Duct Arrangement

Posted in: , on 14. Jun. 2012 - 06:04


I went SILICA processing plant , they have cartridge type dust collectors. my question is for duct arrangement. they use plastic 4" flexible duct for all machines , also they not use proper canopies .

I suggest proper duct arrangement , as fig shown ? any person can be more explain disadvantages of previous arrangement vs new arrangement

duct arrangement model (1)




Uditha Kohowala



Duct Arrangement

Posted on 14. Jun. 2012 - 09:56

The "new" arrangement you show in your sketch is preferred, to maintain optimum transport velocity, limit abrasive wear and avoid excessive pressure loss. For the three 4" diameter branches (and using commercially available ducts) the first duct enlargement should be 6" dia. and the final duct should be 7" dia. This will give reasonably consistent velocity in all ducts.

Silica is dangerous to the health of workers (and machinery). It is also very abrasive and I expect that your plastic flexible ducts will not last very long. You should get expert help to design and build a proper dust collection system.

Michael Reid.


Posted on 15. Jun. 2012 - 07:10

thanks Mr. Michel

they have allready existing 7 dust collectors (cartridge type Japanese 3.7 KW , model dust mic ) these are working very good

but I observe several dust lekage points are there, also existing extrction points have not proper design canopy hood

I try to do re design all canopies and cover lekage points , if unable to cover lekage point i will use canopy for extraction.

for my calculation for extra extraction points I design bag filter for cover these points (I will not use cartridge filter)

thanks for your valuble help



Duct Arrangement

Posted on 16. Jun. 2012 - 07:12


The guidelines for ducting and hood design shown in the publication: Industrial Ventilation- A Manual of Recommended Practice: published by the American Conference of Governmental Industrial Hygienists, will be a big help to you.


Michael Reid.