Some Thoughts...
Hello John,
nice one, thanks for digging it out and putting it on stage!
In the first place, I very much like to congratulate those colleagues for their courage and efforts to undertake R&D at such a scale and level!
So let's have some looks on the ideas.
From a practical point of view, I feel that mine operators are a very much conservative kind of people who will leave their known ground only when really no "stretching" of the currently used technology is possible anymore. We see at least three major "NEW"s here: A) special belt, B) special drive, C) special technology.
These are singularities, and will be weighted against the breakdown of a truck: What if one of them breaks down against the breakdown of a truck. So in order to build a reference which will be crucial to bring this technology on its way it shall perhaps be necessary to have a contract to operate the / a mine.
The test rig picture is unfortunately a CAD - model only (so it seems, or does anyone know of a rig in iron & steel?), and it was not identifiable to me how the tube in itself is supported. Now, I think it cannot be in the usual way, by rollers mounted in a circular pattern on frames which are spaced in regular intervals. Even if the belt's cleats would provide some lateral stiffness, due to the steepness and the incitement by the discontinuous supporting there would develop a "bulging" in the spaces / distances of running between the supporting frames.
Very much alike the peristaltic movement, so it would also be crucial to tightly pack the material and to secure it in the location it has within the tube. Thus the supporting of the tube and the take-up belt tension become major issues to be considered.
From the rig picture and the picture showing the rolled belt, one could conclude that the tube would be supported on strips of sliding material, which would at once bring up the issues of belt wear and power consumption. As well as the "bottleneck" when the tube after being rolled has to enter the main flight. Probably a mix of straight flights on sliding pads and curved sections with conventional roller frames shall be used.
Well, let's see what the discussion (or perhaps the designers) shall provide. I'm however not sure, whether anyone of the design teams or their companies looks into our here forum ;-)
Regards
R. ■
Courage & Effort
The manufacturing process must be so complex. Curing heat will dissipate along the wires and so fixing of the cleats will probably be a separate operation.
From the description it seems that Larry's corkscrew phenomenon just dare not appear here.
With a belt so full of large rocks I would be concerned about side spillage at the head end.
Cleaning is almost impossible and accretion should interfere with troughing/roll up (what's the word here?) and there would be appreciable loss of capacity. A set of clogged up cleats is just a smooth belt in an different position. I imagine a washer will be incorporated eventually: like many fancy belts before.
As you say, sort of, the designers could get some outside insight on this one.
Personally, I despair at open pit mining approaches. If the deposit is shallow then high lift is hardly an issue. If it is a deeper deposit then why not sink an adjacent shaft, buy a hoist and away you go. Problems of a descending workfloor are common to all mines. ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Despair And Hope
What i despair of is that the more complicated the issues get our profession has to handle, the less people are prone to talk seriously / discuss matter. Open a magazine, and there's lot's of b*** making a big picture, like I wanted to buy icecream because it's a nice girl holding the cornet. Look around, how much substance vs. how much commonplaces, and quite always THE fashionable term DEM is not missing, as if that was an argument in itself.
In medieval times, in order to be listened to one had to cite all the relevant saints, lest to finish at the stakes. Final outcome being the indulgence trade, courtesy of Church Incorporated.
It's probably the fear to be robbed of the idea by professional "copyeers" or "reversengineers" that we have to get rid of, if anything like a fruitful discussion shall happen again.
The hope is, that during human evolution COOPERATION turned out to be the / one of the deciding advantage/s, and should get precedence over competition.
I'm quite intrigued what we will hear from the originators of this project.
Regards
R. ■
Dem Bones, Dem Bones
I would have written, later on, that DEM must have been available to the proponents of this tube belt and they might have seen some feasibility or else they told a few porkies to their backers. Well there are always porkies hiding away on bulk handling projects. That's where the fun creeps in. By their absence, I am encouraged to think that the idea has been thought through and seen through during publication of the article but the ball was already rolling. Then again, perhaps the concept was an elaborate red herring, designed to encourage copying and therefore see what the Asians turned up at no cost to themselves......it's been done many times in the past! Tit for tat. Yes, I am baiting.
In a world of diminishing mineral and organic resources (and: dare I say it? demand.) it seems rather pointless to develop devices which will increase the rate of depletion of those resources. A mass flow of 5000th-1 surely increases the rate of depletion, probably well beyond the mines' ability to supply at pit bottom.
Porkies refers to Cockney Rhyming slang for pork pies.....lies. Red herrings were used to train foxhounds to follow a scent. ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Belt Belt Belt Etc.
OH boy,
They are in desparate straights to counter the fifty percent net efficiency(or less)on sandwich or
other conveyor belts. No offense ment to Mr. Nordell or Mr. Dos Santos intended.
Nothing like running run of mine ore within a net square area that will be affected completely by
the size of the run of mine ores primary breaker sizing. They forgot the cardinal rule of crushing ore
to its minimum sieve size to take advantage of simple physics and inherent compaction when it
is collected and guided from the sump hopper to the exiting arc to the horizontal section of troughing
belt to the head pulley.
No different than these fools that take out choker chains from a belt feeder breakers drag conveyor bed
with thier so called wisdom of "because it reduces the flow of material" and dumps more on the belt.
Theres is good reason why- "choker chains are installed inthe feeder breakers to control and regulate flow and to prevent oversize
material from being carried over the primary breaker pick roll". I was told I was stupid and did not know anything.
by a so called expert so.................................................................................................. .......................
The same feeder breakers gearbox and electric motor were damaged due to damaged pick roll bearings, worn out gearbox
oil seals, loose flywheel weight damage to the gearbox shaft and electric motor shaft seal failure.
They missed the 10,000 TPD quota that day for sure.
"UGH; well you cant fix stupid or buy repair parts for it at the auto parts or mine equipment warehouse as my friends say.
I am glad I do not have to shovel out buried transfer points after certain fools leave the belt controls on hand and
walk away unscathed, not reprimanded or written up. ■
What Goes Down Should Come Up.
Since we have digressed onto in-pit crushers I would like to mention my experiences in the late '80s. A reputed mobile rotary toothed sizer was delivered for an exhibition at Hillhead, UK. When the exhibition was over the machine couldn't climb out. The quarry seized their chance and refused to allow dismantling because it would have interfered with production. So the machine might as well stay and work at a very low rental cost. The merits of the machine became incidental.
Most open pit working is blinkered and nowadays masked beneath mine planning software. Personnel are down the hole and will, and should, do it their own way right or wrong.
Continental are not taking the bait after all. ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Pipe Dream Or Flight Of Fancy
John,
I'm so glad you started this thread. I wish I had seen it sooner as I have already posted in the Linked in discussion. I will again post my response here and continue the discussions. Before I do I want to comment on the comments of this thread thus far.
- Your first comments: Here we go.
- Roland's comments: These are on the money. The phenomenon of increased travel resistance due to wedging, with increased troughing angle is long known. In conventional conveyors the effect is not so significant with increased troughing angle to 45 degrees. It is significant at a pipe conveyor with 70% filling of the cross-section and that is reflected in the high power requirements. Essentially it is a relaxation and squeezing of the load past each idler station incurring a dynamic version of passive earth pressure. This effect is dramatized in a 100% filled bulging section as Roland points out. I can't imagine that they really nean to allow the section to bulge to 100% full.
- Until Izaharis: You and Roland are just having fun in philosophy.
- Izaharis Comments: Leon, I have no idea what you mean by 50% efficiency. Please explain. Power wise conveyors in elevating application are 90% plus efficient. The remainder of the your comments have nothing to do with the Krupp Pipe Dream.
- Finally: John you know that I am the inventor of the Continental HAC and I have taken the bait.
Joe Dos Santos Response to the Krupp Pipe Dream article:
This is utter hog wash. We have seen Krupp and company introduce the innovative skip hoist into the pit. Next they will innovate by tying a mule to a cart on rails for modern haulage. We have seen them innovate by using gearless drives that date back more than 50 years for skip hoists and more than 30 years for conveyors, like the Selby project. This has been their answer to haulage from the open pit. Now they innovate by proposing a cleated pipe belt that cannot be continuously scraped clean, proposing material size that substantially exceeds pipe diameter/3. Good luck with that. This is also reminiscent of the HuRise development of more than 20 years ago, which turned out to be a total failure. The similarity is that the propaganda of both systems sought to discredit the Dos Santos Sandwich Belt high angle conveyors in order to justify their system, because once you acknowledge the success of the Dos Santos Sandwich Belts you are left with no basis for this exercise in futility.
The article's claims of the sandwich belt disadvantages are false. We don't have to drive both belts; we choose to drive both belts exploiting the combined tensile strength to achieve higher lifts with belts of modest strength. The article claims that sandwich belts require additional crushing. That is absurd. The 350 mm size that is optimistically claimed for their pipe conveyor of 900 mm diameter (3000 mm wide belt) is easily achieved with a Dos Santos Sandwich Belt of only 2438 mm (96") belt width. Indeed such a system will begin operation at a USA Gulf of Mexico terminal in 2017. That system will deliver a design rate of 4540 cu-m/h. The article claims that the Dos Santos Sandwich Belts are good for conveying at angles of 30 to 45 degrees but everyone knows that many Dos Santos Sandwich belts are in operation for many years at much higher angles to 90 degrees. Indeed many units are in operation at 90 degrees all over the world.
This writer’s emphatic objection is that the development might have been promoted on its own merit but the writers of the article felt a need to disparage the successful Dos Santos Sandwich Belt systems in order to justify their development. This was the approach of HuRise more than 20 years ago and it was an utter failure. ■
Not Even Finally...
What happens to the cleats at the loading impact zone?
How is the wrap achieved? There is already large rock burden settled on the flattened belt: then the cleats move essentially sideways through the big rocks. Either the rocks are longitudinally displaced or the cleats are flattened. It is anybody's guess. Moving rocks sideways while trying to make them climb is not the best use of available power. On the other side of the coin, a flattened cleat is no cleat at all. ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Pipe Dream Or Flight Fo Fancy??
Hello Mr. Dod Santos,
What I am referring to as far as fifty percent efficiency is the fact that
nothing is being transferred on the return to point B, being waste rock overburden returned to the gob pile.
The case in point being my white paper describing in detail how a Pneumatic Capsule Pipeline System could and would
replace a fleet of 400 ton haul trucks in the Powder River Basin of Wyoming USA and any other surface or underground
mining operation where long distance belt conveyors are used. You can buy a lot of pipe for the cost of a 3-4 Million Dollar
Diesel Electric Haul Truck. As Dr. Sanai Kosugi was fond of saying in his lectures describing the work that he and Dr. Henry Liu did designing
the Karasawa Limestone Mines Pnuematic Capsule Pipeline System and the work they did designing the Pneumatic Capsule Pipeline system that they designed and oversaw the construction of for the AKIMA TUNNEL and how efficient it was (98 Percent+-) The biggest cost was the pipe.
When the last subway extension was built in Tokyo(I believe-sorry its been a while) prior to Dr. Kosugi's and Dr. Liu's
passing their designed and implemented system for waste rock tunnel muck in Mining Mass Transportation from the use
of a Tunnel Boring Machine using a Vertical Pneumatic Capsule Pipeline System mounted on vertical rails versus a vertical pipe belt to transfer the waste rock and wet tunnel muck to the surface.
The subway tunnels depth was very shallow and the contractor decided to use a single rail mounted top loaded bottom dumping
Pneumatic Capsule to transfer the excavated tunnel muck and rock to the surface for disposal in this instance as a a
pipe belt system would not have allowed them to work in the middle of the street with out causing massive traffic flow
problems and problems with the subway at the this end location that would have affected the use of the station from
what I remember of the work. ■
Pipe Dream
I will again comment on your latest comments:
John, in fairness to them they describe chevron cleats with 10mm to 50mm spacing. These are not actually high profile cleats they are stripes of increased thickness of the belt's carrying cover. As Roland previously pointed out these will gunk up merely defining a new slide surface at the level of the top of the cleats (increased thickness). We must emphasize that they are taking us backwards to belts that cannot be continuously scraped clean.
Leon, conveyors and Dos Santos Sandwich Belt high angle conveyors can indeed carry material in both directions. It is just a matter of there being a load to carry in the return direction. We engineered such a conveyor for a cement company, that carried limestone 2.8 km from their quarry to Cement Plant #1 on the conveyor's upper strand then carried clinker on the lower return strand from Cement Plant #1 to alternately Cement Plants #2 and #3. The conveyor path which featured nine (9) horizontal curves was engineered to pass proximately to the two cement plants. This system featured many other high tech features including natural and smart booster drives and belt turnovers to utilize the carrying covers in both directions. There are other applications that carry coal to the plant then carry ash on the return strand back to a spoil area.
I have seen your many posts on pneumatic capsules and I don't see an us versus them. Each system will be selected following a technical economic study. This would be no different than the study that determines if haulage will be by overland conveyor or by rail or by trucks or by pneumatic capsule. ■
Any Echo?
Dear Mr. Dos Santos,
did you in fact receive any reply or other input from the originators of this article?
I had the chance to have a look into source reference [2] and couldn't find anything supporting the autors' train of argumentation in the way they presented the facts (concerning the 45 deg inclination limit).
Regards
R. ■
Pipe Dream Or Flight Of Fancy?
Roland,
I have not heard any response from the authors. The editors of the magazine, bsh have accepted and will publish my letter to the editor. Typically they will offer the authors an opportunity to defend. Additionally bsh has provided me with the opportunity to publish an article on our high angle conveyor systems. I have never previously thought to compare our high angle conveyors with pipe conveyors just because they are different animals. The pipe conveyor is not a high angle conveyor. Prompted by that Pipe Dream article's attack I will indeed compare the two systems in my upcoming article.
The idea of conveying at 45 degrees in a pipe conveyor is absurd even with the chevron belt that they describe. You still have a free surface that is not stable at such an angle in the static case let alone in a dynamic case with the belt speeds that the speculate.
Joe Dos Santos ■
Roaring 90ties
Joe,
I was specifically referring to the following claim of the article:
which seemingly conveys the fact that sandwich belt conveyors would be suitable for inclinations up to 45deg and relies for this statement upon sources 2 and 3. This however is not correct at least for source 2, even quite to the contrary!
However, I'm not a natural English speaker and maybe the wording could be interpreted to be inoffensive to the fact. All the best success for your riposte!
Regards
R. ■
Pipe Dream Or Flight Of Fancy?
Roland,
Thanks for your comments. I did not initially pay attention to the references though I did notice that reference 3 is an Article that I co-authored with Mr. Stanisic about the operation of the HAC at Majdanpek in Yugoslavia. I am not familiar with reference 2. I did a google search but I could not find this article. Maybe the Authors of the Pipe Dream will share that with us when they defend their article in response to my letter to the editors at bsh.
Joe Dos Santos ■
Paper
Joe,
it exists but in German, has not been made available to the great public but nevertheless exists still. Around here in printed form only.
And yes, either the Authors come up with it, or else a way shall be found.
Regards
R. ■
Pipe Dream Or Flight Of Fancy?
Roland,
If you have a scanned copy I will appreciate receiving it. My E-mail address is listed below.
Joe Dos Santos ■
Pipe Dream or Flight of Fancy?
The following article came my way.
http://www.bulk-solids-handling.com/...ing-next-stage
Would the learned members care to open a discussion? ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com