Cone Crushers
A Cone Crusher is a compression type of machine that reduces material by squeezing or compressing the feed material between a moving piece of steel and a stationary piece of steel.
Applications
A Cone Crusher will deliver a 4:1 to 6:1 reduction ratio. As we set the closed side setting tighter to create a finer output, we also reduce the volume or throughput capacity of the machine. Generally speaking, multiplying the closed side setting by two is a good guide to the top size of the gradation exiting the machine.
A general rule of thumb for applying Cone Crushers is the reduction ratio. A crusher with coarse style liners would typically have a 6:1 reduction ratio. Thus, with a 3⁄4” closed side setting, the maximum feed would be 6 x 3⁄4 or 4.5 inches. Reduction ratios of 8:1 may be possible in certain coarse crushing applications. Fine liner configurations typically have reduction ratios of 4:1 to 6:1.
Final sizing and reduction is determined by the closed side setting or the gap between the two crushing members at the lowest point. As the wedge or eccentric rotates to cause the compression within the chamber, the material gets smaller as it moves down through the wear liner as the opening in the cavity gets tighter. The crushed material is discharged at the bottom of the machine after they pass through the cavity.
How A Cone Crusher Works
In the Symons principle, which is utilized by the MSP Cone Crusher, each cycle is timed so that the feed material and the upward thrust of the crushing head meet at the moment of maximum impact. The optimum speed of gyration and the large eccentric throw produce two important results: 1) the rapidly closing head catches the falling feed material and delivers the extremely high crushing force and 2) on the other side of the chamber the rapidly receding head allows material to fall freely to the next point of impact or exit the chamber. The combination of superior crushing force and free flow of material in the MSP Cone Crusher results in production levels that are unsurpassed and means lower power consumption per ton.
Ten years of testing went into the final combination of speed, stroke, and head angle to deliver the most efficient use of power. Greater efficiency delivers lower power consumption, reduced cost per ton, less maintenance and higher profits.
The power input imparted by the driven eccentric results in a bearing force in opposition to the crushing force at a point on the lower portion of the main shaft. The bearing force as it is transmitted to the main shaft provides the required moment to crush the rock. The distance between the bearing force and the fulcrum point is called the force arm. The longer the force arm, the greater the momentum, which produces a greater crushing force.
Crushing loads are distributed over a large spherical bearing. The socket liner keeps full contact with the crushing head ball and carries all of the vertical component and part of the horizontal. The long force arm, represented by the main shaft, reduces the load transmitted through the eccentric bushing.
Capacities and product gradations produced by Cone Crushers are affected by the method of feeding, characteristics of the material fed, speed of the machine, power applied, and other factors. Hardness, compressive strength, mineral content, grain structure, plasticity, size and shape of feed particles, moisture content, and other characteristics of the material also affect production capacities and gradations. Gradations and capacities are most often based on a typical, well-graded choke feed to the crusher. Well-graded feed is considered to be 90% to 100% passing the closed side feed opening, 40% to 60% passing the midpoint of the crushing chamber on the closed side (average of the closed side feed opening and closed side setting), and 0 to 10% passing the closed side setting. Choke feed is considered to be material located 360 degrees around the crushing head and approximately 6” above the mantle nut. Maximum feed size is the average of the open side feed opening and closed side feed opening.
Minimum closed side setting may vary depending on crushing conditions, the compressive strength of the material being crushed, and stage of reduction. The actual minimum closed side setting is that setting just before the bowl assembly lifts minutely against the factory recommended pressurized hydraulic relief system.
Overall, industry acceptance of the Symons principle and performance, the McLanahan Cone Crusher works to deliver lower recirculating loads at higher tonnage rates with lower maintenance costs by combining:
- A long parallel zone for uniform, accurate sizing of product
- An ideal gyrating cycle that delivers quick hammer-like blows on free falling material
- Contact between the gyrating head and falling material that rearranges particles before each impact
- Adjustment of the upper crushing member by rotation, giving even liner wear and maintaining setting accuracy around the entire crushing chamber
- High impacts to reduce the hardest materials more effectively
- Large head displacement, allowing a greater volume of material flow at every cycle
- More energy concentrated on crushing with minimal surface friction, resulting in low kw/ton consumption
Why McLanahan Cone Crushers
The technology that makes a MSP Cone Crusher outperform competitive cones on the market is the combination of all of the factors of performance i.e. balanced eccentric, higher speeds, fulcrum point position, and stroke. By using sound engineering with years of field testing a truly tried and tested new Cone Crusher has emerged.
A balanced eccentric coupled with a fulcrum point ideally placed over the crushing chamber yields highly effective compression crushing. This allows higher eccentric speeds to maximize performance without disruptive forces. The eccentric stroke is designed to work with the eccentric speed and fulcrum position to produce higher yields and minimize recirculating loads. The torque and resultant crushing forces are as effective as virtually any Cone Crusher on the market.
Spiral bevel gears provide the turning force to the eccentric. The spiral gear is mounted on a sturdy countershaft of the Cone Crusher, which rides in bronze bushings. The gears are precision cut for quiet operation. Misalignment problems are eliminated.
The MSP Cone Crusher features one of the largest volume displacements by a crusher head. When there is a large volume of material displaced this way, it means that more material is crushed in each cycle, more material can be fed to fill the larger void left when the crushing head recedes, and more material flows through the crusher due to the larger throughput and gyrating cycles allowing material to drop further. The benefits of high efficiency, greater crushing force and high capacity coupled with the durability the market expects are the reasons why this design is the best way to increase your productivity and profitability.
Sleeve bearings make removal and installation of the MSP Cone Crusher head and main shaft simple. The tapered main shaft fits into a large opening at the upper end of the tapered eccentric bushing. The shaft does not require precise alignment. It can be inserted from a vertical position and will self-align.
With the MSP Cone Crusher’s automatic hydraulic overload relief system, the crusher immediately opens in the event of an overload. This action reduces the crushing pressure, allowing the obstruction to pass through the chamber. After the chamber has been cleared, the hydraulic control system automatically returns the crusher to its original setting. Shock loads on the crusher are reduced for longer component life.
MSP Cone Crushers are built to make your operations run more smoothly and easily. It’s simple and easy to read control panel provides you with the necessary information to properly run your crusher. For example, the MSP Cone Crusher shows you the exact cone setting to allow the operator to stay on top of a critical set point.
To enhance your Cone Crusher's life and maintain optimal crushing capacities, an automatic liner change reminder is included for your convenience. When the new mantle and liners are installed, the automated reminder is reset. As the crusher operates, the system will track production capacities and calculate the liner wear rate. When the cone liners reach the maximum wear point, it sends a flashing reminder to 'change cone' on the cone setting meter. After the wear parts are changed, simply reset the automated reminder system and continue efficient, reliable crushing.
The MSP Cone Crushers are built heavier than most competitive Cone Crushers. The extra weight means lower stress on the machine, which results in longer operational life. There is no question that the proper use of mass makes for more durable crushers. Additionally, a broad array of manganese liners is offered for each size MSP Cone. A unique and patented feature allows the Liners to fit without the use of any backing material. Improved Chamber matching with crusher feeds virtually eliminates any trial and error.
McLanahan takes no shortcuts in the fabrication and machining of these Cone Crushers, ensuring the highest quality.
All these factors combine to give producers more effective compression crushing. This reduces liner wear, which reduces wear cost and allows higher yields, resulting in decreased overall cost per ton of finished product.
Frequently Asked Questions About Cone Crushers
Ask An ExpertThe difference between the volume displaced by the crushing head when it is fully closed and fully open is called the displacement volume. A large displacement volume results in greater capacity because:
- More material is crushed with each crushing cycle
- More space is left open as the crushing head recedes, allowing more material to be fed to the crusher at each cycle to fill the larger void
- Greater throw coupled with ideal gyrating cycles allows the material to drop further into the cavity prior to the next blow, resulting in greater flow rate through the crushing chamber
Speed settings are based on the crushing application. Below are suggested guidelines:
- Low speed: Secondary applications, after a jaw crusher
- Medium speed: Gravel applications with coarse feed
- Standard speed: Tertiary applications (0 x ½”)
- High speed: Sand applications (4M or less)
Speed ranges :
- Smaller Head Diameters (48" or smaller): 750-1200 rpm
- Larger Head Diameters(larger than 48"): 700-950 rpm
In order to maintain the maximum levels of capacity, gradation, and cubical product, a Cone Crusher must be choke-fed at all times. The best way to keep a choke-feed to the Cone Crusher is with a surge bin (or hopper) and feeder that are located prior to the crusher. Choke-feeding is almost impossible to achieve without a hopper and feeder.
There are a number of different criteria to consider when selecting the right chambers for your crushing needs. However, the one that must always be considered is that you have a well-graded feed to the chamber. A well-graded feed is generally thought to be 90 to 100% passing the closed-side feed opening, 40 to 60% passing the midpoint, and 0 to 10% passing the closed-side setting.
One thing you should never do is place a new concave liner in a crusher with a worn mantle or place a new mantle in a crusher with a concave liner. Why? If you have properly selected the replacement component, you will change the complete profile of the Cone Crusher by mating new and worn components. The receiving opening will tend to close down, restricting the feed from entering the chamber and causing a reduction in tons per hour.
If the liner is wearing evenly throughout the chamber, you should consider changing out the manganese when it has worn down to about 1" (2.5 cm) thick at the bottom. At about 3/4" to 5/8" (1.9 to 1.6 cm) thick, the manganese will crack, causing the backing material to begin to disintegrate. This, in turn, will cause the liners to break loose. If this should happen, continued operation could destroy the seat on the support bowl or the head of the Cone Crusher.
MSP Cone Crushers are built to make your operations run more smoothly and easily.
Features & Benefits
- Largest head displacement provides greater capacity
- Long lasting bushings stand up to the environment
- Low operating costs
- Patented dust seal system equipped with an auto greaser and protects the crushers' dust-sensitive parts, leading to a longer service life, fewer spare parts change, and lower maintenance costs
- All adjustments and operations fully automated with easy-to-operate control panel that requires only one individual to operate and a wireless remote control offered
- Eccentric assembly imparts a gyrating motion to the main shaft and is fitted with an inner and outer bronze bushing
- Hydraulic relief opens immediately in the event of an overload
- Easy to operate, with online monitoring and automatic wear alerts
- Full hydraulic clamping package with built-in chamber relief for uncrushable material
- Fully self-contained external power lube system with all the controls and monitors, ensuring proper operation in all kinds of weather and operating conditions