Dear Sir

You cannot use ordinary conveyor Belt for pipe conveyor application . pipe conveyor belt is made flexible enough to make complete pipe.

Ply construction at Edges are different so that edges are not straight and form curve at edges.

A R SINGH ■

Designer,

As has been said, you cannot use ordinary belt.

Both fabric and steel cord belts require special fabric reinforcement to induce a crossectional spring-back effect that holds the belt in a circular shape against the idler rolls.

Any spring-back causes additional belt pressure on the idler rolls which causes added rolling losses, belt tension increase, and necessary power increase to drive the belt. Power and tension is further increased for all vertical and horizontal curves due to their pressures.

If insufficient spring-back reinforcement is applied, the belt will tend to collapse from its own weight. This can also happen over time as the fabric carcass is worked and becomes more compliant.

Too much reinforcement, and the belt's spring back will further add to the roll pressure that causes an increase in rolling resistance, belt tension and power increase.

The manner of reiforcement is different for fabric and steel cord constructions. For fabric, the reinforcement can be somewhat disjoint to encourage the belt edges to maintain an arched shape and not collapse. Steel cord construction has differing layers of fabric reinforcement above and below the cables for the top and pulley cover respectively. These layers also act as shape enhancements.

Thus, the belt designer must have sufficient knowledge of the spring-back force and long term belt compliance to achieve a successful installation.

The age of material composites and their proper analytic treatment are upon us. Those that guess as to what degree is required can end up with a sorted set of references.

The process is complex and needs to be practiced with respect for the client's best Total Life Cycle Cost. ■

Dear Sirs

Please be advised it is possible to use conventional troughed belt in a pipe conveyor in an emergency.

It is not prefered and it is not recommended on complex or large projects and it is always recommended to use a pipe belt because of its modified construction to give the correct rigidity and endurance.

A conventional belt does not sit (make tube shape) correctly but it will and can operate on smaller installations.

We have done this in one or two cases but for the best life cycle and durability the pipe belt is best.

Paul Holt

Dosco Overseas Eng Ltd. ■

We have tried to replace 200 dia pipe conveyor belting with conventional belting 800 wide.

Conveyor with pipe conveyor belting was drawing 70 A at full load

However with conventional belt , conveyor was drawing 100 A on no load condition.

May be belt was new and was drawing more power than installed attempt was not successful

A R SINGH ■

Dear Mr Singh

Yes I would expect this.

For diameter 200mm belt width should be 780mm (if you have true diameter) and this will not help.

Until it has run for some time it will pull more power so you need to have this in hand.

There are many factors but for conveyors whivh are not onerous it can work but as I say it is not the best.

Even if you have a company who supplies a pipe belt if the belt is not the correct rigidity etc it can draw more power until is has softened and bedded in.

We have experience with different belt suppliers and it can be very different.

Paul Holt

Dosco Overseas Eng Ltd. ■

Dear Mr paul Holt

I fully agree with you for such smaller diameter it is very difficult for making pipe from conventional belt and belt does not take tube shape at edges. Initially power consumption is more than motor rating and it was not possible to run the conveyor with same drive unit . moreover edges of belt were tangentially straight and fouling between pipe forming roller roller edges and bracket

A R SINGH ■