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Standard ATZAF fans range
ATZAF double inlet centrifugal fan with Airfoil blades series coveer a size range from 12 to 49. All fans within this range have the following characteristics:
- Optimally engineered for HVAC applications
- High quality, compact design
- Clss I and Class II veersions available (as per AMCA operating limts specification 99-2408-69)
- High effiiciency
- low power consumption
- quiet operation
- all fans are fully performance tested and certified in a state of the art laboratory in accordance with DIN, ISO, BS, and AMCA standards.
Technical details
Housing
All fan housings from size 12 to 40 are manufactured in galvanized sheet steel from sizes 12 to 18, the fan sideplatres ae spot welded to the scroll housing. From sizes 20 to 40 the fan sideplates are locked to the scroll housing through a Pittsbourgh seam which ensures a high quality air tight seal, as well as a structurally reinforced housing.
The design of the inlet cones is of vital importance for the fan performance and sound levels. They have been engineered to guarantee an optimal airflow path through the wheel and thus very high performance levels are achieved.
The inlet cones are manufactured in galvanized sheet steel and are bolted ontothe housing sideplates. A series of standard holes are located on the sideplates to allow the installation of frames or mounting base. These holes are positioned is such a way that several standard accessories can be attached with the necessary fixing screws. Housings for sizes 44 and 49 are manufactured in black steel sheet, reinforced with steel stiffeners, completely welded and painted with an anticorrosive synthetic paint. The inlet cones are also manufactured in black steel sheet and painted.
Airfoil Impeller
This high performance impeller is manufactured in corrsion resistant steel, with backward curved, true airfoil shaped blades, welded into position. All wheels are coated with an anticorrosive primer and a final layer of expoxy paint and are balanced both statically and dynamically, to an accuracy grade of G=2.5 in accordance to DIN ISO 1940-1 and ANSI S2.19-1989.
The impellers from size 28-28 T1 to 49-49 T1 and from size 12-12 T2 to 49-49 T2 are secured to the shaft via a steel hub. Aluminium hubs are used from size 12-12 R to 28-28 R and from size 12-12 T1 to 25-25 T1. The hub bore is precicion machined and inporates a keyway and locking screw.
Shafts
All Shafts are designed with a high safety factor and with the first critical speed well in excess of the maximum fan speed. Made with hardened steel, the shafts are precision ground and polished, and includee keyways for the wheel hub and sheaves. All shafts are coated with a protective paint for added corrosion protection prior to shipping.
Bearings
Sizes 12-12R to 28 -28R bearings are self-aligning, single row, deep groove ball type, in pillow block cast iron housings.
Sizes 40-40 T1, 49-49 T1 and from size 20-20 T2 to 49-49 T2 bearings are double row roller bearings in pillow block split cast iron housings. All bearings have been selected to guarantee a minimum L50 life time of 200,000 hours (as per AFBMA standards).
R-framed fans have the bearings mounted in a rubber interliner, which in turn, fits in a sturdy three arm or four arm spider bracket. These bearings are permanently lubricated and sealed for the life time of the fan. T1 and T2 fans have the pillow block bearings mounted on a flat iron bar, welded to the T frame. These bearings are complete with re-lubrication fitting already installed.
Operating temperatures range from -4 deg F to +176 deg F (-20 deg C to +80 deg C) for all Blowers.
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