Research On The Technology Of Coal Mine Active Explosion Suppression And Isolation System

The probability of gas safety accidents were increased as the enlargement of mining scale and digging depth. These measures of insulating and suppressing gas explosion can`t meet the demands of actual production anymore, there exists many shortcomings and few effective associations and cooperation among various devices. It is extremely urgent to develop a more broad-spectrum, scientific and effective system to forbid the gas blasting occurred.The related knowledge about gas explosion was analyzed, the theory of origin, evolution of blast and spread of shock wave was briefed, and then the analysis of gas explosion accident tree which could use for active warning systems was carried. After this the action principle of various explosion suppression technologies and explosion suppression mediums were introduced to prepare for the follow automatic explosion suppression device design.The phenomenon of gas explosive shock wave spread in different types of small size roadways was researched by Autoreagas, especially the explosion processes of 5m/10 m straight roadway, double bifurcation roadway and crisscross roadway was simulated, the overpressure data was statistical collected and whose change rules of ob servation points at typical positions were analyzed. The result shows that longer roadway could slow the arrival of pressure peak though the corresponding overpressure was much larger; the complex fluid change happened at bifurcation point in double bifurcation and crisscross roadway, what makes the overpressure of branches larger than main lines;The maximum explosion pressure and its decay velocity of branch which is perpendicular to main line in crisscross roadway is greater than the branch opposite to main roadway.The simple early warning model based on the volume of gas concentration, change rate wind speed, feed electrical coupling response and multisensory was researched combined with KJ90 coal mine safety monitoring system. The early warning indicators, critical values and recovery values of this model was analyzed, and there presents normal, warning, alerting and danger this 4 states, which can be contributed to the foundation of mine gas safety actively warning system.Combining with the theory of induction period and referencing the design ideas of existing ZYB series, there gets a revised design of automatic explosion suppression device. A detector with ultraviolet/infrared sensor and pressure sensor as the core was designed, so as whose logic circuits. And then the basic structures and principles of PLC(programmable logic controller) were brief introduced. The ordinary explosion suppression medium spraying device was optimized from three aspects: fluid nozzle, spraying radius and container volume. The design target is reducing volume, promoting spray ratio and shorten fogging time that was calculated simply at last.An isolation explosion gate which could be defined as a passive isolation system based on the responsive time was design. The gate was composited by wire mesh fire layers and porous ceramics decompression, spraying nozzles was set on the surface of it. The limit switch was driven by electronic control of mechanical systems; an independent pressure sensor was associated with control module that shares signal with active warning systems and automatic explosion suppression system. This isolation explosion gate can serve as the supplementary measure for the active and automatic device.