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Automatic frozen storage warehouses from viastore

28.01.2013

Intelligent systems save energy

Consumers increasingly are warming to frozen food products. In 2011 the per capita consumption of frozen foods in Germany came to 40.4 kilograms, according to Deutsches Tiefkühlinstitut in Berlin – and has almost doubled within 20 years; all in all, 3.31 million tons of frozen foods were sold in Germany in 2011. The trend continues and calls for increasingly bigger capacities throughout the supply chain – not only for transport, but above all for storage and goods turnover. There is demand for safe, transparent, energy-saving and, in particular, process-efficient solutions.

Frozen storage warehouses are very much in demand not only in food manufacturing and distribution, but also, for example, in the medical technology field and in the pharmaceuticals industry. But all have one thing in common: the cooling chain must be uninterrupted, the flow of goods efficient, and the products completely traceable. Manufacturers, wholesalers and service providers are bound to automate processes involving frozen products in order to create acceptable working conditions, reduce errors, make efficient use of space and minimize passages between different temperature zones, thus saving huge amounts of energy. After all, speed and quality are decisive factors in this competitive business. As supplier and modernizer of turnkey warehouses and goods distribution centers, storage and retrieval (S/R) machines, Warehouse Management Systems (WMS) and SAP Logistics Solutions, viastore systems GmbH, located in Stuttgart, has a high degree of expertise in this field.

Planning and process design determine (energy) efficiency

As a matter of principle, the technical processes in a frozen storage warehouse must be designed so that the process chain is not interrupted and the goods are always optimally cooled, while as little energy as possible is consumed. For this reason, viastore works closely together with the operator on the one hand and the specialists for refrigeration technology, architecture and construction on the other. As a first step the viastore planning specialists determine the key elements needed to meet the requirements of the particular operator. Analysis of the delivery structures plays an essential role here, because it is all-important that the right goods, in the required quantity, reach the recipient efficiently and in highest possible quality. The key elements include process design and process organization, building structure, temperature zones and the passages between zones, individual dimensioning of the refrigerating equipment and methods, design of the conveyor systems and storage and retrieval machines, the order picking concept, and suitable software that mirrors all processes and makes inventory management including sell-by dates, serial numbers and lot management transparent and traceable. It is necessary to maximize productivity in the smallest possible amount of space, to minimize the number of passages, and to design the processes so that the frequency with which doors are opened and the time in which they are open is minimized. This design, in turn, saves energy.

Particularly because of the high cost of energy it is also important to minimize the exterior radiating surfaces and to insulate the floor plate, roof and walls according to the current codes and regulations so that cold losses and damage due to cold bridges and condensation do not occur. The connection of the warehouse to existing or new building sections must already be taken into account during the planning so that the individual building sections can be designed separately. The crossovers ideally should be equipped with air curtains or locks. Doors and gates also must be designed according to the current frozen storage regulations, and a controlled frost heave protection system must be included in the plans.

Refrigeration technologies are not all alike

The correct design of the refrigeration technology also saves energy costs. Ideally, the cooling must be constant in each area of the warehouse. Cold production should take place during the night because electricity costs less then. Moreover, the effects of the refrigeration technology on the rack structure and the fire protection devices must be taken into account. Sufficient space for evaporators (and access to them) in the shelving areas must be provided. As to fire protection, the question of fire avoidance through inertization (oxygen reduction) or fire-fighting by means of a sprinkler system with antifreeze must be addressed.

The refrigerating plant consists of the refrigerant, the compressor for refrigeration, a screw or reciprocating compressor, and the evaporator, which transmits the produced cold and distributes the air throughout the entire space to be cooled. The required refrigerating plant performance should be attainable within 14 to 16 hours.

Machinery for minus 40 degrees Celsius and colder

To enable S/R machines and conveyor systems to provide smooth service in a frozen storage warehouse, they must feature equipment suitable for frozen storage. The drives, like the controls, the electronics and the mechanicals, must be able to withstand temperatures as low as minus 40 degrees. For example, photo sensors should be heatable so that they do not mist up, or control cabinets must be heated – or, if possible, located outside the frozen storage area to ensure that the electric controls work properly. Also, attention must be paid to the use of lubricating greases, oils and seals suitable for frozen storage facilities, foods or pharmaceuticals; special corrosion resistance requirements for metals must be taken into account.

Efficient order picking owing to powerful software

Another major advantage of automatic systems is that the working conditions of people in the warehouse are distinctly improved. Simple storage work is handled by the S/R machines. The picking of frozen articles therefore follows the goods-to-man principle. It is important that the picking station is ergonomically designed, that workers do not have to lift heavy loads in monotonous succession and are not unnecessarily exposed to low temperatures for long periods. A decisive factor influencing this is the warehouse management system (WMS), which, on the one hand, makes the use of picking aids like Pick by Voice or light displays possible and, on the other hand, makes for high transparency in the warehouse and distribution center through integrated management of lots, sell-by dates and serial numbers in accordance with EU directive 178/2002.

The WMS intelligently works out all processes in advance so that they smoothly dovetail without loss of time. In addition, it ensures that from goods reception to storage, to picking and to goods issue, every product is in the right place at the right time so as not to jeopardize the cooling chain. The software quality therefore should comply with international standards like IFS and be capable of GAMP validation.

The efficient software package viad@tWMS is fully scalable both with regard to function and performance. The system optimally controls every warehouse process based on flexible strategies. Operators have real-time access to all information. The operation and the control of viad@tWMS have been adapted exactly to the workflows in the warehouse. A single scan process or a push of a button is sufficient to trigger the subsequent processing steps. viad@t contains all the modules required for controlling storage/retrieval machines, the conveyor system and other mechanical components. Moreover, it handles the control and visualization of the complex material flow systems. Via standardized interfaces, viad@tWMS can be coupled with third-party products such as special haulers', customs or shipping software. viad@tWMS does not depend on a specific operating system, but runs on all common UNIX and Windows platforms. All leading data storage systems such as ORACLE, SQLServer or DB2 can be used. A modern client-server architecture enables the distribution of applications and databases to different computers within the network. viad@t supports several parallel host systems as well as several clients – with fully separated inventories.

Intelligent energy saving

There is great potential for energy savings in frozen storage warehouses and logistics centers. For this purpose viastore has developed the energy saving concept viastore blue, which evaluates not only individual energy consumers but the entire system. An intelligent WMS determines key figures for optimum ABC distribution in the warehouse. This avoids unnecessary movement of goods and is a most effective means of saving energy. To work economically and efficiently, it is possible, for instance, to install energy-saving drives, to use released energy, to design processes more efficiently, to plan the use of packages of appropriate sizes, and to make better use of the cargo capacity of the trucks.

Proven in the food and medical sectors

This frozen storage expertise has proven its value in many cases, as shown by successful international examples from the field. In Friona in the state of Texas in the USA, viastore erected a 20-aisle frozen storage distribution warehouse for Excel Beef Corporation. Included in the scope of delivery of the warehouse, which has some 80,000 carton storage locations, are 20 industrial-PC-controlled viaspeed XL storage and retrieval machines with two side-by-side single-deep load handling devices, the conveyor system, the shelving system and the fire protection devices. The load handling devices (lateral belt transfers), the inbound lanes and retrieval lanes and the shelving system are designed for cartons of three different sizes. Excel Beef is one of the biggest meat producers in the USA and processes around 3,000 head of cattle daily.

A system with 15 viaspeed XL S/R machines was delivered by viastore to the American food manufacturer Cargill Meat Solutions in Schuyler, Nebraska. Here, too, the load handling devices of the ultradynamic S/R machines can handle two cartons simultaneously. In addition, viastore supplied the conveyor and sortation equipment and planned the material flow. The logistics center has room for 50,000 cartons in which beef, pork and turkey meat are stored.

To the Spanish pharmaceuticals company Grifols viastore delivered an automatic frozen storage warehouse that is integrated in a logistics center in the American town of San Marcos (Texas). Grifols stores blood plasma derivatives there. They must be securely stored at reliably low temperatures around minus 35 degrees Celsius, carefully labeled and punctually delivered. The solution comprises a single-aisle double-deep container warehouse, a 55-meter-long roller conveyor, the warehouse software viad@t and five workstations.

Summary

In an automatic frozen storage warehouse from viastore, the stored goods are continuously monitored; an unbroken cooling chain in the warehouse and optimal material flow are ensured. With a larger storage volume and low costs for staffing and administration, stocks are reduced and products spend less time in storage. The range of viastore services comprises process design and process organization, building structure including insulation, the passageways between different temperature zones, the design of the air conditioning and refrigerating equipment, the design of the necessary technologies such as storage and retrieval machines and conveyor systems, integrated order picking solutions, and software.