February 17th, 2015
Top Ways to Improve Wear Part Life
Recently, I was asked the best way to prolong the life of wear parts, specifically HSI blow bars, jaw dies, VSI parts and cone liners. Producers often want to know how many hours can be logged or how many tons of material can be produced before having to replace wear parts. The answer is the same every time: It depends on each operation and application.
There are a number of variables to examine when considering wear parts life, including:
- Feed size. By feeding too large of material or producing too many fines, producers can cause damage to a crusher and dramatically affect throughput production and wear parts life. Using screens to separate the material so that material is at product size, near size or smaller prevents the material from getting reintroduced into the crusher and helps prevent accelerated wear.
- High-quality parts. Using quality OEM wear parts that fit your crusher and application can also prolong wear life. Using after-market or pirated parts can have warranty implications if the use of these parts causes any damage to the crusher.
- Crusher settings and speeds. Crusher settings and speeds can change the outcome of single pass crushing. Improving the efficiency of a crusher can reduce wear and extend wear part longevity.
- Dust suppression. Water is very abrasive and is often the necessary evil, as it has both a health and an environmental impact. Using dust suppression can have positive results if the nozzle type and placement, pressure and volume are correct and meet the goal for dust control. Nozzle placement is very critical for wear parts life. If nozzle placement is incorrect, it can accelerate wear.
- Composition of material. The natural characteristics of material have an impact of wear parts longevity as well. The characteristics include chemical composition, hardness and abrasiveness. Although producers cannot change the material characteristics, they can educate themselves. I often hear from producers that their rock is really abrasive or very hard, but when asked, they don’t know exactly how abrasive or hard the material is. Knowing the exact characteristics of material can empower producers to select the best wear parts for their operations.
The best way to learn about material characteristics is to have samples tested. These tests include:
- A crush test. This determines how friable the rock is. A crush test provides you with information on how much product tonnage you can make in a single pass, depending on your gradation requirements. If the material can be crushed in a single pass, the wear parts only see the material once, thus prolonging the wear parts life.
- The Burbank Abrasion test. This test demonstrates how abrasive material is on steel parts, which enables producers to select the best wear parts for their equipment.
- A chemical analysis. This determines the chemical composition of the rock, which defines the amount of silica oxide, iron oxide and aluminum oxide present in the material. This test provides producers with the percentage of silica present in material, or as we call it, percentage hard parts.
- A compression test. This test determines the psi (pounds per square inch) strength of the rock. In other words, how much energy is required to break the rock? This test is especially targeted for jaw and cone crushers and will help determine your closed-side-setting (CSS) and reduction ratio.
By considering all of these variables, producers can realize significant savings when it comes to wear parts and production. Of course, it all boils down to education. By regularly attending factory training and consulting factory experts, producers can make the right choices to improve their operations. Taking time to invest in education will always help producers save money and improve the efficiency of their operations by eliminating the downtime associated with uninformed choices. We all benefit from ongoing training, regardless of our role in a business.
November 13th, 2014
Top Three Benefits to Pre-Ordering Parts
Analyzing your operation’s wear part needs is a crucial step in keeping equipment up and running throughout the year. There are numerous benefits to pre-ordering the wear parts you need before you need them – here are the top three:
- Guaranteed product availability and reduced downtime. By pre-ordering, you guarantee that the wear parts are available the moment you need them. Pre-ordering is especially important if you require a unique configuration or non-standard alloy. For example, KPI-JCI and Astec Mobile Screens stocks cone liners with 18 percent manganese content. If your preference is for a 14 percent or 21 percent alloy, lead times can be up to 16 weeks from the date of order. When your machines aren’t crushing, you’re not making money. By pre-ordering, you can reduce unplanned downtime and the loss of revenue that comes with it.
- Knowledge of cost. By ordering parts before you need them, you will know the cost upfront and won’t waste valuable time trying to price shop. Pre-ordering also helps you avoid expensive expediting charges and other unexpected surprises that can arise from waiting until the last minute. You can’t crush without wear liners, and pre-ordering removes that as a worry during the height of the crushing season when so much else requires your attention.
- Highest quality parts available. When it comes to crusher liners, poor quality can have several consequences, the most obvious being that liners wear faster than they should. If you’re changing manganese more often, that means you are down more often, paying more in labor costs to change those liners, and producing less. Discount suppliers may also leave you hanging if the parts you bought don’t perform as advertised. At KPI-JCI and Astec Mobile Screens, quality is extremely important in all that we do. We’re original equipment manufacturers and we stand behind all of our products like an OEM should, wear parts included. We continue to work hard to provide high-quality wear components that are also affordable. We’d rather make that investment up front so you don’t pay the price later.
Every operation has different needs, which is why the best way to plan ahead is to work with your local authorized dealer to put together a forecast. Look at the current operating plan, review historical use and consider any potential changes to future operations. Factory parts sales representatives are also a valuable resource in developing a plan by sharing best practices or helping design in flexibility to meet any unique challenges. Make it a team effort, because you have people ready and willing to help.
Contact your authorized KPI-JCI and Astec Mobile Screens dealer today to take advantage of its parts pre-order program.
April 7th, 2014
Top Ways to Reduce Wear on a VSI
When it comes to preventing wear in a vertical shaft impactor, consider these top six tips:
- No steel or metal allowed in the VSI. A metal detector or magnet is highly recommended. A metal detector attached to the feed conveyor works best as it detects stainless steel and items that a magnet will not pick up.
- Check the size. Large rocks must not exceed the mass noted in the manufacturer manual. Top size, as noted in the manual, should never be exceeded. More importantly, however, is the largest allowable mass of a single rock in the input feed. An individual rock should not weigh more than specified in the manual.
- Low feed rates. A less-than-capacity feed rate or inconsistent feed rate will cause abnormal wear and increase the risk of carbide breakage. Ideally, there will be a smooth and uninterrupted flow of rock through the crusher. Choke feeding the crusher provides a smoother flow. A low feed rate results in a higher wear cost per ton.
- Minimize water, particularly in the crusher feed. Water can create abnormal wear traits. Eliminating any free water will significantly increase the life of the wear parts of the VSI.
- Install a screen. Screening increases crushing efficiency and reduces wear costs. Screening prior to the VSI will ensure the proper feed size. In a closed-circuit system, effiecint screening after the VSI will remove sized product and decrease wear costs.
- Feed Tube Adjustment. The feed tube should be properly adjusted within 3/8” of the top of the rotor to ensure proper feed delivery into the rotor. This keeps rock from wearing the top of the rotor and improves crushing efficiency.
March 26th, 2014
Top Three Rules for Maintaining a Jaw Crusher
When it comes to maintaining a jaw crusher and securing the most uptime possible, the key is to develop a proactive preventive care program and become properly trained on the equipment.
While producers are sometimes solely focused on one specific part of an operation — like how large material can be and still be fed into a crusher — what they should be concerned about is how much production can be achieved and the best way to achieve it. That all boils down to maintenance and education. But maintenance is far more extensive than just greasing bearings and miscellaneous housekeeping.
Because of the violent nature of a jaw crusher, the equipment — regardless of application or manufacturer — will fail at some point without preventive care. But a proper maintenance program can help producers avoid costly breakdowns by repairing problems in their infancy. This could be something as minor as a loose or missing bolt, a broken weld, a loose belt, or a buildup of material that is allowed to remain. When taken care of daily, they remain small issues that can be immediately resolved to avoid downtime, but, over time, they can affect the longevity of the equipment.
While new technology can greatly enhance the efficiency of an operation, it can also add a challenge to those who have not been exposed to it. The following these guidelines can help extend the lifespan of your equipment:
- Avoid oversized feed. To establish a preventive care program that will extend the lifespan of a jaw crusher, producers must go beyond greasing bearings daily and consider the application of equipment. Because the jaw crusher is most often the primary crusher in a quarry or recycling operation, it is asked to perform the most difficult stage of product reduction. It is too often misapplied by feeding too large of material, however, which creates loss of production and the potential to damage the crusher. When an oversized rock is introduced into the jaw but is too large to fit into the chamber, it causes an interruption in crushing, which equals no production. A general rule of thumb is to keep the maximum feed size under 80 percent of the jaw opening or gap as measured from the top of the stationary die to the top of the moving die.
- Keep fines manageable. Although too large of material can cause problems for the producer, too many fines can also affect crushing performance. An excess of fine material will fill in all of the voids, which are necessary for the material that is being crushed to expand into. This creates an event called compaction. Compaction amplifies the forces in the crushing chamber, up to five times the normal crushing forces. As with any force that is generated, the energy must find a point of release, which is usually in the jaw base structure or in the shaft and bearings. Over time, this can cause damage. Excessive amounts of fine material also limit production because these fines are taking the place of otherwise crushable larger rock. Compaction can also be caused by improper use of the jaw die or plates. The corrugations of the jaw dies are crucial to the jaw performance, as the corrugations provide the expansion room needed as well as the leverage required to break the rock. Jaw dies should be flipped or replaced once the remaining corrugations get to about 20 percent of their beginning dimensions or irregular wear is detected. The wear of a jaw die should be gauged by the remaining corrugations at the bottom, not the overall weight of the jaw die itself.
- Aim for attrition crushing. If the proper feed size is introduced into the jaw and the jaw die maintenance is performed as recommended, the result will be a higher output, and true attrition crushing will take place. Attrition crushing, or rock-on-rock crushing, helps with output gradations and improves wear cost for the producer, as more of the wear takes place on the rock rather than the jaw dies.
As with all crushers, the maintenance of a crusher depends on how it is applied and taking a proactive approach to maintenance items like wear parts. Replacing wear parts before they are worn out costs less and improves the crusher’s performance, ultimately saving money, increasing uptime, and providing crusher longevity.
Although the fundamentals of jaw crusher maintenance apply to all jaw crushers, it is important to consider each scenario according to each specific producer when it comes to preventive care. Every producer needs to consider what he can do to improve his situation by adding to or developing a program that will work for his specific needs. There are no two identical applications, both in material and in people themselves. But there are similarities that can be the foundation for building a good maintenance program, so it is important to remain flexible. Keeping an open mind to suggestions may save you money and make you more profitable. It also serves as a morale booster to the employees asked to operate and maintain the equipment, and maintaining good employees will help in assuring that proper maintenance is being performed.
For more information about maintaining jaw crushers, visit Aggregates Manager's website for a detailed article. To contact KPI-JCI and Astec Mobile Screens' Field Service Representative Wade Lippert directly, e-mail him at email@example.com.
February 10th, 2014
Employing Fundamentals to Improve Efficiencies
Have you ever found yourself waiting impatiently at a traffic light when there were clearly no cars coming in the other direction? Do you ever find yourself looking for something that you use almost every day, such as your car keys or your cell phone? Have you ever spent a few minutes going through your closet looking for a favorite shirt, only to find yourself filling up a large bag full of clothes destined for Goodwill?
We deal with wasteful activities like these on a daily basis. And if you are engaged in mobile processing, you are acutely aware of the many challenges with which you're faced. Below are common challenges portable producers face:
- Equipment that must be highly efficient and reliable while producing maximum volumes and having the flexibility to produce an array of product specifications or adapt to any material condition;
- The loss of revenue associated with the downtime between moves to prep, clean, tear down, load, set up and wire equipment;
- Working in jobsites that are often too constrained for the footprint of the equipment spread needed; and
- Unpredictable and often volatile fuel costs and trucking expenses.
Fortunately, the same principles that lean professionals employ in equipment manufacturing can also be applied to those who manufacture a product on the run. While there is no substitute for taking advantage of a lean certification course yourself, here are just a few principles that can allow you to employ some common sense fundamentals to your operation in an effort to improve efficiencies.
- Appoint a value stream team. Identify employees from all areas of your operation, including production, maintenance, the office, safety or other non-production-related areas. The idea is to find people who have fresh ideas who are not pre-disposed. These small teams should address the needs of individual work areas in hands-on proactive workshops focusing on quick and easy ideas as opposed to groundbreaking solutions. The mindset should be continuous improvement.
- Apply the 5S's. Once the team has selected the first workstation, it is recommended that it applies a “5S” process to that workstation. This includes sorting, straightening, standardizing, shining and sustaining. It's sort of like cleaning out the pantry. Empty everything out, clean it, throw away what isn’t needed, assign everything a spot, label its place, and make sure it is returned back to that place every time and kept clean.
- Identify and analyze the system. Recognize that each component often works at a different rate, and that optimum production is achieved by balancing the system. For example, how is the jaw crusher set relative to the secondary crusher? How is the cone performing? Are there any issues? How much is it costing to operate? Is it a bottleneck? If the 5S process was thoroughly performed in step two, then this third step should be easier to address.
- Identify a focus area.The status of the 5S system and identification of bottlenecks will indicate where to improve a specific area of the system. Some common opportunities include: crusher configurations, screen configurations (throw/speed/media), conveyor flashing, transfer chutes/liners, safety/inspection reports, and calibration/controls/connections.
- Count and reduce the number of pieces. Many plants have excess processing equipment needed to fulfill their core material demand. This might create an opportunity to reduce waste by decommissioning unnecessary equipment from the plant. Ask yourself: Do you really need that extra chip screen and additional material handling equipment that was installed for the runway project back in 2003 that only produces 37 tph of a product that we could make by changing wire and flopping a chute once or twice a month?
- Accelerate flow. Accelerating flow is one of the main objectives. Just like your car burning fuel at the stoplight, material retained in your processing circuit is costing money. The quicker you can get it out of the circuit and into the stockpile, the less it will cost to produce and the more profit you will make. Ultimately, what we are really talking about here is identifying and relieving production bottlenecks. Use a stopwatch and time how long it takes from your feed material to get from the bucket to the stockpile, and then start to collaborate with your value stream about how to shorten the distance.
This systematic approach may sound complicated, but all it really takes is a group of people who are dedicated to making small, incremental changes on a daily basis in pursuit of a continuous improvement. You can help by dangling some incentives for each and every measured achievement.
While we all dream of making the large groundbreaking change, I have seen how dozens of small, quick and easy ideas tend to have a viral effect on an organization and provide even greater rewards over time through a stronger culture, improved safety and increased profits.