Hi salek,

You have learned by now that there are no instant answers to everything on the internet.

1 - Ask your client for a sample. Pour the sample out on your desk. Measure the angle with a protractor.

2 - Alternatively - go to a chemist. Buy some sulphur powder and do the same.

Regards - John.Rz

www.cospire.com / Engineering Tips ■

The first point that I would make is that the name of a product, such as 'sulpher', may be adequate to define its chemical composition or general description, but is rarely adequate to quantify its flow condition. Features such as particle size, moisture content, state of compaction and other physical variables can have enormous influence on bulk behaviour.

Secondly, the 'angle of repose' of a bulk material is the inclination adopted by its free surface under given conditions of preparation. In practice. this expression only has value with a material that is free flowing and without cohesion, such as dry sand or coarse minerals. Fine powders, damp products and many other materials will hold together at surface angles ranging from horizontal to overhanging, depending on how the 'pile' is formed.

A simple way to assess if the material is likely to form a consistent angle is to place a sample on a surface under an applied load and, after removing the load, cut through the centre and pull away one half. If the remaining section collapses to form a repose slope, one may expect this to be a repeatable condition. ■

Indeed a very difficult question to answer, especially taking into account variations in both material moisture content and climatic conditions. One solution is to install an Acoustic Cleaner, also known as Sonic Horn, to ensure that the material fully debonds from the silo or hopper and to ensure mass flow. Have a look at this short video clip to see for yourself the power of acoustic cleaner's sound waves (http://www.primasonics.com/videodownloads.htm)

We have installed our range of Acoustic Cleaners in a variety of different material silos world wide. If you care to contact me I can advise you further, in the meantime I attach our Silo Questionnaire Form (http://www.primasonics.com/pdfquests/silosq.pdf).

Also please take a look at our web site.

Regards

Donald F Cameron

don@primasonics.com

www.primasonics.com ■