The four pillars of successful bulk material handling system design
Bulk material handling (BMH) engineering involves the design and troubleshooting of systems used to move and store large quantities of materials. These materials can vary from powder to boulder-sized rocks and everything in between. If a BMH system is poorly designed, it will negatively impact the operation and maintenance of the equipment and could lead to early failure of components or system plugging that would partially or completely stop the processing plant from operating.
To ensure reliable and efficient BMH system operation, it is essential to consider a system’s foundational elements. Four key pillars are of critical importance: process, material properties, technologies, and layout. These pillars provide a framework that supports robust system performance and leads to long-term operational success while ensuring that nothing is overlooked in the system’s design phase.
Process: Know what you are doing
The process is at the core of each BMH system. Everything that we design has the ultimate purpose of supporting the process and making it work. In addition, the process establishes parameters that must be clearly understood to correctly design the BMH system. It also significantly influences material properties and can alter them at every stage.
Several operational considerations must be understood to ensure that the BMH system meets the process requirements. Will the operation be batch or continuous? How will it affect the maximum instantaneous equipment throughput rate? Will there be feeders and weighing equipment? If yes, what is the required precision? What are the dust control requirements? In addition to the nominal throughput, what upset conditions must be designed for in the system? These considerations establish the design criteria, impact the material properties, and determine the type of equipment suitable for the application.
Material properties: Know what you are handling
The material properties are at the core of a good BMH system design. They are dictated by the nature of the materials that are being handled and by each process step. A thorough understanding of these properties is critical for predicting the behavior of the materials during handling or storage, which in turn informs the selection of appropriate technologies and equipment that can be used for the application.
Understanding the material properties can also help to identify high-risk systems, such as a transfer chute that has a high potential of wearing out quickly, an elevator prone to plugging, or a silo discharge feeder that may lose control when handling fluidized material. These examples highlight how critical it is to understand the properties of the materials being handled.
To support effective system design, one must be able to work with a wide range of material properties. Typical properties that influence bulk handling system design include particle size distribution and maximum lump size, moisture content, true and bulk densities, and chute/silo design data. Additional considerations include whether the materials are hygroscopic, toxic, combustible, corrosive, abrasive, fluidizable, friable, free flowing, cohesive, or sticky.
Technologies: Pick the right tools
Once the process requirements and material properties are defined, it is time to select the right technologies. This includes physical equipment such as conveyors, feeders, elevators, chutes and silos, and software tools to model performance and confirm the feasibility and design of specific equipment.
Process requirements and material properties will usually narrow the range of suitable equipment. Some equipment will naturally align better with the application and should be prioritized for the system design. Based on the available equipment and guided by a preliminary layout (the next key pillar), calculations will be required to determine if the remaining equipment options are practical to use and capable of operating in their respective sweet spots. While some equipment might seem like a good fit at first, detailed analysis might show otherwise. Examples include calculating the power of a pneumatic conveyor with the software program PneuCalc, determining the required belt rating and shaft size of a belt feeder, or running discrete element method (DEM) simulations to confirm that a chute geometry is optimal. Utilizing specialized software tools for these calculations is critical to informed, confident equipment selection.
At this stage, some specific testing to obtain additional material properties might be required to enable specialized calculations to be made for specific equipment. Examples include conducting a closed-loop test run for dense-phase pneumatic conveying, determining the maximum belt conveyor inclination before roll back occurs, or doing abrasion tests to select the most appropriate liner.
Layout: Optimize space
This pillar encompasses integrating the entire operation into a three-dimensional space in the safest and most efficient manner. During this stage, the optimal equipment arrangement is designed, using the technologies previously identified as suitable for the project. Key considerations include ensuring proper clearances, controlling noise and dust, and providing safe and easy access for maintenance and repairs.
Some equipment can have drastic and positive impacts on the layout. Examples include equipment that eliminates the need for an additional floor, takes up less space, or consolidates equipment to accommodate multiple direction changes. While it might be tempting to assume that this type of equipment is automatically the best choice, that is not always the case. It is essential to select equipment that is reliable and well-suited to the project requirements, process, and the material properties.
No room for error
Failures in BMH systems can always be traced to one of the foundational four pillars being neglected or improperly implemented during the system design phase. Solving issues after the fact can be very challenging and costly.
Bulk material handling may seem simple at first glance and is often trivialized — just equipment moving stuff from one point to another — but designing a system that works flawlessly is anything but simple. The secret to BMH engineering lies in understanding and integrating the process, material properties, technologies, and layout. Taking the time to do the homework and making the calculations to back up design choices allows for a fact-based decision-making process.
Each of the four pillars plays a distinct yet interconnected role in the success of a BMH system. Each needs equal consideration and attention. If even one is left to chance, the whole system can crumble. Designing BMH systems is not just about moving materials; it is about moving them smartly, safely, and reliably — and getting it right from the start.
