Accurate dosing of fine powders can be challenging when materials are prone to binding, compaction and inconsistent flow. Trantec Solids Handling was approached to develop a feeding solution for a cohesive powder with difficult characteristics, while meeting requirements for variable throughput, ±1% dosing accuracy and reliable dosing over 30-minute periods.
Material testing is a key part of Trantec Solids Handling’s approach to developing feeding solutions. Testing the customer’s powder under operating conditions helped establish its behaviour and allowed the feeder design to be refined around the application requirements.
Identifying the Material Handling Challenge
During testing, the material was found to bind to itself and adhere to internal surfaces, including
the auger, feeder body and outlet tube. Material also accumulated at the bottom of the feeder trough, forming a compacted accumulation that increased resistance around the auger and outlet.
As the build-up developed, material began to bind against the moving components, producing a grinding noise and affecting material flow. These findings highlighted the need to actively manage material flow and minimise the conditions causing build-up and binding.
Developing the Feeding Solution
To address these challenges, Trantec developed a loss-in-weight screw feeder incorporating a high internal surface finish across the material-contact areas, including the feeder body, hopper, outlet tube, auger and agitator. The smoother surfaces were designed to reduce material adhesion and retention.
The auger profile was developed specifically for the application, with controlled changes to its geometry and pitch to promote smoother material movement. Both the auger and agitator incorporated designed edges to glide through the material, helping to break up bridging and maintain flow while reducing the risk of further compaction.
A timed vibratory system was incorporated into the hopper. Rather than operating continuously, vibration is delivered in frequent bursts to encourage material movement without excessive agitation. This helps prevent bridging and build-up while maintaining consistent auger filling and supporting accurate dosing.
Designed for Cleaning and Controlled Operation
Two feeders were supplied, each incorporating a quick-release front panel for easier access to the feeding area during cleaning. This simplifies removal of residual material and helps reduce cleaning time.
A control panel was supplied to manage feeder operation and the timed vibration sequence, providing controlled and repeatable operation throughout the dosing cycle.
Material Testing as Part of Feeder Development
The testing identified the causes of build-up and binding, allowing the auger design, surface finish, agitation and vibration system to be refined around the application requirements.
If you are experiencing challenges with powder flow, or accurate dosing, Trantec Solids Handling can provide material testing and application-specific feeding solutions. To discuss your requirements, contact sales@trantec.net or visit www.trantec.net.
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