Operation, maintenance and repair of industrial fans (Part 1)
General information about fans
The basic rules and definitions of radial fans or centrifuges are so called because the fluids enter from the direction of the rotor shaft and then exit in a circular motion. The blades of this type of ventilators are convex, concave and flat shapes. In the first type, the fluid comes out by hitting the back of the curtain, in the second type, the fluid is discharged by being pushed by the inside of the blade, and in the third type The fluid is also driven by the back or front of the blade, but in this case, depending on the operating conditions, one side of the blade is reinforced relative to the other side.
The main and determining parameters in the design of fans are as follows:
• Flux or volumetric flow: is the amount of output fluid in a certain time, for example, in one second, one minute to one hour.
Static pressure: is the amount of force applied to the rotor to overcome the resistance created by the system for the passage of fluid, which is usually expressed in Pascal units.
Dynamic pressure: is the amount of energy that the fluid has at the output of the fan due to the speed obtained from the rotation of the rotor and impeller and is usually expressed in Pascal units.
Total pressure: is the sum of static pressure and dynamic pressure, usually measured in Pascals.
• Rotation speed or rotation: is the rotation speed of the rotor per minute, which is expressed in RPM.
• Performance efficiency: is the ratio of the force applied to the fluid through the aerator to the nominal force applied through the motor to the fan rotor, which depends on the characteristics of the rotor and is a dimensionless quantity. • Absorption power: is the amount of force that the ventilator needs to operate correctly and completely. Operating instructions for maintenance and repair of the dust collection system 12 generated by the engine and expressed in KW.
• Power engraved on the engine plate: This numerical specification indicates the nominal power of the engine that is written on the license plate and should always be greater than the absorption power of the ventilator. This quantity is specified on most electric motors in KW.
Sound pressure level: The sound produced by the ventilator impellers, which is in the range of human hearing and its unit is decibels.
• Sound power: Refers to the set of sound pressure by the blades and other sounds that are generated during fan operation and is expressed in watts (W).
Safety tips for installation operations
Except for the items specifically mentioned in the contract, the ventilation devices of Kavosh Zist Shayan Sanat Company include ventilators, centrifuges and related guards. Therefore, if outside this system, fluids and other devices cause the system to malfunction, the buyer is naturally responsible.
Even with shielded fans, there is naturally a risk of danger when starting the fan due to the high intensity of the air flow. Sometimes in fans with large dimensions this type of danger can lead to severe and fatal injuries.
It is recommended that the necessary safety warnings be installed in places where large pressure fans operate with large dimensions so that people are aware of the safety distance to the device. For more information on the details of these safety distances, you can refer to the international standards SO NI 13349, ISO UNI 12499.
Check the performance of the guards every month and in case of damage or breakage, replace them with the maintenance instructions and maintenance of the dust collector system 13 new guards. Note that to install the fans, use connections that do not loosen due to vibration, and to open them, tools and wrenches must be needed.
Consider a scheduled maintenance program to ensure that the fans are in good condition, making sure the screws and connections are tight at each visit. If possible, check the vibrations using monitoring equipment.
Always keep in mind the potential risks of repairing your device. It is better to always repair the fan in the safest conditions and take the necessary measures such as separating the motor from the fan.