Fan is a kind of general mechanical equipment, which has a wide range of applications. Sales in various industries such as electric power, mining, machinery, metallurgy, chemical industry, etc. cannot be separated from fan. The noise generated during the operation of wind turbines often becomes a source of disaster that affects workers' health and interferes with the environment. In particular, the aerodynamic noise radiated by the air inlets and outlets of fans adjacent to living areas is a major factor in polluting the environment, forming a public hazard, and has become one of the main targets of noise pollution control in China's industrial sector in recent years.

The purpose of ventilation duct muffler is to reduce the noise of ventilation duct fans. Based on the actual testing of the noise sources at the operation site of various wind turbines in the power plant, our factory determines the frequency spectrum range within which the amount of noise reduction is required as the main basis for designing the structure and fluid channel of the sound absorbing sheet. At the same time, we have adopted a narrow rectangular channel with a large sound absorbing material finish to enhance the absorption effect. As we know, when the noise source of a fan is at a large noise level, its frequency spectrum value often exceeds one type, and the requirements for its noise reduction amount vary for different frequency bands. For this reason, this product adopts a resistive structure that can eliminate high and intermediate frequency noise and a resistive structure that can eliminate medium and low frequency noise. At the same time, two types of noise elimination regions, high frequency and low frequency, are used in the resistive channel to greatly widen the noise elimination frequency band, to achieve good noise elimination effect.