| 摘要 |
Device in the air apparatus of a ventilation duct system for adjustment of the airflow and for noise reduction, and including a sound absorption body within the ducting. The objective of the invention is to create an air apparatus which is cheap to manufacture, which is very simple to install even in existing ventilation ducts, which does not require any servicing and maintenance, and which also can serve as a fire shutter to prevent the spread of fire through the ventilation duct. This has been produced by the sound absorbing body being made of a plate shaped baffle along the duct's direction and essentially covering its whole cross section, which at one end is fitted with, or shaped to have, two lips controllably connected with the baffle and movable from a position mainly parallel to the baffle to a position aligned against the duct's inner side. The baffle is also fitted with a device for setting position of the lips relative to the baffle.<IMAGE> |
