Fans Flashcards
List three (3) kinds of pressure found in operating fan ducts?
- Static
- Velocity
- Total Pressures
What is a manometer used for?
Is a U shape tube connected to the fan for measuring pressures.
How can you remove static electricity generated from a fan?
Ground the rotating element with a ground brush and cable assembly.
Name two (2) major type of fans according to flow through the impeller?
- Radial Flow Centrifugal
* Axial Flow Propeller
What is the name of the circular collection chamber mounted around the fan wheel of a centrifugal fan?
The Scroll.
Name two (2) ways of placing bearings on a shaft in relationship to the fan wheel?
- The wheels can be mounted between bearings
* The wheels can be mounted overhung on the shaft
How can control of air through fans be accomplished?
- Inlet Louvre
- Outlet Dampers
- Varying The Fan Speed
Why are some fans mounted on a base with the aid of springs?
Fan base springs are used to dampen out fan vibrations to the base.
What is the type of inspection that allows periodic checking of fans on a routine basis?
Preventative Maintenance.
Troubleshooting of fans is best accomplished by using which type of monitor?
A vibration analyzer.
Fan overhaul is best accomplished by following what directions/instructions?
Original Equipment Manufacturer’s Overhaul Prints And Procedures.
Why should all parts be inspected and measured during an overhaul?
All part need to be inspected for off-specification sizes and fatigue (cracks).
Why would the fan wheel hub be heated before installing it on a shaft?
The bore size is increased with heat, allowing easy installation onto a cold shaft?
Explain the purpose of balancing a fan rotor in a dynamic balancer?
Dynamic balancing is performed to reduce the vibration of the fan to acceptable levels.
What is the purpose of a cold rollover of the fan rotors?
A cold rollover is used to confirm that there are no rubbing metal parts and no cracking noises experienced after a fan overhaul.