| 摘要 |
PROBLEM TO BE SOLVED: To prevent leakage of ultrasonic waves radiated by the oscillation of a vibration board to increase the defoaming effect and obtain a preferable working condition. SOLUTION: The cover 3 arranged at the outside of an oscillation board 2 is constituted of a ceiling cover 10 provided with a reflection curvature face 10b, which reflects ultrasonic waves (a), (b) radiated from both front and rear faces 2a, 2b of the oscillation board 2 and projects to the liquid level 101a of beer 101 in a can 100, two side wall covers 11, 12 arranged below the ceiling cover 10 and positioned at respective front and rear face sides of the oscillation board 2, and the mutually oppositely arranged front and rear wall covers 15 arranged at the front and rear sides of both side wall covers 11, 12 and the ceiling cover 10. The stretched parts 11a, 12a oppositely arranged through the opening end of a can 100 in the defoaming position on the transfer way of containers, are provided at the lower end of respective side wall covers 11, 12. |
