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A Secure Path to the Cloud

Linde has developed an air separation system that allows extremely flexible operation according to the situation on the electricity market. In order to prevent this innovative operating method from causing increased loads or efficiency losses in the system, Linde has set up a sophisticated, cloud-based monitoring system. With its Cloud Connectivity solution, WAGO ensures that the measurement data is reliably transmitted to the cloud.

The air separation plants designed by Linde work almost like Rumpelstiltskin spinning straw into gold: The systems produce valuable chemical elements from air, such as oxygen for the healthcare industry, nitrogen for food manufacturers and argon for the electrical industry. However, there is nothing magical about the system. Instead, the gymnasium-sized systems with their characteristic towers are the result of incredible features of engineering. The method for gas separation that underlies these systems was developed by the company’s founder, Carl von Linde, in the 19th century, and is therefore called the “Linde process” in his honor.

Your Benefits:

  • Highly flexible operation of air separation plants with WAGO

  • Data collection and transmission to the cloud with Cloud Connectivity

  • PFC200 Controller IoT Gateway – Increased Availability, Better Performance

However, it takes a large amount of electricity to break air down into its constituent parts. “This process represents a great opportunity for the global energy transition, because industrial systems of this type can make a substantial contribution to the integration of wind and photovoltaics into the energy system,” explains Dr. Oliver Slaby, Head of IT for Plant Operations at the subsidiary Linde Engineering. This is made possible by making operation more flexible in line in line with the electricity supply: If a lot of wind and solar power are available, then the systems run at their highest output levels; if less renewable energy is available, then they can be throttled down, or even idled.


Secure Networking with Cloud Connectivity

This type of variable operation places significantly higher demands on the system technology than conventional operation with largely constant output. Therefore, Linde Engineering developed a new technological concept, called FLEXASU®, which allows them to operate the air separation systems with a high degree of flexibility. A sophisticated monitoring and analysis system prevents the load changes from reducing the performance and lifespan of the systems. One core component of this is system is the IoT Gateway of the PFC200 Controllers from WAGO, which collects data and sends it to the cloud with Cloud Connectivity.


Increased Availability, Better Performance

To see what air separation systems can offer for the energy transition, one only has to look at Vejle, a town in the southeast of Denmark, where Linde Engineering has installed a FLEXASU® pilot system. It differs from conventional systems in several ways, including the fact that the plate heat exchanger, the core of all air separation systems, is equipped with numerous sensors. “Plate heat exchangers are used to cool the incoming air. At the same time, they heat the products that generated in the system as they are emitted,” explains Paul Heinz, Conceptual Design Engineer at Linde Engineering. The frequent startup and shutdown sequences in the systems cause thermal stress, which can lead to strain on the heat exchanger in certain circumstances. “In the worst case, small leaks could arise. Production would then have to be stopped for repairs, and the interruption in operations would be costly,” says Heinz.

Therefore, experts from Linde Engineering monitor the thermal state of the heat exchanger blocks using the installed sensors. Based on this data, which is collected at one-minute intervals, the engineers can use simulations to predict the lifespan of the blocks. Should it become apparent that a component will soon reach its load limit, the employees replace it promptly or alter the change mode of operation in order to prevent stress on the components.

“Such a predictive maintenance approach increases the availability of the systems,” explains Heinz. In addition, the sensor data also reveals how system performance can be improved – for example, by showing where the local temperatures in the components deviate from optimum levels. Using this information, the process can be adjusted to reduce the energy consumption of the system. This makes the monitoring experts into advisors on system operation. This service benefits not only plant operators within the company, but also external companies to which Linde sells its air separation systems.


In the worst case, small leaks could arise. Production would then have to be stopped for repairs, and the interruption in operations would be costly.

Paul Heinz | Conceptual Design Engineer | Linde Engineering

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Reliability from the Desert to the Tundra

PFC200 Controller

The consolidation of the data, and the analyses, simulations and predictions using them are carried out in Microsoft Azure, the cloud service offered by the US software company. Among other advantages, this makes it possible to work with the data from anywhere in the world, which is a major advantage, since the Linde air separation plants are often installed in remote regions. But how does the data get to the cloud? Linde Engineering relies on WAGO for this crucial step. With its cloud Connectivity Functions, the IoT Gateway in the PFC200 handles data encryption and secure transfer to Microsoft Azure.

There was a whole series of reasons for selecting WAGO, according to the Linde experts. Among others, Paul Heinz cites the robustness required in this application. “Our systems often operate in locations where extreme climate conditions are the norm. We were impressed by the fact that WAGO’s product is just as suitable for use in the desert as in the tundra,” he explains. The more isolated the location is, the more important it is that data recording and transmission can be carried out and operated remotely. “With WAGO, this is no problem. Even the configuration is done remotely,” says Dr. Oliver Slaby. The installation is child’s play and requires no specialist knowledge. Cell phone infrastructure is also not always reliable at more remote locations. Systems operators here can benefit from the data buffer offered by the IoT gateway in the WAGO controllers: if the connection goes offline temporarily, the data is collected from the buffer at a later time and transmitted, so no measured values are lost.

Our systems often operate in locations where extreme climate conditions are the norm. We were impressed by the fact that WAGO’s product is just as suitable for use in the desert as in the tundra.

Paul Heinz | Conceptual Design Engineer | Linde Engineering

Agile and Committed

Slaby also cites WAGO’s ATEX certification as a benefit. “Many of the systems that Linde Engineering provides are used for processing flammable or explosive media. This requires controllers that are certified for these highly explosive areas,” he explains. Last but not least, Slaby emphasizes the many positive experiences Linde Engineering has already had with the company’s products in other domains. Linde uses WAGO solutions in other domains. In addition to technical qualities, WAGO also impressed its customer with its agility and level of involvement in the implementation. “We needed fast, flexible support during the development of our pilot systems. The experts at WAGO did a really marvelous job: They successfully completed their part within only two weeks,” says Slaby.

Linde Engineering now wants to translate its flexible-load air separation system concept into a new product line. This will make the company a trendsetter in the energy transition – and an example for the entire process industry. The potential for the company’s load management is substantial when applied to other technological fields. And WAGO will continue to stand beside them as a reliable partner.

Author: Ralph Diermann
Contacts at WAGO:
Dirk Volkening | Software Product Manager
Carsten Wendt | Software Product Manager

We needed fast, flexible support during the development of our pilot systems. The experts at WAGO did a really marvelous job.

Dr. Oliver Slaby | Head of IT for Plant Operation | Linde Engineering

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