1 stacker crane + 3 shuttles = 90 storage operations per hour

Dambach has installed a high-availability channel storage system for the first time at a Chinese tobacco producer. The customer had high requirements to meet, as Peter Tiebel, Technical Manager of Dambach Lagersysteme, explains: "We had to manage 90 storage operations per hour with a single, approximately twelve-metre-high storage and retrieval machine over a total aisle length of 35 meters. Under the given conditions, this was a very high number, also with regard to the requirements for the dynamics of the SRM. It was therefore important from the outset to optimize load pick-up and delivery. Before implementation, we used a calculation to prove to our client that we could achieve this if the material flow mix was reasonably suitable."

Piggyback tobacco

The storage system is designed for semi-finished tobacco products, which are stored in large containers with the floor area of industrial pallets. Two of the containers with closed walls and lids are placed on top of each other and then handled as approximately two-meter-high containers using the piggyback method.

The channel store receives the tobacco blends, also known as "blends", which come from production and are then still fermented, until they are called off to the production machines for cigarette production.

The continuous and therefore relatively deep storage lanes, each around 34 meters long, are each served by an automatic storage and retrieval machine on both the storage and retrieval sides.

As a special feature, the SRM on the storage side manages the three shuttles used for the storage functions, even though the SRM itself - a "Mono-ESA" single-mast unit from Dambach Lagersysteme - is only equipped with a chain conveyor for transferring loads from the conveyor system.

High storage frequency in single-shift operation

While three shuttles are required on the storage side due to the high frequency in single-shift operation, with which three different article groups can be permanently stored in parallel and sorted by type, two shuttles are sufficient on the retrieval side, as the task volume is distributed over two shifts here. "As far as I know, this is one of the first systems in which an automatic SRM manages several channel vehicles," emphasizes Dirk Lorenz, Head of Control and Modernization at Dambach Lagersysteme.

"The special feature is that the shuttle vehicles equipped with a capacitor operate independently in the channel and their energy storage system is supplied with power from the charging station installed on the stacker crane when the pallets are picked up. As the material flow computer monitors and controls the charging rhythms, timely recharging is ensured."

Saves energy: shuttles in deep sleep

In addition, as Dirk Lorenz explains, "Dambach has built an energy-saving function into the vehicles." This means that if they are not picked up by the RBG in time for recharging, they fall into a kind of "deep sleep" and only need around five percent of the energy otherwise required. This allows a period of one hour to be bridged, for example in the event of a fault in the system. During this time, the shuttle can still drive itself to the RBG for recharging once it has been addressed by the RBG.

To date, Dambach is the only company on the market with this innovative feature. In contrast to some competitors who offer similar systems, Dambach "does not rely on low-voltage technology products, but on products and components from renowned manufacturers in 400 V three-phase technology", as Lorenz emphasizes.

Reliable control concept

"As we implement systems worldwide, we also have to offer a corresponding, reliable service concept. This can only be achieved sensibly and satisfactorily for customers if we cooperate with manufacturers for the products and systems that we purchase for our systems, who are well represented in the respective country and whose products are available everywhere, such as catalog goods."

For this project, Dambach is cooperating "with renowned German manufacturers with whom we have jointly developed the control system for our sewer vehicles". As Lorenz emphasizes, the standard modular system of the cooperation partners was sufficient for the specific requirements of the shuttle control system. The pallet truck and the stacker crane with the handling equipment for the shuttles and the loading station are a standard assembly from Dambach Lagersysteme.

This pragmatic and sustainable concept, which is aimed at international business, the partnership-based cooperation and the resulting efficient products and systems open up further areas of application for the system. According to the Dambach managers, it combines several properties that only appear to be mutually exclusive at first glance: it is highly available, offers very high storage density, storage times of any length and, if required, precise and fast retrieval and storage. The system is ideal for storage strategies such as first in - first out or last in - first out.

Also suitable for deep-freeze centers

Peter Tiebel sees potential applications in the beverage industry with its need for high-throughput channel storage solutions. The system is also "ideally suited for applications in deep-freeze centers with ambient temperatures as low as -28 degrees Celsius." It is also ideal for applications where longer storage and maturing times are required, or for applications where quarantine phases must be observed because certain product batches must first be inspected.

Proven in China

The system in China has proven its worth: After three months of operation, it was readjusted and further optimized in October 2014. "We haven't heard anything from the system since then," say Peter Tiebel and Dirk Lorenz, which is a good sign for smooth operation. However, this does not give Dambach any reason to rest on its laurels, as the two experts emphasize: "We have only just begun to exploit the innovative potential of this technology and we will come up with many more variants and possibilities for further applications."

Reinhard Irrgang

Contact:

Dambach Lagersysteme GmbH & Co KG 76476 Bischweier Tel.: 0 72 22 / 96 60-0 E-Mail: