Briquetting is an excellent technology for transforming biomass waste into high-quality biofuels with a high energy density. However, for these fuels to be competitive, they must be produced at low operating costs and to a high standard. Based on an analysis by experts from the Faculty of Mechanical Engineering at STU, we present an overview of the most common errors that could jeopardise your production.
1. Input material that is too damp
Humidity is one of the key operating parameters to which moulding tools are directly exposed.
- Impact on the process: Moisture significantly affects the friction conditions in the compression chamber.
- Risk to the machine: Changes in friction coefficients caused by moisture alter the forces acting on the tools, which may lead to their accelerated degradation and wear.
2. Unsuitable particle size and material properties
Every machine and its tools are designed for specific conditions. A common mistake is to use material that is not suited to the press’s technical settings.
- Tool geometry: It is essential to select the correct geometry for compaction tools (e.g. tap points or chambers) in view of the specific type of material being compacted and its structure.
- Wear: If the material and geometry of the tool are not compatible, this leads to disproportionately high friction and subsequent damage, such as damage to the tip of a thread rolling die.
3. Poor maintenance and the wrong choice of tools
Press tools are the ‘powerhouse’ of the entire production line, and their failure often brings the whole production process to a standstill. Critical errors in tool maintenance and management include:
- Incorrect heat treatment: If a component (e.g. a piston crown) has been heat-treated incorrectly (e.g. over-hardened), it will suffer brittle fracture or chipping.
- Failure to address abrasive wear: Overly worn tools increase the pressing force and energy consumption, until production comes to a complete halt.
- Inappropriate repairs: For example, using the wrong type of hardfacing material when reconditioning a tap can cause the hardfacing layer to crack and break off.
4. Underestimating design and operational details
Sometimes the fault lies not with the material, but with the machine settings themselves.
- Installation errors: Incorrect installation or the use of a component of the wrong size can lead to the failure of the entire compaction machine.
- Dynamic loading: Cyclic loading during operation can reveal hidden defects that lead to fatigue fractures in critical components, such as the crankshaft at the point of the machining cut.
Why is this important?
Biomass is a promising energy source precisely because it can be stored efficiently in the form of briquettes. However, for the briquetting process to fulfil its purpose, you must approach its operation with the utmost responsibility. Understanding the impact of each parameter of the pressing tools is essential for reducing production costs and eliminating faults.
An illustrative image created using artificial intelligence (ChatGPT).
