The Performance and Mechanism of the Green Explosion Suppressant SGA for Coal Dust Explosion Suppression

Abstract

In recent years, coal processing is developing rapidly, but there are often hidden safety hazards such as coal dust explosions during coal processing. In order to ensure safe production and avoid coal dust explosion accidents, a carrier with unique micro-mesoporous structure (SG) based waste molecular sieves was prepared. After that, the carrier was loaded with (NH 4 ) 2 C 2 O 4 (A) uniformly by ultrasound, which acted as an activity component for the first time. A novel micro-mesoporous coal dust explosion suppressant (SGA) is obtained. The law influence of different compositions of suppressant on the flame propagation of explosion was investigated. The results showed that the best ratio of waste molecular sieve, zirconium dioxide, and (NH 4 ) 2 C 2 O 4 of the suppressant is 1:7:2. The suppression performance increases with the increase of the addition of suppressant. When the addition amount is 70 wt %, the explosion loses the ability to continue to expand. Finally, combining the suppression performance with characterization results, the physical and chemical synergistic suppression mechanism is proposed, which reveals the reason why the suppressant has efficient suppression performance. The study could realize the green reuse of waste molecular sieves and provide guarantees for safe production of the coal processing industry.

Study on the Influence of Vent Shape and Blockage Ratio on the Premixed Gas Explosion in the Chamber with a Small Aspect Ratio

“…In the early stages of the explosion, with the combustion reaction, the combustion exotherm made gas expansion, the pressure inside the chamber gradually increased and for the first time reached the peak P b ; the explosion venting membrane was subjected to the limit state rupture, heating, and mixed gas exhaustion, so that the pressure inside the chamber was rapidly reduced. When the vent was opened, the pressure shock rose due to the change of the flow field in the chamber, causing the occurrence of Helmholtz shock; , part of the premixed natural gas inside the chamber leaks out from the broken membrane under the action of pressure outflow, and the gas cloud formed outside was ignited, , causing a secondary explosion, resulting in a dramatic change of the pressure inside the chamber and the formation of the characteristic pressure peak P ext . With further time, when the explosion flame propagated to the walls of the chamber, the pressure continued to increase to reach a peak, which in turn formed a pressure peak P mfa .…”