Expert Group wins National Seafood Award for R&D

The Expert Group and the commonwealth managed Northern Prawn Fishing Industry Pty Ltd (NPFI) have been congratulated on their achievements for taking out the Queensland and National Seafood Awards for Research and Development.

The award from the Fisheries Research & Development Corporation (FRDC) was for an initial research paper “Refrigeration from Catch to Market - A Study of Refrigeration Technology Options for the Northern Prawn Fishery and the Sydney Fish Markets,” and the “Development of a new refrigeration system reference design and demonstration prototype for fishing vessels.”

Refrigeration is crucial to the successful operation of Australia’s multi-billion dollar commercial fisheries. The very hard-working, very confined and very low temperature refrigeration systems operating on fishing vessels are the first, vital step in a long refrigerated supply line that delivers fresh and frozen fish and crustaceans to markets around the world.

The fishing vessels in the Northern Prawn Fishery (NPF) and other tropical Australian prawn trawl fisheries have one of the most demanding tasks for refrigeration equipment, operating in constrained spaces under heavy load, in common plant rooms with the main engine and other equipment, in high ambient temperatures, requiring snap freezing of tonnes of sensitive product using equipment operating in a moving vessel, with heavy vibration and are exposed to corrosive salt spray and water.

The Australian Seafood Cooperative Research Centre (CRC) and Tropic Ocean Prawns provided the $675,000 needed to design and install the new system. Expert Group initiated the design project with industry workshops that fed a lively debate and produced a greater understanding of the technical, operational and maintenance issues surrounding NPF and other tropical fishery refrigeration systems.

The final result was a system that is both cost-effective and more environmentally friendly that uses less refrigerant due to the improved containment design. The system is more energy efficient and has greater snap freezing capacity of 6 tonnes per day, delivering almost twice the refrigeration harvesting capacity of the previous system. All of this equates to lower emissions per kilogram of prawns caught and processed as the main engine produces more than 65% of the emissions when trawling.

The system includes the latest options in automatic controls, variable speed drives and economisers on all compressors, computer monitoring and remote fault diagnosis for vessels at sea. Other features include:

• Pre-chilling of prawns down to 15^oC to improve the equipment operating efficiencies and enhance product quality.
• A hydraulic deck snap freezer capable of freezing 1 tonne of prawns in 6 hours (versus traditional times of 11 to 16 hours), and a fixed plate snap in the hold with capacity of snap freezing 4.5 tonnes in around 10 hours.

The new system was developed and designed with a focus on refrigerant containment to minimise the risk of refrigerant leaks. This was achieved by eliminating high-risk connections, using stainless steel welded piping and incorporates a 5 point sample draw refrigerant leak detection system.

The project has now been documented in unprecedented detail including system performance results, design standards and manuals for the CRC that has made them available for other vessel operators through its member bodies, the Australian Council of Prawn Fisheries, the WA Fishing Industry Council and the Fisheries R&D Corporation.