| Given ; |
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| Hood Type : Cone Hood |
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| Hood Size : Width :1 ft Length:1.5
ft |
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| Operation:,intermittent container
filling ,low speed |
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| Dust Distance to Hood (X) : 1,25
ft |
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| Duct Size :1 ft diameter round
duct |
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| To Find |
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| Required minumum air volume ,Q |
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| Duct Static Pressure ,SPh |
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| Duct Air Velocity |
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| 1-Our formula for requiered air
volume Q from Table
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| Q=V(10*X2+A) |
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| V= Capture Velocity : 200 fpm
from Table,
(1 m/sn) |
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| Q=200(10*1.25*1.25+1*1,5)=3425
cfm (5754 m3/h ) |
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| Vh=Hood Velocity= 5754 /1*1.5=3830
fpm |
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| Vd=Duct Velocity =Q/Ad |
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| Ad :Duct Area Ad=3,14(0,5*0,5)
=0,785 ft2 |
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| Vd=3425 cfm/0,785=4363 fpm (22,1
m/sn) |
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| PSh :Reqired Duct Static Pressue
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| Ce =Duct entry loss : 0,9 from
table
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| SPh=(Q/(A*4005*Ce))**2 (SQR) |
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| SPh=(3425/0,785*4005*0,9)**2 |
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| SPh=1,46 in (37 mmSS) +%25 safety
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| Sph=1,82 in (46 mmSS ) selected. |
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| This is the static pressure at
the duct entry point to hood |
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