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In order to obtain the most suitable porous explosion suppression material for oil storage containers, the gasoline-air mixture explosion suppression experiment in a closed container was carried out with the three representative explosion suppression materials, such as mesh aluminum alloy, spherical non-metallic material and reticulated polyurethane foam. On this basis, the explosion suppression mechanism was studied, the explosion suppression evolution process was analyzed, and the characteristic parameters of explosion were compared. The results show that the "cold wall effect", "wall effect" and explosion wave suppression theory all play an important role in the suppression of gasoline-air mixture explosion, but various explosion suppression mechanisms have different contributions to the cases with different materials used. When the mesh aluminum alloy and spherical non-metallic material are used to suppress the explosion, the overpressure in the container is inhibited, but the flame develops rapidly due to the disturbance effect, causing the explosion generated rapidly. When the reticulated polyurethane foam is used, the flame and overpressure are well controlled. Herein, the maximum overpressure peak value and explosive power index were taken as the evaluation indexes, and the reticulated polyurethane foam has much better explosive suppression performance than the other two materials. It is indicated that the reticulated polyurethane foam has important engineering application value in the safety monitoring and control of oil and gas.

In real roadways, gas is prone to accumulate, which in turn can lead to explosive hazards. The state of gas accumulation has a significant impact on the degree of disaster caused by gas explosive hazards. In this study, gas explosion propagation in complex situations was investigated in the actual roadway. The mechanism of explosion suppression was explored from the perspective of kinetic analysis of chemical reactions. It is found that the peaks of explosion pressure occur in the gas accumulation zone. The length of explosion flame is 3–5 times larger than that of the initial gas accumulation zone. As the initial accumulation volume increases, the flame propagation velocity (FPV), maximum explosion pressure (MEP) and flame zone length all increase. ABC Powder can effectively suppress explosion flames of gas with different gas accumulation patterns. A prediction model of gas explosion wave energy in the roadway is proposed. The explosion wave energy increases with increasing overpressure ratio. The explosion wave energy decays significantly after 80 m because of explosion suppression. The explosion suppression of ABC powder is a synergistic effect of surface cooling, dilution, physical isolation and chemical mechanisms. The free radical ions generated by the pyrolysis of ABC powder destroy the structure of the flame and make the reaction more difficult, which corresponds to an increase in the critical flame temperature and makes the gas phase dilution effect easier to achieve.

As a highly efficient and environmentally friendly gas fuel, hydrogen has emerged as one of the most promising sources of energy. However, the hydrogen explosion limit is low, the explosion risk is high, and the production, storage and transportation processes are prone to explode. Therefore, it is necessary to explore hydrogen explosion inhibitor to prevent and mitigation hydrogen explosions. In this study, the synergistic effect of the combination of inert gas and ultrafine water mist on the suppression of hydrogen explosion was studied by using a standard 20 L spherical explosive container bomb. The results of the study indicate that the combined use of inert gas and ultrafine water mist yields better suppression effects in terms of explosion pressure, flame propagation speed, and flame cellular structure formation, compared to the use of a single inert gas. Inert gas and ultrafine water mist have synergistic effects, but the synergistic effect of N 2 was significantly stronger than that of CO 2. Through chemical kinetic simulation, it was found that the formation rate of O, H, and OH, which were three active free radicals, decreased significantly compared with that of the single inhibition condition in the process of inhibiting the hydrogen explosion reaction by inert gas and ultrafine water mist. The pairing of nitrogen with ultrafine water mist demonstrates a superior collaborative effect in comparison to the combination of carbon dioxide and ultrafine water mist. • Synergistic explosion suppression effect of inert gas and ultra-fine water mist. • Twin-fluid can effectively slow down the formation of flame honeycomb structures. • Analyzed the synergistic explosion suppression mechanism of twin-fluid. • N 2 is more synergistic than CO 2 with ultra-fine water mist. [ABSTRACT FROM AUTHOR]

Sulfur, as a crucial chemical raw, poses increased combustion-explosion risks when mixed with other hazardous substances due to its dual nature as both an oxidant and a reducing agent. Additionally, sulfur-induced combustion and explosions can result in environmental pollution. Combustion-explosion suppression technology plays a crucial role in industrial production by effectively preventing hazardous chemical explosion incidents. This research investigates the combustion-explosion suppression of black powder, a common hazardous chemical containing sulfur, by utilizing two solid-based blast suppressants, NH 4 H 2 PO 4 and NaHCO 3 . On this basis, examining changes in the oxidation states of sulfur and explaining the mechanisms of combustion-explosion suppression through the examination of combustion-explosion products. Additionally, numerical calculations are employed to analyze the evolution patterns of gaseous and solid-phase products throughout the entire combustion-explosion process. Research indicates that NaHCO 3 exhibits a more effective combustion-explosion suppression effect on black powder compared to NH 4 H 2 PO 4 , which attributed to the valence state transformation of sulfur and the reduction of carbon oxidation. Furthermore, with the enhancement of combustion-explosion suppression effect, K 2 S, which a pollutes the environment, is gradually transform converted into potassium fertilizer K 2 SO 4 , which benefits plants. These results offer new insights into the research of combustion-explosion suppression of sulfur-containing substances and environmental protection strategies., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this paper, the research progress and development trend of gas and coal dust explosion suppression and isolation technology in China are reviewed and discussed from the aspects of basic research, passive explosion suppression and isolation technology, active explosion suppression and isolation technology and development trend. Large-scale test tunnels and test pipes of various diameters are used to conduct experimental research on the propagation law of gas and coal dust explosion flame and shock wave, which provides a theoretical basis for the development of explosion suppression and isolation technology. The active explosion suppression and isolation technology and equipment are developed to detect the explosion signal in advance, spray the explosive inhibitor actively, isolate and extinguish the flame. The passive explosion isolation technology and equipment, such as rock powder shed, water tank shed and water bag shed, have been popularized and applied in underground coal mines in China. The sealed water bag and automatic water injection device are further developed to solve the problems of easy evaporation and pollution of water. The mechanical explosion isolation device has been developed and the passive explosion isolation technology and equipment system have been improved. The technology of gas coal dust explosion suppression and flameproof adapts to the development trend of intelligent and unmanned coal mines. It realizes hierarchical start-up and linkage control through intelligent means to form a regional joint control technology to achieve effective control of gas (coal dust) explosion disasters.

Aiming at the problem that the CO concentration continues to exceed the limit and spontaneous combustion in the goaf after the 1413 fully mechanized mining face of Zhongxing high gas mine of Shanxi Fenxi Zhongxing Coal Industry Company has stopped mining, through analysis, it is concluded that the overlying coal rock in the goaf is broken to form air leakage fissures and the increased air leakage due to gas drainage are the main reasons why the fire in the goaf cannot be extinguished. In order to solve the problem of fire area control under the coexistence of gas and fire, mined-out area is adopted to establish the network monitoring system, integrated explosion suppression and efficient integrated fire control measures, namely arrange mesh temperature burning gas measurement and control system for real-time monitoring, apply rapid oxygen-consumed inerting technique of making the fire area out of explosion, reduce the air leakage in the goaf through the pressure control air technology, use the injection plugging technology to block the air leakage channel, implement the cooling and energy-absorbing technology to continuously reduce the temperature of the fire zone. The results show that the pressure difference between the inside and outside of the 1413 fully-mechanized working face is less than 15 Pa, the volume fraction of CO and O2 in goaf decreases to the normal level, the volume fraction of CH4 is lower than 5%, and the temperature is always below 25 ℃. Finally, the goaf fire area in 1413 workingface is extinguished completely, and the normal and safe production of Zhongxing Coal Mine is guaranteed.

Aim: This paper presents the operation of an active dust explosion (HRD, high rate discharge) suppression system in a confined space. Project and methods: The study involved tests of the developed fire protection system for suppressing dust explosions. The work was carried out under the project entitled “Innovative explosion protection technologies, including for highly protected facilities” No. DOBR-BIO4/052/13073/2013 at the Scientific and Research Centre for Fire Protection in Józefów. A test station designed and constructed to meet the prerequisites of the PN-EN 14034 series of standards was designed for testing. The test equipment consisted of a closed roughly spherical chamber with a volume of 1 m3, an ignition system, a system producing a dust-air atmosphere, and a pressure change detection system. Inside the sphere, a dust-air mixture of a certain concentration was obtained in a reproducible manner. The station was armed with a dust explosion suppression system consisting of: 5 dm3 fire extinguisher tank containing pressurized fire-extinguishing powder, a diffusing nozzle, an explosion detection system. The operation of the extinguishing system is based on the early detection of changes in the explosion pressure of the dust-air mixture, the processing of the signal, and the release of the extinguishing agent inside the apparatus in order to interrupt the explosion process at the earliest possible stage of its development. Results: On the basis of the conducted experiments, it can be concluded that the HRD system effectively interrupts explosive combustion for dust with a Kst ≤ 100 bar · m/s. For the examined potato starch dust, the system significantly reduced the explosion pressure to an acceptable value. The system is also characterised by a short reaction time, and the discharge of the extinguishing powder takes place in less than 100 ms, which is a satisfactory value. Conclusions: The tests were carried out for potato starch and lycopodium. The phenomenon of explosive combustion occurring in the mixture of lycopodium and air is characterised by greater dynamics, compared to starch. This difference allowed to identify the limitation of extinguishing dust explosions in small cubic capacity areas. In addition, research identified issues related to the source of ignition in the form of pyrotechnical heads, the use of which requires the setting of a high-pressure threshold activating the HRD system. This results in a delayed system reaction in the event of ignition of high Kst dust mixtures.