The Merits of a low friction Bottom cover on overland conveyors.

Posted in: , on 6. Aug. 2007 - 11:49

Hi All

Could you please explain the advantages of a low friction bottom cover on an overland conveyor, as it seems to be in vogue now.

I understand that it reduces the friction between carry rollers and the pulley cover belt but what are the real savings and how long do these saving last. ■

Regards Bruce Baker Conveyor Consultants & Project Managers http://www.conveyor-services.com ________________________________________ "Professional Service" As Consultants our Customers expect and demand the right knowledge, expertise and experience and over the last 26 years we've proved we can do this time and time again, we guarantee it. "Worldwide Installations" We've worked all over the world and in all circumstances and conditions, from the Tropics of North Queensland, Australia to the Deserts of Saudi Arabia. "Expert Training" With 26 years experience, our customers bank on our extensive knowledge and expertise when they ask us to conduct training, we create a training programs customized to suit your specific requirements. ________________________________________
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Lyle Brown
(not verified)

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 6. Aug. 2007 - 12:10

Reduction of belt spec etc (CAPEX saving) and ongoing OPEX saving.

Suspect others will be able to provide details.

There are a number of papers on this topic floating around.

Regards,

Lyle ■

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 6. Aug. 2007 - 01:19

I've heard that there is a reduction in motor size required and ongoing power requirements but I would have thought the specs or ST rating would remain the same.

Most I've seen have only the bottom cover as low friction, so when it's on its return leg you have the carry cover in contact with the rollers so you negate part of the gain.

Unless you have a turnover on the return leg.


Originally posted by Lyle Brown

Reduction of belt spec etc (CAPEX saving) and ongoing OPEX saving.

Suspect others will be able to provide details.

There are a number of papers on this topic floating around.

Regards,

Lyle

■

Regards Bruce Baker Conveyor Consultants & Project Managers http://www.conveyor-services.com ________________________________________ "Professional Service" As Consultants our Customers expect and demand the right knowledge, expertise and experience and over the last 26 years we've proved we can do this time and time again, we guarantee it. "Worldwide Installations" We've worked all over the world and in all circumstances and conditions, from the Tropics of North Queensland, Australia to the Deserts of Saudi Arabia. "Expert Training" With 26 years experience, our customers bank on our extensive knowledge and expertise when they ask us to conduct training, we create a training programs customized to suit your specific requirements. ________________________________________

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 6. Aug. 2007 - 03:06

Dear Mr. Baker,

Please read the many posting in BSH that give a reasonable and definitive discourse on the subject:

1. Channar 20 km overland

2. Power of Rubber Part I

and many many more.

These articles and the many others describe how, where, why and by how much a change in rubber viscoelastic properties change the hysteresis loss due to indention of the bottom or top cover that comes in contact with the idler system.

Changing the compound can drop power and belt tension by more than 30%, everything else held equal.

When applied to take full advantage the savings can exceed 50%. Its all published, recorded, and testimonialed. ■

Lawrence Nordell Conveyor Dynamics, Inc. website, email & phone contacts: www.conveyor-dynamics.com nordell@conveyor-dynamics.com phone: USA 360-671-2200 fax: USA 360-671-8450

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 6. Aug. 2007 - 03:50

Mr Nordell

Thanks for the reply.

Do you have anything that shows a side by side comparison, say a system before and after LLR and or visa versa, in real world applications, not on paper.

I just wonder what the outcome is after the covers have worn, or dirt build up on the belt and idlers, worn idlers and bearing wear etc, does the LLR still perform as supplied or is there a increase in the friction properties.

What is the actual cost of 10 klms of LLR belt compared to standard covered belt.

If you can point me towards these papers or information I’d be appreciative.

Thanks.


Originally posted by nordell

Dear Mr. Baker,

Please read the many posting in BSH that give a reasonable and definitive discourse on the subject:

1. Channar 20 km overland

2. Power of Rubber Part I

and many many more.

These articles and the many others describe how, where, why and by how much a change in rubber viscoelastic properties change the hysteresis loss due to indention of the bottom or top cover that comes in contact with the idler system.

Changing the compound can drop power and belt tension by more than 30%, everything else held equal.

When applied to take full advantage the savings can exceed 50%. Its all published, recorded, and testimonialed.

■

Regards Bruce Baker Conveyor Consultants & Project Managers http://www.conveyor-services.com ________________________________________ "Professional Service" As Consultants our Customers expect and demand the right knowledge, expertise and experience and over the last 26 years we've proved we can do this time and time again, we guarantee it. "Worldwide Installations" We've worked all over the world and in all circumstances and conditions, from the Tropics of North Queensland, Australia to the Deserts of Saudi Arabia. "Expert Training" With 26 years experience, our customers bank on our extensive knowledge and expertise when they ask us to conduct training, we create a training programs customized to suit your specific requirements. ________________________________________

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 7. Aug. 2007 - 03:26

The Power of Rubber has a number of illustrations. One in particular is the Southern Ohio Coal installation. This is a 7km overland, installed in 1972, where exactly the same belt was replaced except the bottom belt cover compound was changed. The new belt demand power was 26% less than the prior belt. This was the 3rd belt replacement in it life time.

The last belt removed did not need immediate replacement. It had a good natural rubber compound from the same mfgr as the replacement. The client took advantage of a special belt offer.

Note, new belt typically draw more power than older belts due to thicker covers and unused rubber. So, the comparison is biased in favor of the old belt.

We have been researching rubber compounds since 1988. The science is very solid. We have shared many of our field measurements with the industry in publication and directly with clients in Australia, South Africa, Canada and including:

1. Channar 20 km

2. ZISCO 15.6 km

3. Muja/Collie

4. BHP Port Hedland

5. BHP Yandi 5 km

6. Eastern Range

7. Muja Prok

8. PT Bontang 6 km

9. BHP CRUII 9 km

10. Channar CV-555 10 kmUpgrade w/ new belt and covers

11. Syncrude Oil Sands 3 year study in lab and field

12 On many pipe conveyors

13 NOW!! 20.3km Curragh Overland commissioned in April 2007 ■

Lawrence Nordell Conveyor Dynamics, Inc. website, email & phone contacts: www.conveyor-dynamics.com nordell@conveyor-dynamics.com phone: USA 360-671-2200 fax: USA 360-671-8450

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 7. Aug. 2007 - 03:43

That's interesting, the old versus new, so in fact the power requirement is further reduced over time as the belt wears.

I believe the Channar belt was replaced some years ago, were you involved in this replacement and if so would you have the comparison of the original installation details, details just prior to the change out and the details of the new installation.

That would be an interesting read, as it would also high light the compond improvements over those years from the original installation to the new installation.

As I'm presuming the replacement was also low friction.


Originally posted by nordell

The new belt demand power was 26% less than the prior belt. This was the 3rd belt replacement in it life time.

Note, new belt typically draw more power than older belts due to thicker covers and unused rubber. So, the comparison is biased in favor of the old belt.

We have been researching rubber compounds since 1988. The science is very solid. We have shared many of our field measurements with the industry in publication and directly with clients in Australia, South Africa, Canada and including:

1. Channar 20 km

■

Regards Bruce Baker Conveyor Consultants & Project Managers http://www.conveyor-services.com ________________________________________ "Professional Service" As Consultants our Customers expect and demand the right knowledge, expertise and experience and over the last 26 years we've proved we can do this time and time again, we guarantee it. "Worldwide Installations" We've worked all over the world and in all circumstances and conditions, from the Tropics of North Queensland, Australia to the Deserts of Saudi Arabia. "Expert Training" With 26 years experience, our customers bank on our extensive knowledge and expertise when they ask us to conduct training, we create a training programs customized to suit your specific requirements. ________________________________________

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 7. Aug. 2007 - 04:16

Bruce,

I did the Channar replacement/evaluation as well as the original design. The new supplier is of a different origin than the original. Don't be so sure of the technology advances. Not all mfgrs. are created equal, have equal interest in R&D, and in making for a better environment. Some only wish to get the order.

I tend not to share recent material where there is ongoing intellectual IP. Seems like the competition has a greater need/interest than the clients.

There are a number of very large overland projects in the works. I hate to spoil our chances. ■

Lawrence Nordell Conveyor Dynamics, Inc. website, email & phone contacts: www.conveyor-dynamics.com nordell@conveyor-dynamics.com phone: USA 360-671-2200 fax: USA 360-671-8450

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 7. Aug. 2007 - 04:19

Totally understand, will look forward to it in a few years time, maybe.. ■

Regards Bruce Baker Conveyor Consultants & Project Managers http://www.conveyor-services.com ________________________________________ "Professional Service" As Consultants our Customers expect and demand the right knowledge, expertise and experience and over the last 26 years we've proved we can do this time and time again, we guarantee it. "Worldwide Installations" We've worked all over the world and in all circumstances and conditions, from the Tropics of North Queensland, Australia to the Deserts of Saudi Arabia. "Expert Training" With 26 years experience, our customers bank on our extensive knowledge and expertise when they ask us to conduct training, we create a training programs customized to suit your specific requirements. ________________________________________
Lyle Brown
(not verified)

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 7. Aug. 2007 - 09:35

At a high level (not going into details / using generalisations etc). There is a solid relationship between the demand power / installed counter mass and the belt specification (T1=Te+T2). A reduction in demand power will generally (though not always) result in a reduction of required CWT.

P=Te . s. For a given installation, I suspect the bulk of the Te (sum of retarding forces), particularly for a horizontal conveyor, will be from the carry side friction (where you have material + belt flexing over the idlers, whereas on the return you only have the belt). Consider for a typical conveyor the mass of the material, relative to the belt..

Consider these as generic statements etc and may not be true for all installations.

Regards,

Lyle ■

Lyle Brown
(not verified)

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 26. Aug. 2007 - 06:08

Bruce,

If you are interested, there are a number of papers freely (literally) available on this topic on the following sites:

http://www.ckit.co.za/

(look under the "troughed" or "papers" section)

and

http://www.saimh.co.za/

(click on "search" and a number of Beltcon's C/W papers are available).

A number of the authors appear to be participants of this forum.

Regards,

Lyle ■

Re: The Merits Of A Low Friction Bottom Cover On Overland Conve…

Posted on 26. Aug. 2007 - 06:13

Thanks Lyle

I'll have a look. ■

Regards Bruce Baker Conveyor Consultants & Project Managers http://www.conveyor-services.com ________________________________________ "Professional Service" As Consultants our Customers expect and demand the right knowledge, expertise and experience and over the last 26 years we've proved we can do this time and time again, we guarantee it. "Worldwide Installations" We've worked all over the world and in all circumstances and conditions, from the Tropics of North Queensland, Australia to the Deserts of Saudi Arabia. "Expert Training" With 26 years experience, our customers bank on our extensive knowledge and expertise when they ask us to conduct training, we create a training programs customized to suit your specific requirements. ________________________________________