Re: Hose Is Chocking While Taking Powder.
Dear Mohan,
Although this thread is placed under the chapter Dust Control & Suppression, the system you describe is a pneumatic conveying system.
In a pneumatic conveying system, choking indicates that there is too much material picked up, causing a too high pressure drop whereby the air mover stops.
Moreover, your system is a vacuum system, whereby the air mass flow is reducing with the vacuum, causing a fast increasing Solid Loading Ratio, which leads to high pressure drops.
Additionally, a side channel blower reduces in volume flow at increasing vacuum, resulting in an extra increase of the SLR. (The choice of a Roots type blower would have been preferred)
High pressure drops causes the air flow to become less and thereby lower air velocities.
The air velocity can then become too low and the sand is not kept in suspension anymore and the pipeline chokes.
My first advise would be to check the pneumatic conveying design in respect to particle parameters ( particle size, particle density and suspension velocity) and the application of the side channel blowers (pressure/flow diagram)
A suction nozzle at the 3 m hose with a controllable air by-pass, through a snorkel pipe could (would) improve the situation. ■
Teus
Hose is chocking while taking powder.
Dear sir,
we were installed the centralized vacuum system in our foundry for collecting the sand. the sand is in powder farm and the density is around 1000 to 1500Kg/m3. the longest point of the system is 60m and 8 points between them.The header size is 108mm the drop is 73mm... we are using 25kw side channel blower and at a time one user point.
The problem is, when we collect the sand with 3m 70dia hose, it was chocking... the velocity at the longest point is 35m/s @ 70dia.
Please guide me whether i have to increase the hose dia or to use some speacial tool to avoide chocking.
Thanks,
Mohan ■