HDPE and other low friction conveyor idlers for belt conveyors. I have just had the previlage of viewing you web site regarding the so call innovative no rolling element slidler idler set. This type of slider idler set has been in use for decades and they have been used extensively in heavy duty transfer impact stations and tail loading sections and a photo is shown in the Link-Belt (TM) Mine-Duty Conveyor brochures prior to and since the year 2000. I installed curved impact idler frames for transfer stations which had 16 [100mm wide x 65mm length](from memory) HDPE pads per idler set which were slid in from the end of a curved beam which gave the belt a semi-elipical no crease curved trough profile. the pads had a bolt & washer on either end to locate the pack of 16 pads on the slide of the idler set. There was 14 idler sets in the stations.

It was found that the coal and abrasive wear was an issue but the impact ability was good.. ■

It would be nice to see a list of reference installations. ■

Hi,

Les is right, systems like this have been around for quite awhile. There is a significant increase in friction leading to much higher power consumption. If there is dust or carry back then bottom cover abrasion of the belt is an issue. To overcome some of these issues the air conveyor concept was developed. It is good to innovate and that has been the nature of this industry but this concept has been tried. There may be applications on smaller systems and you may consider using nylon instead of HDPE as our experience has been that this will reduce the friction.

Col Benjamin

Gulf Conveyor Systems P/L ■

Dear Boudreau

Could you send me your product details.

my email id is designsmgr@bevconwayors.com

Thank you

Manoj ■

Ditto with the other respondents. The cradle has been in use for many years and has a lengthy history of use. If your conveyor has a very light load, is small in width, and operates at low speed, it works to some level of satifaction for the uniformed.

The Slider naturally produces higher drag, consumes more power and produces wear. The wear is localized at high pressure points where the 3 linear planes of the Slider form the trough. The Slider must lift and deform the belt's sag developed between supports, distorting the natural catenary or hamock shape developed between Sliders.

Since the procedure slides, a higher friction is produced. These are all well known. Salesmen still try to convert the uniformed into thinking there is an advantage.

Impact tables do use a slider type trough at loading stations. After years of use, most impact tables orient the UHMW plastic support sliders with the long axial support along the belt's axis.

You can find many patents and application by Googling the details.

Continental Conveyor

Richwood Industries

Martin Engineering and a bevy of others

All have products with variants that have been in existents for 20 years with patent:

U.S. Pat. No. 4,793,470 issued Dec. 27, 1988 ■

Hi all..

The earliest conveyors were comprised of leather sheets sewn together and pulled over wooden troughs, with a modicum of burden on top.

Seems like we are trying to take a giant step backwards here, (unless it is for installations not much bigger than the diddy conveyors at the supermarket check-out points.)

Cheers

LSL Tekpro ■

If we didn't get it, you should not blame the messenger. Its your product to sell. ■

When I saw the original post it looked interesting.

I visited the web site but was disappointed. An artists sketch, a series of statements of it's virtues and a bland statement about where it can be used.

Might I suggest the site is updated with engineering drawings of the product, photographs of actual installations and the list of installations included here. ■

I am with Mr. Graham Spriggs on this matter. We went from tarp and leather belts on wooden troughs to rubber covered belts on rolls with anti-friction bearings. This was quite an advance and it seems that the slider bed craze is a step backwards. Some points worth making, from previous posts on this forum:

- Some used to call them impact beds because they were thought to better absorb impact. This is not the case. Work absorbed is the product of force and deflection

- Friction is much higher, typical coefficients range from .3 to .5.

- Admittedly they facilitate a better skirt seal but his can be done, and is being done with variations that put slider bars only at the edges where the load is least. Floating, lapping skirt designs with belts tensioned to lower sag allowed can also achieve good sealing.

- In the field slider beds make no allowance for belt training. This was quite a problem with slider bed feeders at the last job site that I visited. Such feeders are carried nearly entirely on the slider beds with only several idlers with rolls.

My two cents,

Joe Dos Santos ■

"Just to inform you, we have 10 patents covering Canada, USA and all of Europe."

With patents can you be sure they are worthwhile?

Can others prove prior art?

Have any of the concepts contained within the claims been "published" elsewhere?

Do you have deep pockets to enforce your patents? ■

Why do you have the slider set so high above the cross beam?

Seems such a waste of metal. How do we reflect on this? ■

Mr. Jean-Marc Boudreau

Analizing your statements:

1.) "What item on your system gives you the worst headaches? 85% of the answers were idlers."

2.) "you can understand, idler people do not like this idea."

I am susrprised at your first finding. Conveyors tend to be reliable and low in operating and maintenance. Typical availability approaches and often exceeds 99%.

With regard to your second statement, I am not aware of most respondents (of this forum) having an interest in conventional type idlers with rolls. Most are conveyor experts who are open to any better manner of supporting the conveyor line. Such other methods exist and are well accepted. Also, most have utilized slider beds, some as a preference and others because they were specified.

This forum has offered you the opportunity to address concerns in a quantitative manner. Two crucial issues remain that have not been addressed:

1.) What is the operating frictional resistance on the belt line. I threw out that it can range between 0.3 and 0.5. This is not disputed in your responses. Such values would be economically unacceptable for any but the shortest belt lines.

2.) The belt speeds that you have quoted are 350 FPM and 450 FPM. Belt speeds exceeding 1000 FPM are common in overland and in open pit mining conveyors. The economics of such systems often depends on the lowered capital costs of these higher speed systems. How will Slidlers perform at such speeds?

Although I remain skeptical I am anxious to see what the future reveals for your system.

Joe Dos Santos ■

Regrettably having a granted patent is no guarantee of "new knowledge", just that the examiner in his investigations didn't find any previous reference. ■

I attach 2 files to show the eqivalent idlers sets with slider beams and another with independant low friction plates the same as the Slidler setup.

These files are FMC [Link-Belt] Impact solutions from the 1990s.

Files are 12749322100.jpg and 12749319700.pdf ■

I attach 2 files to show the eqivalent idlers sets with slider beams and another with independant low friction plates the same as the Slidler setup.

These files are FMC [Link-Belt] Impact solutions from the 1990s. Go to

href="http://www.fmcconveyors.com" target="blank">http://www.fmcconveyors.com

Files are 12749322100.jpg and 12749319700.pdf

Attachments

1_2749_3221_00 (JPG)

■

Claiming that the patents validate the product is logically incorrect. As Mr. Designer said a patent doesn't even guarantee originality depending on the thoroughness and disposition of the patent office examiner. Persistence can usually get you a patent. I am aware of cases where the same basic design was submitted for patent years later and was granted that patent again.

More importantly, a patent is given (theoretically) for an original design or original variation of a design. Nothing about the patent award process claims that there is merit to that design.

As a well known author (I believe it was Samuel Johnson) once wrote, "it is better to be good than to be original". ■

Repeat sales are always the best indicator for a new product. ■

Once upon a time we made em from wood....& they woooden't work.

So now we make em from steel.....& they steel don't work!

The Devil makes work for idler hands.

I've always found that idlers hold up the conveyor design.

Just a few sayings from EL Bateman's..before the lights went out. ■

Jean Marc,

Wow ! You are taking a beating from the experts on this one.

I'm always interested in new ideas and would be interested in learning more about the Slidler. However, like the experts, I'd need to be convinced that the Slider has definite advantages over roll idlers. I go into many pulp and paper mills and find idlers that were installed in the 1950's, that are still running .

To do your product justice, you really need to have a better webpage.

Paul Janze

Sandwell Engineering Inc.

885 Dunsmuir Street, Suite 600

Vancouver, BC V6C 1N5 Canada

tel604-684-9311

fax 604-688-5913

emailpjanze@sandwell.com

webwww.sandwell.com ■

Mr. Boudreau,

Your system, claimed to be a better way of supporting the belt line, appears to be a very narrow niche product. By your own statements;

- it is not intended for belt speeds higher than 350 FPM to 400 FPM.

- It is not intended for long overland conveyors.

To repeat a previous post;

"What is the operating frictional resistance on the belt line? I threw out that it can range between 0.3 and 0.5. This is not disputed in your responses. Such values would be economically unacceptable for any but the shortest belt lines"

You have claimed a new design that does not incur a high friction but you have not disputed the above friction values nor offered any of your own. Do you know what these friction values are? Answering this question quantitatively, if true, could go a long way in convincing any doubters in this regard. Remaining silent on this issue implies to me that the above frictional values are as true for your system as they are for the slider beds that we are all so familiar with.

Joe Dos Santos ■

Even the most basic test will tell you the coefficient of friction. Take the cartridge, place it on a piece of belt, add a known weight, then with a spring balance measure the force to slide the cartridge over the belt.

Piece of cake! ■

Indeed, as Mr. Designer states so simply, the coefficient of friction is very easy to measure.

Thank you for your reply to the other questions. I look forward, in the near future, to updates on the progress of the slidler system, including:

- A quantitative listing of the frictional resistance to the belt travel of the slidlers.

- Summary of performance at higher speeds, to 1200 FPM and beyond.

I wish you success with this new system for carrying the belt line.

Joe Dos Santos ■

You will not obtain a true coefficient of friction value by placing the device upside down on a flat plane containing the subject belt.

The belt forms a compound shape as it approaches the idler support. These edges of the support will account for a greater pressure and thereby a greater friction, heat, and abrasion than its nominal rating.

Trying to equate such a drag condition verses the rolling resistance of a good idler design will not come close. Recall the drag of the belt is a many dimensional thing which includes the rubber of the belt. Now if the peak and local pressures of the sliding component are significantly below a normal idler then there might be hope.

However, the hype that sliders will improve performance while they cost more, leaves me to believe the original design could also have been improved by spending the funds on an better quality idler system to begin with.

I offer a challenge, to fit the slider on an well designed existing system, to see if better cost of ownership is achieved by:

1. reducing idler roller replacements, now at 1.5% loss per year

2. power within 5% of conventional idler rollers

3. improving noise reduction now at 72 dba at 1 meter

4. reducing belt bottom cover wear now at 20 year wear rate

5. Idler spacing not less than existing - 1500 t/h; 3m carry at 5m/s

6. and so on

7. aggregate cost of ownership guarantee must show a benefit

8. maybe try 30 sets each interlaced - starting new.

9. guarantee will not freeze slider to belt in sub zero weather

10. publish results

If the product does not meet these minimum criteria, then Slider pays for the loss of performance. Such a test can be made with two adjacent conveyors with equal duty or interlace in 3x3 or 5x5 along the length of one belt. ■

Maybe not, but it will be better than the information currently before us, which is nothing! ■

Larry,

I agree with Mr. Designer. The other contributions to resistance will not be different, except maybe the indentation resistance, depending on the approach radius of the pad. If the friction coefficient is not constant then a way to reveal this is by varying the applied load on the pad which slides on the belt. Distinguishing the static from the dynamic friction will also be important. The friction may also be speed dependent and this must also be probed by varying the displacement speed.

Joe Dos Santos ■

1) If you have carried out 5 years of R&D I'm suprised you can't quote the coefficient of friction (see previous).

2) 250 ft/min, I've run chain conveyors at 280 ft/min. For a belt conveyor that's s...l...o...w ! ■

"We are not concern about friction any more. We are concern about ampridge."

Motor current (or more precisely motor power) is proportional to the coefficient of friction. That is why a chain conveyor needs a larger motor than a conventional belt conveyor.

"We hired an independent engeneering firm to merure the amprege intake on one conevevor"

Motor current as a measure of power is inadequate. It fails to take account variations in Power Factor (the cosine of the phase angle) with load. Any decent motor catalogue will usually give Power Factor and Efficiency at full, 75% and 50% load.

"I do imform my custumer that there is more friction in the slidler than the roll and 99% of them tell me that with the advantiges of the slidler, we will simply replace the motot with a bigger one."

The areas I deal in are more and more concerned with conservation of power usage, to the extent of replacing standard motors with energy efficient ones. If a roller assembly has an effective coefficient of friction of 0.05, and a slider has a coefficient of friction of 0.2, that might imply a bigger motor by a factor of 4. Bigger motors require bigger switchgear, bigger fuses and bigger cabling. Then the belt has to be stronger to transmit the extra power.

"it is very hard to calculate the coefficent of friction after the belt has been polishing it. If I would do it, I would keep it for myself.

As an engineering problem it's not that hard. If I wanted to use your slider support in new equipment then without a coefficient of friction from yourself how could I possibly calculate the absorbed power of the machine?? Will you undertake the design of the power requirements of the conveyor for me and guarantee it? ■

There appears to be a melt down here.

Knowing the coefficient of friction or the range of such a coefficient is absolutely essential to power calculations and the determination of operating costs.

Mr. Designer has thrown out the possibility of .05 (for roll idlers) versus .2 (for slidlers). I have mentioned a range of .3 to .5 (for the slidlers). It is unimaginable that this value would not be an essential part of this development. If the results were favorable I am sure we would know about it.

Joe Dos Santos ■

Mr. Boudreau,

We look forward to knowing the friction when you decide to share it in the future.

Joe Dos Santos ■

I am just reading the January issue of "EVOLUTION" from SKF.

They include an article on "Bearings that save energy", new designs to reduce the energy they absorb. Included are single row deep groove bearings that reduce energy by 30%.

There are a lot of bearings on a belt conveyor. ■

I just read this whole back and forth here and the reading was actually quite rivetting reading.

Good luck on your ongoing R&D and wishing you great success in the future.

From one canadian to another....I bid you adieu. ■