Dear Edmond,

It was nice seeing you at SME. I am sorry we did not catch up on current affairs.

As you know, I have a great deal of respect for you as an engineer, before, during and after CDI.

I beg you review the capability of modern belts and the influence of rubber on their performance. A measure of performance, should include belt speed, idler spacing, idler trough geometry, belt wing-to-center-roll junctions stress fatigue control, and related criteria to optimize the 15 year CAPEX & OPEX.

Your quoted 15% difference in capital cost between 4 m/s and 8 m/s belt systems is according to your selected criteria. I claim the gain to be much higher. We can come to a better understanding of the technical advances available today, by comparing some basic analytic results and noted installations that support the claims.

I took an example (hypothetical) to compare performance estimates that will bring understanding to the claims. The example is:

1. Length..................................... 10 km

2. Lift .......................................... 20 m at head, else horizontal

3. Capacity .................................. 4000 t/h coal

4. Bulk Density ............................ 900 kg/cm

5. Ambient temperature ...............20 degree ambient environment

6. Use the 13 km KPC new design criteria of edge clearance or loading, et al ( total rolls and roll failures per year).

I humbly request you answer a few points of interest, at the belt speed = 4 m/s and the alternative highest acceptable speed you design for, to achieve close to the optimized cost to own and operate. This can be at one ambient temperature (20 deg. C), night and day, for all 12 months of the year:

1. Power

2. Belt mass

3. KW / (t/h) / km = consumed power/ per each ton / per each km

4. Number of total idler roll and the predicted number of failures per year

5. Cite a similar belt installation that reflects some association with your choices and accuracy of the claims.

6. % reduction in belt width x belt strength

7. % reduction in idler spacing, if possible, with smaller belt width

Note, I do not ask for speed, for belt strength, belt width, cover stock or rubber compound, idler details, only relative savings expected in belt width x strength, total number of idler rolls, and total expected roll failures per year.

Maybe, you can persuade your friend with, the JP alias, to also join. Let us respect him for his knowledge of rubber covers, core gum, steel cord construction, and other advantages that make his product the best.

I am perplexed by his admission not to know the many high speed conveyors that have been frequently published and cited on this forum. High speed belts starting before the 8.4 m/s Selby (REI) belt installed in 1985. As you know Selby is in the UK, the apparent home of JP. Maybe, JP can demonstrate his skills by offering to join this little exhibition of knowledge. Frankly, I will not hold my breath. No rhetoric, only facts.

If you participate, I will do the same, with backup. Hopefully, this cooperation will advance a more positive atmosphere on this forum.

RUBBER IS KING – let us show why.

Happy Easter. ■

Greetings and salutations from my corner of the slowly defrosting "Eastern Wilderness @1140 feet above mean sea level Mr. O'donovan.

Have you ever looked at capsule pipelines for conveying ores?

An excelent example of this is the capsule pipeline used at the "Karasawa limestone mine in japan that is owned by Mitsubishi and it replaced a railroad delivering limestone ore to a cement plant. A capsule pipeline can run above 25 miles per hour delivering unit trains of up to five cars per train.

An even simpler system is the one developed by brink weaver at www.pnuetrans.net-if that link does not work google thorne pnuematics to access it.

No idlers, no belt, splices, no belt training, no cable or steel stands , no e stops, a lot less work and it will run around the clock with no shoveling as it has done for mitsubishi since the early eighties-add to that they buried it in the old railroad bed coming from the quarry mountain. their system uses a three car train set where mr weavers uses up to five cars per set and multiple sets as desired and with air pressure of 3 to 5 psi.

lzaharis ■

Dear Mr. Izaharis,

Are you aware of the installation history of Mr. Weaver?

I did talk to Mr. Weaver and provided him with details on a number of overlands we are working on. He was very kind and responded.

One critical point of our discussion is the fact, he has not installed one ore handling system in any mining application. How can you tell this forum of the excellence of such a system without operational backup details? Noble, but too big a rock to move without big support.

As you know, without a track record, all the talk in the world, promises of performance, et al, falls on the client's deaf ears. No mid-manager will take the risk even with:

a) Big $$$ supporting the well-healed provider and credential of an excellent engineering staff,

b) Big $$$ savings verse the conventional wisdom

c) Definable $$$ in Risk vs Benefit Control with some consequential damage guarantee.

Take the example of Dawson and Lake Lindsey overlands in Australia. This new Cable Belt System, with a few minor tweaks, still does not operate to specifications after going over a year since it should have started major production. How many dollars has the client lost in investment and production by this imprudent choice. I doubt this client will repeat the scenario in the future. He appears to be the poor recipient of misguided judgement and false advertisements.

Why are miners so conservative? Dawson tells you why. Know the product, know the people, and know the people know the product. The devil and his details. ■

To Add,

Why hasn't the industry made the switch to capsules, if they are the panacea you claim? They have been around for a very long time? A few brave soles did take the plunge. Why not others? Aside from my small hyperbole above, what other impediments have you experienced that can shed light on this point on acceptance? ■

John Paul,

you should not go for speed above 8.5/9 m/s

Balanced idlers are out of price.

They do not solve the problem.

You know better than me the consequences on the belt.

If they award the contract at 11 m/s, just leave... and come back after 6 months with your standard slower reliable solution.

I'll be there too with the Pipe...

Be careful! ■

Dear Känel,

You have quoted

"you should not go for speed above 8.5/9 m/s

Balanced idlers are out of price.

They do not solve the problem.

You know better than me the consequences on the belt"

As for balanced rolls being "Out of Price",

There is at least one idler roll manufacturer that supplies (stock standard) idler rolls which equal or exceed 'Weigh Scale' specifications at the same cost as other manufacturers, With superior corrosion protection and far exceed CEMA load specifications while at a substantial weight savings for OH&S. These rolls are 5"- 6" & 7" diameters with steel 'shell' tubing.

I am at present quoting for 60Kms of "Patent Pending" DunnEasy Idler Assemblies which will also include these rolls for coal infrastructure.

I hope everyone has had a Happy Easter break.

It is good to see you on the forum Edmond. ■

Dear Mr. John Paul,'

FAST-SPEED CONVEYORS

Dear Mr. Edmont O'Donovan

Dear Mr. Nordell

Dear Mr.Izahanis

Dear Mr. Känel etc.

I red your answer for high speed conveyors with much interests.

But my idea is, that we get problems with the rollers and with the area

between the rollers/idlers and the belt.

a) Do you now investigations whats happend with the air

in this area?

b) Do you know investigations whats happend with static electric in this high-speed area?

c) If we have more speed, the rollers/idlers will also have mor problems

with the service. Each steel-idler is incase of a havarie a problem for the rubberbelt

For this case I have found ROLLERS/IDLERS out of RY-FULLPLASTIC

with phantatic results, but with my investigation in this direction -

I'm just in the beginning.

Peter Blaha Rosenstr.5 D-85609 Aschheim near Munich/Germany

https://edir.bulk-online.com/oldedirredirect/204146.htm ■

For many years I have been trying to explain the issues with the idler roll construction materials. I have encountered the following issues which used to be explained away by others as not worthy of being a worrysome issue. I explain a couple of points I have encountered and which have been bought to light in a large number of cases lately especially due to humidity and wet climatic conditions. The one primary scenario is the roll shell to belt friction co-efficient of (Aluminium - Poly - Galvanized - certain Paints - Impregnated grit coatings - Composite types & certain Rubber coatings. ) shell tubings. It has to be realised that without sufficient friction[Smooth slippery], the roll will not turn or will slip causing flat-spotting and / or premature shell wear. The roll has a tendancy to rotate at a slower circumferential speed than the actual belt speed. Poly roll feature heavily in this scenario as they lack frictional forces to keep the roll rotating, and they fail prematurily. Aluminium shells also have the same types of failure. Galvanized and grit impregnated work for a very short time until the spillage and carryback coates the surface and they become greasy and then fail the same as their greasy counterparts. The plain old steel roll appears to be far outperforming the newer rolls, by multiples of times, with less buildup and long lasting L10 bearing life. The poly rolls for belt widths over 1200mm and more than 4 metres per second travel speed, in every instance I have been privy to see or use, have been disastereous. When it comes to any moisture levels on the roll side of the covers of the belting, any minor mis-alignment of the conveyor belt structures causes bad tracking issues, even with the use of self-tracking units. This could be the subject of many reams of paper solutions thread at some point in time.

The best rolls I have found to date are the steel shelled with electrostatically applied and painted baked enamel at high temperature.

New types of roll are needed and must be suitable to applications. ■