Investigation of Dependence between Thermal Stability for Nano-Dispersed Metals and Velocity of Flame Spreading and Time Storage

Nazarenko

et al. 2019

MSF

Self Cite

The article presents the study of factors affecting the ability to control the self-propagating high-temperature synthesis of nanomaterials. It is established that there are two steps in the combustion process nanomaterial: burning of surface layer and deep combustion area, which can be considered as the thermal explosion. It was found that the surface roughness and the thermal conductivity of the substrate do not affect the combustion front velocity. The presence of glass transition on the substrate surface also does not affect the velocity of the front. It was established that the parameters of the deep combustion area do not depend on the nature of the initiation of combustion, being the second stage of the development of combustion; in all cases this stage is characterized by the same parameters. When varying the type of ignition source, the length of the surface burning front can vary up to 33%. The time of induction of a thermal explosion increases when the bulk layer of powder ignites from above.

Section: Resultsmentioning

confidence: 96%

“…A previously performed statistical analysis of the propagation conditions of the combustion front for a number of systems [7] made it possible to establish that the conditions in which the synthesis process takes place, or the control criterion K0, can be described by the following expression:…”

Section: Introductionmentioning

confidence: 99%

Influence of Factors Affecting the Parameters of Combustion of Aluminum Nanopowders in the Bulk Layer

Nazarenko

et al. 2019

MSF

Self Cite

“…Having carried out the statistical analysis of the propagation conditions of the combustion front in a number of systems [17], it was found that the conditions under which the synthesis process occurs can be described by the function (1). The criterion of control K 0 of the system proposed to use the following function:…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Possibility for Control of High-Temperature Synthesis of Nanomaterials

Nazarenko

2019

MSF

The feasibility of creating conditions for control of high-temperature synthesis (SHS) of nanomaterials has been studied. Experiments were carried out to determine the velocity of the combustion wave propagation of aluminum nanopowder obtained by electric explosion. In the course of the study, the factors influencing formation of the induction time: the thermal diffusivity of the substrate, the method of initiation of the combustion wave (flame, spark, heated body), the induction time between the initiating front and the front of the thermal explosion were considered. The relation describing the time of induction of thermal explosion is established.

“…These well-known regulations show the essence of concentration limits of flame propagation in combustible mixture. The notion of limits is widely discussed in papers [10][11][12][13][14]. Method of experimental determination of limits of flame propagation in gas and vapor-air mixtures are set out in [8].…”

Section: Introductionmentioning

confidence: 99%

Investigation of Thermal Explosion Formation in Heterogeneous Systems

et al. 2018

KEM

Self Cite

The analysis and necessity for studying of burning processes of systems formed by coal dust and methane for the purpose of development the effective activities on the enterprises of coal branch were shown. The results demonstrate the role of nonflammable components in the combustion processes of air suspension in heterogeneous systems. Also the dependence of the critical conditions creation for flame propagation in air suspension of sucrose from the average particle diameter at different temperatures of the ignition source is presented. The necessity of taking into account the experimental and methodological experience of other industries for the study of air suspension sensitivity to the initiating influence of the ignition source is explored. The requirements to the installation and methodology for studying the sensitivity of coal dust air suspension as one of the main factors preventing explosions of heterogeneous systems in the coal industry are formulated.