The application provides a pneumatic control cabinet, which comprises a cabinet door and a cabinet body, the cabinet door is fixed to the cabinet body through a hinged mode, the cabinet body comprises an inner plate and an outer plate, a device mounting cavity is arranged in the inner plate, and a certain gap is arranged between the inner plate and the outer plate, so that a
closed cavity is formed between the inner plate and the outer plate, and a liquid is arranged in the cavity. A
thin layer of water can effectively block the sound outside, and after a small amount of sound
waves successfully enter the liquid, the propagation process of the sound
waves in the liquid will rapidly attenuate due to the
viscosity and
internal friction of the liquid, and the
sound energy is converted into
heat energy. The greater the density and
viscosity of the liquid, the more significant the
absorption effect. The inner plate and the outer plate are made of
steel plates, so the sound needs to be transmitted from the air to the inner plate and then to the liquid. The density of the inner plate and the liquid is different, and the
acoustic impedance is also different. Therefore, a part of the sound is bounced back and a part of the sound is absorbed by the liquid during the transmission process, and when the sound reaches the outer plate, the
sound intensity is greatly reduced, that is, the sound insulation effect is good.