Airmax II DX - Unit cooler - Alfa Laval - #1

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Airmax II Application This new range of industrial unit coolers has been designed using the well-known Airmax technology, which has become a standard for all installers and end users. Airmax II is available as a direct expansion evaporator (DX) for all HFCs as well as water/glycol unit coolers. This new industrial line is designed to keep fresh and frozen goods refrigerated from +30 to -40°C, with a high or low humidity content. Thanks to a wide capacity range (from 5 to 180 kW), which can be achieved using several coil combinations, fan diameters (up to 800mm), different fin spacing and a long list of options, Alfa Laval can fulfil every requirement with more than 200 standard models. Standard design Coil The heat exchanger is designed to achieve optimal capacity thanks to the staggered pitch rows that give a high secondary fin surface. The large fin surface ensures longer intervals between defrost cycles, therefore reducing the amount of daily energy used. The coils are manufactured with a special aluminium fin array and have a high efficiency internal copper tube with a grooved inner wall with 12 mm nominal bore. All this allows for a minimal internal volume with the advantage of using less refrigerant. Frame and Casing All units are manufactured using galvanised steel, zinc–coated and finished in corrosive-resistant RAL, except the drip tray which is aluminium coated. The frame has been designed to ensure easy installation and maintenance. A large, deep drip tray allows fast discharge of defrost water and the hinge fastening allows for easy maintenance. The supports have two different positions (ceiling or space) to enable installation of the water defrost cassette. Structural parts are fastened with stainless steel bolts and screws. Structures are made in galvanised steel with optimised length to enable uniform air suction in the coil. All panels such as the drip tray end covers are hinged for easier accessibility, making installation, servicing and maintenance easier than for other standard unit coolers. Fans Air suction fans are available in four different fan diameters: 500, 560, 630 and 800 mm, with a 2-speed, three-phase motor (Ä/Y) 400V 50Hz. The motors have a dynamically and statically balanced external rotor and are manufactured in accordance with VDE 0530/12.84 IP54 class F. Integrated thermo contacts (Clikson), provide reliable protection against thermal overload. All standard motors can work at temperatures down to -40°C. Special lubrification is available on request. R&D has developed the air flow distribution in order to give a uniform air velocity in the coil with: • High efficiency sickle blade • Better distribution in cold rooms • Reduced noise levels • Increased air throw Water/glycol For water/glycol applications, the coil is designed with same fin pattern and smooth 5/8” copper tube. All connections are thread connections with vent and drain plug as standard. All other characteristics are the same as for the Airmax II DX. Test Each DX heat exchanger undergoes a pressure and leak test with dry air at 31 bar, and is finally supplied with a nitrogen pre-charge, while the water/glycol is tested at 11 bar. Unit cooler Airmax II DX