All the Industrial Air Fans & Blowers
manufactured
are tested at the manufacturers end and performance testing report is
generated. It is highly recommended that the user should actualy
witness the testing of the air blower and make sure that the air blower
performance test results matches the design parameters.
On this page we explain the simplified procedure of
testing air blower
- Connect an extended piece at inlet and outlet of the
Blower. Extended piece length should be atleast the diameter (or
greater length of rectangular outlet). This is to ensure mixing of the
air flow. Please refer fig of Air Blower Test Setup given below
- A plate with tapping at the centre to fix manometer is
bolted with extended duct at outlet.
- When the Air Blower is started the plate is completely
bolted such that no air can move out. So the air velocity is neary
zero.
Note the pressure reading on the manometer. Corresponding current
reading of drive motor to be taken.
- Next open some threads of the bolt and loosen the plate.
Now air will start passing through the outlet
and same amount of air will make entry through inlet side. Measure the
velocity of air at the inlet and corresponding Pressure on manometer at
the outlet. Measure the motor current Reading.
- Repeat the same procedure and take readings for few more
points.
- Make sure to take one reading at designed operating
pressure. If the blower design is accurate you will get the desired air
flow at the operating pressure. Otherwise also take one reading of
pressure at desired air flow.
- So you have Pressure values corresionding to variations in
air flow. Plotting the graph of this flow and pressure readings will
give you system resistance curve for the particular blower.
- For particular flow and pressure reading you can calculate
power consumed from the current readings.
- Theorocial Power vs actual power will give you the
efficiency of blower at various operating conditions.
Formulaes
to Use
- Air Flow (cfm or m3/sec) = Velocity of Air (fpm or m/sec) / Area of Inlet Opening (ft2/ m2)
- Area of Opening = (3.14/4)x sq. of Diameter
- Motor Power Kw =(1.732 x Voltage x Avg of Current readings
x Power Factor) / 1000
|