Re: Pneumatic Conveyor For Paper Fiber
Dear Jake,
I assume a vacuum system.
We miss the paper fiber particle size, material density and bulk density.
Summarizing the given data:
Rate: 10 lbs/min = 0.075 kg/sec = 0.27 ton/hr
assumed paper fiber:
material density = 450 kg/m3
bulk density = 250 kg/m3
suspension velocity = 0.7 m/sec
Conveying length = 45 m
pipe size 4” = 95 mm
vacuum pump = 500 cfm = 0.236 m3/sec
Calculation results in:
air velocity approx. 33 m/sec
pressure drop approx 0.19 bar
SLR = 0.075/(0.236 * (1-0.19)) = 0.392
Remarks:
air velocity is very high
due to the very low SLR, the vacuum is mainly caused by air flow losses and additional pressure losses (cyclone, filter.etc.)
Vacuum decreases significantly, when the air flow is decreased.
An eductor venturi could also solve your installation design.
See:
http://www.foxvalve.com/
Success
Teus ■
Teus
Re: Pneumatic Conveyor For Paper Fiber
Conveying the paper fiber's is the easy bit. The rates & distance you are after can be easily done with a 2” pipe with 12 m/s pick up velocity in a negative conveying system using a simple side channel exhauster with 100 mbar pressure diff. If the feed is coming consistently from the hammer mill then it will be fine you will not need anything on pick up side vacuum will pull the materiel in the conveying line.
The interesting bit is the filter receiver, due to the very low particle density these fiber will form a layer on the filter media and will not clean of using conventional pulse jet cleaning. Mechanical shaker filter will be a better option. Since the material will be in the de-aerated state it will also cause discharge problem as you have rightly mentioned. If you want to use flap valves then don't size them on throughput make them big so that the material does not arch in the outlet. ■
Re: Pneumatic Conveyor For Paper Fiber
Dear Mantoo,
Recalculating your advice of 2”and a pick up velocity of 12 m/sec, resulted indeed in a much smaller and more efficient paper fiber vacuum pneumatic conveying installation.
Jake:
It would be interesting to know where you got to the 4” installation with 500 cfm.
Success
Teus ■
Teus
Pneumatic Conveyor for Paper Fiber
Anyone have experience with airveying paper fiber? I have 10#/min of fiberized paper (done with an existing hammermill) that I need to convey 150' without any elevation changes. The material is metered and needs to be delivered at the same metered rate. I am thinking of using a 4" line with a 500-600cfm vacuum system. I would like to use a cyclone receiver with integral dust collection. I also might need to use a double flap valve instead of a rotary to prevent discharge problems. Any ideas or comments are appreciated. ■