just a thought, are you sure that there isn't extra capacity in your system exactly as it is? In my experience, there normally is unless they raised their capacity already on the site at an earlier time. If you wish, send me your details and I'll send you back a form. Fill it in and I'll put the details into the computer programme we have here and it'll tell you exactly what your capacities should be at your present speed, belt width, troughing angle, motor wattage, etc etc etc. Perhaps you just need to upgrade your present belts when they wear out.

Stan Holcroft,

Regional Sales Manager,

Fenner Dunlop B. V.

Drachten,

9203 SR,

Netherlands.

+31 512 585 565

stan.holcroft@fennerdunlop.com ■

Yes, the existing belt may be able to carry the load providing:

1. material is loaded to its center and the loading dynamics produce a maximum surcharge angle that makes the material fit to the belt width available

2. if item 1 is not true, then a redesigned chute is in order

3. there is sufficient structural capacity, including belt, idlers, pulleys, supports, reducer and motor ratings ■

Dear Mr. Pablonici

You intend to increase the capacity of belt conveyors. This is only one aspect of the integrated system. The belt conveyors will certainly be operating in conjunction with various machines, crushers, screens, and so on. Therefore, the available options and methods to increase system capacity should be analysed in context of the complete system (including mechanical, electrical, structural, etc.). As for the belt conveyors, the available option to increase the capacity are as below :

1) Increase the speed (if there is a scope for increase).

2) Increase the troughing angle, if there is scope for it. The increase in troughing angle will have a repercussion on transition distance, suitability of belt for new troughing angle etc.

3) Increase belt width. This means you will have freedom to select new speed, new troughing angle, etc. This will amount to change of many of the mechanical components, conveyor frame work and possibly structural also if there is much increase in the width.

It is not possible to give specific answer without full understanding of the system, various limitations therein, various options therein, and so on.

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 ■

■

you still have not told us much of anything.

You are moving 15000 tons per day assuming a 365 day operating period. with the desired increase you will need to move 17000 tons per day. the simple solution is to increase operating hours.

What experience do you have with conveyors or lack thereof? ■

There really isn't enough information; but increased belt speed might be your only real option. Materials that you are handling will have to maintain their surcharge. If you have Vee belt drives between the motors & gearboxes then it is straightforward. Otherwise there is a baseplate design issue to accommodate the Vee belt drive. Alternatively new gearsets might be available.

After that your idlers will wear out quicker unless they are presently in very good condition & well maintained thereafter.

Widening the belt would require a lot of capital expenditure; new drums & idlers for a start. Observe the present behaviour of your transfer chutes because they might need enlarging.

Background issues explaining the increase in downstream capacity would help. Yours is a familiar scenario. What would be the eventual expected plant demand within the remaining conveying system & overall plant lifetime? What is involved in increasing the downstream plant capacity, just like that? ■

Dear Mr.

To have turnover of 6,5 instead of 5,5 milllions tons per year you will have an extra capacity of 18%

You will have the possibilities as mentioned hereafter:

1.) Upgrade your beltspeed with 18%

The effect will be that your power consumption is 18% extra.

The wear of the discharge points and other positions will be more than 18% higher.

The maintenance costs will clear up will be at least 18% more.

Solution:

When your drive motors don,t have the required power; install an extra frequency controlled drive pulley on the tail end pulley

for running with an higher speed you will have to change the gear boxes of your drives or install frequency controlled drives on your motors or have your totally power system upgraded with 10Hz.

2.) enlarge the cross section of your belts by changing the troughing angle from 30 into 40 degrees.

In this situation you power consumption will rise with approx. 8%

The wear will rise with approx. 10%

The maintenance cost and clear up costs will remain the same.

Solution:

Install an extra frequency controplled drive on the tail end pulleys for extra torque in case that the existing drives don't have this extra capacity available.

Replace all your troughing idlers stations; an investment of approx. € 2,50 per kg including erection.

3.)extend your operational hours as long a there are some hours free available. your average capacity bnased upon 8000 working hours per year is only 700 tons per hour.

Your power consumption will increase with approx. 18%

The wear will rise with 18%

The maintenance cost and clear up costs will rise with a bit less than 18%.

Solution:

No mechanical investment required

I hope I have been of help for you

Kind regards

Johan Brands

i.s.t@wanadoo.nl

tel. 0031-622 515 981

The Netherlands ■