Dear Mr. Banerjee,

if it's a true Conti make, you'll be welcome to put your question to the manufacturer. There's detail in the composition of the top cover & in the heat load vs. sojourn time characteristics that could maybe help you. Nevertheless and as you seem to have it done already, please tell what was the outcoming of your decision?

One could also consider buffer bunker with cooling / spray curtain installations.

Regards

R. ■

The above responses are all correct.

The size of material will be of great influence as a dusty material will cool less than a lumpy material and transfer more heat into the belt. Also the length of the conveyor will be of importance, as the belt wil be allowed to cool down on the return. Effectively it will be the degree of heat transfered into the belt that will determine belt life.

The rubber will continue its vulcanising curve at these high temperatures and only very good compounds can withstand such high metarial temperatures. In the end, the rubber will become harder and loose flexibility due to the increased cross-linking inside the rubber. This will effectively lead to cracks.

With respect to the fabrics, it is a different story. On one side, the high temperature reduces the adhesion between rubber and fabric, also as the fabric treatment is affected by these high temperatures. Especially on critically designed conveyors (curves/small pulleys/short transitions etc.), this can/will lead to ply separation. As the splice area is always the weakest spot, the splice will be affected in time and typically show signs of separation after a while.

On the other side, with respect to fabrics, please note that when the temperature of the fabric (so inside the belt) exceeds about 100 deg. C a significant amount of additional stretch will occur.

Given all the above, a good quality belt and rubber compound will show its value in these extreme conditions. Should stretch become the main issue, a steel mesh carcass could be a solution, but bear in mind that is likely to require some design changes to the conveyor. And in general, the higher the temperature, the shorter the lifetime. Our Deltahete product is specified at 200-400 deg C range and can deal with these high temperatures, but when you really have 400 deg C continuous you should seriously consider steel carcass belting and accept a significantly shorter life than when running at 200 deg C. ■

Originally Posted by sganesh

Dear all,

We faced frequent joint problems in a steep angle conveyor ( made of fabric belts ) of similar application. The material is Do-lime. Average temperature is 125 deg Celsius and occasionally upto 180 deg Celsius. The splice joints were frequently failed- once in a month.

When there was no more margin left for hot vulcanized joint, we tried with mechanical fasteners. But it worked. Since last few months the conveyor is running ok. How this could be possible? I was thinking hot vulcanizing is better than mechanical fastener joints!

Regards,

With this temperature range, a proper (selected) belt with vulcanised joint should pose no problems for a long time. Perhaps some geometrical issues in the conveyor or a bad quality belt/splice material is your problem? ■