The critical charge diameters were determined for the emulsion explosives sensitized with different
sizes and quantities of resin microbdloons with average diameters between 0.05 mm and 2.42 mm. A
reaction model was controlled based on the assumptions that the reaction in the explosive starts at the
surface of the shock induced void followed by the progress of reaction in the bulk explosive to the
adjacent void. The expanding rate of the void is assumed to be proportional to the square of the void
diameter, the surface area of the void in other words. Lineadty was observed between the critical
diameter of the explosive and the void surfaced istance. For the same void volume faction, the explosive
sensitized with smaller void is rather governed by the reaction at the void surface due to its large
surface area and shorter distance between next void. On the other hand, the critical charge diameter
of the emulsion explosives sensitized with larger voids depends on the reaction rate in the bulk explosive.
In both cases, the critical diameter is proportional to the void surface distance.
It was also shown that the critical chrge diameter relates to the void volume fraction and it is
proportional to the reaction zone length in the explosive that is derived from the charge diameter effect
when the void size is constant.
平均粒子直径が0.05 mmから2.42 mmである, 粒子密度の小さな有機質の気泡体を含有するエマルション爆薬において,それら気泡体の大きさおよび量が限界薬径に及ぼす影響が検討された｡反応モデルとして,ホットスポットとしての気泡体の表面に接触する部分の爆薬が反応を開始し,反応生成ガスの増大に伴うホットスポットの大きさの成長が気泡体直径の2乗に比例する,すなわち面積に比例するという仮定が設けられた｡その結果,限界薬径は爆薬中の気泡体表面間の距離に比例することが示された｡同一の爆薬空隙率では, 気泡体直径が小さいほど気泡体表面積が大きく,気泡体間の距離も小さいことから,爆薬の限界薬径は気泡体表面に接触する爆薬の反応速度によって支配される度合いが大きい｡これに対して, 気泡体が大きい場合はその表面櫛が小さく,爆薬の限界薬径は爆薬自体の反応速度に依存し, 気泡体間距離に関係するが,いずれの場合も限界薬径は気泡体表面間距離によって決まる｡また,気泡体の大きさが一定の場合には,限界薬径は爆薬の空隙率と相関し,爆轟速度の薬径依存性から求められた反応領域の長さと限界薬径とは比例関係にあることが示された｡