Microwave Plasma System for Continuous Treatment of Railway Track

Braking conditions are a fundamental issue for the railway and have been a limiting factor in network capacity and timetabling. Leaf fall, especially during the autumn season, creates low-adhesion problems on railways, causing braking problems for trains. To address the requirements of the novel plasma industrial applications towards environmental applications, this work developed and tested a 2.45 GHz microwave atmospheric pressure plasma system for in situ removal of the third body layer deposited onto the railway so as to improve braking. The plasma reactor consisted of a 15 kW, 2.45 GHz magnetron-based microwave generator and a plasma reactor (dielectric tube placed in a TE01 monomode microwave cavity); the atmospheric plasma ignited and sustained at different power levels (2–15 kW) in different gases (nitrogen, argon) as well as mixtures of these gases with reactive molecules (water, oxygen) was jetted directly onto the railhead as to change the conditions for the wheel–rail interface. This technology is hoped to be a game-changer in enabling predictable and optimized braking on the railway network. Challenges encountered during the demonstration phase are discussed. Subsequent work should validate the results on a working railway line during the autumn season.

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Microwave Generated Plasma Railway Track Treatment

Proceedings 17th International Conference on Microwave and High Frequency Heating ◽

10.4995/ampere2019.2019.9778 ◽

2019 ◽

Author(s):

Julian Swan ◽

Matt Candy ◽

Marilena Radoui

Keyword(s):

Network Capacity ◽

Atmospheric Plasma ◽

Inert Gases ◽

Railway Track ◽

Microwave Cavity ◽

Limiting Factor ◽

Railway Network ◽

Dielectric Tube ◽

High Power Microwave ◽

Power Microwave

Braking conditions are a fundamental issue for the railway and have been a limiting factor in network capacity & timetabling. This work was focused on taking high power microwave generated plasma out of the laboratory into a railway environment. The Imagination Factory with no experience in microwave generated plasma has partnered with experts in this field to develop a mobile system which delivered 15kW 2.45GHz microwave generated plasma – Fig.1. The plasma was created within a dielectric tube placed in a monomode microwave cavity; the atmospheric plasma sustained in different inert gases (nitrogen, argon) gases as well as mixtures of inert gases with reactive molecules was jetted directly onto the railhead as to change the conditions for the wheel-rail interface. This technology is hoped to be a game changer in enabling predictable & optimized braking on the railway network. Challenges encountered during the demonstration phase will be discussed.

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Atmospheric Pressure Microwave Plasma System and Applications

10.1109/icops35962.2018.9576019 ◽

2018 ◽

Author(s):

Waqas A. Toor ◽

M. Ashraf ◽

Anis U. Baig ◽

Nauman Shafqat ◽

Raafia Irfan

Keyword(s):

Atmospheric Pressure ◽

Microwave Plasma ◽

Plasma System

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Energy coupling efficiency of a hydrogen microwave plasma reactor

Journal of Applied Physics ◽

10.1063/1.1337593 ◽

2001 ◽

Vol 89 (3) ◽

pp. 1544 ◽

Cited By ~ 11

Author(s):

M. H. Gordon ◽

X. Duten ◽

K. Hassouni ◽

A. Gicquel

Keyword(s):

Microwave Plasma ◽

Plasma Reactor ◽

Coupling Efficiency ◽

Energy Coupling

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Design and characterization of an electromagnetic-resonant cavity microwave plasma reactor for atmospheric pressure carbon dioxide decomposition

Plasma Processes and Polymers ◽

10.1002/ppap.201800153 ◽

2018 ◽

Vol 16 (2) ◽

pp. 1800153 ◽

Cited By ~ 3

Author(s):

Sina Mohsenian ◽

Shyam Sheth ◽

Saroj Bhatta ◽

Dassou Nagassou ◽

Daniel Sullivan ◽

...

Keyword(s):

Carbon Dioxide ◽

Atmospheric Pressure ◽

Microwave Plasma ◽

Plasma Reactor ◽

Resonant Cavity

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Nanoparticles generated by combining hot wall and microwave plasma chemical vapor synthesis

MRS Advances ◽

10.1557/adv.2018.134 ◽

2018 ◽

Vol 3 (4) ◽

pp. 213-218

Author(s):

Alexander Levish ◽

Markus Winterer

Keyword(s):

Iron Oxide ◽

Microwave Plasma ◽

Plasma Reactor ◽

Chemical Vapor ◽

Process Window ◽

Chemical Vapor Synthesis ◽

Second Stage ◽

Structure Surface ◽

Oxide Phases ◽

Precursor Decomposition

ABSTRACTControlling the oxidation state of iron and the crystal structure of iron containing compounds is the key to improved materials such as iron oxide nanoparticles for cancer treatment or heterogeneous catalysis. Iron oxides contain iron in different oxidation states and form different phases for one valence state (α-Fe3+2O2-3, β- Fe3+2O-32, etc.). Chemical vapor synthesis (CVS) allows the reproducible production of pure nanocrystals with narrow size distribution where particle formation and growth take place in the gas phase. Through the controlled variation of synthesis parameters CVS enables the synthesis of diverse iron oxide phases. In this study the energy for the CVS process is supplied by a hot wall furnace and a microwave plasma. The advantage of an plasma reactor as the first CVS stage is the fast and complete precursor decomposition at low temperatures. This results in a larger process window for the hot wall reactor in the second stage. The nanoparticles are examined regarding their structure, surface and valence by XRD and TEM.

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Composition, Mixing State and Water Affinity of Meteoric Smoke Analogue Nanoparticles Produced in a Non-Thermal Microwave Plasma Source

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2017-1053 ◽

2018 ◽

Vol 232 (5-6) ◽

pp. 635-648 ◽

Cited By ~ 5

Author(s):

Mario Nachbar ◽

Denis Duft ◽

Alexei Kiselev ◽

Thomas Leisner

Keyword(s):

Silicon Oxide ◽

Microwave Plasma ◽

Plasma Reactor ◽

Stoichiometric Composition ◽

Plasma Source ◽

Mixing State ◽

Iron Oxide Particles ◽

Pure Silicon ◽

Meteoric Smoke ◽

Water Affinity

Abstract The article reports on the composition, mixing state and water affinity of iron silicate particles which were produced in a non-thermal low-pressure microwave plasma reactor. The particles are intended to be used as meteoric smoke particle analogues. We used the organometallic precursors ferrocene (Fe(C5H5)2) and tetraethyl orthosilicate (TEOS, Si(OC2H5)4) in various mixing ratios to produce nanoparticles with radii between 1 nm and 4 nm. The nanoparticles were deposited on sample grids and their stoichiometric composition was analyzed in an electron microscope using energy dispersive X-ray spectroscopy (EDS). We show that the pure silicon oxide and iron oxide particles consist of SiO2 and Fe2O3, respectively. For Fe:(Fe+Si) ratios between 0.2 and 0.8 our reactor produces (in contrast to other particle sources) mixed iron silicates with a stoichiometric composition according to FexSi(1−x)O3 (0≤x≤1). This indicates that the particles are formed by polymerization of FeO3 and SiO3 and that rearrangement to the more stable silicates ferrosilite (FeSiO3) and fayalite (Fe2SiO4) does not occur at these conditions. To investigate the internal mixing state of the particles, the H2O surface desorption energy of the particles was measured. We found that the nanoparticles are internally mixed and that differential coating resulting in a core-shell structure does not occur.

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