Discrete Element Modeling

DEM (discrete element method) is a numerical technique that models the interaction between individual particles and boundaries to predict bulk solids behavior.  This tool can easily model moving boundaries and is used to gain better understanding of particle flow dynamics.  The knowledge is then applied to design more efficient equipment, thus improving process efficiency and product quality.

DEM is used to predict:
RockChute_15sec

  • Bulk material flow patterns
  • Bulk material flow rates
  • Force, torque, and power consumption of equipment
  • Impact forces on particles and boundary surface
  • Wear patterns on boundary surface
  • Velocity profiles and dead zones
  • Particle distribution in segregation and blending

Technology

Your process is modeled by our engineers with our in-house developed proprietary code that has been extensively used to solve many handling problems around the world in industries including mining, chemical, agriculture, food processing, pharmaceutical, and power.  These project examples below are proof that our DEM capabilities are a dependable tool to quickly develop the right solutions for your material handling process.

Jenike & Johanson has a passion for particles.  We know that though spheres are computationally attractive, they in many cases will not provide accurate or representative DEM modeling respects.  Look at the simulation below, illustrating the behavior of a sphere vs. clustered spheres vs. polyhedral particles.  Clearly the spheres and clusters do not mimic the true flow behavior of the shaped particles.

As shown below, we can accurately model particle shape using our 3D particle scanner and our polyhedral algorithm in our code.  Computational speed does matter for efficient engineering, thus, using polyhedral algorithms with particles having extraneous facets is not beneficial to the DEM analysis because every facet must undergo tracking and calculations for acceleration, velocity, position, and impact, torque, sliding, etc.  We’ve optimized our DEM code to use polyhedral geometries that reflect you material processing so you get prediction results that can help engineer improvement to your bottom line.

We have experienced engineers who are knowledgeable and specialize in DEM practices to perform accurate analytical modeling.  We understand the importance of making sure the models are scaled geometrically and calibrated to measured bulk material flow properties.  Our laboratories can measure the relevant flow properties for DEM analyses, such as bulk density, cohesive strength, wall friction (coefficient of sliding friction; both dynamic and static), particle density and shape, and abrasive wear.

 

DEM example: particle motion on multiple complexity levels

Our DEM code has the ability to model motion on multiple levels of complexity and degrees of freedom.  As shown in the DEM simulation below, the motion is occurring at three separate, but interactive, levels:

  1. The screw (auger) is rotating the flights about its central shaft
  2. The screw is following a sweeping motion around the cone interior surface
  3. The screw shaft is pivoted from the cone’s center to the periphery

This simulation is extremely complex, yet, vital for understanding how a planetary mixer operates.

Experience

When you partner with us, you are working with experts who know how bulk materials flow and how to apply the best DEM technology to your material handling process.  We are able to model your unique system in a matter of days.

At Jenike & Johanson, we use a highly effective and efficient DEM engineering tool, for modeling flow of your iron ore in a chute at 14000 tph, filling a dump truck with 100 t of limestone, or loading odd-shaped candy into a small volume unit package.  We have the tools and engineering knowledge to reduce risk and ensure your project’s success.

Full Service

While working with us, you have the full support of the world’s leading materials handling firm with over a half-century of bulk material experience.  When we model your process using DEM, we provide you with both the data generated from the model and the experience to apply that information in a meaningful way.  Our engineers work with you to find solutions that best meet your operational and business needs.  Learn More.

In this DEM analysis, Jenike & Johanson engineers modeled mixing of materials in a paddle blender.  Through this analysis we were able to determine fill level, paddle sizes/numbers/angles, as well as paddle shaft speeds.  This model was vital in determining direction of blender selection and operating conditions.