Re: Solid Particle Transport Calculation
Dear Mr MiguelO
Indeed, the question is simple.
Basicly any particle can be moved pneumatically. The art is to determine how. The main key to that decision is the suspension velocity and additionally the solids flow characteristics.
I have seen some calculation methods and I developed one of myself. (as many others did)
The methods I have seen are mainly based on applying a product multiplication factor (K) to the gas pressure drop plus calculating some additional pressure drops.
The modeling of the pipeline and bends is based on equivalent length.
Another method of designing a pneumatic installation is using tables, based on product, pipe lengths and pipe diameters and gas velocities.
Although these programs are based on the physical events in pneumatic conveying, the calculation algorithm is rather rough and inflexible to “off-standard” installations.
Various articles and books can be found in the bulk online portal.
The program, developed over the last 25 years, calculates the physical effects of one particle, s.a. acceleration, deceleration, elevation, collision losses, suspension,velocity of gas and particles, etc.
From this calculation, the pressure drop can be derived.
This calculation iterates, until the output values match the input values.
This can be done for every pipeline- and pump configuration.
But also here, the product properties must be known.
That means that the same program has to run for a known installation and instead of calculating f.i. the capacity at a certain pressure, it calculates back the required product-loss-factors.
Developing a calculation algorithm requires a long period of theory building, testing, feed back, and (re)programming.
Therefore almost nobody is eager to share this knowledge into detail, as this knowledge makes it possible to do there job.
(one eye is king in the land of blinds)
May be other members on the forum have better news.
success ■
Teus
Re: Solid Particle Transport Calculation
Miguel
You will find offers for free spreadsheets and charts from various places.
Our firm has been selling and updating PNEUCALC, for over (20) years. There are thousands of users who find our software both user friendly as well as reliable and accurate.
If you would like additional information, please e-mail me directly.
Regards ■
Re: Solid Particle Transport Calculation
Miguelo,
Your question refered specifically to vertical pipes, the previous answer was I think more related to general conveying.
In vertical pipes the simple answer is you can just work out what the falling velocity (terminal velocity) of the largest particle would be in a static air stream and if the upward gas velocity is greater than that then the particle will go up. there are a number of programmes for predicting terminal velocity including http://www.processassociates.com/pro...te/termvel.htm
The sting in the tail (and with solids handling isn't there always?) is that if your effective upward particle velocity is low because you gas velocity is only slightly higher than the terminal velocity, the phase density (amount of solid/unit gas) can increase dramatically. If it gets too high you will move out of a lean phase regime and will effectively be in a dense phase regime which in a vertical pipe is effectively a tall fluidised bed. You then have to consider what type of fluidisation you are likely to have, will you get bubble formation, etc, etc. ■
Solid particle transport calculation
I think the question is quite simple.
How do I estimate if a particle of known density and diameter can be transported in a vertical duct with a gas of known P,T, composition and speed?
Are there softwares/spreadsheets availabe at the internet? ■