PLYMOUTH, MINNESOTA, US —Bühler describes its new mill E3 as a completely new re-imagination of the flour mill, providing significantly greater efficiency in the way it's engineered, installed, and operated. The company said it meets today’s challenges of rising infrastructure cost with faster installation and a new compact footprint and delivers substantial energy savings, reducing costs as well as benefiting the environment.

Hendrik Weichelt, the first in charge of commissioning the Arrius in the United States, recently spoke with World Grain about the unveiling of the new integrated grinding system. Weichelt is a sales account manager for Specialty Grains & Pulses for Bühler North America.

WG: How does this system differ from a traditional roller mill?

Weichelt: At first I was skeptical when I heard it is not a roller mill anymore. Instead, it is changed to be an integrated grinding system. The roller mill is the heart of the mill, these are big shoes to fill. Of course, I was very curious about this new technology. For example, I wanted to see the new pre-stressed roll package and how it would perform. In internal briefings, I learned this would eliminate the clearance in the system and be more accurate during the grinding.

WG: Was the commissioning of the Mill E3 a smooth process?

Weichelt: Even with new things to learn, the installation went very well. It took me some extra time to check all the sensors and I/O on the prototype. The degree of automation of this machine is much higher than in other models. However, the mechanical and electrical installation is really easy. The new drive module, with integrated motor and gearbox, speeds up the mechanical installation. On the electrical side, the control cabinet is incorporated in the machine. We just need to connect a power line and the network to it. Overall, the installation time was reduced, being faster with mechanical and electrical components, but a bit longer with sensors and I/O check. We learned from this experience. So, in order for Bühler to ensure the highest quality and further decrease the installation/startup time, the series machine will be I/O tested in the factory. This will save a big amount of time on site.

WG: How did the machine perform then?

Weichelt: After we started the integrated grinding system, it was noticeable how smooth the feed system adjusted itself. I am used to adjusting a parallel feed gap and setting the feed roll parameters, so we have a nice even flow. With the Arrius I didn’t have to do this work. This feature, along with the new scraper concept, will make the life of a head miller much easier. The new feeding system is fully automated and self-regulating. It quickly adjusts to product fluctuations. The result is a constant and uniform spread of product along the full length of the rolls. We already had a good feeding system in Bühler roller mills, but the previous systems require an inspection and adjustment from time to time. With Arrius, the head miller won’t adjust the feed gap anymore. It is a bit too soon to confirm, but in the long run we might notice a longer lifetime of rolls, because of the improved usage of the roll length. And the new scrapers are really effective, too. The flexible scraper blade adjusts automatically, so it will be always parallel to the roll. The new design provides enough pressure for scraping the rolls, cleaning them thoroughly. Furthermore, this new solution eliminates the usual screw adjustment in the grinding room, which means one less adjustment to perform during the daily operation. 

WG: Is the automated gap adjustment of the rolls a unique feature?

Weichelt: This feature was already available in previous Bühler roller mills such as the Antares MDDR/MDDT. Since Arrius has a more advanced control system, the gap adjustment became more effective. When a mill changes its product, the recipe changes and the grinding system will adapt the grinding gaps. This helps to save time for the production by returning quickly to the most efficient mill setting. 

WG: Can you tell us about the new HMI?

Weichelt: The Arrius HMI is very intuitive, with a lot of new parameters that control and adjust the equipment. It is capable of registering several operational outputs and storing them for further data analysis. You can access it remotely to verify and adjust the equipment using a mobile phone, tablet or a personal computer. However, to fully profit from the mobile option of this HMI, the mill will need Wi-Fi infrastructure, allowing connectivity with it.

WG: Are there any other interesting innovations in the Mill E3?

Weichelt: Yes, the new drive system. Arrius has an integrated drive consisting of motor and gearbox, enabling mechanical energy recovery. This improves the energy efficiency, while maintaining a hygienic and simple system. It also allows a fast roll change. Also worth mentioning here is that with Arrius this can be done while the other side of the machine is still in operation.

WG: Considering your field experience and process knowledge, where would you recommend using Arrius?

Weichelt: For sure in greenfield plants, following the Mill E3 concepts. Also on mills planned for a large variety of recipes, with Wi-Fi infrastructure to control and perform data analysis with the production parameters. On existing plants, Arrius might be useful on key-passages such as the first break, providing data points for the milling operations. The incorporation of Arrius in an existing line is facilitated by its integrated electro cabinet and drive system, which makes it a straightforward process with low investment cost of electro components. Also, it can be flexibly positioned due to the integrated design. Besides all the mechanical and electrical improvements, Arrius delivers a higher automation degree and the capability to gather more data. The milling industry will be able to use this data to improve processes, through production stability and flexibility. At the end, Arrius carries a full package of innovations that will bring many benefits to the flour milling industry.