Your question is an interesting one, from a mechanics point of view you should:

1. Decide if you are willing to spend more on maintenance on your reclaimer.

2. Decide if you are willing to spend more on repairs for your reclaimer if the units productivity is increased.

3 Decide if you want to increase the stress on the design of the machine was designed to absorb and work:

More stress on hydraulic cylinders if so equipped.

Greater operating amperage fed from you high voltage load center feeding the reclaimer.

The electrical wiring/cable to the reclaimer from the load center may need to be enlarged to a larger cable size/gauge.

Lower bearing life.

Shorter conveyor belt life.

Shorter splice life of conveyor.

More stress on electric motors.

Shorter bearing life.

Greater stress on wire rope used if any.

Greater wear on the turntable of the reclaimer.

Greater wear and stress on the ring drive.

The folks that designed and tested your reclaimer before they offered it on the market designed it with the amount of flow at a fixed amount in either stacking or reclaiming.

The decision you make will affect the operating life of the reclaimer and it individual components.

The easiest decision to make is to run the reclaimer longer within its design flows.

Since I do not know the downstream requirement of your operation I am not the best judge of what is needed.

Relating to cross travel speed and depth of cut:

If you look at bucket wheel trenchers and look at how they operate you will see a parallel with your unit in relation to production levels.

If you operate the reclaimer at a slower shallow

digging depth you will maintain the rated output

levels of the reclaimer.

Will the bridge of the reclaimer rhandle the extra weight of product?

If the buckets are jammed to capacity they may or may not empty fully and reduce capacity of the ring. Another problem is shock load on the conveyor belt and splices etc. if the buckets dump their full amounts suddenly possibly tripping out the conveyor drive due to overload.

I hope I did not bore you to much. ■

The previous reply has covered most points with no boredom in sight. Bearing life was mentioned twice which is right & fitting since the bearings will drop to bits almost immediately after increasing the operating speeds.

Material discharge onto the yard belt will be/should be another problem. Wrap would probably have to be increased at the yard belt drive. If there is no problem with increasing the capacity of the downstream equipment the only question is "Why is the reclaimer capacity smaller than the rest of the system?"

If the remaining lifetime of the equipment allows it then perhaps it is feasible to rev up the machinery & live with the astronomical maintenance bill. It is also possible to supplement the yard belt flow with mobile plant actvity which would coveniently shift expense across to the production budget: whence this situation presumably originated. There's always an easy answer. ■

Thank you john, I hope we helped him with his decision.

lzaharis ■

Hello MB,

You are using bucket wheel on bridge for reclaiming of coal. So, possibly it might be also with the purpose of achieving certain homogenisation of the coal.

In case of bucket wheel on bridge the material output has to pass through three steps viz.:

- The material from stockpile face should flow to the bottom of the stockpile face, where bucket wheel would be reclaiming the material. Therefore, the machine output firstly also depends upon the flow rate / capability across the face. This is achieved by harrow. Thus, harrow operation parameter also contributes in the capacity. The stockpile cross section face angle is maintained between repose angle and sliding angle. The manipulation of the harrow angle can contribute in capacity, to some extent.

- The material so arriving at the base is to be reclaimed by bucket wheel. The bucket wheel does this function by bucket wheel rotation, depth of cut and cross travel speed. The material arriving at the base will have different quantum at cross section ends and at middle of the cross section. If you have got a triangular stockpile, there would be large difference between the available material at the ends and the material at the centre. In case of trapezoidal cross section the difference will be comparatively less. To compensate for this difference in availability of the material, the cross travel speed is higher near the ends and less at the centre. Cross travel speed is also different during bucket wheel cross travel in one direction compared to other direction, in conjunction with bridge conveyor.

- The third step which controlling the output is the depth of cut. The depth of cut remains constant in one cross travel cycle. Theoretically this can be up to 90 or 95% of the bucket depth, but this cannot be manipulated in isolation.

You have not mentioned how much capacity you need to increase. If this increase is marginal, you can manipulate by increasing the depth of cut, i.e. by setting the electrical system monitoring the depth of cut. However, as I have mentioned all the three steps contributing to capacity are correlated as per the specific design procedure and any arbitrary manipulation in one parameter can affect the performance or even be detrimental to the machine itself. This also concerned with the safety of the entire machine.

The best course for you is to refer to the supplier of machine who will have all the data of their original design and available spare margin in various functions contributing to the capacity. This will ensure safe working without adverse affect and also maintaining the blending quality etc.

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 ■