Compressed air measurements in a rolling mill

Various compressed air measurements at the compressor stations, in the distribution network and at the consumers as part of energy management in accordance with ISO 50001

At the world’s largest production site for packaging steel, thyssenkrupp Rasselstein manufactures tinned or special chromium-coated steel (cold-rolled steel plate in thicknesses from 0.100 to 0.499 mm). The steel industry is characterised by energy-intensive processes. This also applies to the production of packaging steel. The efficient use of energy is therefore an important competitive factor, especially in energy-intensive industries.

Energy has been a priority at thyssenkrupp Rasselstein for a long time. In 2008, the Andernach plant was awarded the Environmental Prize of the state of Rheinland-Palatinate for its efforts in identifying and increasing energy-saving potential. Since 2010, it has had a certified energy management system in accordance with ISO 50001. The essential goal of systematic energy management is the continuous and verifiable improvement of energy efficiency.

The core processes at thyssenkrupp Rasselstein are rolling, annealing and refining. In addition to electricity, natural gas and steam, these processes require a considerable amount of compressed air.

This is used on-site for a variety of purposes. Compressed air is fundamentally an unfavourable medium in terms of energy as its generation requires much more mechanical or electrical energy than can be used by itself. Nevertheless, it is indispensable in many production processes. At thyssenkrupp Rasselstein, it is particularly needed for discharging at the many production lines, for moving pneumatic drives or for flushing measuring systems (e.g. camera systems, thickness gauges, etc.).

Despite considerable effort, the Rasselstein energy experts have yet to fully map the complex structures of the compressed air network via stationary measurements. Therefore, they have been looking for a suitable mobile alternative, with the help of which production and consumption can be better balanced and at the same time also, possible weak points and potential for improvement can be identified.?

Solution

The quantities of compressed air generated in the three compressor stations on site are recorded as part of the energy management system by means of thermal mass flowmeters. Such wetted measuring technology is out of the question for the temporary recording of compressed air flows through the distribution network and the consumption of individual plants, since production operations should not be disturbed. In addition, one of the aims of compressed air monitoring is to track down possible leaks and not to create potential new ones. Therefore, the energy managers from thyssenkrupp Rasselstein were interested in non-invasive clamp-on ultrasonic technology from the very outset.

The impressive solution for this measuring task is FLUXUS? G601 CA Energy. The portable all-purpose device from FLEXIM measures the flow rate of liquids, gases and thermal energy flows and was specially developed for the non-invasive flow measurement of compressed air. One of the advantages of non-invasive measuring technology is that it can be easily checked for suitability before purchase. This is one of the main tasks of the field sales staff: make an appointment and present the device. A routine exercise for Axel Dickfeld, the field engineer responsible for the region, which he mastered successfully: his test measurement not only impressively demonstrated the performance of the clamp-on ultrasonic system, but it also detected a leak in the compressed air network.

Since it was purchased, the device has been in constant use as part of various energy-saving projects and has already paid off through various efficiency measures and the associated cost reductions. Energy management expert Kay Alt is convinced: “more effective always works!“

Selling Points:

• ?Reliable and accurate non-invasive recording of compressed air quantities (standard volume flow)
• Cost savings by detecting leaks and recognition of efficiency potential through optimised operational management
• Extremely versatile measuring system: one single device for many measuring points and tasks

“Through its use in various energy saving projects, the practical device has already paid itself off.“?

Measuring Points and Instrumentation:?

Pipelines: steel, stainless steel, typically DN50 to DN150

Medium: compressed air, pressure 6 to 8 bar

Measuring equipment: 1 portable clamp-on FLUXUS? G601 CA Energy ultrasonic system for non-invasive flow measurement of liquids, gases and hot and cooling flows 1 pair of GRP1NC3 clamp-on ultrasonic flow transducers (Lamb wave) for gases, pipe diameters 15 – 60 mm 1 pair of GRM1NC3 clamp-on ultrasonic flow transducers (Lamb wave) for gases, pipe diameters 30 – 180 mm

Customer

ThyssenKrupp Rasselstein GmbH, Andernach, Germany

thyssenkrupp Rasselstein GmbH is a leading global supplier of high-quality, precision-made packaging steel. At its site in Andernach, Germany – the world’s largest production facility of this kind – 1.5 million tons of packaging steel are produced annually. 2,400 employees serve around 400 customers in 80 countries in a variety of markets – from manufacturers of food and pet food cans to manufacturers of beverage and aerosol cans, containers for chemical and technical products, as well as crown caps and screw caps. Expert teams in service, sales and technical customer support complete the product portfolio. They work closely with customers to deliver on the promises of thyssenkrupp Rasselstein’s consistent quality and reliability worldwide.

For further information, please contact FLEXIM:

[email protected], flexim.com.