Cold Link Africa May 2019 | Page 32

PROJECT INCORPORATING COLD CHAIN Ammonia packs replace old central plant By John Ackermann When the time came for Gansbaai Marine to upgrade their flake ice-making system in 2018, they approached Everflo, who subsequently designed and manufactured a unique ammonia cooling system comprising four packaged refrigeration units piped to four flake ice makers. G ansbaai Marine in the Western Cape was founded in 1962 and requires 100 tonnes of ice daily to cool sardines caught at sea. The sardines are then brought back, pumped off the boat, and canned in their factory. Although some fishing boats have an ice maker on-board or refrigerated seawater (RSW) systems, at Gansbaai Marine, because of the short duration at sea, the ice is made onshore. Before leaving for sea, flake ice is conveyed from a bunker about 50m from the quayside and mixed with seawater in the hold to create slurry ice to cool the freshly caught sardines. OLD DIMPLE PLATES Their existing flake ice maker was of the ‘falling film’ design with vertical dimpled plates. The harvested ice dropped into a vertical 8m bunker with raking system and conveyor to the quayside. Gansbaai Marine was an ideal application for Everflo’s packaged ammonia units. To meet the maximum daily Everflo has access to the plant control panel via the mobile network to advise on fault finding or setting of parameters. requirement, Everflo proposed four packaged units piped to four vertical flake ice makers. The new system was installed during the months when no fishing took place and was ready for the new season in August 2018. STANDARD PACKS ADD FLEXIBILITY Evert Potgieter, managing director of Everflo, gave insight to the design of the plant. “Instead of going for a more conventional central plant, we selected four of our packaged ammonia packs and these were piped to four imported Geneglace flake ice makers designed for pumped ammonia circulation,” he explains. Each package has a cooling capacity of 145kW at -25°C evaporation and +30°C condensing temperatures. Each ammonia package has a mass of four tonnes and is transported to site on conventional road vehicles. Site work required installation of suction and liquid ammonia piping between ice makers and the Everflo packages. 32 Being close to the quayside, the packages are cooled by seawater in a marine shell and tube condenser with titanium tubes. www.coldlinkafrica.co.za COLD LINK AFRICA • May 2019