As I said elsewhere

I don't see a reference to the number of pages, although there is reference to "200 photos, graphs and illustrations".

At the moment I think I'll keep my £GB equivalent of $AU 350 in my pocket.

But later when there is a review of it's contents I could change my mind. ■

Spending that kind of money, I would want to know that they have thoroughly validated design guidance and/or have a vast library of valuable data.

Does the guidance transfer into solid design recommendations? Are there features, when followed, result in "Best Practices"?

Are the authors "The Authority in Chute Design"?

How many attributes of chute design can be modelled or made known with a reasonable accuracy?

1. Belt-to-particle impact spectrum distributed over belt/liners/particle interactions and surfaces

2. Belt-to-particle shear work spectrum distributed over belt surface/liners/ ......

3. Granular acceleration work - power to accelerate all particles in the field to quantify magnitudes with various chute geometries

4. Chute wall pressure, shear work either as rate or sum in time

5. Cohesion of individual particles on all surfaces and internal friction summed in time

6. Adhesion of individual particles on all surfaces

7. Various rheological material flow models - different muds with different water content, particle size and correlated to shear-rate (centistroke) strength

8. Complexity of chute geometry - build by Inventor, Pro-Engineer; other parametrics

9. Size of chute volume for accurate definition of gas turbulence

10. Ability to evaluate various gas plenums to produce decanting of larger micron size particles - define efficiency of plenum and dust emission from chute at all leakage points.

11. Design restrictions, allowances, limitations, etc.

12. Particle interaction and wall surface dependent properties - elastic, viscoelastic, plastic, viscoplastic, and other rheologies with high, low, inverse strain-rate behavior - paint, honey, catsup, classical rheologies, et. al.

13. Many other properties covered by the book?

How many chute attributes are quantitatively improved and/or qualitatively improved or what will still be unknown?

What gains will I likely have and to what degree, by attribute?

We await a informed reply to raise interest to buy. ■

The posting by Larry Nordell requires an answer as it implies that the parameters that he outlines can be allowed for empirically and I presume are allowed for in his DEM Programmes.

Firstly none of these parameters can be accurately allowed for in any empirical equation and therefore cannot be accurately allowed for through any computor modeling as we have far too many variables. Secondly all of these issues can vary significantly on any mine site on a daily basis through variations in one variable, moisture or water content of the ore. This of course varies on whether water sprays are on or off, the ore is coming from Pit A or Pit B etc. There are far better ways for the designer to aproach these issues and we do cover them extensively in the book.

Another point I need to make is that DEM is not a design tool but a design aid. The transfer designer has to develop a design concept first and, if justified, test it before getting it built and installed. We see a place for DEM but we are very cautious about its use. We detail other methods that can be used to check and evaluate designs which we believe are more effective.

Concluding, transfer design is not about empirical accuracy but having a knowledge of how to accomodate the many variables that must be allowed for. This book works through these issues in some detail and represents over 100 man years of successful transfer chute design experience.

It has been read by a few select people, we look forward to many others reading it over time and posting informed comments

Colin Benjamin

Gulf Conveyor systems P/L ■

Hey Colin,

You miss my point. I prefaced my diatribe with a comment about the excessive price. So, my comment still holds, why won't you either tell why the exorbitant price or tell why the exorbitant price. With such a price, we should know it will be worth it.

Therefore, by a list of superlatives I asked can you do it? Answer was no. Thus, if you cannot do it, what can you do? You answer with no answer, just trust me with the 100 years world of experience. I know you and Mr. Donneker. I do have respect for his experimental work with the Rio ATD lab equipment. I also have worked to correct someone's chute design, maybe you have done the same with mine?

In conclusion, none of Our work is conclusive. I did not challenge the work, only is it worth the whopping 340 smackers. You would get a lot more bites on 140, including CDI. Your total take would be higher, and we all would want to know what you have to say. I, for two say I cannot do 340, until I believe you have something to offer, or until

I can find someone who can show me. Best would be if you could show me/we all.

In any case, best of luck. Vino Tino. ■

For $AU350 it will need number of pages, contents page and selected pages from each chapter before I reach for my wallet! ■

Hi Larry,

Thanks for the reply. I accept the comments about the price but it is all relative. We need to sell a hell of a lot of books just to get our direct costs back as we took the effort to include many drawings and pictures and everything is hard bound and in colour. When you consider the book took 6 years to write then we will never be rewarded directly from book sales for the hours we put in.

As to the contents, there are 12 chapters

> Introduction - basically about transfer horror stories and why transfer design is important.

> Basic Transfer Types - we describe all transfer types that are typically in use today.

> Trajectory calculation - a lot of this was extracted by Dr Shams Huque PhD that we sponsored. It covers all the popular published calculations methods, comments on their accuracy and makes a recommendation as to what is the most accurate and basically what we use today very successfully.

> The next Chapter is on basic design, very practical and very much geared to site based personnel who can take advantage of what they observe in a chute that is not performing.

> Chapter 5 is on detailed design and covers all transfer types including Cascade or Weba type chutes

> The next is on design aides where DEM gets a mention along with scale modeling and the trajectory software we have developed.

> Chapter 7 is on maintenance issues particularly wear (liner selection) and skirt system design

> Chapter 8 covers designing for cohesive materials and water laden ores.

> Chapter 9 covers designing transfers to minimise dust without the use of baghouses. In fact we talk about why bag houses add to the problem, not solve it.

> Chapter 10 is 3 worked examples

> Chapter 11 is the Appendix which also contains quite a bit of information on angles of repose. This is a critical element in chute design.

> The final Chapter is a very extensive bibliography for those who want to read on or check references. There 8 pages of references and addional readings covered.

In terms of value for money, it is a damn sight cheaper than any piece of software that we use for design of transfers and far more practical and useful for the average designer. It is also cheaper to purchase and refer to the book than getting in a consultant or putting up with a poorly performing transfer.

Trust this gives a little more background to you and others

Cheers

Col Benjamin

Gulf Conveyor systems P/L ■

Yes, we can shell out the money honey, but, who gives the guarantee the book solves the problem?

When we design a chute we guarantee performance:

1. flow, with know material properties, size distribution and moisture content

2. dust emission level by particle size - implies we demonstrate dust control methods and have a scientific knowledge of gas dynamics in a solidf flow field.

3. liner wear pattern and expected life,

4. belt life increase over conventional chute together with wear patterns

5. power savings to accelerate material over alternatives

6. belt tracking to its centerline

7. material capacity and improved consolidation in chute-skirt zone

8. Solve complex geometries and design choices not covered by common knowledge

9. common things not to do

10. flow illustrations of alternative designs comparing performance including flow loading on inclines and high speed conveyors.

"DAMN SIGHT CHEAPER??" is a modest slap at those of us that have spent far more man-hours developing the DEM codes than it took to write your book.

However, I read your words of wisdom and cajoling of DEM science. Ah, and then, you say that DEM is OK!!?? By the way, simple spheres do not provide a good predictor of chute trajectory, spherical clusters are better, polyhedral- quadrics are better yet, and multi-faceted angular particles come closest to fitting site data so long as all particles and their rheology are reasonable represented.

I accept you and yours have studied the subject in great detail, and have substantial knowledge in chute science. It remains to be seen if the book trumps all other bodies of knowledge.

Then there is 340 dinero. A long pause, questioning of wisdom, wishing it were affordable to the masses and not to a few elitist. Can you consider a discount to less fortunate among us or ---- tell us that failure is not an option with book in hand? ■

Thanks for th reply Larry. I guess you identify 2 options, one from an expert consultant that you hope comes up with a solution (and many don't) and the book. I think the book is a very cheap option when you look at these 2 options. In the end the value of the book will be judged by others, so far the response from those who have copies (either early drafts or the books we had air freighted in) has been very positive and complimentary. There will be a formal review done (through Wollongong University) and published in Australian Bulk Handling Review I expect in October and that will offer further third party expert comment.

From my viewpoint and motivation for the book, there are far too many transfer chute problems occurring especially in the hard rock industry and this is translating into major maintenance back log issues and lost production. Even if you and I lived for another 100 years we would not be able to address these issues as consultants as more problems are created daily than are solved. This book sets out to help those that have to put up with these problems or the designer with a set of logically and well defined steps that if followed will avoid most of the pitfalls. No doubt there will still be enough difficult problems to still keep the quality consultants very busy.

In regard to DEM, I have every respect for those that continue to work in this area. If you recall many years ago, I did talk and look at the early work Paul Cleary of the CSIRO did in this area. I have also continued to keep abreast of developments. I am however far from convinced that these computer based models give good representative flow for material that is cohesive, has high moisture content or has a broad range of ore sizes (typically ROM material). Further before you use a DEM programme you have to develop a design to model. How is such a model developed in the current environment unless by an experienced designer. The book covers this design development then gives the designer the option to either test his designs using DEM or other methods if he so chooses. The book by the way is about 280 pages.

I guess in summary, consultants can justify their hourly rates to themselves and their clients otherwise they would not be consultants, software developers can justify their cost of their DEM programmes based on the time they took to write it. We can most definitely justify in our minds the cost of this book based not only on the hours we took to write it, the very significant amount of valuable IP in the book and the cost of the books production. It all gets back to where you are coming from and what your own perceptions are. I am comfortable with where I am at.

Cheers

Col Benjamin

Gulf Conveyor Systems P/L ■

Colin,

I wish you success and goodwill.

I wish I could afford it. Maybe the Uni will convince the rest of us to spend it and be happy you did it. ■

Thanks Larry

Cheers and all the best

Col Benjamin

Gulf Conveyor systems P/L ■

Colin:

As a post nuptial point, I offer an illustration for those who wish to know more about granular physics with gas such as:

1. Image of rock flow without gas file name: chregas

2. Gas flow in rock stream with file name: chrerock

3. Image of rock & gas with file name: chrerock-gas

4. More images will come on another thread demonstrating DEM's many virtues.

This set of illustrations has been tampered with to highlight gas convection currents that occur within the chute and their insight to dust emissions, at many levels of leakage. This illustration is not a demonstration of a proposed solution. It does show where DEM-Gas modeling can take us.

There are very many attributes that can be observed from DEM coupled to gas and DEM coupled to a liquid bridge rheology group.

You comment on rheology properties, which can also be modeled with reasonable accuracy for sticky - cohesive materials. This usually refers to fines with moisture. Jenike-Johanson, Prof. Alan Roberts & Tunra and many others have studied these rheology properties giving rise to doing the math on flow behavior.

We all see a value in building scale modeling and infusing the product or some estimate of the product into a physical model. I will not now debate the + & - of this approach. I do note, none of us has the Midas Touch to guarantee conclusively the solution will not need further tuning or modification.

I anticipate your book will offer good insight, maybe job saving insight to many who practice without a license, and many who do have such a license. I have made my argument on why I posted the initial comments. I leave this and offer, through a series of illustrations, the path some will take to nearly optimize the chutes of tomorrow and the need to redo many chutes of today.

Clients do not possess the wisdom to evaluate their losses from poorly designed chutes. DEM can give much needed insight and guidance to demonstrate the benefits of superior chute designs vs. present practices. DEM provides:

1. power savings,

2. belt life savings,

3. control of belt spillage from mal-designed chutes,

4. degradation of product,

5. elimination of pluggage – sticky, cohesive modeling with buildup and agglomeration

6. etc.

I see us on the same side with different methods to achieve the same goal.

Peace,

Attachments

chre_1_gas_2 (JPG)

chre_1_rock (JPG)

chre_1_rock_gas (JPG)

■

Hi Larry,

I think the work you, J&J and the Universities in Newcastle and Wollongong to mention just a few on DEM is great and I do agree the models are improving but they are not design tools, they only evaluate the effectiveness of a design. In the book we classify dynamic scale modelling the same way. In the last few years I have looked at over 50 transfers where DEM was the method used to evaluate the design and it failed to identify the flaws in the design (hence why I was asked to look at the transfer). Conversely I have observed many transfers in the coal industry where DEM has been an effective tool to evaluate the flow dynamics and I believe this is because coal flow cab be reasonably defined in a DEM model so I stick by what I said earlier in respect to where I see limitations in DEM.

I think we need to re-focus this interaction on the process of transfer design. If we accept that the basic conveyor engineering issues have been addressed then the design process follows four sequential steps regardless of the transfer type being designed.

Step 1: Accurate calculation of the material trajectory. How this is done is covered in the book by examining most of the published and well used methods and commenting (based on the thesis done by Dr Shams Huque) on the accuracy. We do make recommendations as to what is the most accurate method and the therefore the method we now use in our work.

Step 2: Flow control. The designer, using his trajectory model as the starting point must develop a flow pattern in the transfer that is predictable and controlled. We go through how this is done for all types of transfers. Without flow control there is chaos.

Step 3: Speed control. This is very important. If you have highly abrasive material you want to minimise the speed, if you have wet, cohesive material you must maintain higher speeds to avoid the transfer blocking through build up. If you have a combination such as in a ROM ore you have compromises to make. All this is covered in some detail in the book.

Step 4: Ore presentation. This is how the ore is presented onto the receiving belt. It is the final and important step as failures n this area lead to belt damage, excessive belt wear and skirt systems that are a source of high maintenance. Once again we go through this in detail in the book.

Once all this is done the designer can move directly to detailed design or he can elect if he has some doubts to test his design using DEM or dynamic scale modelling. In many instances our understanding of the customer's needs allows us to move forward without testing but where we do test you need to understand the pro's and con's of the two basic methods hence my earlier comments. Most definitely in the iron ore industry and also where we have wet sticky or cohesive materials there has been quite a significant shift towards dynamic scale modelling. We go through why and do describe the two methods. We have spent more time in the book on dynamic scale modelling as it is not as well publicised as DEM.

I guess in conclusion, we are talking here about two different things. The book is about design and the design process. It does cover design aids such as DEM but it is a about 20 odd pages in a book of 280 pages. If there are readers who would like more details as to the table of contents please email me on cbe10699@bigpond.net.au.

Cheers

Colin Benjamin

Gulf Conveyor Systems P/L ■

Originally Posted by Colin Benjamin

Step 1: Accurate calculation of the material trajectory. How this is done is covered in the book by examining most of the published and well used methods and commenting (based on the thesis done by Dr Shams Huque) on the accuracy. We do make recommendations as to what is the most accurate method and the therefore the method we now use in our work.

While not being a significant designer of belt conveyors, I have had an interest in the material discharge trajectory for many years. To this end I have collected assorted 'learned papers' on the subject a lot of which have been the listing of published methods and the comparison of the results of each method.

Where all have fallen short is in taking a variety of actual discharge trajectories and showing the variation between the different theoretical methods and actual trajectory. I don't know to what extent real life comparisons have been included in the publication, but for authoritative comments I would expect a significant number of examples to be referenced covering a range of belt speeds, belt loadings, together with a range of bulk materials having different properties. ■

Your interest in trajectories over the years seems to very much parallel mine. It was one of the major motivating factors in sponsoring Dr Shams Huque's thesis. In it he did a great deal of analysis of the various published papers on the subject and he had the advantage of access to work our company had done and work the University had done. After the thesis was published, Shams and I developed a model based on the the most accurate model and added a number of significant refinements and then incorporated this into a software package (it takes far too long to do this from first principles). We have used this model since 2004 and have been able to apply and check it against many, many actual transfers with a very broad range of materials. We have also been able to us Peter Donecker's dynamic scale model methodologies to further evaluate the trajectories we come up with. All in all, the model we have has proven to be very close to actual. To the point we have been able to rely on it and as a consequence had very few problems with this part of transfer design. When I look back on some of the problems we had in the '90's i.e. before we had this model, many of the problems become self evident as far as why we had the problem.

Like most we started actively looking at transfers based on coal. What I can now conclude is that sized washed coal has very easy and very predictable flow paths. It is only when you try to broaden your activities to other more complex materials do you find just how inadequate these basic trajectory models are.

As for examples in the book, we give some. We are making the software package we developed available separately and this can be seen on the web site. The book also covers other ways to develop an accurate trajectory model without going back to mathematical first principles.

Cheers

Colin Benjamin

Gulf Conveyor Systems P/L ■

Colin makes a valid point when he says that DEM, like physical scale modelling, is a design aid, not a design method.

The fact that there is poor design out there in the real world is well known to anyone experienced in the field. Here are just a few examples of some fundamental flaws centred on design and the design process that I have encountered. For obvious reasons I am not going to identify the source of these examples, but I will say that they are all from large international engineering companies.

Some of these examples illustrate that there are benefits to having someone actually attempt to construct a model of the equipment, quite separate from testing the performance.

1)A beautifully contoured deflector, with 32 individual facets and matching plate developments and tile layouts, destined for the discharge end of a steep conveyor. The leading edge of the deflector was horizontal. This meant that more than half of the complex internal surface of the deflector could not possibly come into contact with the ore.

2)Three copies of drawings of the same chute design in circulation for discussion at the same time, all purporting to be drawn to the same standard, but each with its own unique set of dimensions.

3)Similar to the above, 3 separate drawings of an existing, installed head pulley, all drawn to the same standard, all from the same drawing office, but only one of which matched the actual pulley in the field.

4)Two parts of a large multi-million dollar machine, being fabricated in workshops on different sides of the world, which were not going to fit together.

5)A curved deflector which was configured to turn the ore back on itself, instead of delivering it vertically downwards, to such an extent that it hit the wall of the chute underneath the head pulley.

6)Endless examples of chutes providing biased loading on the outgoing conveyor, either by segregation of different sized fractions in the ore, or simply because of the flow in the chute.

7)Cohesive ore being slammed into flat chute walls and impact plates at high angles, causing cyclic build-up and collapse.

8)Chutes where the estimated trajectory was so far from reality that the ore was not even going to hit the receiving belt.

This handful of illustrations is provided not to push my own barrow, but to illustrate just how basic some of the design mistakes are out there in the real world, right now. ■

I have been using DEM modelling software for about 5 or 6 years and have designed many transfer chutes for the company I work for. I use DEM to "tweak" the design and to find flaws in existing chutework designs. I totally agree with Colin that the design criterea must come before the DEM. So for me his book is very welcomed.

After reading Colin's book I now have a much greater knowledge and understanding of what makes a great chute design and I am now starting to put his methods into practise.

But like Colin says the design must come before the DEM analysis can be run. They both play a very substaintial part in my world of design and definately have their place and one cannot be without the other.

So instead of arguing about one being better than the other lets all work together for the betterment of the industry as a whole. I believe this book is a great foundation for doing just that.

Gary ■

Originally Posted by Gary Blenkhorn

After reading Colin's book

Care to give us a review? ■

We have been reading posts by Mr. Benjamin for awhile and having him endorse the book is argument enough for us, so buying this book is an easy decision.

At Tecnipak we have been designing, building and installing transfer chutes with curved deflectors for leached ore, transporting from 800 to 8000 tph. People were skeptical because of its stickyness but the transfers are working great. The steps we take are very similar to Colin's. Determination of ore trajectory, deflectors for are controlled, predictable flow and then estimation of speed at different places.

We also manufacture curved ceramic and metallic linings which are easily replaceable on the curved surfaces, both on the upper and lower deflectors (spoons). Although this is nothing for some people here, we are proud of our achievments and our clients keep requesting more. We have gained alot of experience in few years by learning from every possible source on the web and in textbooks, and by applying and perfecting concepts empirically.

We have learned that no book or study will ever have 100% entirety. Expecting a book to be perfectly complete and comprehensive is an exercise in futility. On the other hand, most books and studies by knowledgeable people in the field, have at least the amount of added value to be worthwhile for us.

I wish I could afford the time to discuss the to-buy-or-not-to-buy issue extensively, but I can't. Time is money.

This book is so well structured that it will be a valuable learning tool for our team of younger engineers, draftsmen and students, so thank you gentlemen for writing this book. After reading, we'll post our reviews here to help others decide.

Is it only paper or is there an electronic version? Are there any volume discounts? ■

Hi Joerg,

Thank you for your posting. We are getting good feedback and from this feedback we get a lot of information as to things we may be able to add in the future, for instance there a lot who have developed great faith in the use of DEM as an aid to design, logically we need to add a lot more in future about DEM and how to integrate this into the design process. Like you we find the greatest challenge is with designing for cohesive and adhesive ores and once you have some success so much of the design process starts making sense.

In respect to the book, there are substantial discounts for volume, if you email me direct we can work through this. We should reflect this on the web site so I will also look into this.

We are also interested in creating one on one dialogues so we can share and develop design expertise on transfers. I really do respect what the Universities and others are doing research wise in this area but in many cases such as DEM the use of these advanced ideas is high risk in the hands of the inexperienced. This is why the book was written and why we believe that it is fundamentally important that as we use more and more advanced computor aided system we do not lose sight of the design fundamentals.

Regards

Colin Benjamin

Gulf Conveyor Systems P/L

colin.benjamin@gcsm.com.au ■

Hi Colin,

thanks for your reply. I have e-mailed you my request. ■

We note the various comments on the book posted on the Forum and would like to update the feedback we have after 4 months of book sales. We have distributed over 100 books to 16 countries plus Australia. The feedback we have had has been very positive which is gratifying but there have been issues raised that we would like to address:

1.Treatment of Discrete Element Modelling:

The major reaction has been from various people who have either promoted DEM or have a vested interest in the development of DEM. The criticism has ranged from our “lack of understanding” of recent advances to not being up to-date in the latest technology. None of this is true. DEM does NOT design a transfer chute, it only models the flow properties of a material through a transfer design so the fact we do not devote a great deal of time on DEM starts with the fact this is a design manual. Having said this, we accept that there have been significant advances in DEM but with all such advances in such an area of complex mathematics the sophistication of the software becomes such that the programmes become extremely expensive and require a great deal of training and time to run. The best programme we know of today costs nearly US$100K. More importantly when we get into difficult transfers it is necessary to do a great deal of reverse engineering so as a designer, if you are not aware of the mathematical logic behind the DEM programme, how can you question the design logic when errors occur. Our position on DEM remains;

Most commercially available programmes have flawed trajectory paths and therefore will only give you a basic understanding of the issues arising with the design.

Very few programmes have tackled the complex problems encountered with variable product sources, adhesive and cohesive materials and the effect of moisture content. Where they have, the imbedded mathematics makes what if and reverse engineering difficult unless you involve the designer of the software and this just adds significantly to the cost of any design.

This is why we believe the best and cheapest way currently to evaluate a transfer design is using dynamic scale modelling. No doubt in time DEM may take over but we believe it is a long way off. We had one comment recently from a University Professor proudly saying that their DEM model was able to predict the wear points and build up issues in a transfer handling bauxite. No doubt this is a step forward for DEM but a good designer using very basic dynamic scale modelling was doing this 15 years ago. So DEM still has a long way to go just to catch up.

2.Recommended Trajectory Calculation:

We have devoted quite a bit of space in the book to the calculation of the trajectory. We have done our own research and have developed our own trajectory calculation software. In the book we do outline our approach but not to the point that a reader can fully duplicate our design method without his own research. We do not apologise for this as we do make our software available for purchase separately from the book.

3.Delivery Issues:

We have had a few delivery issues that have required sending free of cost second books. In a couple of Countries their Customs Dept has caused us some problems as we have had to put a value on the customs declaration. In all cases we have endeavoured to speedily rectify the issues.

Finally we have posted on the book website a few of the comments made (www.conveyortransferdesign.comwww.conveyortransferdesign.com ). The website on which the book is purchased is linked or you go direct to www.conveyorsystemstechnology.comwww.conveyorsystemstechnology.com if you want to purchase the book.

Thanks

Colin Benjamin

Gulf Conveyor Systems Pty Ltd ■