1. What does reverse wind mean for axial fans
When using axial fans, sometimes reverse wind operations are performed, and many friends may not know what reverse wind means , In fact, the reverse wind of the axial fan means literally, that is, the wind flow is reversed.
Axial flow fans are generally used in industrial and mining sites to prevent harmful gases from entering the work area when a fire occurs in the air intake system.
Second, there are several ways to reverse the wind of the axial flow fan.
If the axial flow fan needs to carry out the reverse wind operation, there are many kinds. There are generally three types of anti-wind methods commonly used:
1. Use the anti-wind door and the side anti-air duct to reverse the wind
Axial-flow ventilation The machine has two anti-air doors. When the wind is against the wind, you can lift the anti-air door a and lower the anti-air door b. The surface air enters the ventilator through the shutters and the valve b, and then enters the side anti-air duct through the valve a, enters the air shaft and flows into the well. To achieve the purpose of anti-wind.
2. Adjust the angle of the fan blade to counter the wind
There are two ways to adjust the blade installation angle of the axial fan. One is to use hydraulic pressure during operation. Adjustment, often used in the fan adjustment of power plants. The second is to use mechanical adjustment. When the fan stops, adjust the angle of the impeller to achieve the purpose of anti-wind. The rotation direction of the impeller remains unchanged, and it is only necessary to turn the impeller to the anti-wind position.
3. Reverse the rotation direction of the fan impeller to reverse the wind
This method is to exchange any two-phase wiring of the motor power supply, so that the motor changes direction, Thereby, the rotation direction of the fan impeller is changed, and the downhole air flow is reversed. This method has less capital construction cost and is convenient to reverse the wind, but the air volume of some old models of axial fans cannot meet the requirements after the reverse wind. In some new axial flow fans, the rear guide vanes are designed to be adjustable in angle. When the wind is reversed, the rear guide vanes are twisted at an angle at the same time, and the air volume after the reverse wind can meet the requirements.
Three, the axial flow fan reverse wind operation process
If the axial flow fan needs to carry out the reverse wind operation, there must be an order from the mine dispatcher or technical director , and then operate. The specific operation process is as follows:
1. When the wind is reversed, press the axial flow fan to stop the operation normally, and stop the axial flow fan motor. Operate the fan impeller brake handle to stop the primary and secondary fan impellers respectively, and then restore the brake handle to its original position.
2. Turn the knife switch in the control cabinet to the “reverse” position, and then press the green button of the fan start control cabinet to start the fan, the yellow light is on when starting, and the green indicator after the start is completed When the light is on, the ventilator enters the anti-wind state, that is, from the extraction ventilation to the pressure ventilation. Reverse wind must be completed within 10 minutes.
3. Observe the instructions of each instrument, make a record, and report it to the mine scheduling room or the technical person in charge.
