Resources search results "Electrical "

Get More Performance Out Of Your Crusher
Stedman Machine Company
Get More Performance Out Of Your Crusher impactor maintenanceThere’s an urban legend out there about the company whose maintenance crew mistakenly installed a new crusher with the rotor spinning backwards. It still worked! And you think you have issues? To get the most from your equipment investment, you need to put in the time. Yes, a crusher costs a bit more than your average automobile, but that doesn’t mean it’s maintenance-free. An automobile needs oil changes too, right? Performing regularly scheduled maintenance on impact crushers is crucial for guaranteeing day-to-day reliability and optimum product output. Did you know you can boost output and quality by doing just a little bit more? Even daily cleanups and inspections can increase service life. It’s a no-brainer, though possibly easier said than done. Here are some steps and practices to incorporate in your ongoing operations and maintenance. Beginning with maintenance team education, parts logs, and general maintenance record keeping, plus troubleshooting, these guidelines will help your crusher go the distance. Training: Proper training for consistent maintenance is one of the most fundamental requirements for successful, reliable production. Begin with the crusher’s operation and maintenance manual. Incorporate the manual’s suggested routine maintenance schedule into the maintenance team’s duties. Appoint a “lead person” for each crusher as the go-to for that machine. This person is the historian for the unique operational adjustments the producer has incorporated for raw feed and product requirements. Daily log (document the following every 8 hours): Amperage draw: See if it changes from day to day. If amperage is exceeding normal levels, it could be a signal of bearing problems, loose belts, or general feed issues. Coast-down time: You’re going to need to know (and log) how long it takes the machine to come to a complete stop after shutdown. Here’s why: If the time starts to shorten, this could indicate a bearing problem. Oil pressure: You’ll want to record performance in a variety of operating conditions. This will allow you to identify trends and help to detect problems before they cause costly damage or downtime. Daily maintenance (every 8 hours): Check oil level, sight glass, grease appearance, and other lubrication schedules. Check high temperature or low hydraulic pressure indicators and switches. Check wear parts. Tighten bolts. Inspect belts. Remove dirt and debris from crusher frame surfaces and areas around the machine. Check intake/discharge chutes for any obstructions and/or build up. Check alarms. If electrical changes are made or programs are altered in automated systems, verify that all alarms and interlocks function properly. Don’t be afraid to replace switches or timers that appear damaged or are in poor condition. This is more economical than a major overhaul, but never disable or alter any alarms or interlocks! Lubrication: Completely drain and thoroughly clean out the inside of the oil tank (if you have one) to eliminate any contaminants before refilling. Find contaminant sources. Contaminants such as dust particles and water can get in where oil leaks out. Inspect hydraulic systems and tag any leaks for corrective action on the very next maintenance cycle. Use the proper grade of oil. Use the proper specification of filters. Keep the oil breathers clean. Understand grease versus oil lubrication. Grease requires less-intensive maintenance than that of oil-lubricated systems. Automatic oil lubrication systems or sealed cartridge bearings are for higher speed crushers like vertical shaft impactors, air swept fine grinders, or high-speed cage mills. Most horizontal shaft impactors, hammer mills, and cage mill applications are below 1,000 rpm and grease is sufficient. Maintain a scheduled oil sampling program. By creating a baseline of normal wear, it helps indicate when abnormal wear or contamination is occurring. The exact condition of a mechanical assembly is reflected in the oil. Belts: Inspect V-belt drives for damaged belts or loose belt tension. By replacing cracked, glazed, torn, or separated belts, plus maintaining proper belt tension, you’ll optimize your plant’s performance. Wear parts: Don’t overextend wear parts. Avoid running them so long that they become too worn. You may find that you can no longer rotate breaker bars or interchange wear plates to lower wear areas — and now, you’ve lost half of the wear. Guards: Rubber and chain curtains located in the feed and discharge openings of the crusher are subject to wear and tear. Since they are a first line of protection, it’s important to inspect them regularly and to establish a schedule of regular maintenance. Electrical: When (or if) electrical changes are made, you’ll need to verify that all alarms and interlocks still properly function. Same goes for programs when altered in automated systems. Always check with the manufacturer before making any modifications. Spares recommendation: Keep the recommended spares on hand and order replacements as soon as they are used. A list of recommended spares may be included with your equipment operations manual. If not, contact the manufacturer for recommendations. Update your equipment: All equipment evolves, and the recommended manufacturer upgrades are a good investment for increased life and better crusher performance. Check with the manufacturer for any possible updates. Unapproved modifications: Manufacturer design engineers have considerable field experience, which helps them as they calculate the design and perform prototype testing. Their engineering tasks include calculating bearing loads and bearing clearances. They’ve also worked to maximize throughput by establishing the most efficient speed and setting combinations to optimize impact on the material undergoing reduction. So when plant personnel suggest modifications that alter the intended design, these changes will more than likely hurt the purpose of the original design. As a result, you’ll have a less productive and reliable crusher due to potential damage and overload. Since the manufacturer has a vested interest in how well the crusher performs, contact them before making any modifications Cage Mill Operation and Maintenance Requirements for optimum production and wear part utilization include the following: sleeve wear patterns cage wear pattern identification To increase multi-cage sleeve life, cage rotation should be reversed regularly, if possible. (Some cage mills can be reversed, while others cannot.) By reversing the cage direction, sleeves will be worn from both sides, thus extending wear life. Wear parts: Index and or replace sleeves periodically. Inspect or replace hopper ring and shaft protector, if needed. Cage rebuilding is an option. Bearings: Follow the manufacturer’s recommended specifications and schedule for lubrications, temperature, and vibration ranges of spherical roller bearings in pillow block housings. Horizontal Shaft Impactor Operation and Maintenance Variables affecting product gradation include the following: Rotor speed – Higher rotor speeds produce finer product output.Breaker bar wear & new edges crush finerBreaker bar changes. Apron gap settings – Closer gaps retain the feed longer producing a finer product. Breaker bar wear – Regular inspection and turning will lower operating costs. Throughput (tons per hour) – Overfeeding a crusher can make the output more coarse, but it also causes a number of wear and longevity issues making overfeeding a major concern to avoid. Moisture – Moisture cushions the impact, producing a coarser product. Apron wear – Worn plates can be replaced or moved to areas of lower wear. Spring bridge operation – Spring set height is critical to maintain proper operation of spring bridges. Spring bridges return the aprons to their original positions after an overload situation. The use of altered or non-specified springs can cause equipment damage or catastrophic failure. Requirements for optimum production and wear part utilization include the following: Protect inlet and outlet. Restrict maximum feed size. Maintain feed rate within allowable limits. Check rotor rotation. Use metal detection (required). Check for wear. Follow recommended breaker bar rotation setting sequence. Check rotor breaker bar, wedge, and stop block or jack screws. Check liners and breaker plates. Vertical Shaft Impactor Operation And Maintenance The vertical shaft impactor uses high rotor speeds (1,000 to 3,000 rpm) to apply high energies to the material, and since Energy + Material = Size Reduction, it can create sand from 2-inch feed. Requirements for optimum production and wear part utilization include the following: optimized parts in rotor tube Limit feed size. Use metal detection (required). Observe any vibrations with the use of continuously monitored vibration sensors. Listen to the equipment, if something sounds unusual, shut down and inspect. Limit recirculating product in a closed system. If using water for dust suppression, introduce it into the discharge area if possible. Introducing water in the intake will increase wear. Place weight match shoes opposite one another. The image above shows rotor tubes indexed 90 degrees providing a new wear surface. Wear parts include the following:recommended parts for vertical shaft impactors Shoes and tubes Anvil ring or other inserts Housing liners Rotor table liners and assembly Spares recommendation: Shoes (one complete set) Table liner Anvils (one complete set) Discharge plate The spare parts inventory shown above is recommended for vertical shaft impactors. Hammer Mill operation and Maintenance Up running hammer mills combine impact and shear to reduce material. Down running hammer mills primarily use shear by immediately taking feed to the screen or grate bars where hammers shear the material, until it passes through the openings. Requirements for optimum production and wear part utilization include the following: Lubricate bearings regularly. Regularly inspection (unclamp or unbolt front upper half housing for access to screens and hammers) liners, hammers, hammer bolts, rotor discs, grate bars, and screens. Spares recommendation: Hammers Screens Liners Grinding plate Summary A partnership begins between the manufacturer and the customer when the crusher is installed in the field. The manufacturer needs the customer’s help as much as the customer needs the manufacturer’s help to achieve the highest performance possible. Maintenance service after the sale, although mentioned last, is a central part of crusher system performance. And just in case, the manufacturer will have the people and the parts available 24/7 to assist with any problems. Regardless of the field application, the training of personnel is key to successfully and optimally operating equipment. For the size-reduction industry, crusher maintenance problems are mostly related to inadequate training. This exists at plants both large and small. The most effective education is a current and ongoing program for crews — and that’s what will result in legendary performance.
How Much Does It Cost To Operate a Crusher?
Stedman Machine Company
How Much Does It Cost To Operate a Crusher? By Chris Nawalaniec Crushing equipment is the heart of an industrial material-processing system. The size reduction choice you make will have a profound impact on the profitability of your business. When the right choice is made, you should expect many years of profitable operation. How do you make the right crusher choice? Crushers are not glamourous. They are brute force workhorses and what they do is simple, really. Size-reduction equipment in all forms is adding energy to a material to make big pieces smaller. Simple, right? Cost versus Value What does it cost or what is it worth? Producers need to keep that simple equation in mind. We all have to keep our eye on the ball and stay focused on profitability. What are Crushing Costs? Capital acquisition cost Base machine Structures and chutes Motors, drives, guards Energy consumption per unit produced Electricity Compressed air Wear parts cost Normal maintenance Planned downtime Lubrication costs Oil Grease Major repairs Infrequent maintenance Unplanned downtime Labor Normal maintenance Special or unique tools required When the above costs are all accounted for, they are used to quantify the production costs related to size reduction and are expressed in cost per unit of measure production. For example, $0.50 per tph. What Does Value Mean? There are always opportunities to buy a machine at a lower upfront cost. This usually translates into paying higher operating costs over the life of the equipment. Higher service labor cost. Higher wear parts costs. Higher energy costs. Often there is a justifiable case to spend additional capital dollars for the better machine. When evaluating crushing equipment suppliers, crusher manufacturers should quantify both costs: purchase price and operating costs. Before you purchase, ask for reference customers to visit. Selecting Equipment Why are there so many types of equipment? Our team brainstormed this question, and we came up with more than 50 tools or machines that are used for size reduction. What we are addressing here is industrial size reduction of dry, solid materials, which are grown, mined or chemically synthesized, and need to have a physical dimension alteration to be put to use. Customers are asked five questions to begin the equipment selection process. What is the material? What is the moisture content? What is the maximum size going into the machine? What is the size range desired after crushing? What is the desired production rate of finished product? When it’s time to dive a bit deeper to define the problem, we ask some additional questions. How long do you expect to operate the plant? Are you looking at mobile, skid-mounted or fixed installation? Are there electrical limitations or special power requirements at the plant site? Is the system open or closed circuit? Do we need to consider future expansion plans now? The variables above all affect your costs. Let’s take the first question as an example. How long do you plan to operate? There are times when mines reserves, stockpiles, permits, project contract terms affect expected life. If a project is limited by any factor, then “good enough” could be the best choice. As long as the equipment is safe and there are machine wear parts and service available, then going “cheap” may be the best choice. Another factor to consider with low-cost is limited post-sale assistance if there is some process change or major equipment problem. You don’t want to be hung out to dry. Aggregate producers typically expect to be running and profitable for many years. Always buy a crusher from an established company, develop a relationship, and expect ongoing service and personal contact. Ask before you buy about how they approach post-sale parts sales and service. Ask the company quoting how they intend to offer service for their crusher. How many field service people do they have? Are they local, regional or too far away? Not having responsive suppliers will have a significant impact on your plant profitability. Summary Investing in the best size reduction equipment for your specific needs is a big decision. The above should give you a lot to think about so equipment solutions can be objectively analyzed. Chris Nawalaniec is vice president of sales and marketing at Stedman Machine Co.
Teamwork Helps Integrate Design, Manufacture and Installation of Size- Reduction Systems
Stedman Machine Company
Teamwork Helps Integrate Design, Manufacture and Installation of Size- Reduction Systems By Eric Marcotte, Inside Sales Manager, Stedman Machine Company Designing and deploying size-reduction systems takes experience. Many people can collect and install some of the pieces they feel are needed to create a working system, but experience with the interrelationships between components is harder to find. And to ensure safety and performance, crushing, screening, storage and handling systems need to be professionally engineered. A system is always more than just a collection of parts; they must work together whether it’s a properly designed chute or an elaborate processing plant. Retrofitting new crushers, conveyors, screens or other pieces of equipment is also not always an easy process. Even if drawings and specifications no longer exist, plant designers need to make sense of what is there and know what it takes to make new pieces fit in an existing puzzle. If continuing production during the upgrade is required, system bottlenecks will need to be prevented. For example, raw material or finished product stockpiles may be required to keep downtime to a minimum. Also, access and space requirements need to be confirmed and double-checked. First - Assemble a Team Engineering and expertise in a variety of areas are required to develop size reduction systems, including: crushing, screening, structures, conveyors, chutes, hoppers, dust collection and storage, whether for a small equipment retrofit or a large turnkey facility. CAD and process design software applications are must have. Limit multiple layers of personnel. Work directly with the engineers and personnel to select the equipment and design the system. Project management, installation, scheduling and tracking experience will be needed. Be sure supervisors and installers are MSHA trained and have experience in fieldwork. Second - Process Design While most projects present new challenges, a widely experienced team will bring in ideas from other industries. Typical projects involve the following processes and types of equipment. industrial crusher Load out and material receiving This can be a feed hopper with an apron feeder, belt feeder, vibratory or screw feeder, truck dump or railcar unloading system. Bulk material transportation Designing, building or procuring belt conveyors, stackers, apron conveyors, screw conveyors, and pneumatic handling conveyors. Crushing Crushing is the basic building block of a size-reduction system. Experience with a large range of crushing equipment offers many solutions. Properly feeding material into the crusher greatly increases its efficiency, contributes to even wear and maximizes wear metal costs. Bulk material storage Specifying, providing and installing a range of silos, hoppers or other bulk storage solutions. aggregate crusher Screening Experience with many screening manufacturers to include the right screening solution into the system. Dust Collection Including the proper dust collector and dust collection system is a key component to allow a crushing system to work properly. Experience with many dust collection vendors will facilitate properly sizing, connecting and installing the best dust-collection system solution. Controls and Electrical Components To make sure that all components of a system work together, work with control system engineers, panel builders and electrical contractors to create a working, integrated system. Buildings, Foundations and Structure Design, procurement and specifications for buildings, foundations and structures for the equipment supplied on any system. Third - How to Do It Every project has a different set of circumstances that are unique to it. Try to follow a simple checklist to ensure the best possible solutions to the problems. Initial project team meeting. Crusher and screening testing as required. Define required scope for the system. Create preliminary concepts and drawings. Review with operators and supervisors. After receiving feedback, fine-tune the drawings, concepts and put forth a detailed proposal. Set up kick off meetings as required. Proceed with the purchase of major components. Proceed with a detailed system arrangement. Detail major assemblies. Assemblies put out for detail drawing creation. Drawings are self-checked and then crosschecked for accuracy. Assemblies are re-entered into system layout from detail assemblies to verify fit. Approval drawings sent out as required. Vendor drawings checked and approved. Items checked as they are received. Work with vendors and shipping to verify shipment accuracy. Pictures are taken of all shipments for record purposes. Installation supervisor works with install crew to identify, locate and erect items as needed. As installation finish date nears, begin check of motor rotations, sensors etc. Final customer acceptance – formal reviews to finalize “punch list,” follow up items and document the system is performing as specified. Example - Typical Quarry Expansion A limestone quarry running since the 1950s and producing 500,000 tons per year wanted to increase yearly production capacity up to 1.5 million tons with a new automated plant. The new design needed to have the capability to stockpile hundreds of thousands of tons of finished product. The focus was on creating a state-of-the-art plant with designed-in flexibility to do different product sizing. The automated plant needed to have the ability to run production all day as well as to be able to change the product sizes within 10 minutes. The design and fabrication of a new plant may take up to two years to complete as each idea is considered and "wish lists" are sorted out. You don’t want to come back and say we should have done this or done that. Get the very best of everything you can get into the plant for longevity. The project will include numerous conveyors, sensors, controls, vibrating screens, feeders and other equipment. size reduction machine Installed electronics and control systems feed a programmable logic controller. Each conveyor at the plant is equipped with terminal strips that are all wired to communicate information to one main processor, bringing all of the information together in one place to make it easy to operate. All of the feeders and conveyors are monitored to collect all of the information required to operate the plant. With the ability to monitor the speed of the conveyors and feeders, the quarry can keep an eye on production and troubleshoot maintenance issues. The reason for having an automated control system is that if something goes wrong on one of the conveyors, you’ll see it fast enough to prevent a catastrophe that might require digging out a conveyor. If something does go wrong, the computer can take over and begin dropping conveyors, discharging material and shut the feeder down. Since the quarry can now monitor the conveyors moving, the speeds and the tons per hour, limitations can be set to help catch problems before they become too serious. If something is going wrong, say conveyor 2A is slowing down, you can put limits on how much you want to allow it to slow down before the feeder is paused and then limit how long that feeder stays paused. In the end, the quarry was able to more than double their production capacity with the help of the automated plant. The plant was built, delivered and installed as planned with no problems. This is an ideal situation if a quarry is sitting on huge reserves of limestone and plans to operate the crushing plant well into the future. Projects such as this are successful when the customer’s needs are defined and understood, and the project team – including the customer and all supplier partners work to accomplish the project goals.
Expect More from your Horizontal Shaft Impactor
Stedman Machine Company
By Eric Marcotte The mineral processing industry usually evolves rather than revolutionizes, but the Horizontal Shaft Impactor (HSI) has revolutionized the crushing process in numerous industries.32 IMPACTOR 400 There are several varieties of the HSI, and their similarities are more numerous than their differences. All varieties feature externally fed horizontal rotors with breaker bars, which propel material into a series of apron-mounted breaker plates that crush or pulverize many different types of materials to specified degrees of fineness. In 1946, Dr. Erhard Andreas of Muenster, Germany, patented the “Andreas Impact Crusher System.” His design utilized old torpedo tubes and steel from decommissioned tanks. Since then, there have been many unique features of the design patented, but they all operate similarly. This article reviews current techniques employed to get the most from this versatile design. Versatility Reduction ratios of up to 30:1 are achievable in a single stage. The simple design offers low capital and operating cost. Low headroom requirements make it easy to install. Product sizes may be varied by changing rotor speed and the clearances between rotor breaker bars (also called blow bars or hammers) and apron breaker plates. HSI applications have gone beyond soft and nonabrasive materials such as limestone, phosphate, gypsum and weathered shales, to harder minerals thanks to the introduction of alloy steel rotor breaker bars. Typical alloy steels contain manganese and/or high or medium chromium content. There are many different crushing chamber designs on the market, and proper selection will depend on the knowledge of the application for proper feed, crushing chamber configuration, metallurgy of the crushing chamber components, gap setting and rotational speed. Finally, computer controls can automatically adjust HSI settings on the fly to adjust for wear or changing specs. Operation HSIs have a lined crushing chamber with rotating breaker bar rotor on a horizontal axis. The size reduction takes place quickly along short fracture lines, producing a more cubical product to meet aggregate specifications. This fast impact fracture is different from the slow compression breaking in cone or jaw crushers that produce more slabby or flat material (5:1 length to height ratio). 32 IMPACTOR2 400Feed enters the primary crushing chamber and meets the rotor breaker bars, which impel the feed against the first apron lined with breaker plates. Impact with the rotor, the breaker plate, and inter-particulate collision all contribute to comminution. Material is reduced in the primary chamber and passes by the front apron breaker plate gap, entering the secondary and, in some configurations, tertiary chambers, for final reduction. A high percentage of the initial size reduction comes from the first impact with the rotor breaker bar. Aprons are shaft suspended at the front and from a spindle in the rear, allowing for continuous gap adjustment as wear progresses. Unlike hammer mills, the open discharge impactor has no screens or grates holding material inside the crusher; material is efficiently processed at high rates for low costs. The rotor breaker bars operate best at specific speed ranges for maximum results. As the total processing capacity and rotors get larger, the number of breaker bar rows increases. On smaller sizes, there are only two rows; on larger rotors, there are four or more rows of rotor breaker bars. The optimum configuration has material delivered to each row of rotor breaker bars in a continuous bed over the width of the rotor for optimum performance and consistent wear part utilization. Some rotor interiors are open, and some are closed depending on feed conditions. For example, concrete recycling requires a closed rotor so rebar doesn’t get entangled. Application The HSI is used for all types of material with compressive strength less than about 20,000 lb. per sq. in. It’s widely used for sand and rock for roads, railways, reservoirs, electrical grid isolation, building materials and many industrial applications such as metal reclamation and recycling.34 IMPACTOR3 400 Wear part metallurgy is critical to proper applications and performance. It’s a good idea to keep a log of these items to determine the best wear part selection and maintenance schedule: feed and discharge information, throughput rates, change out records and measurements of worn parts. Proper selection of wear part metallurgy will result in optimum production rates; longer maintenance cycles and fewer changeouts, which reduce costs in labor, increase the wear part’s life as well as reduce downtime. Materials with high moisture content can be successfully handled by using heaters and air cannons to reduce and dislodge material adhering to the crushing components and chamber. Size Control The spacing between rotor breaker bars and breaker plate aprons can be adjusted to produce different products within one crusher. It is possible to crush soft raw material limestone or high-grade harder limestone for cement or asphalt applications with one crusher by externally adjusting the breaker bar and plate settings. Gap adjustment between the rotor breaker bars and breaker plates by manual or computer controlled systems adjusts the crushing gap so that product particle size distribution remains constant. Maintenance HSIs have multi-turn breaker bars for extended life before changeout. Design simplicity offers safe and easy access for breaker bar replacement and access to all areas of the crushing chamber. Front-opening models eliminate the need for a crane in some cases. Rear-opening models can allow unique installation applications. Summary 34 IMPACTOR 400 HSIs have evolved from humble beginnings through improved crushing chamber design and metallurgy advancements to automation controls. HSIs have proven they are capable of size reduction of all types of material sizes and hardness with minimal maintenance and excellent cubical particle size distribution control. Stedman Machine Co., www.stedman-machine.com Eric Marcotte is inside sales manager for Stedman Machine Company