Re: Down Hill Conveyor
Your idler failures are most probibly due to water pentrating poorly designed seals on the idler rolls.
This can be confirmed by bottom bearing failure and corrosion around the shaft
The water will come from rain or plant wash down which usually occurs on one side of the belt. ■
Re: Down Hill Conveyor
Experience in idler and roll failure of iron ore and mangetite mines.
Points to check.
1/ Loading of ore is truly centred from the chute.
2/ Lumps exceeding maximum are not being loaded. (Not un-usual to see a +1000Kg lump in the product being loaded.)
3/ Lumps are not all being loaded on one side from chute discharge.(Common issue)
4/ Check if the frames have any distortion or breakage. (Good indication if the system is being overloaded.)
5/ Check if the product is being loaded with excessive water content. (Obvious side spillage will be evident.)('Slug' water can cause side spillage with disasterous consequences.)
My experience is that the Client is not going to admit they have abused the system. Armed with ALL the facts, I have found that much extra remedial maintenance work can be obtained by showing the Client where their failures are and the REASON why and a SOLUTION to their issues
BEEN THERE, DONE THAT. ■
Down Hill Conveyor
Dear Sir,
If the idlers are tested properly, then I do not find any reasons for its failure even with ingrace of water. I assume that this conveyor runs on regular basics.
Regards
A.Banerjee ■
Re: Down Hill Conveyor
To ALL,
I have been in the industry for decades and can attest to the obvious that idler rolls are checked for manufacturing only on about 1 in 1000 and by the time the faults or defects have been identified, many thousands have passed through the system. With the increased demand for rolls, delivery times have blown out by months and the checking is not done.
A recent experience was many thousands (23,000 plus) were installed in a system where new belt was fitted to the conveyor. The rolls have now been identified as having 6305 instead of 6306 bearings and the TIR on the bulk exceeded 0.125 (3.2mm) and some as high as 0.234" (6mm) on a CEMA C 6" (152mm) 708mm long. This is a common occurrence within the industry.
Having said that, if the rolls are truly checked and pass the specifications then there should be no degradation to the rolls, I also have another set of conveyor rolls that are failing at an alarming rate even though checked for specifications before being fitted. The reason is that the alumina dust at high temperature is electro-statically adhering to the dust shields and wearing through in hours and the labyrinths seals then deteriorate as do the zs bearing seals. Even felt seals included have not helped much. The whole conveyor rolls are changed out on a yearly basis due to failure rates.
Has anyone dealt successfully with high temperature alumina being conveyed over long distances inside a sealed gallery system where the rolls last at least a year? ■
Re: Down Hill Conveyor
Originally posted by tecmate
To ALL,
I have been in the industry for decades and can attest to the obvious that idler rolls are checked for manufacturing only on about 1 in 1000 and by the time the faults or defects have been identified, many thousands have passed through the system. .................................................................................................... ..
I also have another set of conveyor rolls that are failing at an alarming rate even though checked for specifications before being fitted. The reason is that the alumina dust at high temperature is electro-statically adhering to the dust shields and wearing through in hours and the labyrinths seals then deteriorate as do the zs bearing seals. Even felt seals included have not helped much. The whole conveyor rolls are changed out on a yearly basis due to failure rates.
Has anyone dealt successfully with high temperature alumina being conveyed over long distances inside a sealed gallery system where the rolls last at least a year?
It just proves the redundancy of the ISO9000 bit which we are all forced to agree to somewhere down the line.....I've had to request dispensation for marginally unacceptable vessel flanges (0.0015% carbon) from the AI & Owner and in the meantime the QA/QC Manager was telling the supplier to send a new doctored certificate showing compliance. So much for quality issues..........
Have you tried charging the shields to repel dust? Can you even? If you say its a long distance conveyor then I am assuming its outside the potrooms. ■
Re: Down Hill Conveyor
Many years ago I attended a conference on bulk materials handling. One paper related to the improvement in idler life by the use of some ZYX seal arrangement.
Poor chap had his legs chopped from under him a bit when his methodology was questioned as his "life" related to how much play there was in the bearing and the questioner suggested that this might have been more related to the tolerence of the bearing to dust and dirt the the features of the seal. ■
Down Hill COnveyor
Dear Sir,
We have supplied only Idler sets to a down hill conveyor Length 500mt. designed by customer.
Lift (-) 30 mt BW 1000mm Capacity 570TPH. Material handled Iron Ore.
The belt was torn two times and some idlers with bracket fall down on the ground.
Presently customer is complaining about the failure of Idler rolle.
We have visited the site and observed the followings
Idlers are seized in one side of the conveyor i.e. opposite side of the motor.
Only one no bearing was seized of some of idler rolls.
Customer is using the same Idler roll which was felt on the ground.
Premature failure of roller is 5 to 7% only. Disc break is being used by the customer.
Roll DIs 140mm Shaft 25 mm Bearing ID 25 mm . Bearing Sieze resistance.
Kindly help us to prevent the premature failure of the idler rolls.
Thanks
Rajarshi ■