I have often wondered about the situation you describe. Fortunately I have always been able to select alternative equipment.

So, the carrying strand has snapped and the lot, belt, buckets and crap go shooting down and fill the casing with a right old mess. The object should clearly be belt restraint. To collapse: the belt must buckle: to restrict buckling you could constrain the belt edges to run normally between close fitting strips giving minimum running clearance between the belt faces and the strips. Also the strips would have to be arranged to prevent the buckets from pulling the belt out of the clearance gap.

You could go a step further and introduce spragged roller sets along the strips' path.

The investment cost is not so high and the reduced clean up would pay for itself first time round.

Let us see what other suggestions are presented. Thank you. I almost feel confident about bucket elevators now. ■

Adding to what Louis has said are issues with space or the lack

of it on the head drive platform to commit to retrieval activities

in the event of a belt failure.

The problem is the point of breakage and how much of the bucket

elevator belt /chain is dropped or compacted upon itself when the

failure occurs.

You need to prepare to have the ability to tie off sections of the bucket

elevator conveyor rubber or chain links as you retrieve them en mass.

You must be able to winch up the conveyor chain or belt with good

rope AND tie it off below the section you are cutting away to prevent it from

falling back down into the chute as you retrieve it.

in order to allow you pull sections of the rubber conveyor and

buckets/chain and buckets up and remove them/cut away the

rubber conveyor belt-yes cut away the belt as you winch up sections

of it to retrieve the buckets.

Unless you have a conveyor belt slicer you will need to have a good sabre saw

with good blades to cut away the belting as you retrieve it the question remains

whether you are going to retrieve the buckets and the elevator bolts/nuts and washers

as soon as you pull each section out or simply do it at another location with more room

to work(which is preferable for all concerned as it limits the working area available

during the recovery phase of the damage repair. ■

Originally Posted by DmitryM

And what suggestions would be on how to reach elevator belt end in casing.

If we imagine. that belt has broken at the drive pulley ( where the tension is maximum), then the end of the belt will fall some distance down the casing ( due to partial belt buckling and free space between casing and belt).

Usually casing don’t have an inspection doors big enough at the every point of elevator ( or at least at every section). How to reach this belt end to tie it to the rope to pull up? What usually is done in this case?

The only way to over come this is to add doors to the shell

and as a result it allows you to have instant access.

If you have down time you could remove sections of the shell and add doors.

The only other option is removing the shell to the point where the belt has

dropped and wadded itself and then remove the web belt over the head drive. ■

My experience has always been to remove the bottom section of the elevator at the boot and pull the belt & buckets out at that panel until you can drop a cable down on both sides over the head pulley long enough for both ends to reach the bottom and come out of the elevator boot panel opening. Loop the belt on the floor if necessary.

Set up wire rope sheaves at the bottom of the elevator and connect the belt to the rope at the bottom pull from the bottom and pull the belt up over the head pulley. Make sure you pull the right cable and are not pulling against the back stop. Once the buckets start going over the head pulley make sure the other end of the belt is tied off to prevent it from getting away on you when you get close to being balanced over the head pulley. Make your repair splice in the normal way you would splice the belt. Inspect and replace any damaged buckets just before they are pulled into the elevator. ■

If you have a good inspection prevention program, you surely will not have any suden brake down of the belt, and will have the chance to program the repair. Usually you have a maintenance door, from where you can dismantle the old belt, take the precaution to have one end fix with a support and chain. After that you fix the new belt to the other end of the old belt, and pull the old belt out. You must pull from the upper end of the belt and fix the new belt to the lower end. You can pull with any machine, tied with a wire cable. You may help with small movement of the elevator. ■

Dear Experts,

Having VSD ( Variable Speed Drives ) is required or not required for bucket elevator conveyors ?

Thanks and regards, ■

I think every time you have to keep the inspection and keep the maintenance of your elevator because every elevator belt have a period in that you have to replace or have to check. ■