Remixing segregated product

(not verified)

We have little or no control over the filling/loading of our bulk container and segregation is high. Hence packing becomes a major problem. The product has 2 particles of very different size, shape and density. One is a light, flat and chip shaped the other small and pelletized. Once the bulk container is filled it is moved to a packing line and dumped (avalanched) into the packing hopper (hopper has four to six discharge channels). As expected lighter chips tend to surf to the top, pellets tend to segregate to the bottom however lateral segregation tends not to change. Any ideas on how to reblend this very fragile product? Currently using a baffle midway through the hopper to redirect /reblend but still can't get consistency in the final packed product. Will proper filling of the bulk container necessarily help when the product is avalanched prior to packing? There are a total of 3 avalanches before the container is completely empty. There are no other causes/points of segregation between filling and dumping.

This is not a powdered product. chips are oval and approximately 0.5 inches (longest axis) and VERY fragile. Pellets have approximately 0.25 inch diameter.

Remixing Segregated Product

Posted on 4. Apr. 2003 - 05:08

FROM IPT Industrial Powder Technology

Our mixing system is able to remix the segregated layers and eventually segregated vertical columns. This by minimum shear – displacement of the mixer content – thus good applicable for fragile products.


Best regards


Dr. Ivan Peschl

Countering Segregation

Posted on 9. Apr. 2003 - 10:03

From the description given it would seem that there are two separate components of the product that are collected in a bulk container in a specific ratio, which is required to be replicated at the packing point. The distinctively different composition of the particles makes them especially prone to segregation. Segregation is a pernicious phenomenon that will occur each time that movement of the bulk materials takes place. There are various techniques to counter or mitigate these effects and also to restore a degree of homogeneity to a mass that has differentiated the fractions within the volume occupied. My book, ‘User Guide to Segregation’, published by the British Materials Handling Board, outlines the various significant factors, mechanisms, processes and operations that cause such separations and indicates methods of avoiding and/or correcting their effects. Copies are available from

Without precise details of the equipment in use and the operational circumstances it is not possible to suggest what is the best approach. If you care to send these particulars to the above email address I will attempt to advise further.

In connection with particle attrition, this is also covered to some extent in the BMHB publication ‘User Guide to Particle Attrition in Mechanical Handling Equipment’. In the given circumstances it is clearly necessary to minimise impact and flow pressures during the solids handling, filling and emptying of any containers. These can be taken into account when considering a solution.

Lyn Bates

(not verified)


Posted on 8. May. 2003 - 08:49

Dear Lyn:

Thanks for all your help and for sending the User Guide to Segregation. All the bulk handling publications you forwarded were tremendously useful. I will keep you posted on our progress.

Many thanks again,

-M. Wagter

Re: Remixing Segregated Product

Posted on 23. May. 2003 - 09:00

ITASCA Consultants Germany can simulate these segregation effects via direct particle simulation with the PFC (Particle Flow Code on the basis of the Discrete Element Method). This makes it possible to study different parameters and insert designs.

Have a look at or send a mail for more information to

Torsten Gröger

ITASCA Consultants GmbH