Re: Pneumatic Conveying Design For Al Pellets
hi
the outlet pressure of air mover is about 40KPa, if the air flow is 770m^3/h, for inner diamteter 77.9, the outlet velocity is about 44m/s, and inlet velocity is 31m/s, it sounds good for conveying the al particles, i think the bend should be specially made. the suspension velocity can be calculated, and the coefficient should be given result of suspension calcultaion. but i think if it is possible , take a test is very suitable for al particle pneumatic conveying
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Re: Pneumatic Conveying Design For Al Pellets
Dear Enej,
The suspension velocity of the Al particles of 12 mm will be approx 25 m/sec.
An end air velocity of approx 44.6 m/sec is therefore reasonable.
The SLR, resulting from your set up is 630 / (0.213 * 0.6 * 1.2 *3600) =1.13
This is a very low SLR, indicating a non efficient pneumatic conveying system.
A blower of 770 m3/hr at 0.4 bar requires a drive motor of approx 15 kW.
This results in an energy consumption of 15/0.63 = 23.8 kW/ton
Furthermore, this installation will create a lot of noise as a result of the Al pellets smashing against the wall.
Whether the pellets stay in one piece is doubtful.
best regards
teus ■
Teus
Re: Pneumatic Conveying Design For Al Pellets
Dear Kevin and Teus thank you,
I realise that the power consumption will be an issue. However I am inheriting an existing Howden Dresser 56RAI Blower with 18.5 kW (speed of 2407 rpm) motor that was not in operation for about 4 years.
I have few more concerns/questions.
Teus, what drag factor did you used when working out the suspension velocity?
As I did not have much to do with piping out the lean phase pneumatic conveying pipe runs, are there any absolute “do nots”. Can one have successive horizontal and vertical pipe runs or do you have to keep going up with incline runs until the destination point is reached.
Thanks once again for all your advices, assistance and help.
Best regards
Enej ■
Re: Pneumatic Conveying Design For Al Pellets
Dear Enej,
Suspension velocity is estimated:
v-susp = SQRT(4/3 * 0.012/0.05 * 2700/1.293) = approx. 25 m/sec
Drag factor 0.05
Have you calculated the pressure drop over the 120 m – 2 inch pipeline ?
That might already be more than the pressure which the blower can generate.
In that case there will be no pressure left for conveying.
Have you also imagined how 12mm pellets are moving through a 78mm pipe line?
BR
Teus ■
Teus
Re: Pneumatic Conveying Design For Al Pellets
Hi Teus,
Pressure drop calculations were carried out fore the following:
Total pipe run: 120m
Vertical elevation: 20m
Number of bends: r/d >6 = 10
Air filter x 1
Pipe entry x 1
Pipe exit x 1
Tee, flow through run: x 4
Full bore valve: x 1
Surface roughness: 0.00005, pipe is carbon steel with 0.07792 internal diameter
Tem of air 89oC, Flow 0.752 t/hr,
Flow of solids, 0.5 t/hr
Pressure drop was 48kPa., more than 40 kPa. I am in the process of confirming exactly the pipe run lengths.
Teus, I did not imagine how the pellets are moving through. The operator who run the blower 4 years ago when it was last in operation said that it was not noisy?
Do I need to consider anything here? ■
Re: Pneumatic Conveying Design For Al Pellets
Dear enejc,
I modelled your installation and ran the computerprogram and found that
the gas pressure drop is already 4500 mmWC.
Your calculation could therefore be a realistic indication.
The SLR is only about 0.66 and that should result in a low pressure drop for product losses.
Energy consumption = approx. 40 kWh/ton
Air velocities 27,9 m/sec – 38,4 m/sec
The diameter ratio/pelletsize = approx. 6.6. Big particles compared to the pipediameter.
There are not many particles required to form a plug.
Furthermore, I did not refer to the blower noise, but to the noise, generated by the Al particles bouncing through the pipeline.
best regards
Teus ■
Teus
Re: Pneumatic Conveying Design For Al Pellets
Enjay
Have you considered a Pneumatic Capsule Pipeline to transporting the aluminum pellets for you? Pneumatic Capsule Pipelines carry the pellets in a capsule from the loading point to the discharge point quickly, quietly and safely.
Your current objective is to transport 630 kg/hr both quickly and quietly. That is difficult because of the nature of your system layout and the size of the product. Each aluminum pellet will rattle around each elbow. Not only will this be noisy but also cause abrasion possibly to the point of causing replacement of the elbow(s). Also, aluminum dust is very explosive. A piece of tramp metal or stone inside the pipeline could cause a spark - that would be real trouble.
A Pneumatic Capsule Pipeline would transport your aluminum pellets quickly at 630 kg/hr, with little noise and with no wear to the pipeline elbows also no possibility of sparking. Further more the existing blower may be utilised. Without doing the calculations, a 100mm diameter pipe/tube may be required. A Single Line Reversing system may do the job for you. That is, capsules would be shuttled back and forth quickly; one way carrying pellets to the unloading point while the other way is returning empty capsules to the loading point.
Before designing the system it is important to know if the system is vertical or inclined up or down. The number of bends must be reduced. The bend center line radius will be about 5000 mm.
If this is of interest to you please email me at bweaver@pneutrans.net .
Brink Weaver
Pneutrans Systems Ltd. ■
Re: Pneumatic Conveying Design For Al Pellets
Hi all
Her is my concern over power consumption. In my view the densephase would be the key driver for conveying. Why do we prefer the dilutephase instead we have densephase. In todays competitive market the power consumption had hightened to take it into the consideration. Well iam not intesnsifyying to go but putting both the system in a double weighing M/C and differentiating both of them in teir operation aspects, power aspects and economical ways as well
Looking any comments...........
RAHUL CHAUBEY ■
Pneutrans Systems
Dear Mr. Brink Weaver
Pneutrans Systems Ltd.
In your website, the references to existing installations of Pneutrans Systems are not available.
Can you elaborate on the same, please?
Regards
P. Rekhawar ■
Re: Pneumatic Conveying Design For Al Pellets
Rekhawar
You have asked for references for Pneutrans Systems - there are many answers to that question.
Pneutrans is located near Toronto, Ontario, Canada. We have sold and installed many Pneumatic Tube Systems (same technology as Pneumatic Capsule Pipelines only smaller diameter) to industry and hospitals. P.C.P.'s are used for heavy industrial and mining applications.
To the best of our knowledge there are NO Pneumatic Capsule Pipelines installed in North America by anyone including ourselves.
There are 5 Pneumatic Pipeline Systems installed in Japan transporting
- burned lime in a steel mill
- limestone from a quarry to a cement mill
- tunneling application
These systems have been operating for 15 to 20 years.
There were/are 3 systems operating in Russia to transport agrigate, fertiliser and garbage. There is almost no information available on these systems.
There were 2 systems in Romania. One transported agrigate the other transported munitions for the military.
There were Pneumatic Tube Systems transporting mail between the major postal buildings within Paris, London, NewYork City, Houston, and Los Angelese.
There were 4 people subways built - England, Ireland, New York City and the Pentigon (Washington).
There have been tens of thousands of Pnetmatic Tube Systems installed in industry and hospitals. P.T. Systems are a small diameter P.C.P. with exactly the same technology. Check out the Pneumatic Tube System in a major hospital near you. Remember the air power and diameter of these systems can be varied to transport your product requirement. In your case it is a matter of automating everything including the loading and unloading stations.
If this subject is of interest to you email me at bweaver@pneutrans.net.
Brink Weaver
Pneutrans Systems Ltd. ■
Re: Pneumatic Conveying Design For Al Pellets
Hi Teus and other members,
Do you have any recommendations about the piping layout of the pneumatic conveying system?
Can I have combinations of horizontal and vertical pipe runs or do I have to have an inclined run.
Any advices on the piping are most welcomed as I do not have experience in this area.
Many Thanks
Kind Regards,
Enej ■
Re: Pneumatic Conveying Design For Al Pellets
Dear Enej,
I understand that you are intending to go on with your project.
I hope that you have redesigned this project after your original setup, as you explained in this thread.
If you have not, there will be a significant risk of building a non-performing installation.
The routing of your pipe system is free, taking into account the well-known don’ts.
F.i. bends, separated by straight sections.
Be careful,
Teus ■
Teus
Another Question For Teus!
Dear Teus,
I have redisgn the system so that the total pipe run is shorther and therefore pressure drop smaller than 40kPa.
The last hurdle that I have is selection of the appropriate set up to feed the Aluminium pellets out of the hopper into the moving air stream.
There is an existing hopper (pressure vessel) on site with the pinch valve on the outlet. As far as I know Pinch Valve is an absolute no in pneumatic conveying as its rubber seats will get damaged very quickly and the valve does not allow dosing.
We have considered installing a rotary valve but concern is that the pellets are rather large (12mm) and will cause blockages.
Another option we are considering is MATCON valve but our production department is not keen on it because this is something "new" and there are concerns regarding the maintenance (when hopper is full) and also need to redesign the feed hopper in order to integrate it
Teus, what is your experience about the above and do you have any other suggestions.
Regards and thanks once again
Enej ■
Re: Pneumatic Conveying Design For Al Pellets
Dear Enej,
For the feeding of 12mm Al-pellets into a vacuum system, you have to consult feeder equipment specialist.
Success
Teus ■
Teus
Pneumatic Conveying Design for Al Pellets
Dear all,
I have 12mm Aluminium pellets (assume to be spherical) with a particle density of 2700kg/m3 and bulk density of 1500kg/m3.. the pellets are specified as being 5mm -12mm but I want to assume the worst case scenario,12mm.
I am trying to design the system to convey these pellets in a lean phase a distance of 100m horizontal and 20m vertical. As I am not sure of the exact pipe run I have assumed a nominal number of 10 elbows.
Maximum flowrate of Aluminium pellets is to be 630kg/hr. Air will flow at the flowrate of 770m3/hr. Discharge air pressure is 140kpa absolute and the discharge temperature of the air is to be 89oC.
Selected internal diameter of the pipe is 77.9mm carbon steel.
My first concern is that the maximum size of the aluminium pellets is rather large, 12mm in size. What will the saltation velocity be of these particles? Is the above design sound? What else do I need to look for or consider from the practical point of view?
Any help is greatly appreciated.
Many Thanks
Enej ■