The recent concept of inherent safety uses the properties of a material or process to eliminate or reduce the risk thus removing or minimizing the hazard at the source as opposed to accept the hazard and looking to mitigate the effects. In this framework the control of particle size in dust explosion prevention and mitigation is recognized as a major inherent safety methodology. Indeed, the increase of particle size may allow significant reduction of particle reaction rate eventually reducing the risk. 
 
In this paper a novel model is developed to quantify the effect of particle size on dust reactivity in an explosion phenomenon. The model takes into account all of the steps involved in a dust explosion: internal and external heating, devolatilization reaction and volatiles combustion. Varying the dust size can establish different regimes depending on the values of the characteristic time of each step and of several dimensionless numbers (Damkohler number, Da; Biot number, Bi; thermal Thiele number, Th). Results from the model are reported in terms of the deflagration index (KSt) as a function of dust diameter in all regimes and at varying Da, Th and Bi. Comparison with experimental data from polyethylene explosion tests shows promising results. Finally, the results of the model are presented in the form of a dust explosion regime diagram, which is helpful to make a draft evaluation of the role of dust size on explosion behavior and severity.

Modelling the effect of particle size on dust explosion

Experimental and numerical study of the influence of initial temperature on explosion limits and explosion process of syngas-air mixtures

Synthesis mechanisms and effects of BaTiO3 doping on the optical properties of Bi0.5Na0.5TiO3 lead-free ceramics

Effect of incorporating hematite on the properties of ultra-high performance concrete including nuclear radiation resistance

Effect of Obstacle Location on Explosion Dynamics of Premixed H2/Co/Air Mixtures in a Closed Duct

The flow field behaviours of under-expansion jet flame in premixed hydrogen/air explosion venting

With the emergence of hydrogen economy worldwide and the increase of safety problems caused by the highly flammable and explosive characteristics of hydrogen (H 2 ), it is urgent to develop the portable sensors that can sensitively and quickly detect H 2 leaks. In this work, the H 2 sensing characteristics of Pd/SnS 2 /SnO 2 nanocomposites synthesized via hydrothermal route as well as impregnation route were systematically investigated for the first time. The influence of different SnS 2 and Pd loading on the H 2 sensing performances of SnO 2 nanoparticles was revealed by varying the addition levels of thiourea and palladium chloride. The H 2 sensing experimental results demonstrated that SnS 2 and Pd modification can greatly enhance the sensing capabilities of SnO 2 , where 1.0 at% Pd/SnS 2 /SnO 2 sensor exhibited high response (95) and rapid response/recovery time (1/9 s) to 500 ppm H 2 at 300 ℃, thus outperforming the current reported sensing performances of SnO 2 -based H 2 sensors. The superior sensing characteristics of Pd/SnS 2 /SnO 2 were attributed to the simultaneous synergistic effect of the three components. This study will supply a rational strategy for designing high sensitive and rapid response H 2 sensors. • Pd/SnS 2 /SnO 2 nanocomposites were synthesized via hydrothermal/impregnation method. • 1.0 at% Pd/SnS 2 /SnO 2 sensor exhibited fast response for H 2 detection. • The sensitization mechanism of Pd/SnS 2 /SnO 2 -based H 2 gas sensor was proposed. 

Ultrasensitive gas sensor based on Pd/SnS2/SnO2 nanocomposites for rapid detection of H2

Study on the effect of simulated nuclear industry working conditions on the explosion severity parameters of zirconium powder and the explosion mechanism.

Through experiments and numerical simulation methods, the parameters of each flow field and their effects on dust explosion intensity under different ignition delay time in a 1 m3 explosion vessel were quantitatively studied. The results showed that the explosion pressure and pressure rise rate of corn starch first increased and then decreased with increasing ignition delay time, and the maximum value were obtained when the ignition delay time is about 600 ms, which were 0.884 MPa and 17.9 MPa/s, respectively. The comparison between the numerical simulation and experiment proves the accuracy of simulation calculation. Furthermore, the turbulent distribution of airflow and particles before ignition was quantitatively studied. The particle distribution is gradually uniform after 300 ms, and the turbulent kinetic energy is in a low range. The root mean square velocity and average turbulent kinetic energy of the airflow are 3 m/s and 3.5 m2/s2 at 600 ms. 

Qiuping Xiao

Papers

The flow field behaviours of under-expansion jet flame in premixed hydrogen/air explosion venting

Ultrasensitive gas sensor based on Pd/SnS2/SnO2 nanocomposites for rapid detection of H2

Study on the effect of simulated nuclear industry working conditions on the explosion severity parameters of zirconium powder and the explosion mechanism.

Experimental and numerical simulation study on the effect of ignition delay time on dust explosion in the 1 m3 vessel

Premixed Syngas/Air Combustion in Closed Ducts with Varied Aspect Ratios and Initial Pressures

Qiuping Xiao

Papers

The flow field behaviours of under-expansion jet flame in premixed hydrogen/air explosion venting

Ultrasensitive gas sensor based on Pd/SnS2/SnO2 nanocomposites for rapid detection of H2

Study on the effect of simulated nuclear industry working conditions on the explosion severity parameters of zirconium powder and the explosion mechanism.

Experimental and numerical simulation study on the effect of ignition delay time on dust explosion in the 1 m3 vessel

Premixed Syngas/Air Combustion in Closed Ducts with Varied Aspect Ratios and Initial Pressures

Experimental and numerical simulation study on the effect of ignition delay time on dust explosion in the 1 m3 vessel