Conveyor experts Jason Coe and Adam Wright from Flexco sit down with Ben Creagh to discuss common conveyor belt issues and how to prevent them.
When it comes to conveyor systems, it’s not always easy to spot a common problem and what can appear to be a small issue can quickly escalate into lost productivity, safety issues, costly repairs and hours of downtime.
Jason Coe, National Heavy Duty Field Specialist, and Adam Wright, Western Australia Manager at Flexco are experts in the conveyor belt field. With more than 25 years of experience between them they share their top tips for conveyor maintenance and failure prevention with Australian Mining.
What are the key causes of conveyor problems and failure?
Adam: Carryback is one of the main causes of conveyor issues. On top of that there is also the issue of mistracking, spillage and slippage.
What is carryback?
Jason: Carryback is the fine product that gets stuck to the belt. It can get carried down the line and cause all sorts of issues. It can get caught on rollers and idlers which then causes the belt to flap. It can also drop onto the conveyor structure causing hang up issues and making a mess on the ground.
How can carryback be prevented?
Adam: One of the ways to prevent carryback is to use belt cleaners. The idea behind the cleaner is to remove carryback from the conveyor itself and into a controlled environment. You can never get rid of carryback entirely, but a cleaner is there to do the best possible job.
What is mistracking?
Jason: Mistracking is when the conveyor belt drifts off onto one side and runs into the structure. This then causes belt damage and can cut into the structure and cause significant damage.
How can mistracking be prevented?
Adam: Industry standard is actually a quick fix, which is tracking frames. They are cost-effective and serve the purpose of essentially tracking the conveyor back centrally.
Whenever there is the issue of mistracking you have the potential to install a tracking frame that will grab the belt and put it back centrally. It stops the belt from digging into the structure and causing damage.
What is slippage and how can it be avoided?
Jason: Slippage is when the belt slips on the conveyor pulleys, it mainly happens on the drive pulleys. There can be build up on the pulley or the pulley could be lagging, especially if the lagging is installed incorrectly. Usually what happens is the lagging just won’t grip and this can cause the conveyor to burn out, have premature belt wear or even cause a fire.
You can prevent this from happening by making sure that the lagging is correctly installed, that it is in good working order and it is free from any build up and damage. Regular maintenance is key – as well as keeping the conveyor and all associated parts clean.
Finally, what does spillage entail and how can you prevent it?
Jason: This is when excess product falls off the conveyor belt and gets carried down the line. Mining companies want as much product shipped as possible so the less on the ground the better. Spillage can cause downtime and more resources spent on cleaning up the spillage. From a safety point of view, you want to keep the product on the belt. To prevent spillage, you should be looking at your chutes and making sure that the belt is centre at all times.
Is it common for a conveyor to have more than one of these issues at the same time?
Adam: Absolutely. A lot more can happen when there is carryback – it can build up on your return rollers, causing the belt to flap and then the cleaners won’t work properly which results in lagging issues. There is so much that can happen as a result of carryback.
If you have an issue at the head pulley, which you don’t get sorted it will affect everything down the system.
What do you recommend in terms of a maintenance strategy?
Jason: Conveyors, especially belt cleaners should be looked at on a weekly basis. One absolutely essential thing is that conveyor systems need to be kept clean. They should be hosed off on a regular basis – they have moving parts that need regular maintenance and it’s important that these are all working as best as they can be.
Why is a visual inspection so important?
Jason: Some of these conveyors work 24/7, you might have walked the belt yesterday but something may have been caught up in in it the next day. It’s so important to prevent any issues by physically walking around the belt. You can get caught up watching a computer system or just assume things are okay but it’s not until you really walk the system and start recording what’s happened that you get a real understanding of how it’s working.
Do you need a certain skill set or tools for a visual inspection?
Adam: Yes, it’s really important not to just throw people out in the deep end. We see people still learning trying to do inspections and quick fixes but this is such a specialist area that training should be implemented before carrying out these tasks.
Another crucial part in managing conveyor systems is the auditing process, why is it important and what benefits does it provide?
Jason: Audits are great because things constantly change. Conveyors get sped up so the original cleaners that may have been put in from construction when the belt was running at a much slower speed and may no longer be fit for purpose.
All four key issues can be focused on during audits. You can pick them up and record them and put them in front of decision makers on site. Regular audits are a huge advantage for mining companies.
What happens during the process of an audit?
Jason: We walk around the belt and visually inspect the entire conveyor from the tail to the head. We look at all the pulleys, watch the belt run, look at the underside of the conveyor and see if the cleaners are working.
Main key is to just walk the conveyors – it’s so important to visually inspect what’s going on.
This interview was originally published on the Flexco Mining Matters podcast. Readers can subscribe to the podcast on iTunes.