Sampling Sizers/Roll Crushers

Sample Double Roll Crushers and Mini-Sizers are simply smaller-scale versions of the Double Roll Crusher and Direct Drive Crusher (DDC) product groups for which McLanahan has become well known. These machines retain the key features and benefits of the larger machine designs but are packaged into compact, cost-effective solutions specifically tailored to reliably and efficiently handle lower capacity applications.

Double Roll Crushers are a widely used crusher type and offer advantages in relatively high capacity for a given machine size, low overhead requirements, relatively low power requirements, integral tramp relief, the ability to handle sticky materials and the ability to produce a cubical product with minimal fines generation.

Sizers offer many of the same performance features as Double Roll Crushers, with the added features of directly driven rolls, very low overhead requirements and a relatively small footprint for the machine size.

Why McLanahan Sampling Roll Crushers/Sizers

McLanahan has extensive experience in crushing applications, particularly crushing applications involving Roll Crushers and Sizers. In addition to being backed by this experience, Sample Double Roll Crushers and Sizers offer a simplified design and long-term, reliable operation with minimal maintenance requirements. Low profile designs (and minimal footprint in the case of sizers) make for easy implementation into plant layouts. Rugged construction, oversized roll shafts, replaceable liners and hard-wearing rolls ensure that these machines will handle difficult applications while continuing to reliably produce crushed material. Adjustable roll settings, along with a number of other design options, help tailor crushed product size and deal with difficult-to-handle, wet and sticky materials. On-site testing is also available to ensure that the crusher configuration selected is the best option for your application. 

How Sampling Roll Crushers/Sizers Work

Sample Double Roll Crushers and Mini-Sizers operate in a similar, simple fashion. Material to be crushed is fed into the top of the machine, where it is crushed through two rotating roll assemblies and passed out through the bottom of the crusher. The crushed product size and gradation is based on the distance between the rolls and the tooth profile on the crusher rolls. Fewer, larger teeth and wider roll settings result in a coarser crushed product, whereas more, smaller teeth (or simple beaded rolls) and smaller roll settings result in a finer crushed product. Regardless of the tooth configuration or roll setting, the crushing principles are the same. Material is crushed as a result of the combination of impact, shear and compression. Despite the fact the rolls are rotating at a relatively slow speed, some material breakage occurs when feed material enters the crusher and is impacted by the crusher roll teeth. Shearing occurs when feed material is captured between the roll teeth and/or between the roll teeth and sizing combs. Compression occurs when material is forced between the rolls or between the rolls and sizing combs.

Sizer rolls are directly driven by right-angle gearmotor units. This arrangement allows for differential rolls speeds that aid in processing wet and sticky material, but it also simplifies the design of the machine and allows for the minimal footprint associated with sizers.

Sample Double Roll Crusher rolls are driven in one of two ways. The first is a dual drive arrangement where each crusher roll is driven by its own V-belt drive and motor. This permits differential rolls speeds that aid in processing wet and sticky material. The second arrangement is a single drive in which the first crusher roll is driven directly from a V-belt drive and motor arrangement, but the second roll is driven by an inter-roll V-belt and tensioner arrangement.

Sample Double Roll Crushers also offer a spring-loaded toggle arrangement for tramp relief. In this arrangement, the on-crusher roll is movable. When uncrushable objects enter the crusher and are drawn down in between the rolls, the movable roll rebounds away from the stationary roll engaging the toggle. When uncrushable material clears the crusher, the roll springs back into its original position without interruption to the crushing operation.

Regardless of which type of machine is used, feed material is fractured along naturally occurring fault lines in the material particles, reducing the feed material to the desired crushed output size while minimizing fines generation. 

Popular Applications for Sampling Roll Crushers/Sizers

Sample Double Roll Crushers and Mini-Sizers can be used in a wide variety of applications and industries. These machines are widely incorporated into mining and power generation applications that handle soft to moderately hard, friable materials such as coal, coke, limestone, salt, potash, clay, oil sands, trona, shale, bauxite, and other materials with similar characteristics.

Benefits of McLanahan Sampling Roll Crushers/Sizers

  • Cost-effective option for low feed rate applications
  • Robust construction for success in difficult applications
  • Low roll speeds ensure minimum dust and fines generation
  • Product setting adjustability for flexibility in product size requirements
  • Integral tramp relief via spring toggle assembly
  • Design options to handle wet or sticky material
  • Direct, right-angle mechanical drives
  • Compact design and small footprint for installation where height and floor space are at a premium
  • Product setting adjustability for flexibility in product size requirements

Frequently Asked Questions

What is tramp?

Tramp is a term used in mining-related applications to refer to uncrushable objects that may unintentionally enter the product stream. These objects are often associated with the mining process (e.g. mining machine bits, loader teeth or roof bolt pieces) and are difficult to prevent from entering the product flow. Tramp can also refer to inclusions in the material feed to a machine (i.e. crusher) that the machine is not designed to handle. For example, a large particle of hard rock would be considered tramp for a Double Roll Crusher since Double Roll Crushers are not typically designed to crush hard rock. Conversely, other types of crushers are designed to crush hard rock, so hard rock would not be considered tramp for those crushers.

What other technologies should I consider?

If the material to be crushed is not a hard rock application, is not abrasive, and fine material generation is not an issue, a Sample Hammermill Crusher can be used. If the material feed is not a hard rock application, is not abrasive, has larger lumps of material or a small amount of harder inclusions and fine material generation is not an issue, a Rockertooth Crusher may be a good option. If the material to be crushed is hard rock or is abrasive, a Sample Jaw Crusher should be considered.