PROBLEM TO BE SOLVED: To execute proper control when it is not a saturation state, and monitor a state of saturated vapor always in a sterilization step.SOLUTION: A steam sterilization device calculates difference between current temperature and saturated steam temperature, if the calculated difference is in a range of an upper limit threshold or lower and a lower limit threshold or greater, determines that steam in a sterilization tank 32 is saturated steam, if the calculated difference exceeds the upper limit threshold, determines that steam in the sterilization tank 32 is overheated steam, then reduces steam temperature of steam to be introduced into a jacket part 34 for reducing temperature in the sterilization tank 32, then closes a drain valve 65 for promoting vaporization of drain, and if the calculated difference is less than the lower limit threshold, the device determines that steam in the sterilization tank 32 is wet steam or there is possibility in which non-condensation gas is left, and increases steam temperature of steam to be introduced into the jacket part 34, or opens an exhaust valve 63, for executing deaeration operation in the sterilization tank 32, these steps are always performed in the sterilization step.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2020,JPO&INPIT【課題】 滅菌工程中常時飽和蒸気の状態を監視し、飽和状態でないと判断した場合に的確な制御を実行する。 【解決手段】 現在温度と飽和蒸気温度の差分を算出し、算出した差分が、上限閾値以下且つ下限閾値以上の範囲に入っている場合は、滅菌槽３２内の蒸気が飽和蒸気であると判断し、算出した差分が、上限閾値を越えている場合は、滅菌槽３２内の蒸気が過熱蒸気であると判断し、ジャケット部３４に導入される蒸気温度を下げることにより滅菌槽３２内の温度を下げ、且つドレン弁６５を閉じてドレンの蒸発を促し、算出した差分が、下限閾値未満の場合は、滅菌槽３２内の蒸気が湿り蒸気であるか又は非凝縮性ガス残留の可能性があると判断し、ジャケット部３４に導入される蒸気温度を上げるか、又は排気弁６３を開き、滅菌槽３２内の脱気動作を実行するように制御することを、滅菌工程中常時行う。【選択図】 図１
