Study on a countermeasure of self-sustained tone by a baffle plate in boiler tube banks with a cavity

Abstract

In heat exchangers such as boilers and gas heaters, tube banks are set in a duct and the water passes through inside the tube and warm gas outside the tube. Then, the resonance phenomenon that is called the self-sustained tone occurs at a certain velocity. The self-sustained tone might cause the surrounding noise problem, and also cause the damage of halting factory work etc. Then, the insertion of baffle plates in the duct is one of a few countermeasures of the self-sustained tone. However, the mechanism of suppressing the self-sustained tone is not understood. Therefore, the use of the baffle plate in the tube bank has unclear points in the baffle plate length and the insertion conditions. Thus, the purpose of this study is to clarify a new mechanism of suppressing the self-sustained tone by the baffle plate insertion and the best insertion condition of the baffle plate in the tube bank. Copyright © (2011) by the Institute of Noise Control Engineering.