Clean Circles

Laminar combustion wave velocity and structure investigation in Bunsen type iron dust burners

The aim of this project is to experimentally determine the resulting oxidation/combustion wave velocity, the gaseous and solid temperature and the oxidation wave structure as well as the resulting iron particle oxidation degree of iron dust flames as a function of the air preheating, the overall air to fuel ratio, the particle diameter and, in a later stage, the air/particle relative velocity under well-defined reference boundary conditions. To achieve this goal, the first step is to the design and manufacture of an iron “dust” particles burner, which is designed as a Bunsen burner. The creation of a homogeneous loading is of particular importance to and enable operation without additional hydrocarbon fuel such as methane and, above all, to correctly determine the influence of the air-to-fuel ratio.

Subsequently, the measurement methods required to determine the flame velocity and the analysis of the thermal wave structure are tested and, if necessary, adapted to determine the flame velocity and the temperature distribution as a function of the relevant variables mentioned.

Furthermore, the resulting differences in the effective combustion wave velocity due to the relative velocities between particles and surrounding air are modeled in collaboration with numerical data from the project of C. Hasse.

The collected combustion products are analyzed or reduced in the subprojects of O. Deutschmann, U. Kramm and H. Nirschl. There is a close cooperation in the field of measurement techniques, data evaluation and practical aspects of burner operation with the research groups of B. Böhm and A. Dreizler, who investigate iron combustion in other types of burners. In later phase of the subproject, the turbulent iron flames are foreseen, which are numerically modeled by the group of O. Stein.

Scientific questions:

  • What is the relationship between effective oxidation/thermal wave speed under laminar flow conditions and parameters like temperature of the educts, the overall oxygen to fuel ratio, the particle diameter and the particle number concentration?
  • What is the influence of particle structure and local size distribution under laminar flow conditions on flame stability?
  • Is it possible to obtain reference data for a turbulent combustion wave/flame velocity model through measurements under well-defined reference boundary conditions, from the relative velocity of the particles to the ambient airflow?

 

Scheme of the iron burner

 

Experimental test rig
Measured laminar burning velocity of iron dust [doi.org/10.1016/j.jaecs.2022.100111]

High speed (10 kHz) imaging of iron flame. Air-fuel equivalence Φ=1 ratio (based on Fe2O3), particle size d50 = 13 µm. Outlet pipe diameter is equal to 20.5 mm. Average outlet velocity off the tube u0 = 30 cm/s.

 

Photos of iron flames under different oxygen concentration in the gas phase. Air-fuel equivalence Φ=1 ratio (based on Fe2O3), particle size d50 = 5 µm. Outlet pipe diameter 2R0 = 20.5 mm. [link]

 

Publications:

  • M. Fedoryk, B. Stelzner, S. Harth, D. Trimis, Experimental investigation of the laminar combustion wave velocity of iron-air flames in a tube burner, Appl. Energy Combust. Sci. 2023, 13, 100111 [doi.org/10.1016/j.jaecs.2022.100111]
  • S. Buchheiser, M. Deutschmann, F. Rhein, A. Allmang, M. Fedoryk, B. Stelzner, S. Harth, D. Trimis, H. Nirschl, Particle and phase analysis of combusted iron particles for energy storage and release, Materials, 2023, 16(5), 2009. [doi.org/10.3390/ma16052009]

Conference contributions:

  • M. Fedoryk, B. Stelzner, S. Harth, D. Trimis, Laminar burning velocity measurements and stability map determination of Fe-N2/O2 mixtures in a tube burner, Proceedings of 11th European Combustion Meeting, 2023, France [link]
  • M. Fedoryk, B. Stelzner, S. Harth, D. Trimis, Bestimmung der laminaren Brenngeschwindigkeit von Eisenstaub-Luft Flammen (Vortrag), Jahrestreffen der DECHEMA Fachgruppe Hochtemperaturtechnik, 2023, Karlsruhe
  • M. Fedoryk, B. Stelzner, S. Harth, D. Trimis, Experimental Investigation of iron-air flames in a tube burner (Vortrag), 1st Workshop on Metal-enabled Cycle of Renewable Energy (MECRE), 2022, Eindhoven
  • M. Fedoryk, B. Stelzner, S. Harth, D. Trimis, Laminar combustion wave velocity and structure investigation in Bunsen type iron dust burners (Poster), 773. WE-Heraeus-Seminar Materials and Energy ‐ New Directions for the “Energiewende”, 2022, Bad Honnef
  • M. Fedoryk, B. Stelzner, S. Harth, D. Trimis, Laminar combustion wave velocity and structure investigation in Bunsen type iron burner (Poster), 9. Jahrestagung KIT-Zentrum Energie, 2022, Karlsruhe
  • H. Heidarifatasmi, N. Zarzalis, D. Trimis, Numerical Simulations of Iron Particle Dispersion in a Fan-stirred Closed Vessel (Poster), 9. Jahrestagung KIT-Zentrum Energie, 2022, Karlsruhe