Pneumatic conveying of alumina powder

(not verified)
Posted in: , on 18. Aug. 2003 - 18:42

We use pneumatic conveying of our alumina .We face significant problems of pipe wear ----unfotunately most of the pipes are normal carbon steel pipe and the wear is evidend mostly in bends . What is the recommended material for this pipes

Can u suggest any software or design techniques for such pipelines ----sizing /pressure drop/flow etc

Sudip Ghosh

Aluminium Bahrain

Dennis Hauch - Freeport, TX, USA
(not verified)


Posted on 21. Aug. 2003 - 06:10


Convey the alumina at the lowest possible velocity because pipeline erosion is exponentially related to conveying velocity. Dense-phase conveys at velocities an order of magnitude lower than those of dilute-phase. The lowest possible dilute-phase velocities occur at the pressure drop minimum point on the Zens conveying diagram.

The wear characteristic of long radius sweeps, e.g. 10D, is worst, 5D is only slightly better. There are special bends such as the Gamma bend, Vortex bend and blind tee that can significantly reduce erosion. In certain extreme cases the best results are obtained by conveying through rubber hoses.

Undoubtedly conveying companies and various consultants will offer their design services, but at a cost. I do not recommend commercial software; the results must be taken on faith because key program calculations are proprietary and inaccessible to the user.

I would recommend a short conveying course to quickly bring you up to speed. From time to time companies like Coperion-Waeschle and Zeppelin offer courses and workshops that are excellent and well worth the investment.


Dennis Hauch

biplab K. Datta - POSTEC, Norway
(not verified)

Re: Pneumatic Conveying Of Alumina Powder

Posted on 27. Aug. 2003 - 08:40

Hello Sudip,

I could not see any information about the alumina transport rate, air flow rate, pipe diameter and pipe length! Pipe layout would alos play a vital role !

We have been quite successfully solving alumina transportation and erosion related problems for Norsk Hydro in Norway.

Unfortunately as it has been already pointed out by Dennis there is no ready made software for such purpose and even if you get one you are in for a even bigger problem !

Hence in such situation it is best to try to solve the problem based on some lab scale test results or data collected from the actual plant.

You may please contact me at the address given below. My email address is


Jan van Heerden - RSA
(not verified)

Pneumatic Conveying Of Alumina Powder

Posted on 3. Sep. 2003 - 08:01

Hello Sudip,

I have recently joined this forum - see my thread on pressure drop across an orifice plate. If I look at the number of views and the number of answers, it seems to me that in this forum there are a lot of persons looking for answers and very few giving answers!

Let me try to give you some advice on your wear problem.

1 Replace the bends with tee-pieces with one leg blanked off.

Material will collect in the blanked-off leg. The solids entering

the tee-piece (bend) will collide with the material and not the

metal. Bends like this outlast normal bends at least 4 times.

The downside of this arrangement is that it increases your

pressure drop across the bend. If you have enough pressure

to play with, it is a small price to pay.

This arrangement is basically a short radius bend. As you

know, the particles are decelerated in a bend and you need

a straight after the bend to accelerate the particles again. If

you replace your normal bends with a blanked-off tee, the

deceleration of the particles will be more pronounced. It is a

common phenomena for solids to drop out of the air stream

just after a bend. This can lead to blockage. If you had

blockage problems in the past, you must be aware of the


2 You can use ceramic lined bends. Although much more

expensive than normal bends, they outlast normal bends

several times. If you take the savings in downtime and

maintenance cost into account, they are well worth it.

Good luck,

Jan van Heerden

Conveying Alumina Powder

Posted on 13. Sep. 2003 - 02:30

I've done a number of systems handling various grades of alumina and used just about every style elbow (for various reasons) and have found that the best type of elbow was ceramic lined, second to this would be a blind tee or vortice -el. These systems were all dilute phase but there is a definite plus to a dense phase system for abrasive materials.

Allen L. Powell

Solution For Your Wear Related Problems

Posted on 22. Jun. 2010 - 05:34

Dear Sir,

Your problems can be solved by lining the pipes and bends by 92% Alumina Ceramic Liners for Alumina Conveying.

Average life can be Eight times than that of Carbon Steel.

Please visit our web site: www,



Re: Pneumatic Conveying Of Alumina Powder

Posted on 24. Jun. 2010 - 08:14

Dear Sudip,

Your main problem is bends. These should be replaced. You have many options given above. Well designed pocket Tees will be the cheapest.

Carbon steel pipe will also wear off but you could postpone its replacement until it gets real worse. At that time you could replace it with stainless steel. It is much harder than carbon steel.

For sizing/designing the conveying system, you may use the method given in my article. You could use this method to find out how to minimize the conveying velocity.


Amrit Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Charleston, WV, USA


Ph 304 346 5125

Re: Pneumatic Conveying Of Alumina Powder

Posted on 7. Jul. 2010 - 12:10

For some very good and affordable information concerning numerous aspects of material handling, including flow from bins and hoppers, mixing and blending, as well as pneumatic conveying- look at the lecture series now available at

In addition, contrary to the views of Mr. Hauch concerning commercially available pneumatic conveying sizing software, PNEUCALC has been on the market for nealry 20 years and has been update several times and is in succesful use by companies and individuals all over the world.

The results have been time proven and the basis of the program is not a "secret" as Mr. Hauch suggests.

If you are looking for a easy to use software and you have a basic fundamental working knowledge of pneumatic conveying, PNEUCALC may be just what you need to help you in your analysis.