Search Stories by: 
&/or
 

Crushing, Maintenance, Plant & Equipment

Articles from CRUSHERS PLANT & EQUIPMENT (730 Articles), MOBILE CRUSHERS (504 Articles), CONSULTANTS & CONTRACTORS - CRUSHING & SCREENING (41 Articles)











Each year, more and more companies send their operators for training to ensure the best performance from their assets.
Each year, more and more companies send their operators for training to ensure the best performance from their assets.

Caring for your cone crusher: A guide to optimising performance

Giles Lambertson explains how a combination of training, maintenance and the right tips can maximise a producer’s cone crusher performance.

A cone crusher punishes itself in every minute of operation. It squeezes a dense mass between heavy castings until the mass disintegrates. It abrades and minces aggregate until the material yields to the applied forces. It rumbles and vibrates and bangs as its core shaft spins eccentrically to capture and reduce chunks of aggregate. All of this finely engineered ‘chaos’ demands that an operator be alert to what is happening to his/her machine. Otherwise, imminent component failure can be overlooked amid the crusher’s normal chaotic operation, and the machine’s performance will suffer.

Training

Some manufacturers conduct classes to train new cone crusher operators.

The volume of participants in such classes is increasing every year across the industry, suggesting that owners of crusher operations increasingly recognise the need to protect their investment.

These training classes introduce proper operating techniques – and advise improper ones to be avoided – as well as daily, weekly and monthly maintenance recommendations.

The goal is to maximise the performance of a crusher.

 A cone crusher literally punishes itself in every minute of operation.
A cone crusher literally punishes itself in every minute of operation.

Such training also can extend the life of a unit. A thoroughly maintained and properly operated cone crusher can process material for 20 to 25 years without major overhaul or junking. However, this expected life span shrinks when operator inspections are cursory, or bad operating procedures are regularly practised. All the best practices in the world are of no effect if an operator – or owner – wilfully ignores them.

Maintenance tips

At the heart of training are common-sense maintenance procedures that rely on the eyes and ears of an operator:

• The walk around.
To start a day, an operator should circle a cone crusher to visually confirm the soundness of the unit. Evidence of an oil leak or excessive puddling of lubricant is a red flag. Lubrication and hydraulic oil levels should rest at the full line – and accessing the oil reservoir should be accomplished without knocking contaminant into it. The oil strainer should be clear, conveyor and drive belts aligned and taut, and bolts tight. Visual and tactile inspection of the drive shaft housing can ensure there are no issues there. Material spillage underneath the machine may need to be addressed, particularly if the material is situated so residue could find its way into a component and contaminate lubrication. A daily morning walk-around survey establishes a baseline for operating the crusher at an optimum level.

• The peer-in.
Overlooking into the crushing chamber from a safe point is a simple way to ensure no foreign material has ended up there. Such material will either pass through the chamber or contaminate product or, in the case of metal, jam up the crusher and cause damage. A quick check will avoid both eventualities. A few minutes spent examining the chamber liners, while the crusher is stopped and locked, can ensure no cracks have developed, dangerously exposing the casting beneath the wear plates to damaging forces.

• The warm-up.
After starting the crusher’s power plant, the operator should determine that gauges are registering according to the manufacturer’s recommendations and that settings are correct for the material to be processed. Oil and hydraulic pressures should hover within acceptable limits. Idling the crusher during warm-up is acceptable, but not for an extended period. Once the crusher is running at crushing speed and material is introduced, another check of gauges and computer readouts will ensure all components are meshing as engineered and that production can proceed.

• End of day check.
Some inspections are best made after the crusher is shut down. An oil leak that developed during the day may still drip warm oil at that point. Tramp material from failed components may be freshly in evidence. Spilled material may require removal. Some checks made at the work day’s end will not have to be duplicated the following morning.

Peering into the crushing chamber from a safe point is a simple way to ensure no foreign material has ended up there.
Peering into the crushing chamber from a safe point is a simple way to ensure no foreign material has ended up there.

• Weekly inspections.
These build on daily observations. An oil filter and tank may pass muster each day, but a more complete examination at week’s end might show corrosive failure in a line. Liners shown to be intact each day should be examined weekly for uneven wear, particularly when abrasive material is being processed. Pinion shaft lubrication and drive shaft play should be checked each week. The integrity of seals will be evident at the end of a week’s operation, and unaligned conveyor and drive belts will show unevenness.

• Annual inspections.
A yearly top to bottom inspection – better yet, once every 2000 hours – is a best maintenance practice. However, it is rarely done. Relatively few cone crusher owners take the time to order a thorough, invasive examination of a crusher unit. Yet opportunities to do so are common. Changing out a liner, or performing an emergency repair, can require a crane. With the heavy lifting equipment already present and the site’s operation already disrupted, what better time to further dismantle a unit and look for niggling issues, eg the thin sleeve, the worn bushing, the compromised seal or disintegrating hose? Catching a failing component before it fails and causes ancillary damage is pure preventative maintenance, generally cost-effective, and ensures a crusher is operating at full capacity.

Operating tips

Cone crushers are built to withstand pressures and the grind of abrasive materials, hour after hour, without flying apart or otherwise self-destructing, but a savvy operator will heed a handful of guidelines to extend the life of crusher components and produce more uniform aggregate products.

• Homogenised feed.
What is dumped in the cone crusher’s hopper will, of course, determine what drops out below. Yet regardless of the type of material being crushed, it ideally is homogenised; that is, mixed together so finer and coarser elements uniformly congregate in the crushing chamber. If the conveyor process allows material to segregate, an operator can end up with coarse material on one side of the chamber and finer material on the other. The resulting uneven load creates imbalance, uneven crushing and undue strain on the crushing mechanisms. The fruits of a non-homogenised feed of material can be seen and heard and, ultimately, felt in the pocketbook as chamber liners and balance are sacrificed, resulting in poor product quality.

• Full crushing chamber.
Fitfully feeding a cone crusher’s chamber because of loading or conveyor issues can create uneven wear on liners. Not only are crushing forces magnified by the weight of material constantly pressing down from above, the machine itself is given full traction to do its work. A full, then partly full, then full crushing chamber sometimes is compared to a car travelling down the highway without cruise control. Accelerating to 105km per hour and dropping back to 88kph and accelerating again, and so on, not only wastes the car’s fuel, it can eventually foul the integrity of the fuel injection system. When it comes to cone crushing material, a full chamber is the best practice.

A homogenised, non-segregated feed will help keep the cone balanced while in operation and minimise wear.
A homogenised, non-segregated feed will help keep the cone balanced while in operation and minimise wear.

• Correct application.
Cone crushers are versatile machines, but using them as they are set up to function is the best idea. A 4:1 reduction ratio is a standard crusher application. Opting to use it for a 6:1 or 8:1 reduction of material could fall outside the parameters of its intended function, with punitive impact on the machine. Cone crushers can be utilised in the various stations of a sequential crushing process, but some applications are more effective than others. The owner-operator of a cone crusher should distinguish between tasks for best performance.

• Dry material.
Water sprays can dampen dust rising from a crushing operation, but actual crushing performance will suffer. Generally speaking, material that is wet when it falls into the hopper causes problems. The water molecules mud together with dust molecules, and finer material becomes pasty. The result is material that doesn’t fall out of the crushing chamber and creates unwanted pressures in the chamber, unnecessary wear of liners and less than optimum performance.

Poorly maintained and operated cone crushers are neither a mystery nor a rarity. They can be found at aggregates operations where rock is scattered on catwalks and oil tanks are covered with several days’ debris. Such signs of neglect are not the hallmarks of a high performing crusher operation, nor of a well maintained and operated cone crusher. The cost of such neglect, ultimately, is high.

Article courtesy of Aggregates Manager. Visit: Aggman.com











enewsletter banner 2
advertisement








Saturday, 24 August, 2019 12:35pm
login to my account
Username: Password:
Skyscraper 3
advertisement
Free Sign Up

Receive FREE newsletter and alerts


CONNECT WITH US
Display 1
advertisement
Skyscraper 2
advertisement