The effect of solid inertants like rock dust on explosion suppression was experimentally tested.By adding solid inertants with different concentrations into three kinds of coal dust,the maximum explosion pressure P ma...The effect of solid inertants like rock dust on explosion suppression was experimentally tested.By adding solid inertants with different concentrations into three kinds of coal dust,the maximum explosion pressure P max and the rate of explosion pressure rise(d p/d t)max were acquired.Based on this,the suppression effect of rock dust on coal dust explosion was analyzed.The experimental and analytical results show that there are two major factors that play an important role in explosion suppression:composition of solid inertant and particle size of solid inertant.The higher the concentration of solid inertant and the smaller the particle size of solid inertant,the better the suppression effect.In addition,the smaller the particle size of coal dust,the larger the amount of rock dust.展开更多
In coal industry,gas explosion accidents emerge constantly,causing enormous casualties and poorer material property.In the course of studying gas exploding mechanism,the propagation velocity of the flame wave front is...In coal industry,gas explosion accidents emerge constantly,causing enormous casualties and poorer material property.In the course of studying gas exploding mechanism,the propagation velocity of the flame wave front is one of the most important factors.A set of flame velocity measuring system was designed according to the horizontal pipelined experimental facility of North University of China to study the effects of the quantity and blockage ratio of the circle ring obstacle on the flame propagation velocity in the inclosed tube.The research results show that the obstacle has obviously accelerating effect on the flame wave of gas explosion With the increase of quantity and blockage ratio of the obstacle,the flame accelerating effect becomes more obvious and the flame accelerating persistence is intenser,of which the effect of the quantity of the obstacle on the flame accelerating persistence is larger,but the effect of the blockage ratio of the obstacle on the flame accelerating persistenceis not obvious.展开更多
In order to test the thermal decomposition of 1,3,5-trinitro-1,3,5-triazinane(RDX),the linear temperature rise experiment of RDX was carried out by differential scanning calorimeter under different heating rate condit...In order to test the thermal decomposition of 1,3,5-trinitro-1,3,5-triazinane(RDX),the linear temperature rise experiment of RDX was carried out by differential scanning calorimeter under different heating rate conditions.The kinetic calculation of RDX thermal decomposition curve was carried out by Kissinger and Ozawa methods,respectively,and the thermal analysis software was used to calculate the parameters such as self-accelerating decomposition temperature.The results show that the initial decomposition temperature range,decomposition peak temperature range,and decomposition completion temperature range of RDX are 208.4-214.2,225.7-239.3 and 234.0-252.4℃,respectively,and the average decomposition enthalpy is 362.9 J·g^-1.Kissinger method was used to calculate the DSC experimental data of RDX,the apparent activation energy obtained is 190.8 kJ·mol^-1,which is coincident with the results calculated by Ozawa method at the end of the reaction,indicating that the apparent activation energy calculated by the two methods is relatively accurate.When the packaging mass values are 1.0,2.0 and 5.0 kg,respectively,the self-accelerating decomposition temperatures are 97.0,93.0 and 87.0℃,respectively,indicating that with the increase of packaging mass,the self-accelerating decomposition temperature gradually decreases,and the risk increases accordingly.展开更多
To understand the combustion characteristics of potassium nitrate and evaluate the magnitude of combustion risk, ox-idation solid test apparatus is used and the updated experimental criterion of the United Nations is...To understand the combustion characteristics of potassium nitrate and evaluate the magnitude of combustion risk, ox-idation solid test apparatus is used and the updated experimental criterion of the United Nations is adopted to measure the pack-aging category of potassium nitrate. The new criterion puts calcium peroxide and microcrystalline cellulose as references and burning rate as evaluation index. Effects of mixing ratio and insert medium on burning rate are reached. Test results show that pure potassium nitrate doesn＇t burn under normal temperature and pressure, however, its oxidation is very strong and the packaging category should choose the class I. As the mass fraction of potassium nitrate reduces, the burning rate first increases and then decreases. When the ratio is 2 ： 1,the combustion rate reaches the maximum, and the effect of combustion is the best. When 1 ： 3, the combustion rate is the minimum. The mixture combustion can be suppressed by silicon dioxide and hy-drogen phosphate, which is not fired when silica concentration is 40% or ammonium hydrogen potassium phosphate is 55%, their effects are very obvious.展开更多
基金Special Foundation for Platform Base and Outstanding Talent of Shanxi Province(No.201705D211002)National Natural Science Foundation of China(No.11802272)
文摘The effect of solid inertants like rock dust on explosion suppression was experimentally tested.By adding solid inertants with different concentrations into three kinds of coal dust,the maximum explosion pressure P max and the rate of explosion pressure rise(d p/d t)max were acquired.Based on this,the suppression effect of rock dust on coal dust explosion was analyzed.The experimental and analytical results show that there are two major factors that play an important role in explosion suppression:composition of solid inertant and particle size of solid inertant.The higher the concentration of solid inertant and the smaller the particle size of solid inertant,the better the suppression effect.In addition,the smaller the particle size of coal dust,the larger the amount of rock dust.
基金Major Research and Development Project of Shanxi Province(No.201603D121012)
文摘In coal industry,gas explosion accidents emerge constantly,causing enormous casualties and poorer material property.In the course of studying gas exploding mechanism,the propagation velocity of the flame wave front is one of the most important factors.A set of flame velocity measuring system was designed according to the horizontal pipelined experimental facility of North University of China to study the effects of the quantity and blockage ratio of the circle ring obstacle on the flame propagation velocity in the inclosed tube.The research results show that the obstacle has obviously accelerating effect on the flame wave of gas explosion With the increase of quantity and blockage ratio of the obstacle,the flame accelerating effect becomes more obvious and the flame accelerating persistence is intenser,of which the effect of the quantity of the obstacle on the flame accelerating persistence is larger,but the effect of the blockage ratio of the obstacle on the flame accelerating persistenceis not obvious.
文摘In order to test the thermal decomposition of 1,3,5-trinitro-1,3,5-triazinane(RDX),the linear temperature rise experiment of RDX was carried out by differential scanning calorimeter under different heating rate conditions.The kinetic calculation of RDX thermal decomposition curve was carried out by Kissinger and Ozawa methods,respectively,and the thermal analysis software was used to calculate the parameters such as self-accelerating decomposition temperature.The results show that the initial decomposition temperature range,decomposition peak temperature range,and decomposition completion temperature range of RDX are 208.4-214.2,225.7-239.3 and 234.0-252.4℃,respectively,and the average decomposition enthalpy is 362.9 J·g^-1.Kissinger method was used to calculate the DSC experimental data of RDX,the apparent activation energy obtained is 190.8 kJ·mol^-1,which is coincident with the results calculated by Ozawa method at the end of the reaction,indicating that the apparent activation energy calculated by the two methods is relatively accurate.When the packaging mass values are 1.0,2.0 and 5.0 kg,respectively,the self-accelerating decomposition temperatures are 97.0,93.0 and 87.0℃,respectively,indicating that with the increase of packaging mass,the self-accelerating decomposition temperature gradually decreases,and the risk increases accordingly.
基金Major Research and Development Project of Shanxi Province(No.201603D121012)
文摘To understand the combustion characteristics of potassium nitrate and evaluate the magnitude of combustion risk, ox-idation solid test apparatus is used and the updated experimental criterion of the United Nations is adopted to measure the pack-aging category of potassium nitrate. The new criterion puts calcium peroxide and microcrystalline cellulose as references and burning rate as evaluation index. Effects of mixing ratio and insert medium on burning rate are reached. Test results show that pure potassium nitrate doesn＇t burn under normal temperature and pressure, however, its oxidation is very strong and the packaging category should choose the class I. As the mass fraction of potassium nitrate reduces, the burning rate first increases and then decreases. When the ratio is 2 ： 1,the combustion rate reaches the maximum, and the effect of combustion is the best. When 1 ： 3, the combustion rate is the minimum. The mixture combustion can be suppressed by silicon dioxide and hy-drogen phosphate, which is not fired when silica concentration is 40% or ammonium hydrogen potassium phosphate is 55%, their effects are very obvious.
