| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform a more precise pressure control when an inside part of a processing tank is kept at a set pressure under a high vacuum state of a final stage of vacuum cooling process.SOLUTION: This invention relates to a vacuum cooling apparatus for cooling an object 7 to be cooled that is stored in a processing tank 2 by making vacuum in the processing tank 2. There is provided in advance a surrounding air taking valve 3 for taking in the surrounding air in order to adjust a pressure reducing capability at a vacuum generating device 1. In order to hold the pressure in the processing tank under a state in which the inside of the processing tank is kept under a high vacuum, when a measured pressure in the processing tank is lower than a target pressure, an operation for opening the surrounding air taking-in valve 3 to increase an opening degree and in turn when the measured pressure in the processing tank is higher than the target pressure, an operation for closing a degree of opening of the surrounding air taking-in valve 3 is carried out and an operating amount is adjusted by a slight motion for an opening action and a wide motion for a closing action in respect to the operating amount of the surrounding air taking-in valve 3.</p> |
