| 摘要 |
PROBLEM TO BE SOLVED: To assuredly prevent propagation of miscellaneous fungi or the generation of of offensive odor in a cooling tank or a piping in a vacuum cooler. SOLUTION: An outside air introducing line 3 and a vacuum suction line 2 are connected to a cooling tank 1. An ozone generator 5 and an outside air introducing valve 6 are provided in the outside air introducing line 3. A vacuum suction means 11 is provided in the vacuum suction line 2. A controller 13 is provided for outputting a control signal to the vacuum suction means 11, the outside air introducing valve 6 and the ozone generator 5 upon stop of a vacuum cooling operation to sterilize the cooling tank 1. During the stop of the vacuum cooling operation, after the vacuum suction of the cooling tank 1 is performed, ozone is introduced to the cooling tank 1. Then, while the ozone is continuously introduced, the vacuum suction of the cooling tank 1 is intermittently carried out. After the introduction of the ozone is stopped, the vacuum suction of the cooling tank 1 is performed to introduce outside air and exhaust residual ozone. |
