Is Elvis In The Building?
Probably not until you give more details of the issue.
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Re: How To Calculate Particle Residence Time
Dear pandaba,
Residence time = travel distance/particle velocity.
Probably not enough to answer your question, as it shifts the problem to: “What is the particle velocity (not constant in time)”
Also read the posts on:
https://forum.bulk-online.com/showth...=18485&page=33
from # 220 and on.
Success
Teus ■
Teus
Re: How To Calculate Particle Residence Time
Hi Teus,
I have also no idea about the particle velocity. In most of the experimental papers , gas velocity and SLR is given along with the particle diameter and geometry.
Can I take particle velocity as equal to the gas velocity at inlet.
Near the wall , whether the particles will have zero velocity ??? ■
Re: How To Calculate Particle Residence Time
Dear pandaba,
Have you also read the articles on the BulkBlog?
Pneumatic conveying, Performance and Calculations:
https://news.bulk-online.com/?p=65
Dense phase- or dilute phase pneumatic conveying:
https://news.bulk-online.com/?p=238
Pneumatic conveying, turbo- or positive displacement air mover:
https://news.bulk-online.com/?p=309
Energy consumption per ton of a pneumatic conveying system:
https://news.bulk-online.com/?p=331
Pneumatic conveying, an unexpected relationship.
https://news.bulk-online.com/?p=445
Pneumatic unloaders: Problems to avoid
https://news.bulk-online.com/?p=74
Influence of electro static charge on pneumatic conveying.
https://news.bulk-online.com/?author=15
Bacterial heating of cereals and meals.
https://news.bulk-online.com/?p=216
Can I take particle velocity as equal to the gas velocity at inlet.
No, the average particle velocity is always less than the gas velocity (except at a pipe diameter increase).
Assume vertical conveying, where a particle is at least falling back in the airstream with its suspension velocity, relative to the air flow.
In horizontal flow, the drag force on the particle would become zero and the particle sinks to the bottom.
Collisions, the Magnus force and turbulence keep the particle in suspension.
The collisions reduce the particle velocity.
Moreover, the air velocity increases along the pipeline, due to expansion.
Near the wall , whether the particles will have zero velocity ???
Indeed, the wall air velocity needs to be higher than the suspension velocity to prevent sedimentation starting along the wall.
The wall air velocity is a function of the Re-number.
Success
Teus ■
Teus
How to Calculate Particle Residence Time
I am solving a problem on pneumatic conveying from vertical to horizontal pipe flow with a bend.
SLR and gas velocity is given . How can I calculate the particle residence time.
Some one please help me. ■