Why McLanahan Roll Crushers
Since patenting the first Single Roll Crusher in 1894, McLanahan has become an expert and leader in the industry in the design and manufacture of single and two stage Roll Crushers. The selection process for each application is based on extensive equipment knowledge and a wealth of test data developed in our research lab or through on-site testing.
McLanahan offers belt-driven Roll Crushers in four designs: Single Roll, Double Roll, Triple Roll and Quad Roll Crushers, which provide a substantial return on investment by operating at low cost and maximising yield by generating minimal fines. The rugged design, which incorporates a fabricated steel base frame lined with replaceable abrasion-resistant steel liners, stands up to the toughest mineral processing applications while providing safe and simple operation, including an automatic tramp relief system to allow uncrushable objects to pass while the crusher remains in operation. These crushers are also versatile, allowing for adjustments in roll speeds and gap settings to meet most any application requirement.
How Roll Crushers Work
Whether the application requires a single-stage or two-stage crusher, the forces necessary to perform the crushing remain the same: a combination of impact, shear and compression. The impact force occurs as the material enters the crusher and is impacted by the rotating roll. Shear and compression forces occur as the feed material is pulled between the crushing plate and/or crushing rolls.
Depending on the feed size, material is fed into the crushing chamber and encounters a single or a pair of rotating rolls. If a two-stage reduction is required, either a Triple or Quad Roll configuration can be used. In this scenario, the top stage of the crusher performs the primary reduction either by crushing the material between the roll and crushing plate or between a pair of rolls. The material is then fed directly between the two bottom-stage rolls for additional processing.
If a single-stage reduction is required, then depending on the feed-to-product-size ratio of reduction, either a Single or Double Roll Crusher can be selected. Regardless of the crusher type selected, Roll Crushers allow for the material to fracture along naturally occurring cleavage lines, which helps with minimising fines generation.
Benefits of McLanahan Roll Crushers
- High throughput capacity
- Accepts large feed sizes while producing small product sizes
- Cubicle product with minimal fines
- A variety of roll tooth profiles available
- Proprietary designed tungsten carbide-impregnated tooth for increased wear life
- Adjustable for change in product sizing
- Automatic tramp relief
- Minimal maintenance required
- Low cost per ton operation
Frequently Asked Questions
How do I know whether to use a single-stage or two-stage crusher?
The main factors to consider are the feed size and desired product size. Once this information is known and based on the ratio of reduction, the appropriate crusher selection can be made.
Will a wet, sticky feed material affect the crusher selection?
Yes, it will. When a wet, sticky feed is fed to a two-stage crusher, you run the risk of plugging the crusher between the top and bottom stages. If a wet, sticky feed is anticipated and the ratio of reduction requires two stages of crushing, it is recommended that two separate single stages be used.
What other technologies should I consider?
What is the typical ratio of reduction?
A good rule of thumb is: Single Roll Crushers have a 6:1 ratio of reduction, Double Roll Crushers have a 4:1, Triple Roll Crushers have a 6:1 on the top stage and a 4:1 on the bottom stage, and Quad Roll Crushers have a 4:1 on both the top and bottom stage.
What are common types of Roll Crushers?
Single Roll Crushers
Single Roll Crushers are typically used as primary crushers that provide a crushing ratio of up to 6:1. They crush materials such as ROM coal, mine refuse, shale, slate, gypsum, bauxite, salt, soft shale, etc., while producing minimal fines. Designed with intermeshing roll teeth and a curved crushing plate, they are extremely effective in reducing slabby feeds.
Double Roll Crushers
Double Roll Crushers provide a 4:1 reduction ratio. They are typically used as a secondary or tertiary crusher for materials such as ROM coal with refuse, limestone, gypsum, trona, shale, bauxite, oil shale, clean coal, coke, salt, quicklime, burnt lime, glass, kaolin, brick, shale and wet, sticky feeds. Each machine is custom engineered with roll elements and tooth patterns selected depending on the application requirements to produce a cubical product with minimal fines.
Triple Roll Crushers
Triple Roll Crushers are ideal for producers who want to accomplish two stages of reduction in one pass. They can be used in coal, salt, coke, glass, and trona operations, among others. Triple Roll Crushers combine a Single Roll Crusher with a Double Roll Crusher to form a crusher that is capable of achieving a 6:1 reduction ratio in the primary stage and a 4:1 reduction in the secondary stage while producing a cubicle product at high capacity.
Quad Roll Crushers
Quad Roll Crushers are ideal for producers, including those with preparation plants, who want to accomplish two stages of reduction in one pass. They can be used in coal, salt, lime, pet coke and potash operations, among others. Quad Roll Crushers are capable of achieving a 4:1 reduction ratio before feeding the crushed material to the secondary stage for an additional 4:1 reduction to make the final product.