I presume that the conveyor is already in operation and is operating without problems.

You want to increase design capacity from 960 TPH to 1500 TPH an increase by about 57%.

You are equipped with a 800 mm wide belt running at 4.00m/sec.

You may be able to increase speed of belt to 6.m/sec.

If existing motors are 980 RPM you could replace them by 1480 RPM motors. Gear box will then remain same as torque load will not change.

Supplier of existing belt system will be able to comment on this. ■

There are not many conveyors in the world with 17 km length that are horizontally curved. If fact, I know of only one in India/Bangledesh. It looks like Lafarge Surma wish to increase their capacityto 1500 t/h.

Conveyor Dynamics, Inc and Laing O'Rourke have just completed commissioning of the world's longest trough overland and its controls at 20.3km in Australia. It works as advertised - quiet, efficient and meets the specifications. It is a very competitive design with Total Life Cycle Cost advantages over most, if not all, other similar overland systems.

Do you wish assistance? ■

Hello there Ash..

We have recently been presented with an award following, among other things, the design of the upgrading of a 12.8km long horizontally curved conveyor from 2000t/h to 3000t/h

No mean feat!

Suffice to say this is serious stuff, and your conveyor has to be fully analised for all dynamic aspects by experienced materials handling people.

In other words you have to formally consult with people like myself or Larry and do it properly.

LSL Tekpro ■

Mr Bhatnagar,

Only few conveyors in the world up to 20.4 km lentgh with horizontal curves are in operaton. In my Knowledge Lafarge suma is a conveyor with horizontal curves running successfully since after commissioning in 2005. In your case you have to increase the belt speed up to 6 m/s. You may concern your desiner for one additional drive in sec pulley to overcum the power loses. Think about horizontal take up arrangement which is more reliable take up specially in rainy days. I am looking a project of longest pipe conveyor centre distance is 7 km with 46 nos of horizontal & verticla curve carrying capacity is 1500 t/h carring side and 600 t/h on return side.

Rajesh Verma ■

Best advise?

Take Graham Spriggs' advise.

Not as simple as just increasing the speed - what happens in the horizontal cuve?

Careful analysis is required.

Regards,

adi ■

Mr. Bathnagar,

As ADI told, do not forget to simulate the dynamic conditions of this belt, starting and breaking.

Mr. Nordell,

I would like to find more informations about this 20,3 km long distance conveyor in Australia.

Where can I find it? Thanks.

Regards

Alexandre Calijorne - caltrapc@yahoo.com.br ■

Dear Alexandre,

What do you wish to know about the 20.3 km overland? ■

Dear Graham,

We did an upgrade to Channar raising the second 10 km overland capacity from 2200 t/h running at 4.1 m/s to 4600 t/h running at 6.5 m/s.

The numbers tell a 1.6 x increase in speed, while the tonnage increase 2.1 times. We did this while dropping the belt strength from ST-3000 N/mm to St-2800 N/mm. The strength dropped 7% although the belt crossection increased 32%!!!!!!

How is this possible? Its all in the rubber. The old belt was designed with a belt safety factor = 5:1. The new belt maintains the belt safety factor.

Not mean, but different than the norm. ■

Dear Lawrence,

Material, capacity, belt speed, width, length and lift...so, general informations about drives.

Just to know a bit more about this application.

Thanks. ■

Dear Alexandre,

Some details you requested on Curragh:

Material .............. Coal

Capacity ............. 2500 t/h

Speed ................. 7.5 m/s

Belt Width ........... 1200 mm

Length ................ 20.3 km

Lift ...................... 64 m

Power ................. 4250 kW

Idler spacing ....... 5 x 10 m ■

Can you give details on finding the paper? I have not been informed. ■

I also tried to find it at Google without any success.

I am very impressed with these technical data : 7,5 m/s for a 1200 mm belt conveyor for coal, and 5/10 meters idler spaces.

Far beyond I imagined.

It is time to me to reveal some concepts.

Thanks ■

Dear Shri Ashwini Bhatnagar,

You have two options, as below.

Use existing 800 mm belt and increase the speed to the extent allowable and see whether the capacity what you can get is acceptable. Even if you are keeping the same conveyor and same width still you have to get your conveyor analysed by conveyor designers concerned with such type of long distance conveying. In this situation, mostly conveyor main items will remain same but it may require adjustment in conveyor operational control logic, take-up, etc.

As a second option, if you have to increase the belt width then by large it becomes a new conveyor.

My point is that simply increasing the speed does not end the exercise, without design analysis and corrective measures.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■