| 摘要 |
PROBLEM TO BE SOLVED: To provide an inner cover, ventilation structure and handling tool capable of preventing vibration of duct.SOLUTION: An inner cover 30 is arranged on peripheral surface 11 of a duct 10 transferring upper side air in a greenhouse 2 to downward or a suitable region, and may be moved on the inner peripheral surface 11. The cover 30 has a cylindrical shape and a length within a range from about 80 mm or more to about 600 mm or less. The cover 30 may move from a blowout port 13 of the duct 10 to an inlet port 12 of the duct 10. On an outer wall surface 31 of the inner cover 30 or an end part, a ring body, sandpaper or an adhesion part is arranged as a slide stopping means. Thereby, vibration of the duct 10 may be prevented and strength of the duct 10 is improved.SELECTED DRAWING: Figure 1 |
