DENMARK
Dybvad Stål Industri has a new product
Plate freezers now for continuous freezing Dybvad Stål Industri makes plate freezers for the production of frozen blocks that are used by fish, and other food processing companies. The company designs and manufactures manual or automatic vertical and horizontal freezers that it supplies to processing plants on land as well as on board fishing vessels in countries round the world.
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n a quiet corner in north east Jutland is the town of Dybvad (pop. 628), home to Dybvad Stål Industri, a company established in 1969 that specialised at the time in steel components. A decade later building on the experience and abilities gained working first with steel and later with aluminium DSI manufactured its first plate freezer and in 1997 the company decided to pull out of component fabrication altogether and concentrate on plate freezers. Today the company has one of the widest ranges of plate freezer models in the world. As the name suggests the basic unit of plate freezers are two hollow extruded aluminium plates which contain the refrigerant. The material to be frozen is filled into the cavity between the two plates. As the plates are in direct contact with the material the freezing is relatively rapid and results in a block, the thickness of which corresponds to the distance between the plates. This distance can be adjusted depending on the size of the block that needs to be produced.
Raw material quality determines that of the frozen product Freezing is a way of locking in the freshness of the fish and preventing its deterioration. By freezing products it is possible to prolong their shelf life substantially and 44
Eurofish Magazine 1 / 2015
Most of the production operates on board fishing vessels
and developed. The company can offer a range of vertical and horizontal plate freezers that can be used wherever there is a demand for the production of blocks. We work very much with the fishing industry, says Peter N Christensen, the Sales Director at DSI, roughly 60 of our production is intended for fishing vessels, and we serve both the small vessels that have one or two freezers on board as well as the big Dutch pelagic trawlers that may have 50 freezers in operation and can process 400-500 tonnes of fish per day. The remaining 40 of the production goes to the on shore processing industry, where it is used to freeze fish fillets or crustaceans. Building plate freezers is a specialised operation that calls for specialised knowledge and tools so the barriers for entry are relatively high. Plate freezing is among the most effective ways of freezing, both in terms of freezing speeds as well as energy consumption, says Mr Christensen, which is also why DSI decided to focus on this type of freezing. Installation costs for a plate freezer are somewhat higher than, for example, for a blast freezer, on the other hand a plate freezer requires less space, which is an advantage particularly in the constrained space on board a vessel.
At DSI plate freezers are not just manufactured, but also designed
A plate freezer is designed to produce blocks, so for any
Peter N. Christensen, Sales Director, Dybvad Stål Industri.
if the freezing is done properly and with care the quality of the product will hardly be affected. For optimum quality however, the fish should be frozen as soon as possible after it is caught and should be kept refrigerated while waiting to be frozen. The quality of the final product is determined by the quality of the raw material – the quality of poorly handled raw material will not improve after being frozen. Once frozen, fish, if stored properly, can safely be shipped halfway around the globe to be thawed, processed, and then frozen again and sent to the market. Proper freezing and storage are among the factors that have contributed to the development of a processing industry in China and other parts of Asia that depends on frozen raw material in the form of whole round or headed and gutted fish from the US and Europe.
Fish is typically frozen either individually (individually quick frozen) or in blocks. Plate freezers are used for the manufacture of blocks. They are made to ensure the blocks are not too thick as this will negatively influence the efficiency of the freezing. Small pelagic fish are often the raw material for the production of blocks. However, their high fat content makes it necessary to glaze the blocks to prevent the fish from coming in contact with atmospheric oxygen and the fats within the fish from getting oxidised (rancid). The finished blocks are often wrapped in plastic for the same reason, before being packaged in cardboard cartons.
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