Exercise -2
A fan draws exhaust gases at  from the hood of a furnace as shown below
Figure 22.2: |
Arrangement of hood to discharge exhaust gases |
The exhaust gas flow rate is 
The duct is rectangular cross section  and is joined by an elbow as shown in the figure. Total length of the duct is 90 m. Calculate horse power of the fan from the following data
Friction losses due to contraction and expansion are 0.4 and 1 respectively.
. to calculate friction factor. Equivalent length for elbow  .
Hint: Apply mechanical energy balance between plane 1 and 2 and get the following expression
 |
(5) |
 |
(6) |
Substituting the values.
Power = 8.8 hp.
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