- Fan Type
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 allow convenient withdrawal of the wheel for maintenance and cleaning.
- Quality Standards
The fan shall be tested in accordance with AMCA Standard 210 and 300, The manufacturer must own the production license for industrial products and ISO9001 quality system authentication.
The wheel shall be steel backward curved centrifugal and fully welded. The wheel shall be statically and dynamically balanced to level G4.0 in accordance with AMCA204. When the wheel is operating at the highest allowable speed, the volume shall be stable and the noise shall be low. Wheel features shall be able to avoid performance downgrade resulting from sliding of the working points. Wheel material shall be Q235 for the temperature under 60 degrees centigrade, Q345 for the temperature between 61 and 250 degrees centigrade, and 304SS for the temperature between 251 and 450 degrees centigrade to ensure the wheel’s strength and no creep deformation in high temperature and high speed running in working condition
- Fan Housing
The fan housing shall be steel, the thickness and strength shall be adequate to support fan max running weight. 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 smoothly transit the air to the wheel cone, it will have good commutate effect to effectively 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.
- Transmission Device (Only for belt drive and coupling drive type)
Fan shaft shall be heat treated through soaking furnace to the hardness level between 251 and 450 degrees centigrade, and the maximum load is 35% higher than that of the max RPM, the shaft shall be furnished with cover. The material of shaft shall be 40Cr when the working condition temperature under 250 degrees centigrade, and shall be 35CrMo when the working condition temperature between 251 and 450 degrees centigrade. The support structures shall be whole drum-type bearing box. The bearings shall be selected for a minimum (L-10) life in excess of 80,000 hours at maximum cataloged operating speed. The bearing lubrication shall be adopted thin oil between N32 and N46, the amount of lubrication oil shall be according to the requirements of the oil level mark. The Bearing box shall be equipped with water cooling device for choosing whether or not through water according to the conditions in the field for the temperature between 61 and 250 degrees centigrade. The Bearing box shall be equipped with water duct and through water for the temperature up to 250 degrees centigrade, the water consumption increased as the temperature varies, generally can be considered as 0.3~1m3/h. The pulley shall be constructed of cast-iron; Fan pulleys shall be sized for a minimum of 130% of driving power. The pulley and belt shall be furnished with cover. The coupling shall be elastic coupling with cover, too. Its safety of conveying power and torsion shall meet the design requirements.
Motor shall be carefully matched to the fan load, IP54, and insulation class F. Motor bearings shall be lubricant ball type. Motor and drives shall be out of 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.
Permanently fixed aluminum nameplate shall be fixed on fan body clearly display fan mark, product model and serial number (i.e.: unique ID for each fan), so that the customer can use this number to find out the parts used.