The axial flow fan is widely used, which is the air flow in the same direction as the axial direction of the blades, such as the electric fan, and the fan of the air conditioner is the axial flow mode running the fan. It is called axial flow because the gas flows parallel to the fan axis. Axial flow fans are usually used in situations where the flow requirements are high and the pressure is low. Axial fan fixed position and air movement. Axial flow fans consist of fan impeller and chassis, simple structure but very high data requirements.
The basic principle of
Normal axial flow fan can be used for general factory, warehouse, office, residential and other places in ventilated take a breath, can also be used for cooling fan, air cooler, evaporator, condenser, spray drop, and so on, also has the mining axial flow fan,
Anti-corrosion and explosion-proof type axial flow fans adopt anti-corrosion materials and explosion-proof measures, and match explosion-proof motors, which can be used to transport explosive, volatile and corrosive gases.
The gas that is required to be sent by the axial fan should be free of obvious dust, non-viscous and fibrous material; Motor type direct temperature is not more than 40 ℃, belt drive type temperature less than 60 ℃. The amount of dust transporting gas must not exceed 150mg/m3,
Axial flow fan is mainly composed of impeller, casing, motor and other parts. The bracket is connected with the windpipe of the casing. Among them, the anti-corrosion type axial flow fan impeller and casing are made of fiberglass, and other type axial flow fans are made of steel plate.
The working principle of
When the impeller is rotated, the gas enters the impeller from the inlet shaft and is pushed by the blade on the impeller to increase the energy of the gas and then flow into the guide leaf. The guide blade turns the deflected air flow into axial flow, and introduces the gas into the expansion tube, which can be converted into pressure energy and finally introduces the working pipeline.
Axial flow fan blades work in a similar manner to airplane wings. However, the latter is to lift the lift upward on the wing and support the weight of the aircraft, while the axial fan is fixed and moving the air.
The cross-section of axial fan is generally a wing profile. The blade can be fixed or rotated around its vertical axis. Blade and airflow Angle or blade spacing may be unadjustable or adjustable. Changing blade Angle or spacing is one of the main advantages of axial flow fan. The small blade spacing Angle produces lower flow, while increasing the distance can produce higher flow.
The advanced axial fan can change the blade spacing (which is similar to the helicopter rotor) when the fan is running, thus changing the flow accordingly. This is called the rotor blade adjustable (VP) axial fan.
Axial flow fan is also called local ventilator, is a fan of industrial and mining enterprises commonly used, but is different from general and wind vane of the fan it's motor in a cylinder shape is a cylinder, for local ventilation, easy installation, ventilation effect is obvious, safe, can take hair as the wind sent to the designated area.
Energy saving reconstruction
Axial flow fan at startup, the motor current will be higher than the rated 5-6 times, not only affect the service life of motor and consumes more electricity. The system in the motor when the design selection will have a certain margin, the speed of the motor is fixed, but in the actual use process, sometimes at a lower or higher speed, so the frequency conversion reform is necessary. The inverter can realize the motor soft start, the input voltage frequency of the equipment to achieve the goal of energy saving speed, and can provide the equipment with the protection function of flow, overpressure and overload.
The difference between that
The main difference between centrifugal fan and axial blower is:
1. The centrifugal fan changed the flow direction of the medium in the air duct, and the axial flow fan did not change the flow direction of the medium in the duct.
2. The former installation is more complicated
3. The former motor is connected with the fan by the belt, which is generally in the fan.
4. The former is usually installed in air conditioning unit, outlet, boiler drum, fan, etc. The latter is often installed in the air duct, or the outlet front of the duct.
There are also inclined flow (mixed flow) fan, the wind pressure coefficient is higher than the axial flow fan, the flow coefficient is greater than the centrifugal fan. Fill the gap between axial fan and centrifugal fan. It also has the characteristics of simple and convenient installation. The mixed flow (or axial flushing) fan combines the characteristics of axial flow and centrifugal fan, although it looks more like a traditional axial fan. Weld the curved plate blade to the conical steel wheel hub. Change the flow rate by changing the blade Angle in the outer casing of the impeller. The shell can have an open entrance, but more often, it has a right-angled bent shape that allows the motor to be placed outside the pipe. The excretory shell expands slowly to slow the flow of air or gas, converting kinetic energy into useful static pressure.