The fan shall be single-inlet with steel backward curved centrifugal wheel. The drive type shall be direct drive, coupling drive and belt drive. Structure of the fan shall be undone easily for maintenance and cleaning
The Design and manufacture of the fans are in compliance with the following standards:
ü JB/T 10563-2006(Technical Specification for General Purposes Centrifugal Fans)
ü JB/T 9101-1999 (Fan Rotor Balance)
ü JB/T 6445-2005(Over speed Test for Industrial Fan Impeller)
ü JB/T AMCA210-99 (Laboratory Testing & Fans Evaluation Method)
ü JB/T 10213-2000(Technical Specification for Fan Welding Inspection)
ü GB/T 19074-2003 (Industrial Ventilation Fans- Mechanical Safety Standard for the protection case)
The wheel shall be steel backward-bladed centrifugal and fully welded. The wheel shall be statically and dynamically balanced to level G4.0 in compliance with ISO standard 1940. Steady air-flow and noise should be minimal when the wheel is operating at the maximum allowable speed. The performance of the fan will not be affected because of the special characteristics of the wheel.
The fan housing shall be made in steel and its thickness and strength should be able to withstand the maximum running weight of the fan. The volute shall be continuously welded and equipped with access door for removing possible foreign objects entered into the scroll.
Fan inlet shall be aerodynamic design round curved section to transit the air to the wheel cone smoothly, it shall have good commutated effect to reduce turbulence, improve fan efficiency and reduce noise.
Fan surface shall be polished and cleaned up to remove particulates, welding slag, burrs, sharp edge, iron, oil, then epoxy coating or high temperature coating for high temperature environments use, fan surface shall be free of sags, wrinkle, blisters, exposed metal or peeling after coating. It shall be no corrosion and rust at least 10 years in allowable working condition.
Belt drive and Coupling drive
Fan shaft shall be heat treated through soaking furnace to the hardness level between HB250-280, and the maximum load should be 35% higher than the maximum fan operational speed. The shaft shall have shaft cover. It shall use 40 Cr steel when it is operated under 250。C and 35 CrMo shall be used when operating between 251。C - 450 。C. Cylindrical bearing box shall be used to support the fan shaft.
The service life span shall be longer than L-10: 80,000 hours at the maximum operating speed. N32-N46 lubricant shall be used inside. The bearing box shall equipped with water cooling system when operating between 61。C - 250。C. Water can be added depending on the actual operating environment. Water delivering system shall be added when operating above 250。C. The rate of evaporation shall be considered base on the operating temperature between 0.3 – 1 m3h.
The pulley shall be made of cast-iron and its construction size is determined corresponding to 130% of the driving power. The pulley and belt shall be furnished with cover. Flexible coupling shall be used for coupling drive. The safety of conveying power and torsion shall meet the design requirements. It shall have coupling guard.
Motor is carefully matched to the fan load, protection level IP54, and insulation class F. Motor ball bearings are used and lubricated. Motor and drives are isolated from the air stream to avoid grease or dirt accumulation.
Explosion-proof Structure (Only for explosion-proof type)
Fan shall conform to Spark C explosion-proof structure according to AMCA99 Standard. The inlet shall mount copper ring and the motor shall adopt explosion-proof type. The whole fan should own CNEX certification and the manufacturer must own the production license for anti-explosion electric products.
Aluminum manufacturer name plates each containing serial number and model type are mounted permanently on all fan bodies. All name plates are traceable by customers.