Study On The Key Explosion Parameters Of Titanium Dust

As a kind of Non-ferrous metal, Titanium has been widely used in producing a varietyof advanced machinery, parts, weapons and equipment, because of its excellent physical andchemical properties. China is a very important titanium sponge production country, thelocation of the titanium sponge production has became the world’s first, more than onehundred thousand tons of titanium sponge has been produced every year. However, with thedevelopment of titanium sponge production, production accidents also becomes more andmore frequent, Dust explosion accident is most prominent in many kinds of accidents.Therefore, the study on the explosion characteristics of Titanium dust is very meaningful.This paper mainly studies the changing rule of titanium dust’s minimum ignition energy,lower explosive limit and minimum ignition temperature in different dust concentration,particle size and dust injection pressure. Three kinds of particle size of titanium powder,63-55μm,55-43μm,﹤43μm, had been selected. The relevant conclusions are as follows:(1) Dust concentration is a extreme value factor of titanium minimum ignition energy.With the increase of dust concentration, the minimum ignition energy of titanium decreasesfirstly, and then increases. When the minimum ignition energy of titanium achieves theminimum value, the dust concentration is1400g/m3, and at this time three kinds of dustparticle size titanium’s minimum ignition energy respective are136mJ、64.94mJ、42.17mJ.Three kinds of dust particle size titanium’s minimum ignition energy fitting curve is a linearrelationship. When the dust particle size is＜43μm, the dust sensitive concentration and theminimum ignition energy respective are1380g/m3and45.314mJ.The effects of dust particle size on titanium minimum ignition energy is also verysignificant, with the decrease of the titanium dust particle size, the minimum ignition energy under the dust concentration also reduces. The change curves of63-55μm、55-43μm、﹤43μm particle size titanium dust have been fitted in this experiment, after calculation thesensitive concentrations of three kinds of dust particle size titanium dust respective are1367g/m3、1509g/m3、1380g/m3, and the values of the minimum ignition energy respective are130.193mJ,60.593mJ,45.314mJ.(2) In this experiment, under the condition of fixed energy, the lower explosive limitconcentrations of three types of titanium powder particle size was determined, the results are280g/m3、260g/m3、250g/m3. By comparing the results, the lower explosive limitconcentration decreases with the decreasing of titanium powder particle size, and the declinealso decreases. The reason is associated with the specific surface area and the dispersion ofdust.(3) Dust injection pressure and dust particle size was selected to research the changes ofthe minimum ignition temperature of titanium dust in different conditions. According to thetest results, dust injection pressure is monotonous factor of the minimum ignition temperature,with the increase of dust injection pressure, titanium dust’s minimum ignition temperaturealso increases, and the greater the dust quality, the lower the temperature is. When the qualityof titanium dust is50mg and the dust injection pressure is0.5bar, the ignition temperatureachieves maximum, which is865℃; When the quality of titanium dust is500mg and thedust injection pressure is0.2bar, the ignition temperature achieves minimum, which is594℃.Under the condition of fixed dust injection pressure, with the decrease of the titaniumdust particle size, the minimum ignition temperature under the dust concentration also reduces.And the reduction is in the range of35-40℃.