Re: Pneumatic Conveying System
We run a two day short course on pneumatic conveying in London, UK twice a year (May & November). Details and downloadable booking form are on our website at: http://www.bulksolids.com/educatio.htm.
We also sell the course notes seperately at £100 sterling a copy (plus p&p) if you cannot make it over to the UK.
If I can be of any further help, please let me know.
Regards
Richard Farnish
e-mail: r.j.farnish@gre.ac.uk
The Wolfson Centre for Bulk Soilds Handling Technology, Univ.Greenwich, London, UK.
URL: www.bulksolids.com ■
Resources
This very website offers excellent resources. Click the button eLibrary on the top tool bar. Input the search topic. After you select the articles that are of interest to you, click order information. There you can order individual articles, magazine issues, or a collection of the best articles. These prices are quite nominal in comparison to other alternatives.
Dennis Hauch ■
Pneumatic Conveying Problem
Dear Ms or Mr :
This is a second writing in this Forums to me. Many thanks for your kind advices.
To be honest, I'm studing PCS with my colleague during the serveral days ago. Our plant have 6 pneumatic conveying systems which are dilute phases. The transfered material is polypropylene powder(BD:0.45) and carrier gas is nitrogen.
In these days I have some problems about the transfered rate. Originally, the designed capacity is 3.0t/h, but the actual is under 2.3t/h. I don't know how can I approach to solve the problem.
The operating conditions of our system is like this :
Design Actual
- Pressure(kg/cm2.g) 0.816 over 0.82
- Temperature(Celsius) 40 40
- Gas flow rate(Nm3/Hr) 500 500
- Line size(inch) 3 3
When the flow rate was reached to 2.3t/h, the system was shut down because of high pressure of the lines. So we are operating the system under the 2.3t/h.
Would you make me clear about the problem?
I wonder it is correct to reduce the gas flow rate to solve the
problem.
Is there any ideas to fix the problem?
Best regards, ■
Re: Pneumatic Conveying System
Your pick up velocity is about 72 ft.sec, a bit too high for a 3 inch line. You can reduce it to 65 ft/sec. This will reduce the pressure drop but will not be enough to run the system at the desired maximum rate. To further increase the rates, you can install a centrifugal blower at the end of the conveying line. This will reduce the system pressure drop and allow you to increase the rates.
Regards,
Amrit Agarwal
Pneumatic Conveying Consultants
polypcc@aol.com
www.powderandbulk.com/pcc
Fax: 304 346 5125 ■
Pneumatic Conveying Problem
There are a few unknowns here which make it difficult to address your problems. The most important being pipeline length and configuration and, actual pipe diameter (internal). 3" being a nominal size could reflect anything from 3" OD tubing x 0.120" wall (2.76" I.D.) to 3" sch 10 pipe (3.26" I.D.)
This range of diameters could reflect a terminal velocity range of 25.8 m/s to 36.1 m/s, which seems a bit high for PP powder at 0.45 BD.
Most curious is, what is your system pressure drop without material (air flow only?) It seems there may be some problems here.
Again, without knowing the specifics as outlined above, just as an example, a system conveying PP powder at 3 tph over a distance of 60m horizontal and 30m vertical with 4 x 90 deg. bends should not require much more than 350 Nm3/hr at 0.5 bar and 6.0 kw.
Good luck,
Dean Kriskovich
NOL-TEC SYSTEMS, Inc. ■
Re: Pneumatic Conveying System
You should attend our 4 day course on pneumatic conveying. It has been given for the last 30 years. After taking this course you will understand pneumatic conveying whether you are involved in designing, operating, or in maintaining these systems. We also give in-house courses.
Feel free to contact us.
Amrit Agarwal
Pneumatic Conveying Consultants
www.powderandbulk.com/pcc
polypcc@aol.com
or
pccsolt@enter.net ■
Pneumatic Conveying Problem
Ehfanrp,
I have considered the operating data that you have provided and I can say the following.
The system is running quite comfortably at 2.3 Mt/h, the pickup and terminal velocities are 14.3 and 25.8 m/s, respectively, and the solids loading is a reasonable 4.28. The only concern is the system pressure, 0.8 bar, which seems to be higher than it should be, and which prevents conveyance of the desired 3.0 Mt/h.
You indicate a gas flow of 500 Nm3/h. But if, say, 20% of that is lost as leakage (principally through the rotary valve) the actual conveying flow becomes 400 Nm3/h. Then the pickup and terminal velocities fall to 11.4 and 20.6 m/s, respectively, and the solids loading climbs to 5.35.
If the above is true, it could well be that the conveying pressure is artificially high because you are conveying at too low a velocity, to the left of the pressure minimum point on the pneumatic conveying diagram. In that case, increasing the velocity will actually decrease the system pressure. This pressure decrease will now provide room to accommodate an increased conveying rate.
To prove the above, increase the conveying velocity and observe the system pressure, it should fall. For added proof, decrease the conveying velocity and observe the system pressure, it should rise. But be careful, blockage of the system is possible. Perform this simple test before making any arbitrary changes to your system.
I trust this is helpful for you.
Dennis Hauch ■
Pneumatic Conveying System
I'm a chemical engineer from south Korea. I work for Samsung Atofina Company for 8 years.
In these days, I'm very interested in Pneumatic conveying system.
So I'm studying the PCS system a few days ago, but it's very hard to understand to me.
If possible, would you recommand me a good education course about the PCS?
In our company, there are 6 dilute phase PCS systems and the transfered materials are the powder and pellet of polypropylene.
Many thanks. ■