SILENCING DUCT FOR COOLING TOWER

PURPOSE:To prevent the penetration of rainwater and facilitate the installation on a fan casing by forming a duct body in several divided sections longitudinally and integrating a cover with the duct body at the upper and lower ends. CONSTITUTION:A duct body 8 is divided into four sections longitudinally. An upper cover 9 is inwardly projected and installed to the upper part of the duct while a lower cover 10 is inwardly projected and installed to the lower part of the duct respectively. Both the upper and lower covers are integrated with the duct body 8. A connection piece 11 is respectively installed to the end of the duct body on both sides. If an attempt is made to overlap the connection piece 11 with the adjacent connection piece 11 of the duct body 8 and connect both the pieces with a bolt 16, the duct body 8 is bent in such a manner that the outside diameter may take a cylinder shape almost identical to a fan casing 3. An acoustic material 12 is provided all over the inner side of the duct body 8. The acoustic material 12 is installed to the inner side of each duct body through a net 13, a support frame 14 and a presser pin 15. The net 13, the support frame 14 are consecutively brought in contact with the acoustic material 12. Both the upper and lower parts of the support frame 14 are fixed with the duct body 8 with a bolt so as to prevent the acoustic absorbing material 12 from breaking away from the duct body 8 and the acoustic absorbing effect from degrading as well.