Three major causes of noise produced by the hottes

2022-08-24
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Three major causes of noise produced by pressure reducing valve

the causes of noise produced by pressure reducing valve can be divided into the following three categories: 1 Mechanical vibration noise of pressure reducing valve; 2. Hydrodynamic noise; 3. Aerodynamic noise

I. noise caused by mechanical vibration. The components of the pressure reducing valve will produce mechanical vibration when the fluid flows. The mechanical vibration can be divided into two forms: ① low frequency vibration. This kind of vibration is caused by the jet and pulsation of the medium. The reasons are that the flow velocity at the valve outlet is too fast, the pipeline layout is unreasonable, and the rigidity of the valve moving parts is insufficient. ② From the government level, service-oriented has become an important force to lead the upgrading and sustainable development of the manufacturing industry. This vibration will cause resonance when the natural frequency of the valve is consistent with the excitation frequency caused by the medium flow. It is produced by the pressure reducing valve within a certain pressure reducing range, and once the conditions change slightly, the noise will change greatly. This kind of mechanical vibration noise has nothing to do with the medium flow speed. 80% of the capacity is lithium copper foil, which is due to the unreasonable design of the pressure relief valve itself. The measures to reduce mechanical vibration and noise are to reasonably design the clearance between the pressure reducing valve bushing and the valve stem, the machining accuracy, the natural frequency of the valve and the rigidity of the moving parts, and correctly select materials

II. Hydrodynamic noise hydrodynamic noise is generated by the turbulence and eddy current after the fluid passes through the pressure reducing port of the pressure reducing valve, and its generation process can be divided into two stages: ① turbulent noise, that is, the noise generated by the interaction between the turbulent fluid and the pressure reducing valve or the inner surface of the pipeline, its frequency and noise level are relatively low, and generally does not constitute a noise problem. ② Cavitation noise, that is, during the pressure reduction process of the pressure reducing valve, when the fluid flow rate reaches a certain value, the fluid (liquid) begins to vaporize, and when the pressure on the bubbles in the liquid reaches a certain value, it will explode. When the bubble explodes, it will produce high pressure and shock wave locally. The instantaneous pressure of the shock can reach 196 MPa, but the pressure will decay sharply away from the center of the explosion. This shock wave is a major factor causing cavitation and noise of the pressure reducing valve. The measure to reduce mechanical vibration and noise is that when designing the pressure reducing valve, the pressure reducing value of the pressure reducing valve must be controlled below the critical value, and it is better to Δ P below the initial value, because the actual pressure reduction value of the pressure reducing valve reaches Δ At the initial value of P, the liquid begins to produce cavitation, and the noise will increase sharply. In addition, pay attention to the flow direction of the fluid medium relative to the valve disc

III. aerodynamic noise when steam and other compressible fluids pass through the pressure reducing part in the pressure reducing valve, the mechanical energy of the fluid is converted into sound energy, and the noise generated is called aerodynamic noise. This kind of noise is the most troublesome noise in the pressure reducing valve. There are two reasons for this noise, one is due to the turbulence of the fluid, and the other is due to the shock wave caused by the critical velocity of the fluid. Aerodynamic noise cannot be completely eliminated, because the fluid turbulence caused by the pressure reducing valve during pressure reduction is inevitable. PVC door and window semicircle lock jg/t 130 ⑵ 000

to sum up, fundamentally speaking, the noise produced by the pressure reducing valve is related to its own design and manufacturing process

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