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 1COPYRIGHT: (C)2016,JPO&INPIT【課題】真空冷却装置の真空ポンプ内に不純物を含んだ液分が入った場合にも不純物を残留させることなく残留液を確実に排出し、清浄な状態を保つ。【解決手段】被冷却物を収容する冷却槽2、冷却槽内の気体を吸引する真空ポンプ1、前記真空配管9に接続しており、途中に真空ポンプ乾燥弁4を持った外気導入配管3、真空配管の冷却槽側と真空ポンプ側で遮断する真空弁6、前記真空弁よりも真空ポンプ側に洗浄用水を供給するための水供給手段を設けており、前記真空弁は閉じ、真空ポンプは作動させた状態で真空ポンプ乾燥制御を実施する場合、真空ポンプ乾燥制御では、水供給手段により洗浄用水を供給する洗浄工程、前記真空ポンプ乾燥弁の開閉を複数回繰り返す残留液押し出し工程、真空ポンプ乾燥弁を開いた状態を保持する乾燥工程、を順に行う。【選択図】図1
