Original charts were published in Jenike bulletin 123, 1964 Utah University. Latest version I have seen is in Michael Rotter book Economic Guide to the Design of Circular Metal Silos (ISBN 0 419 23460 8 Published by SPON Press). Both publications are very good get yourself a copy.

Don’t know if anyone has published them on the internet. I guess some things in life are not free. ■

Hi Mantoo,

Jenike Tables are pretty old technology [1964]. A lot of development has taken place since then, not only by Jenike, but also TUNRA in Australia.

If you want the updated version why not contact Jenike Johansen direct. They would be delighted to give you the latest information.

The other point to consider is - tables can be deceiving. You need specific test information from the product you are planning to handle. Jenike Johansen could do that for you at a price. So can a number of other test laboratories.

Regards - John.rz ■

Hi John

First of all I was only providing the source for Jenike charts and not testing any material.

Indeed Jenike Work is getting close to 50 years old but then Archimedes screw principle is centuries old and still in use. I am sure advances have been made this field which is very good and I do try to keep up with them. But even if you take the original work Jenike work it is still very adequate and does the job. To use these table one has to do the powder characterisation tests i.e. wall and internal friction etc. I am absolutely against using the generic values for different materials for using these charts. Fortunately I have access to both type of shear call (Jenike & Annular) and in my experience I have found them very reliable. In my personal opinion only drawback with Jenike method is it take ages to do internal friction tests on Jenike shear cell, for which I normally prefer annular or walker type cell. This is because I am a very lazy person and doesn’t mean that Jenike shear cell doesn’t work it just save time.

“Technology changes everyday but the Physics remains the same”. ■

Put another way

"Ye canna change the laws of physics" ■

I concurr the Australian work of all of them specially Dr. Arnold from Wolongong University (TUNDRA ) are helpfull. They are the equivalent to Hermes , the messenger of the gods, lowering Jenikes and Johanson Work to human levells.

Hope I spelled the names , specially yours, right Jerry ...

Marco ■

By the way. if you need a material tested , there are many suppliers now. Many using the Indexator from Jerry Johansen . or you can test it yourself , the test arrangement is simple enough, if your material is cold and your wall too,

Hot testing is not that simple , and you must be carefull with the surface quality of your wall,

Some years ago I run a number of tests for HYL Steel technology, for an alleged solids flow problem in Russia , in their installations of course .

I designed a lab for this purpose , the only problem was that , as we were being hurried for answers , by the project coordinator , as smart woman but not nice to say something, we quenched the base plate , thereoff changing the surface structure and invalidating the following results

Not that the results would be important , the whole problem was generated surprisingly enough by the plummeting of the price of sponge iron, and the finantial structure of the commercial deal.

After the plant sarted up and was about to meet the production goals.

Never loose sight of the overall picture . It is easy to do it when you are at the lab....

1.- the plant had watercooled walls , so hot friction angle to the wall was not a required data.

2.- the client was facing multimillion dollar losses if they continued production of a cheap product with expensive gas.

Regards

marco flores ■