Getting The Best Of Cold Stores Featured

As Asia rebounds from the global financial crisis, changes in disposable income and living habits have seen a higher demand on frozen foods. Mobile racking solutions for cold stores offer good economic returns for companies looking to step up their operations. By Brian G Miles, regional MD, Schaefer Systems International

As Asian economies rebound from the global financial crisis, most are in a far stronger position than pre-crisis time: their GDPs’ are up, employment levels are high and most countries are posting positive growth factors.

Against this backdrop, multinational corporations (MNCs) are ramping up production to meet higher demands. As disposable income rises, life style changes are taking place, not least eating habits.

The days of daily shopping at the wet market, is now being replaced by regular visits to the cold store, where sales of frozen foods are rapidly growing.

In order to service this increasing demand for frozen food, a new industry of cold store operators is growing throughout Asia. These operators are moving away from the smaller custom built units and are building multi-user units with goods stored on pallets and a variety of cold store cells to accommodate a wide range of frozen goods in varying temperatures of up to -30 Deg C.

The cost of running a cold store can be up to 10 times the cost of an ambient warehouse. Therefore, careful planning is necessary to obtain the optimal return on this investment.

Flexible Designs

With the growth of the cold supply chain, a number of European and American cold store operators are moving into Asia, bringing with them their latest technologies. Invariably, these systems are designed to maximize the use of the footprint and available height.

This means moving away from the more conventional racking systems, such as double deep and drive in racks, to systems which will provide increased pallet locations, as well as offer the facility for individual case picking if necessary.

The key to designing any new cold store is to plan the storage system design at the greenfield site stage, where the dimensions of cold store suit the system to be used. It is surprising that many designs on the drawing board do not consider critical dimensions of the racking system.

European operators have realised that size matters. For example, a 15,000 pallet cold store only requires marginally more electricity to run than a 30,000 pallet store at the same temperature, provided that both rooms have the same number of doors.

The positioning of doors and access to the cold room with airlocks can have a significant bearing on power consumption. For high activity cold stores, the use of pallet conveyors that can deliver pallets in and out of the cold store with operatives using heated cab trucks, can reduce cold air loss and substantially increase operational efficiency.

The use of smaller personnel doors, in the larger stores have now become regular feature. Investment in high quality fast reaction doors, which open and close automatically, can reduce air movement into the cold room and ice formation.


Mobile Pallet Racking

By far the most popular storage option for the modern cold store is mobile pallet racking, where banks of selective pallet racking are mounted on electrically driven mobile bases, set on tracks inlaid to the concrete surface. In Europe over 80 percent of cold stores use mobile racking system.

In Asia, customers have also been fast to appreciate the benefits of these systems, with one supplier having built over 50 installations in Asia over the last eight years

With the use of adjustable pallet racking, the end user has 100 percent selectivity of every pallet, with lower levels available for case picking. Albeit at the expense of access aisles, as only one aisle is available per block, which could consist of as many as five to eight double entry racks.

This requires some careful assessment of pallet movements and case-picking requirements per hour/day, as only one truck can practically work in each aisle.

Previously considered operationally too slow, new hand held controls with radio frequency operation on the materials handling equipment allow the racks to be moved immediately once the reach truck exits the aisle. With an average time of less than one minute to reopen the next aisle, double pallet cycles of 20-25 pallet movements per hour is achievable.

The use of mobile pallet racking, which was once considered one of the most expensive options, has proven to be extremely cost effective, particularly so for a new greenfield sites, where the cold room can be designed to suit the optimum operational features of mobile racking.

All the cost of mobile racking is in the first two metres. Therefore, cold store consultants should be encouraged to maximise the height to suit their material handling (MH) equipment: typically more than 12 m for a reach truck operation or more than 16 m for a very narrow aisle. Optimum rack lengths are between 30-40m. Too short rack runs will require more movement of the racks.

Safe & Green

Mobile racks are now offered with a number of safety features that protect pedestrian and fork lift access. They can be fitted with automatic zone picking features which will subdivide the operational aisle into two or three smaller aisles for case picking.

Night parking is another feature to consider when the cold store is not in operation. It allows equal distribution between all aisles to permit airflow when racks are stationary.

Another important feature of mobile racks is that the aisle lighting can be fitted to the rack, which only lights up when the aisle is opened. This can reduce the use of power and energy, as well as the heat created. Using high-energy 250 watt bulbs over conventional 400 watt ceiling fittings, which can require another 200 watts to reduce the heat, it is possible to reduce the cost of lighting in the cold store by up to 80 percent.

Whilst flow racks remain a popular choice for operations which handle high numbers of homogenous product with limited stock-keeping units (SKUs) requiring first in, first out (FIFO), their cost per pallet location can be prohibitive.

Channel storage using an electrically operated satellite, which operates on a rail set below the pallet is an excellent economical solution. The satellite, which is operated by the MH driver, can automatically store or retrieve in both first in, last out and first in, first out designs.

It also has a shuffle mode which will automatically shuffle pallets from the on load to the off load position and can undertake an inventory count of the number of pallets stored per channel.

Whilst most system uses rechargeable batteries, a system which works from a direct rack power supply has been introduced. This configuration is suitable for high activity stores that work twenty-four hours a day, seven days a week.

Batteries can lose about 25 percent of their power capacity when working at extreme temperatures, so this alternative system is popular in cold stores, particularly those designed with automated storage and retrieval systems (AS/RSs).

Singapore currently has the highest cold room in South East Asia that is over 30 m in height with an aisle changing AS/RS. Similar systems have been installed in Vietnam and China, although not at the same height. These systems provide full-automated storage, which can operate 24 hours a day. They can be provided with picking tunnels to allow operatives to work at the lower levels case picking to pallets or belt conveyors.

[This article originally appeared in the January/February 2013 issue of APFI.]

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Asia Pacific Food Industry (APFI) is Asia’s leading trade magazine for the food and beverage industry. Established in 1985, APFI is the first BPA-audited magazine and the publication of choice for professionals throughout the industry with its editorial coverage on the latest research, innovative technologies, health and nutrition trends, and market reports.

Asia Pacific Food Industry is published by Eastern Trade Media Pte Ltd. The company owns numerous trade and consumer titles, including Asia Pacific Metalworking Equipment News and Industrial Automation Asia.


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