Hermes Fulfilment – energy upgrade at the Haldensleben dispatch center

Ordering goods online is something almost everyone has done, be it spontaneous gifts for a loved one, the bargain cushion covers on special offer or an item of clothing from the latest fashion collection that would be even better with the matching shoes. Depending on their type, size and weight, these goods are placed in bags, packets or larger packages.

However, few people realize all the logistics and technical work involved in processing their orders. Nor are they aware that, as in the case of Hermes Fulfilment, drive solutions from SEW‑EURODRIVE in the associated plant technology very often ensure the necessary reliability, flexibility, efficiency and sustainability.

Long roller conveyors and sorting systems typically handle the packaged goods. When using bags, however, this type of materials handling technology is not without its problems, because the packaging film can get caught between the rollers, especially in the sorting area. "Bags with a grip hole are a particular problem," explains Matthias Melahn, Group Leader of Process and Control Technology at Hermes Fulfilment in Haldensleben. After all, if a bag with a hole of this kind gets pulled between two rollers, the entire system jams. For this reason, bags are normally handled by separate sorting systems. That was also previously the case at Hermes Fulfilment.

For the modernization in Haldensleben, it therefore quickly became apparent that the new system needed to be equipped with belt conveyors. The contract for this went to the conveyor technology specialist Transnorm in Harsum and SEW‑EURODRIVE was commissioned to supply the energy-efficient drive technology.

Handling bags separately makes you dependent on the associated sorting system. "What happens if the sorter happens to be out of action due to a fault or for scheduled maintenance?" Melahn asked himself this very question. The solution was to handle everything – goods in cardboard packaging and bags as well as bag crates made of plastic – using a single conveyor line and a sorting/buffering section.

This system's inbuilt redundancy will mean Hermes Fulfilment is ideally equipped to deal with any faults that occur in the future, because having to transport bags to a different dispatch center by truck due to a lengthy plant stoppage is now a thing of the past. Another benefit is that the modernized materials handling technology has a special accumulating function to circumvent faults. The systems can thus be used as a buffer section that is separate from normal operation.

which places high demands on the drive technology. Hermes Fulfilment and Transnorm instantly agreed that this called for drives from SEW‑EURODRIVE. The MOVIGEAR^® performance drive units in use following the modernization move and coordinate twelve buffer belts for this purpose. If the sorter stops working, these buffer belts continue operating until they are completely full. This buffering ensures intelligent bridging of occasional delays – an invaluable contribution to boosting productivity at Hermes Fulfilment.

You quickly grasp the concept of "breakaway" and "breakaway torque" if you think of a dogsled. The huskies have to pull hard on their reins to get the sled, its load and the musher moving. They jump, strain and pull with all their might. However, once the sled runners that are stuck in the snow are finally released and break away, as it were, the dogs pull their sliding cargo seemingly effortlessly through the winter landscape.

At the Hermes Fulfilment dispatch center in Haldensleben, Transnorm has used long belt conveyor sections with an integrated accumulation function. Rather like a dogsled, packaged goods that are buffered by a timed belt must "break away" before continuing their journey. The more bags and packages there are, and the greater the weight involved, the higher the short-term overload force the drives need to generate to get them moving again on the conveyor belt in the normal S1 duty cycle (continuous duty). The necessary breakaway torques often exceed the torques required for the S1 duty cycle many times over.

Melahn explains the situation at the Hermes dispatch center: "We can have 25 bags or 25 packages moving along the conveyor line. Bag crates are the worst – they can weigh up to 30 kilograms. We can then very quickly find ourselves having to synchronize a total weight exceeding half a metric ton. Even then, though, we can't have a shaft breaking or a drive failing."

Fortunately, MOVIGEAR^® performance is the ideal drive system for such a situation. With a high overload capacity exceeding 300%, Hermes Fulfilment now effortlessly handles breakaway torques of this magnitude during the synchronization process. Eliminating the need to oversize drive technology that is often associated with such requirements had a positive impact in terms of both investment and energy efficiency.

At a dispatch center where hundreds of drives are operating around the clock and the fans required for cooling whir away continuously to keep the long conveyor lines running smoothly, you can well imagine the noise levels that staff are normally exposed to during their shift.

That is not the case with MOVIGEAR^® performance. The drive system requires no fans whatsoever and, at 65 dB, it is far quieter than a conventional gearmotor. The previous sound pressure level has been almost halved.

At the same time, the permanent-field synchronous motor integrated into MOVIGEAR^® performance delivers a level of energy efficiency that far exceeds IE5, the highest class to date, and even exceeds it significantly.. This makes it possible to save a huge amount of energy and reduce the connected load. Freeing up reserve capacity in Hermes Fulfilment's transformer station in this way gives the company vital scope for expanding operations. Another big advantage of the high efficiency is that it significantly restricts the thermal losses for each drive. As a result, the drive systems emit less waste heat and, consequently, less energy is required to cool the factory building.

Gear unit, motor and electronics in a single housing – MOVIGEAR^® performance decentralized drive units incorporate an inverter from our MOVI‑C^® modular automation system. This also includes on-board I/Os, meaning data from connected sensors can be read and forwarded.

Sebastian Hartmann, the Transnorm Design Engineer responsible for the project, considers this to be invaluable: "We obtain all light barriers directly connected to the MOVIGEAR^® performance on-board I/Os, which eliminates the need for the customer to have decentralized I/O stations."

Another big bonus is that the safety technology can also be integrated into the conveyor system without much installation work, because communication takes place via PROFINET^® and PROFIsafe.

Last but not least, MOVIGEAR^® performance drive systems are extremely compact, and their lightweight design makes them easy for a single person to install and remove.