| 摘要 |
The present invention can easily and stably generate a large amount of bubbles by minutely cutting bubbles moving to an outer pipe from an inner pipe or to the inner pipe from the outer pipe by periodically opening and closing the through-hole of the inner pipe while a plurality of balls or cylindrical rollers with a simple structure do not generate friction with the inner pipe and the outer pipe by allowing the balls or cylindrical rollers to selectively and periodically open and close the through-hole of the inner pipe when the inner pipe or the outer pipe rotates by placing the balls or cylindrical rollers between the inner pipe and the outer pipe, wherein the inner pipe has a plurality of through-holes on the circumferential surface and the outer pipe is in contact with the inner pipe. |
