Dear S.Ganesh,

Seeing the picture and comments I don't think this has anything to do with the location around the conveyor where the splice pulled apart.

I'd suggest you take a much closer look at your splice and your splicing practices.

Questions you should be asking your internal splice crew or splice company:

What is the rating of the belt?

What is the length of the step(s) supposed to be? What is it actually? In the picture it looks very short.

Was the correct splice material used? (Did they use material designed for Steel Cord belt or did they use fabric belt splice material?)

What was the vulcanizing pressure used?

What was the cure temperature and pressure? How were these measured and recorded?

How old was the splice material?

Did they prepare the cords following the belt manufactures recommendations? Describing the cords as "shiny" suggest that all the manufactures original core rubber was removed.

There could be some other issues such as the humidity, cleanliness, temperature etc when they did the splice.

Steel cord splices failures like this should be investigated very seriously to figure out what happened and make sure you don't have similar issues with other splices in your operation.

Best regards,

Andrew Hustrulid

Originally Posted by sganesh

Dear Mr.Ronald Heilmann,

Please find the photo attached. The bonding between the cord and rubber was lost and all the cords were seen very shining.

Thanks & Regards,

■

Respected Seniors,

Possible reasons at the time of splicing/splicing practices are beautifully covered in above reply. Such failures may occur irrespective of their location of failure. I have faced such failure on return belt near tail side bend pulley of take up pulley.

As Sir. Andrew has rightly suggested to investigate such failures seriously, It would be interesting to Analyse the Operation Trends recorded in DCS w.r.t to feed rate, speed, drive current, Sequence of Events at the time of this breakdown, to find/eliminate any possibility of Operation faults.

Please enlighten whether Operational aspects can be a reason behind such failure? ■

Dear S.Ganesh,

To generate high tension in the return strand of the belt, in the area you have described, you would need to lock up/restrain your belt some where between exiting your take-up and the break location. It wouldn't be your tail pulley because that is after the break location. I expect if the takeup pulley got jammed the drive would slip before generating enough tension to break the belt. (With the takeup jammed the T2 tension would drop really quickly leading to slip.)

It could be that due to the failing splice, part of the belt rubbed against (or got caught up on) the return structure generating enough force to complete the failure.

Even if the failure had been at the head pulley with a fully loaded belt, the main focus of the investigation would be on the splicing - procedures, materials and equipment.

Best regards,

Andrew Hustrulid ■

Hello,

Since how long this conveyor is in use ? The response from readers will have some relevance to this point. As an example, if you are using this conveyor since 7 - 8 years, and such a thing happens first time is one situation. As against this, the conveyor being new and happening of such failure during commissioning would be different situation.

Regards,

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

Originally Posted by I G Mulani

Hello,

Since how long this conveyor is in use ? The response from readers will have some relevance to this point. As an example, if you are using this conveyor since 7 - 8 years, and such a thing happens first time is one situation. As against this, the conveyor being new and happening of such failure during commissioning would be different situation.

Regards,

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com

Hi guys!I'm new to this forum, and I arrive so late replying this thread, sorry!

I just use this thread to ask you one thing: how long do conveyor belts like these work? What do you think about?

Thank you so much! ■

Originally Posted by Thom80

.......to ask you one thing: how long do conveyor belts like these work? What do you think about?

Thank you so much!

The useful life of a correctly designed and maintained belt is subject to the loading frequency and the severity of those loadings. Loading frequency is inversely proportional to the belt length but proportional to the number of loading points. It is further subject to ozone and UV attack. If the belt is long enough many manufacturers forecast lives in the region of 10 or 12 years on the grounds of rubber deterioration although their software predicts differently. Ask some manufacturers.

Since you only ask about belt life the only thing a designer thinks about is the original selection in terms of burden compatibility, environment and working tension. Other important issues have not been asked for so further complications are deemed unnecessary. ■

Originally Posted by Roland Heilmann

Hello,

I'd like to point you to the search application in the upper right corner of the Forum's screen. Esp. advanced search will bring you to previous posts concerning your request.

However, I took the libery to remove the link you inserted under the notion of >conveyor belt< and would like to ask you not to repeat that. If interested in advertisement, you may want to contact the Forum Admin per PM, addressee "Author"

Regards

R.

Typical free advertiser that ruins their company's reputation by being sneaky and embedding links into what they try to make look like a question. Good catch Roland. ■

Dear Sridharan,

There has been some interesting comments re your posting but I am far more concerned that the cords that pulled away in the splice were clean and shiny. You CANNOT bond bare cable to rubber in a normal splicing operation. There are some very specialised techniques to do this but I seriously doubt this was the case in this instance so the first question is why are there shiny cables. There are only three logical answers;

A) The belt manufacture was very poor. If this is the case go to the parent and strip back fresh cables and if the rubber peels away from the cables leaving a bare cable then it a very poorly manufactured belt that would be and will be very difficult to splice

B) The belt splicers seriously over cooked the belt during splicing causing the rubber to revert breaking down the bonding between rubber and cable. There should be ample evidence of this in that the rubber around the splice should be sticky or tacky.

C) very poor splicing techniques wherein for some reason the belt splicers decided to strip all the rubber away from the cables during their splice preparation. If on top of that they decided to "buff"the cables as though doing a fabric splice even worse as they will remove the zinc covering on the steel filaments making splicing using any technique impossible. Any splice manual will tell you you need to leave rubber around the cables when you prepare the cables prior to laying them up in a splice.

Looking at the picture you supplied there is absolutely no doubt there was no chemical bonding in this splice so it was held together my mechanical shear forces only. There also would be no doubt that the splice did not fail dramatically. There would have been evidence of cable buckling in the splice before failure. The fact that it failed near the tail is irrelevant as this is a flat belt so the tension variation head to tail would not have been significant. This splice was always going to let go, it was just a matter of time. It may well be that the buckled cables in the splice hooked a return side plough or fouled on an idler and this created the necessary addition boost for the belt to snap. Whatever it was inevitable event based on your pictures

Cheers

Colin Benjamin

Gulf Conveyor Systems Pty Ltd

www.conveyorsystemstechnology.com ■