Hi Lyn,

I could not agree more with your sentiments but I will also argue that much of the problems stem from the way we try to grossly simplify the way granular material flow in the hope there is some form of computational logic we can use to come up with solutions. I have spent the best part of 35 years first faithfully following the flow logic generated by your centres of excellence, interacting with them only to repeatedly come up with problems that defied their logic. In the latter part of my career I now understand why and will shortly be publishing another article that will further explain why. While I initially focused on transfer chutes I now realise that the implications of what we have found has very broad applications and as a consequence will be working with another University to further advance our findings. What is exciting as to what we have found is that in applying these principles we are achieving very dramatic improvements from what has been obtained using the approaches promoted by these centres over the last 40 years.

While I admire your practical logic in the many posts you have made I believe we, collectively, have misled a generation of engineers and wasted a lot of energy by trying to create computational models for what is a highly complex dynamic by making heroic assumptions to simplify the mathematics and then promoting the software so created as the answer to a maiden's prayer. Any engineer working in the industry where the granular materials are complex (variations in size distribution and possibly water also being present) will know that there are serious problems as you recognise. Unfortunately I now question whether these centres of excellence could be part of the problem by blinding us to an alternative approach.

Cheers

Colin Benjamin

Gulf Conveyor Systems Pty Ltd

www.conveyorsystemstechnology.comwww.conveyorsystemstechnology.com ■

My own case:

Some say that a degree is a nice thing to fall back on. That is foolishly optimistic in this day and age: and even earlier. Things, mainly software, develop at such a pace that if you forsake it don't even bother trying to get back in. This ought to frighten the bejabers out of school leavers.

"The output of universities where bulk technology figures high in the syllabus of chemical engineering, is minute in relation to the applications of equipment made each year." Thank goodness for small mercy's!

The same can be said for any University course in any sector of engineering except perhaps electronics where bench testing is possible. In our case we have a nagging sense of overwhelm to the tune of 16 billion tonnes. Similitude can be applied to the liquid and gas phases but not to solids behavior and so the expense of solids testing conveniently excludes it from most university budgets. Now, if you cannot perform reliable tests there is little to no point in teaching the subject. If you don't agree check with Lord Kelvin. In the good old days students could verify stress distributions using magnetised paper, an earthing clip and a voltmeter probe. Once we'd done the experiment we could almost accept that teacher knew his onions, or at least the book he was reading to us on Saturday mornings.

I graduated, honorably, from a much overrated University of Technology,School of Aeronautical Engineering, in the British East Midlands which was hell bent on increasing its funding by accepting a much larger intake of freshmen than it was interested in developing beyond the first year. On my course 7 graduated out of the original 41. During my final exams I remember the shock I produced by answering the hardest, top score, questions with no trouble at all and then walking out of the room with 2 hours to spare. I had understood the university staff motives and I still do (I could read them like the books they read to us). After scorning the exams I vowed never to do another calculation and although I soon mellowed in this I have never had any bother in solving any engineering problem put before me. If something is really giving a problem the initial approach or directive was flawed. In a seat of learning if the teacher is induced to mislead, willingly or otherwise, then perhaps a few kids have been led down the garden path. Seeing as how we are talking about a select few Chemical Engineering graduates their deception is rather irrelevant in the broader field of engineering activity and anyway they will learn all too soon. There are 2 approaches to the situation: either increase the university budget or eliminate it and let the kids find out for themselves. It is not a case of the more things change the more they stay as they are. We have seen, in the course of this forum, over the past few months a readiness to cast common sense aside in pursuit of academic posturing. Shifting large ships to and fro beneath a single loader springs to mind. This young person had claimed to be in charge of engineering projects of much larger equipment and yet he came up with this post. I won't even mention a certain Sub Continent. No amount of education can prevent this happening. Britain needs to resurrect & reinforce the HNC/HND mentality rather than just tolerate it with the provision that an HND can lead to a higher degree and thence professional registration. That situation merely tops up the Unifarcity funding even more. I see no problem with the status quo: only with the fashionable engineering concept that engineers are poorly paid and that is why there are so few of them. That surely defies the laws of supply and demand and yet we hear it ad infinitum from Britain. ■

There is no doubt that specialists like Colin are essential to advance the subject and the results they achieve can be demonstrated. The market will then bring out their value, but they are far too few and too specialised to oversee all the work that goes on in this enormous industry. My target is the immensely greater number of personnel who are not professional bulk solids experts, who nevertheless come to have some involvement with the selection, purchase, design, installation and operation of the vast range of storage, handling and processing equipment and where a basic understanding of the technology and good practice can avoid many common mistakes that prevail throughout the industry and point them in the right direction for answers instead of trying brute force or depending on the 'flow aid' industry. The old Technical Colleges and Higher National Certificates produced practical engineers with knowledge and experience of the fundamentals, which gave a grounding for industry, whereas too many graduates fall by the wayside and not many specialise in this field.

I hope that I have never suggested the subject is simple. Even NASA realises that our limited knowledge of bulk solids behaviour represents a serious hazard to the exploration of the moon and Mars and Alan Roberts reports that industry poses problems that are beyond our current technical ability to answer. This is not to say that what we do know has no value, and the wider spread it can be distributed at any level must be an improvement over its absence, so I will keep on trying. ■

Hi Lyn,

I agree that training and shared knowledge is essential but we must also encourage our engineers to question and query as we do not have all the answers nor all the solutions. This is so obvious when you go to the many sites I go to and see maintenance engineers repeatedly putting in band-aids that only leads to more work. In the last 20 years we have moved materials handling aggressively into faster and wider conveyor systems, managing more and more complex ores and yet the simplest part of the whole equation today is the power demand and even here depending on what design standard we use you can get serious variations. Sure by being conservative we can avoid problems but what about the stockpiles, bins, hoppers and transfer chutes. Our approach to screen and crusher selection is also pretty crude. The next generation of engineers must be encouraged to seriously question what has gone before otherwise we will be building systems with serious redundancy factors just to ensure we get the nameplate throughput.

Cheers

Colin Benjamin

Gulf Conveyor Systems Pty Ltd

www.conveyorsystemstechnology.comwww.conveyorsystemstechnology.com ■

Dear Mr Bates

you have absolutely right when you say that the bulk materials handling is to study more intensively.

This can be seen from the two energy crises worldwide, in the 70's of the first and the second crisis in September in 2008, generally referred to as the world financial crisis.

During the first crisis, the price of coking coal was increasing twice, at the last crisis, however, 10-fold. What happens during the third crisis? No one dares to say.

In addition, the physical and chemical phenomena in Bulk MateriaIals Handling are the same as in the case of all processes at all, be it in the fields of chemistry, physics or mechanics or even if in medicine.

The supply of living beings with oxygen atoms is a process that is not studied and controlled at all. If these events could be studied closer, you will see that there are many diseases and psychological problems could be solved in human life. It is a mass transportation phenomen.

Energy phenomena and incineration are also mass and heat transportation phenomena , to study in detail.

We are talking about energy limitation worldwide we are sitting on an unusually rich source of energy.

In this sense I wish a Merry Christmas and a Happy New Year 2015.

Dr. H. Ergun ■

I graduated from Cornell with a B.S. and Masters in Civil Engineering with my major in structural engineering and minor in Soils mechanics. I really did not anticipate or prepare for a career in bulk materials handling. A great promoter in this field and Cornell Alumnus recruited me and showed me what a neat field it was and especially how big the equipment was. So I began my career at Dravo Corporation (former employees of Dravo fondly refer to the company as Dravo University). Attempting to broaden my scope I began taking additional courses at the University of Pittsburgh's Engineering school then enrolled into a master of mechanical engineering degree. The academic pursuit was now more targeted reacting to the challenges of the bulk materials handling field. There was no curriculum in bulk materials handling in the USA and to my knowledge there still isn't. Nevertheless we did learn the principles and then developed our expertise by applying those principles. I strongly agree with John that once your in you better stay in. In the absence of a few years the world will pass you by. It's a continuous life long endeavor. I remember a discussion with a colleague where we both were puzzled, in light of the importance of bulk handling, why the field was so ignored by academia. Some days afterward I was leafing through my old transportation book and came across a single chapter that did indeed cover troughed belt conveyors including idlers, pulleys and drive systems, etc. That chapter was skipped in my transportation course in favor of endless linear programming routines in timing traffic lights for optimal traffic flow.

Joe Dos Santos ■