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INDUSTRIAL VENTILATION DUST COLLECTION SYSTEM DESIGN
PUSH PULL HOODS
PUSH
PULL HOOD |
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| PRESSURE
HOOD |
EXHAUST
HOOD |
| Quantity
of air supplied Q1=Q2/(D*F) |
Quantity of air exhausted Q2=100-150
cfm of tank area (ft2) ,depend temp,ext. |
| Throw
length ,D feet |
Entrainment Factor ,E |
Hood height =Tan(10')*D=0,18*D |
0-8 |
2.0 |
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8-16 |
1.4 |
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16-24 |
1 |
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>24 |
0.7 |
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Slot width w designed for slot velocity
of 1000-2000 fpm |
| Where ; |
| Capture Velocity |
V |
fpm |
Air velocity at any point in
front of the hood or at the hood opening ,neccesary to capture
the contaminated air at that poinby causing it to flow into
the hood. |
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| Face Velocity |
Vf |
fpm |
Air velocity at the hood opening |
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| Slot Velocity |
Vs |
fpm |
Air velocity through the openings in a slot
type hood |
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| Plenum Velocity |
Vp |
fpm |
Air velocity in the plenum |
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| Duct Velocity |
Vd |
fpm |
Air velocity through the duct after hood. |
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| Transport Velocity |
Vt |
fpm |
Minumum air velocity through the duct required
to move particules in air stream. |
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| Dust Distance |
X |
ft |
Distance outward along center axes of hood. |
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| Air Flow |
Q |
cfm |
Required minumum air flow to capture dust
particles |
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| Area |
A |
ft2 |
Area of hood opening |
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| Diameter |
D |
ft |
Diameter of round hoods |
Dust Exhaust
system Hood Entry Losses Table
Back
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