ELECTRON BEAM STERILIZER

To certainly sterilize the whole area in a vessel by irradiating the vessel with an electron beam from its opening.SOLUTION: An electron beam sterilizer 1 includes a conveying mechanism 2 for holding a preform 3 in a state where an opening 3a is directed upward and making it pass through a sterilization section A and an electron beam irradiation mechanism 4 for irradiating the opening 3a of the preform 3 with an electron beam EB. The sterilizer further includes a pair of magnets 6, 6 on right and left both sides in a conveying direction while sandwiching the preform 3 in sterilization section A between the magnets and a pair of yokes 7, 7 that is arranged inside the magnets along the conveying direction. The upper end part 7B of the yokes 7, 7 is an inclined part where a height at an upstream end part 7C in the conveying direction is the lowest and a height at a downstream end part 7D in the conveying direction is the highest. When the preform 3 passes through the sterilization section A while being irradiated with the electron beam EB, the flow of magnetic flux generated by the magnets 6, 6 and the yokes 7, 7 is changed over the range from the bottom 3b to the opening 3a in the preform 3.SELECTED DRAWING: Figure 4 【課題】容器にその開口部から電子線を照射して容器内の全域を確実に殺菌する。【解決手段】電子線殺菌装置１は、開口部３ａが上を向けた状態でプリフォーム３を保持して殺菌区間Ａを通過させる搬送機構２と、プリフォーム３の開口部３ａに向けて電子線ＥＢを照射する電子線照射機構４とを備えており、また殺菌区間Ａのプリフォーム３を挟んで搬送方向の左右両側に一対の磁石６、６を備えるとともに、それらの内側に搬送方向に沿って配置される左右一対のヨーク７、７を備えている。ヨーク７、７の上端部７Ｂは、搬送方向上流側の端部７Ｃの高さが最も低く、搬送方向下流側の端部７Ｄの高さが最も高くなる傾斜部となっている。プリフォーム３が電子線ＥＢを照射されながら殺菌区間Ａを通過する際に、磁石６、６とヨーク７、７による磁力線の流れがプリフォーム３内の底部３ｂから開口部３ａにわたって変更される。【選択図】 図４