PROBLEM TO BE SOLVED: To highly efficiently release air from a treatment tank while preventing useless vacuum-cooling of a heated object and storage water in a saturated steam heating machine evaporating water prestored in the treatment tank and heating the heating object in the treatment tank by the steam.SOLUTION: When the both of an object temperature and a water temperature are lower than a heating target temperature, the pressure of the treatment tank is adjusted according to the temperature of a heated object, the temperature of water stored in the treatment tank and a heating target temperature of a next process and executes an air release process for retaining the saturated steam temperature in the treatment tank to the highest temperature among the object temperature, the water temperature and a saturated steam temperature in an initial decompression setting value. In this case, when the water temperature is lower than a temperature to be retained, the water stored in the treatment tank is heated and the pressure of the treatment tank is retained till elapsing a set time or more in the state where the water temperature reaches a temperature to be retained or more.COPYRIGHT: (C)2008,JPO&INPIT【課題】 処理槽内に予め貯留しておいた水を蒸発させ、その蒸気により処理槽内の被加熱物の加熱を図る飽和蒸気加熱機において、被加熱物や貯留水を無駄に真空冷却してしまうのを防止しつつ、処理槽内からの空気排除を効率的に行う。【解決手段】 被加熱物の品温、処理槽内に貯留された水の水温、および次工程の加熱目標温度に応じて、品温および水温のいずれもが加熱目標温度より低い場合には、品温、水温、または初期減圧設定値における飽和蒸気温度の内、最も高い温度に処理槽内の飽和蒸気温度を維持するように、処理槽内の圧力を調整して空気排除工程を実行する。その際、前記維持すべき温度よりも水温が低いと処理槽内に貯留された水を加熱して、水温が前記維持すべき温度以上の状態が設定時間経過するまで、処理槽内の圧力を維持する。【選択図】 図5
