General information on industrial bulk powder classifiers needed.

Kiki B.
(not verified)
Posted in: , on 5. Feb. 2003 - 15:00

Hello All,

I was referred to this forum via As part of a research project, I am required to do a comprehensive survey of industrial classification methods of bulk powders. What I am ultimately trying to achieve is a discussion through a comparison tables of different technologies, including information on

-What current technology is used

-Operational Issues


Lyn Bates has already recommended me 'Glossary of Terms in Particle and Bulk Technology', published by the British Materials Handling Board. The British Library does not seem have this particular one in its collection, but I have found other publications by the British Materials Handling Board, which may be useful.

I have only basic knowledge on current laboratory scale classification/sizing techniques (sieving, microscopy, light scatter etc.). However, I am looking to expand my knowledge on industrial scale classifiers and screeners. It seems as if the widely available publications (e.g. Powder Technology Series: Particle size measurement by Terence Allen) do not cover the areas I need information on.

If you have any on-line inks or sources of information I could refer to, or maybe if somebody from the industry would come forward to offer me some information, I would greatly appreciate it. Thank you.

Classification Technology

Posted on 7. Feb. 2003 - 06:21

Dear Kiki B.

I would be glad to offer you some background information on classifying technology. Underneath you will find the basics, but you can always contact me for more specific questions.

The principle of dynamic classification; where the fine product and air-processed agglomerates are separated from the coarse material by use of specially designed classifying wheels is very well explained at:

and open the working principle PDF

The principle of static classification; where the working principle is based on the difference in centrifugal force of individual particles, which are exposed to a strong spiral shaped air current is well explained at:

and open the working principle PDF

If you would like to know about the latest in classifying technology, I would like to refer to the breakthrough between Eirich and Noll.

Going through February’s Powderandbulk’s 174 newsletter (or the link below) you will find a news article about the dynamic classifying technology used for Eirich’s attrition mills. Although full documentation is not yet available I would be happy to inform you on the latest designs, working principles and possibilities in finest classification of bulk materials D97<3um on industrial scale.


Marc Zwart

Technical communications

Noll processing technology / Germany