External rotor axial flow fans are divided into two types: single-phase asynchronous capacitor operation and three-phase asynchronous operation. Single phase capacitor operated motors operate at 120V, 60Hz or 220-240V, 50/60Hz, while three-phase asynchronous operated motors operate at 380V, 50/60Hz. We can also produce motors with different voltages and frequencies according to customer requirements.
There are thirteen models of external rotor axial flow fans, ranging from 200mm to 900mm, depending on the diameter of the fan impeller. The number of blades is 5 or 7, and the materials are low carbon steel and plastic. There are various blade angles to choose from, with a wide range of options.
According to the different wind directions, fans can also be divided into blowing or suction. The suction wind direction is from the fan blades to the mesh cover direction; The blowing direction is from the mesh cover towards the wind blades. In addition, it is also possible to distinguish whether it is blowing or sucking based on the degree of concavity and convexity of the blades at the outer rotor lead out end, with concave sucking and convex blowing.
According to different protection levels, it can be divided into IP54, IP44, and fully open axial flow fans. IP54 axial flow fan, mainly used for equipment such as fresh-keeping cold storage, evaporator, air cooler, chiller, condenser unit, etc; IP44 axial flow fan is mainly used in central air conditioning, heaters, heat pumps, dehumidifiers, and ventilation circulation fields. Fully open axial flow fan, mainly used in ventilation equipment with relatively clean environment and low humidity such as air purifiers.
According to the different characteristics of the fan, it can be divided into two types: with and without a mesh cover. The mesh cover has a flat plate type, a flat plate type, a concave mesh type, a wall shaped flat mesh type, and a wall shaped concave mesh type. The installation methods include mesh cover, cylindrical frame, air guide panel (cylindrical), and air guide tube.
According to customer requirements, we can produce single speed, dual speed, and three speed motors.
Product Application
Depending on the installation method, there are also different applications:
Duct type: used for indoor ventilation and air exchange in building facilities
Air guide panel type: used in occasions such as air coolers, evaporators, outdoor air conditioning units, radiators, dehumidifiers, etc
Mesh cover: Used in conjunction with heaters, welding machines, high and low temperature boxes, air conditioning module units, central air conditioning outdoor units, and other equipment for ventilation and air exchange in places such as kitchens, bathrooms, bathhouses, bars, hotels, opera houses, as well as in conjunction with fresh-keeping cold storage and freezers.
Design selection instructions
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1. The external rotor fan can achieve stepless speed regulation through a transformer or frequency converter, with a wide speed range. Three phase motors can achieve dual speed or dual voltage through wiring method Y/△ conversion, while single-phase motors can achieve multiple speeds through tap speed regulation; The thyristor speed controller can achieve stepless speed regulation by changing the input voltage.
Our air volume curve test is conducted in an air state with a density of 1.2Kg/m3 and a temperature of 20 ℃, strictly following national standards. The measured air volume curve is true and reliable, making it easier and faster for users to choose the model.
3. The noise shown in the technical parameters is at A sound pressure level, measured at one meter from the air inlet according to national requirements.
4. Our company installs permanent lubricated sealed deep groove ball bearings inside the production fans. In terms of the mechanical structure of the fan, modal analysis is carried out through structural finite element method to obtain the first two natural frequencies of the fan. The design is made to move it away from the natural frequency of the bearing and avoid the resonance zone to increase the bearing life. Depending on the application scenario and surrounding environment, the average lifespan of the fan is over 30000 hours.
5. The motor can be directly led or a junction box can be installed at the bottom of the motor. The special length of the lead and the junction box need to be specified.
6. The single-phase motor is equipped with thermal protectors inside, which can operate in an environment of -30 ℃~60 ℃. If a thermal protector is required for a three-phase motor, it should be specified when ordering. The protection levels of motors are IP54 and IP44
7. Insulation level: Class B or Class F. For applications with high ambient temperatures, our company adopts F-level insulation and B-level assessment.
8. Our company also specializes in producing long shaft outer rotor motors and outer rotor motors with flanges. If the customer only needs an external rotor motor (without fan blades and mesh cover, model without installation diameter and fan blade diameter) for centrifugal fans, the speed, power, and installation data of the motor operating point should be provided, and it is best to provide wind turbine and volute samples.
Before using the motor, the motor grounding wire must be effectively connected to the external grounding device.
Fan structure
The external rotor axial flow fan consists of fan blades, external rotor motor, mesh cover, lead wires, and other components. The fan structure is subjected to strength verification, modal analysis, harmonic response analysis and other methods through structural finite element calculation, ensuring that our products have advantages such as structural stability and reliability, high safety factor, low vibration, and strong anti-interference ability! According to customer requirements, thermal protectors, junction boxes and other components can be installed, or different installation methods such as cylindrical and box can be selected.
The blades are designed according to the principles of aerodynamics, acoustics, and acoustic performance requirements. They twist according to a certain pattern from the blade tip to the blade root, and are made of high-quality steel or plastic. After dynamic balance verification, they have good starting performance, smooth operation, and low noise.
