Mechanical Air Movement And Controls Flashcards
Describe fan total pressure
The sum total of a fan static pressure and its velocity pressure
Describe fan static pressure
The difference between found total pressure and discharge velocity pressure
Describe velocity
Speed at which air is moving
Describe velocity
The pressure exerted as a result of the motion of the airstream
Name two general groups are classes of fans
Axial (propeller)
Centrifugal (radial)
Three types of axial flow fans
Propeller
Tubeaxial
Vaneaxial
What fan is almost the used the most
Propeller
Tubeaxial fans are considered to be what
Heavy duty propeller fan
Vaneaxial fans are considered to be what
High efficiency
Centrifugal fans are built how
In a direction at right angle to the fan
Four types of fan blades
Forward curved
Backward inclined
Airfoil blades
Radial blades
13x13x4=……./3.14……square x 2.5 =
?
What are performance charts for
Cfm
Static pressure
Rpm
Propeller disc fans are designed to
Have no ducts
What type of fan is used pollution control with high particulate loads
Radial
Which fan should never be used in a duct less system
Forward curved blade centrifugal fan
Best fan to be used on a blow pipe system saw mill
Radial axial flow fan
The most accurate volume control of air is obtained using
Opposite blade damper
Which damper is usually in locations where it’s fully opened or closed
Parallel blade
Parallel blades are the best for modulating airflow
False
Can propeller fans handle large volumes of air
Large volumes with low static
Uses for radial fans
Wood chips and grain systems
What are air extractors used for
They are used to move air when splitters can’t be used
Two styles of multi blade dampers
Parallel
Opposite
