The chevron belts fill a need for material that is difficult to convey with standard flat ply conveyor belt such as wood bark, salt in short high angle runs, paper, news print, card board, glass bottles, plastic bottles are elevated to a typical recycling plants sorting deck platform which allows for sorting and segregating materials to be recycled and then dropped by gravity to be packaged and sent for shredding, smelting and reuse.

Anything being conveyed above a 20 degree angle will probably have a belt of this type not to doscount conveyor belts with ribbed side walls used on flat conveyors to hold material while it is elevated.

Locating reading material:

The CEMA web site, Goodyear, Dunlop, Bridgestone, Uniroyal, Kumho rubber-I think thats the right spelling anyway. this is start any way and there is a lot of material availabe. ■

Chevron belts are expensive and horrible to clean

Rather use a slightly shallower angle and use normal belt.

If you must go steeper use Aerobelt or pipe conveyor

LSL Tekpro ■

Scientific, probably none.

Practical experiment, thats more likely.

And most companies tend to keep the results of their experiments confidential so they have a commercial advantage over their competitors. ■

Kayem

From what I have found from my experience bonding cleats to belts with SC 2000, is that a cleat is just a cleat.

I found that it has two objectives. One is for the cleat to stop stuff rolling back, and the other is for the cleat to stay on.

From my experience the latter is just as important as the former so select your cleat accordingly.

(I still say avoid them at all costs though, unless it is a short term solution)

Cheers

LSL Tekpro ■

Cleats and pins are used when the soil, ore, and other products' internal friction exceeds the belt-to-product surface sliding friction when negotiating a slope section of the conveyor.

Cleats, chevrons, and pins are aids to restrain the product from sliding on the belt surface before it will sluff or rill from exceeding or breaking the products internal cohesive strength.

Once the cohesive strength is exceeded, the product needs another aid such as forming a pipe/pocket or using a bucket or similar container.

Depending on the product depth to cleat height, round and rolling ball like materials can be conveyed up some slope.

They also aid in allowing water to separate from the product.

Care should be taken with the angle and height of cleat to make sure its stress does not exceed its endurance limit, when bent over pulley surfaces, engaging belt cleaners, and that it has relief at the idler wing roll junction. ■

There are good reasons why our chevrons are designed the way they are. You'll notice that during the return route of the belt, where the pattern is in contact with the rollers, the belt will bounce up and down. This tends to be noisy, causes dust, bolts come lose,...all in all not too satisfactory. We actually design our belts to be in contact with the rollers more often to stop this bounce. This reduces the wear, dust noise etc,.....It can save a lot of money!!!The chevron pattern with Fenner Dunlop belting is also moulded onto the belt at the same time as the belt is manufacturered, thus increasing the strength of the chevron, so it doesn't wear so quick either. The type of pattern can be changed to suit the type of product required to carry, and the degree of the elevation. We can also increase the actual height of the pattern to, and width across the belt. There IS more to it than you think!!

Stan Holcroft,

Regional Sales Manager,

Fenner Dunlop B. V.,

The Netherlands.

+31 620 49 88 29 ■

Some other things that were likely considered when the patterns were designed are troughability and water runoff. You will notice some patterns have relief in the V.

Also some patterns are designed to be made in slabs (60", 72", or more) and slit to smaler withs, therefore a smaller more repeitive pattern across the width is used, while others patterns are made to width.

Some patterns go right out to the edge while others are inset to allow for skirting in the loading area to come closer to the belt.

Also as Stan said it is important for the pattern to overlap (or come close) to avoid bouncing on the return.

These are some of the things I have been told. ■

Kayem,

As indicated by other responders, the various styles and heights of cleats are on flat belts to address specific production requirements. Generally, the use of cleats allow the operators to move material with out roll-back (i.e. the cleats overcome the angle of repose problem). If you need to design a cleat to carry material up a steep slope you will need to consider the slope angle and the materials angle of repose. From that information you can calculate the height required. As far as the cleat strength is concerned, you need to calculate the weight of the material that the cleat will support and, using the physical properties of the cleat material, calculate the the cleat thickness and shape.

As a manufacturer, you can copy cleat designs (as long as they are not patented) without knowing the rational behind the design. Or you can do calculations and conduct some trials before finalizing your design.

Regards, ■

There are a variety of embossed patterns for the carrying cover of belts. The purpose is to eliminate the material on belt friction interface and replace it with a material on material friction interface which is generally higher. This allows conveying bulk materials at angles approaching their angle of repose. In woodchip handling this also eliminates the slickenslide phenomenon with frozen chips. This is done at a serious operating and maintenance cost, that is, such belts cannot be scraped clean. Others have introduced dish patterns, attempting to acheive the same without giving up the ability to scrape the belt even if missing the material in the dishes.

The various raised patterns are design to overlap so that they can ride the return rolls with minimal bouncing.

There is a better solution; DSI Snake Sandwich High Angle conveyors by Dos Santos International. These systems use two smooth surfaced rubber belts that sandwich the conveyed material between them. The hugged material can be conveyed at any high angle up to 90 degrees (vertical)

Joseph A. Dos Santos, PE ■

..but at what extra capital cost? ■

Where high angle conveying is advantageous then the DSI Snake Sandwich Conveyors will be competetive for the function performed.

Many have been specified for the advantages. Many have been installed.

Joseph A. Dos Santos ■

To improve my knowledge -

1) Competetive with what, sidewall belt elevators, bucket elevators, and at what capacity (te/hr or m3/hr) ??

2) The belts used, are they off the shelf, run of the mill conveyor belts that are held by stockists, or are they a special design of limited availability ?? ■

The function to be performed is to elevate bulk material from point A to point B, where the net path is at a high angle, that is an angle that cannot be accomplished with a comventional troughed belt conveyor because the material will roll or slide back. From here one must decide what else is required or desired. Is it required that the material be discharged completely.

At the extreme of absurdity, a scateboard costs less but it does not perform the desired function.

If clean discharge is not required then there a variety of methods to elevate the bulk from point A to Point B.

1.) Sandwich Belt High Angle Conveyor

2.) Bucket Elevator

3.) Pan Conveyor

4.) Pocket Belt

5.) Conventional conveyors with single or multiple switch backs

6.) Other methods

In such a case, if the required volumetric rate is high, 1000 cu-m/h plus and the vertical lift is high, 30 m plus, then the DSI Sandwich belt system will, in most cases, have the lowest initial cost. This is at the heart of our slogan "THE BIGGER THE LOAD THE HIGHER THE LIFT THE BETTER WE LOOK". The operating and mainetenance costs will also be most favorable. If the required volumetric rate is lower, say 200 cu-m/h or less, the initial cost may favor the bucket elevator or the pocket belt system. Operating and maintenance costs will still favor the sandwich belt system.

If complete, clean discharge (without carry back) is required then only methods 1 and 5 remain and method 1, the DSI Sandwich Belt system, will be most economical.

Though the initial cost advantage is at the higher rates Many Dos Santos Sandwich Belt Systems have been built for the lower rates. This is because the customer has determine that the required function is not performed by the other systems or the customer has evaluated the total life costs which include operating and maintenance.

As you may know, in elevating wood chips, at pulp mills, blow lines were dominant because of the very low initial costs. The recurring costs of power and chip degradation were very high. The first sandwich belt system to replace a blowline had a payback period of 6 months to one year. This in the extreme case where the blowline already existed and the cost of the sandwich belt system included removal of the blowline.

I hope this helps.

Joseph A. Dos Santos ■

Thats what I thought, thank you.

What about the belts? ■

The belts are not special but they are special order. They are of nylon x nylon construction, the old Goodyear Plylon, Goodrich Flexseal, Scandura Royalon 110 multy-ply belting. These were the standard for the industry but, in their effort to minimize stretch, the belting companies have replaced them with polyester warp nylon weft carcass construction. Elastic stretch is desirable for the Dos Santos Sandwich Belt systems, conforming to the radius of curvature constraints of troughed belts at tight transition curves.

Joseph A. Dos Santos ■

Ah, so in critical installations you would need to hold stock of spare belt. ■

Indeed we recommend a spare belt, the longer of the two belts (the bottom belt in case of an S-shape profile). We are presently working on buying such belting to stock. Depending on user response, commitment, we will proceed soon and DSI Snake belting will be available from stock.

Joseph A. Dos Santos ■

Cleat profile design is based on the size of the material vs. cleat height to prevent roll back, drainage if required, silent return on standard idlers, pattern width to accommodate skirting or not, and material containment on the edge of the belt. There will be a variation on performance between a standard chevron patter and a bucket type pattern depending on the material. One will handle materials such as wood chips better than river rock, and the other will do better with river rock than wood chips. A lateral cleat will do better with freer flowing materials.

Our cleats or integrally molded, not bonded to a finished belt. It allows for greater belt life. Also, with many of our cleat designs, you can have a different cleat material, for say abrasion resistance, than the base belts, improving performance while minimizing costs.

This is a link to some of our cleat profiles. http://www.leggbelting.com/profiles.htm

Regards,

Ron Marler

www.leggbelting.com ■

I'VE USED CHEVRON BELTS AND ALSO FIND THAT CLEANING IS A PROBLEM. ALTHOUGH THERE ARE CHEVRON BELT CLEANERS OUT THERE I TRY NOT TO USE CHEVRON UNLESS THERE IS NO OTHER WAY.

A METHOD THAT WE LIKE VERY MUCH IS INTERNAL CLEATS. WE SIMPLY HAVE MADE UP A TEMPLATE AND ACTUALLY GROVE OUT THE PATTERN FROM THE BELT COVER. IT WORKS VERY WELL FOR CHIP HANDLING AT A GREATER THAN 20DEG. INCLINE.

USING THIS METHOD HAD HELP US TO HAVE OUR CUSTOMERS COVERED WITH OUR REGULAR INVENTORY OF SMOOTH TOP BELTS.

JUST AN IDEA I WANTED TO PASS ON. AS FOR THE VARIOUS TYPE CLEATS, I DON'T KNOW IF THERE IS ANY PARTICULAR REASON FOR THE PATTERNS THAT ARE USED.

R.BABIN ■