Research On Influencing Factors Of Delay Precision Of Millisecond Delay Electric Detonator

The research status of millisecond delay electric detonators at domestic and overseas and influencing factors of delay precision are introduced in this paper. It took coal mine permitted MS electric detonator as the object of research, designed a dedicated sealer and established a delay time sectionalized test system of commercial electric detonators, for the research of the impact of the electric ignition component, middle chucking and error in length of delay on the delay precision of MS electric detonator. It paves the way for the further research of the precise control of the combustion process of the delay composition as well as provides a theoretical basis for the improvement of the delay precision for the other series of detonators. Through the experiments, the conclusions are as follows:(1)The sectionalized test system for delay time of commercial electric detonator can imitate the real environment of combustion or detonation reaction of delay elements in the detonator, and measure accurately for the process from igniting to flaming of lead delay element in the detonator. Also, it make a segmentation measurement for the delay time of each array in electric detonator, including on-off time of Bridge Wire, ignition time of the fuse head, delay time of delay element and the total delay time of the electric detonator.(2)The electric ignition component has an impact on the igniting of the fuse head and the stable combustion of delay composition. Bridge Wire resistance is not the main cause of low precision of igniting time of the fuse head on the error lever of factory. The fuse head are in different sizes that have significant influence on the igniting of fuse head and the stable burning of delay element. The big fuse head can cause the short igniting time and high precision of igniting time. If the quality of fuse head increase from13mg to18mg, the delay time of MS-2delay element will reduce1.1ms and the delay time of MS-5delay element will reduce6.44ms, the time precision of delay element will firstly increase and subsequently reduce generally. If the quality deviation of fuse head is small, the time precision of igniting and delay element would be high.(3)The middle chucking have an impact on combustion performance of delay element, including the significant increase of delay time of delay element, the decrease of average linear burning rate and burning rate precision of delay composition. The delay time of delay element will tend to increase and the burning rate precision tend to decrease with increasing pressure of middle chucking between0.2MPa-0.6MPa. The delay element is fixed well, no shift, and the time precision is high with pressure on0.2MPa.(4)The error in length of delay element is not the main cause of low delay precision of MS delay electric detonator on cutting technology of delay element in factory.