Periodic Reporting for period 2 - PowFEct (Preventing Explosions: How do Powder Flows Electrify?)
Berichtszeitraum: 2022-11-01 bis 2024-04-30
Flour, coal, polymer, and other dust explosions in industrial plants led to tremendeous financial losses, injuries, and even fatalities. These catastrophic explosions were often caused by electrostatic discharges. Moreover, electrostatic charge causes dust to deposit on component surfaces, increasing the facility's resources and energy demand. However, to date, it is impossible to predict the rate at which powder charges during processing.
The PowFEct project develops an open-source simulation tool that couples fluid mechanics, surface science, and electrostatics to reveal the distinct mechanisms determining the charging rate of powder flow. To formulate a model for the charging of individual particles when contacting surfaces, we conduct single-particle experiments of extremely low scatter. Since no method is currently available to validate these simulations, we develop a new experimental technology to resolve powder flow charging in space. Unlike conventional measurement devices that only show the average charge, this new technology can find dangerous local charge peaks; thus, it can identify hidden threats to powder flow safety.
The PowFEct project will significantly enhance our understanding of powder flow charging and deliver experimental and theoretical methodologies to support safe and clean powder processing in a variety of industrial applications.
The PowFEct project develops an open-source simulation tool that couples fluid mechanics, surface science, and electrostatics to reveal the distinct mechanisms determining the charging rate of powder flow. To formulate a model for the charging of individual particles when contacting surfaces, we conduct single-particle experiments of extremely low scatter. Since no method is currently available to validate these simulations, we develop a new experimental technology to resolve powder flow charging in space. Unlike conventional measurement devices that only show the average charge, this new technology can find dangerous local charge peaks; thus, it can identify hidden threats to powder flow safety.
The PowFEct project will significantly enhance our understanding of powder flow charging and deliver experimental and theoretical methodologies to support safe and clean powder processing in a variety of industrial applications.
During the first reporting period, the project team members were hired and the experiments were set up.
In the first Work Package, we built up the single-particle test rig. Acoustical levitation allows the exact control of the particles. The upcoming measurements with this rig will deliver the data to formulate a charging model tailored for implementation in simulation tools.
In the second Work Package, we built up a large-scale powder flow test rig. Using this rig, we have already developed a new measurement technology to resolve the turbulent powder flow charge in space. The technology applies an electric field to the flow. A laser-based Particle Tracking Velocimetry (PTV) system measures the response of the particles to the field. Based on the response, a new mathematical approach delivers the powder's time-averaged, spatially resolved charge.
In the third Work Package, we developed and implemented particle charging models into our computational tool pafiX. The first simulations using these models showed that turbulence suppresses powder charging. These results indicate we can trigger powder flow charging by controlling the carrier flow.
In the first Work Package, we built up the single-particle test rig. Acoustical levitation allows the exact control of the particles. The upcoming measurements with this rig will deliver the data to formulate a charging model tailored for implementation in simulation tools.
In the second Work Package, we built up a large-scale powder flow test rig. Using this rig, we have already developed a new measurement technology to resolve the turbulent powder flow charge in space. The technology applies an electric field to the flow. A laser-based Particle Tracking Velocimetry (PTV) system measures the response of the particles to the field. Based on the response, a new mathematical approach delivers the powder's time-averaged, spatially resolved charge.
In the third Work Package, we developed and implemented particle charging models into our computational tool pafiX. The first simulations using these models showed that turbulence suppresses powder charging. These results indicate we can trigger powder flow charging by controlling the carrier flow.
In this reporting period, in particular, the new technology to measure the powder flow charge goes beyond the state of the art. Conventional technologies give the total sum of all particles' charges or apply only to a known or constant flow field. Our technology, on the other hand, can spatially resolve the powder charge in a turbulent flow. In the next reporting period, we will enhance the technology by AI.
Further, our simulations of bipolar particle charging changed the paradigm that not the smallest but mid-sized particles charge most negatively: turbulence controls and suppresses size-dependent charging. We expect to deliver an experimentally validated tool to predict powder flow charging in the next reporting period.
Accomplishing the PowFEct project establishes a world-leading research laboratory that excels on all scales of powder flow charging. The output of this laboratory can serve the safety and sustainability of many industrial applications and, thus, prevent economic losses and save lives.
Further, our simulations of bipolar particle charging changed the paradigm that not the smallest but mid-sized particles charge most negatively: turbulence controls and suppresses size-dependent charging. We expect to deliver an experimentally validated tool to predict powder flow charging in the next reporting period.
Accomplishing the PowFEct project establishes a world-leading research laboratory that excels on all scales of powder flow charging. The output of this laboratory can serve the safety and sustainability of many industrial applications and, thus, prevent economic losses and save lives.