Monitoring in real time within industrial processing vessels is essential for advancing process analytical technology. Sensors that follow the flow are an ideal approach for delivering continuous data directly from the process stream. Their deployment, however, is limited by the physical barriers of sealed metallic vessels and by harsh environments in which batteries cannot be used reliably.
To overcome these limitations, a noninvasive system for wireless power transfer is presented that can be retrofitted to existing equipment. The metallic vessel itself is repurposed into a microwave cavity resonator with several modes at 5.23 gigahertz, with the microwave energy coupled in through existing standard flanges.
Electromagnetic simulations validate that this method provides continuous energy coverage throughout the dynamic flow zones, demonstrated with a fluidised bed granulator as an application example. To harvest this energy, an omnidirectional antenna and a compact prototype of a rectifier that converts the radio frequency energy into direct current were developed.
By enabling the continuous operation of autonomous mobile sensor nodes without batteries, the framework provides a practical and scalable foundation for spatial analytics with a high density of sensors and for industrial optimisation based on data.
The study was carried out at Hamburg University of Technology within project A07 of the Collaborative Research Centre CRC 1615 (SMART Reactors).
Marvin Jaeger, Maximilian Becker, Maike Orth, Simon Schulz, Stefan Heinrich, Thorsten A. Kern, Alexander Koelpin (2026). Powering Mobile Sensor Nodes in Fluidized Beds: A Non-Invasive RF Energy Harvesting Proof-of-Concept. Ind. Eng. Chem. Res.
