Instead of hold back you will need a breaking mechanism to stop conveyor. ■

sorry for mistake in earlier post. Brake is required to stop the conveyor. ■

Originally Posted by sunyahnil

Dear Sir,

Is there a need to provide a hold back mechanism in an declined conveyor when 3/4 of the conveyor length is horizontal ? Considering the declination is around 4 degree..

If only the inclined length is loaded, or the loaded length of the inclined length is more than the loaded length of horizontal portion, there may be a chance of reversal of conveyor.

It again depends on the materials bulk density, TPH of the conveying, gear box type, rollers conditions etc.,

Regards, ■

As Vinayak says, you will need a brake: on the highest drum.

Some clever souls fit a dynamo to generate power for other users. ■

sunyahnil ..

You will need a brake, especially if the declined section is at the head end.

This is because if the downstream half of the conveyor is loaded, then after the initial coasting, the decline portion is still loaded, and will keep on going.

Put a disc brake on the high speed coupling.

(Forget about re-gen power.)

Cheers

LSL Tekpro ■

So "decline" means regenerative conveyors, having the received length is horizontal and discharge end is downwards.

I agree with suggestion of brake.

Sorry for my ignorance. ■

Originally Posted by Graham Spriggs

''''''(Forget about re-gen power.)

Cheers

LSL Tekpro

I thought of your input to a previous thread when I mentioned it (because I was impressed). What happened? ■

Regenerative braking is provided by induction motor running at super-synchronous speed. This system will generate power when conveyor is generating power as downhill movement of load requires negative power input. No power is generated when power is switched off to the motor.

Hold back / brake is required when conveyor is stopped while loaded due to some reason. In case of rising inclined conveyor, hold-back prevents reversal. In case of downhill conveyor brake will stop movement in same direction. ■

Suppose you have a conveyor which is 1000m long doing 3500t/h.

The initial 750m is horizontal, and the last 250m is declined at - 4 degrees.

When you run this conveyor fully loaded it absorbs 131kW.

If only the last 250m is loaded, it generates 22kW.

Since the conveyor will probably operate 99.9% of the time with load all the way, then it is not worth the bother to try and reclaim 22kW (which depletes to zero due to purging in less than a minute) when running with the last bit loaded only.

If you want to harvest the energy when stopping you will only get a bit and the electricals will cost you. So...put on a brake and keep it simple.

If however the conveyor is say half horizontal, and half downhill at - 4 degrees, it would be a different situation and would produce about 35kW re-gen when fully loaded. Then you could harvest the regenerated energy by operating above synchronous speed all the time.

I would still stop it with brakes though. One on the high speed coupling and another on a pulley shaft extension as a back-up.

Cheers

LSL Tekpro ■