| 摘要 |
PROBLEM TO BE SOLVED: To perform a positive discharging of residual liquid and keep a clean state without leaving impurities even if liquid containing impurities enters into a vacuum pump of a vacuum cooling apparatus.SOLUTION: A vacuum cooling apparatus comprises a cooling tank 2 storing items to be cooled, a vacuum pump 1 for sucking gas in the cooling tank, a surrounding air feeding pipe 3 connected to a vacuum pipe 9 and having a vacuum pump drying valve 4 in the midway part of it, a vacuum valve 6 of the vacuum pipe for shutting off at the cooling tank and the vacuum pump, and water supply means for supplying cleaning water to the vacuum pump rather than the vacuum valve. In the case that vacuum pump drying control is carried out under a state that the vacuum valve is closed and the vacuum pump is being operated, the vacuum pump drying control is performed in an order of cleaning step of supplying cleaning water by the water supply means, a residual liquid pushing out step of repeating opening or closing of the vacuum pump drying valve by several times, and a drying step of holding a state in which the vacuum pump drying valve is opened.SELECTED DRAWING: Figure 1 |
