Thank you for the suggestion Peter. I will look into this. ■

Have you examined the copyright situation applicable to this book?

It might be possible to obtain a copy privately but the members will be loath to upset J & J through the forums: or you could ask J & J yourself.... ■

I presume that you have a copy of Bulletin 108 which is (or at least was recently) available online.

I recently did an extensive search to see if I could find a copy of Bulletin 123, which is much more often quoted, online. I could find nothing. So I approached the library at the University of Utah. The librarian was very helpful but after investigation, she told me that Bulletin 123 was not available as an electronic document.

This method having failed, I approached the local library system and was able to obtain a copy of Bulletin 123 on inter-library loan. I suggest that you try the same approach.

The two documents are quite similar, but from my point of view, Jenike says something very significant in Bulletin 108 that he does not repeat in Bulletin 123. What he says, very clearly, is that his analysis is limited to the movement of solids at low velocities and that it is not applicable to high velocity flows. Here is a small portion of what he says, which you can verify for yourself.

"In the analysis of the stress fields, the equations of equilibrium have been used. For these equations to be

applicable, the dynamic forces must be negligible, compared with the gravitational forces. "

In other words, his analysis applies to low values of the Froude Number.

In situations where we have rapid flows, such as in transfer chutes, dynamic forces are not negligible in comparison with gravitational forces. In fact they are vastly more important. So, while Jenike's theory has shown itself over many decades to be useful in the analysis of quasi-static flows such as occur in hoppers, attempts to extend this theory to the case where dynamic forces are dominant (high Froude Number, dense granular flows) are doomed to failure, as noted in his own words of caution.

Despite this, how many time have you seen claims of shear cell test data being applicable to transfer chute flows? ■

an alternative is a more practical book that covers bul 123 and additional solids handling fields, 'gravity flow of solids' by Roberts, Arnold and McLean from TUNRA based at the University of Newcastle. N.S.W. ■

Hi Raghu:

Thank you for your interest in bulletin 123. Please contact me directly and I would be happy to arrange for a copy to be mailed to you. In addition, you may want to check out our website as we have the latest insights and critical thinking on the flow of solids. You may also find some of our courses we run throughout the year helpful in this regard. http://jenike.com/education-training/course-calendar/. We could certainly assist you in determining exactly what testing methods or flow patterns are appropriate for the type of materials, and storage or conveying equipment you are working with. ■

Hi Tara,

It is good of you to offer to provide a copy of Bulletin 123.

This is not the first time that someone has asked about getting a copy of this document on this forum.

I don't know what the copyright situation is exactly, but given the pivotal position of this document in the field, and the fact that it is out of publication and unavailable from the University in electronic form, I wonder if you might be in a position to be able to arrange for it to be more readily available within the public domain? A high quality online version perhaps? Or even a new printing for purchase. I would certainly purchase a good quality reprint for my library if it was available.

Regards,

Peter ■