes, our collaboration is far from over. Sometimes this will be in the form of periodic maintenance only and sometimes, when new projects are in the pipeline, cooperation will be intensified for a certain period of time. All in all, I can conclude that the communication between Linde Gas and CoNet is very good. CoNet is always accessible and always quickly available when needed. They respond well to the questions we have and they are open to criticism and to improvements. They would never say: we’ve delivered what you’ve asked for and that’s that. Just like us at CoNet, they are always working on the question ‘how can we improve this together?’”

“Also when it comes to training our people, CoNet does a good job. Recently, they trained seven more people and I am very pleased with the result. We want to work towards a situation where our people first look at where the disturbance is coming from and then make a well-considered decision as to whether they can solve the disturbance themselves or whether external help is needed. In that sense, we are actually asking CoNet to destroy their own jobs. I have to say: they deal with this very fiduciously. They understand where we want to go and they go for it to achieve that together with us.”

The result
When the cooperation between Linde Gas and CoNet began, a steering group was set up. This was a management-like setting in which the processes, business drivers and automation issues were mapped out. From there, the entire maintenance assessment was also built up. At the moment, all processes are standardised to such an extent that the steering committee has ceased to exist. “And that’s a good sign,” says Wagenaar with satisfaction. “I am also proud of the maintenance database that Linde Gas and CoNet have set up together. This has even resulted in a standard maintenance concept that is also used for other companies. Of course, it is customized for each company. At Linde Gas, we have now reached the point where all work processes have taken full shape. We recently opened a fourth factory, which we were able to set up in no time on the basis of our maintenance concept. A massive gain.”