The inlet and outlet silencers of Roots blower are key components to ensure stable operation of equipment, and their role goes far beyond simple noise reduction. The following provides a detailed analysis of its core functions and technical points from a professional perspective:
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**1、 The core function of imported mufflers**
1. * * Acoustic treatment**
-* * Broadband noise reduction * *: Targeting the frequency noise (usually 125-4000Hz) unique to Roots blower blades, impedance composite design can achieve a noise reduction of 15-35dB (A)
-Control of Airflow Regeneration Noise: By optimizing the flow channel design (such as porous diffusion structure), the frictional noise of the airflow is controlled at ≤ 78dB (A) @ 10m/s
2. * * Air intake optimization**
-Flow field correction: The built-in guide grid reduces the turbulence level of the intake from 15 to below 5, improving the volumetric efficiency of the fan by 3-5
-* * Pulse attenuation * *: The resistant chamber can absorb pressure pulsations of over 80 (pulsation amplitude reduced from ± 8kPa to ± 2kPa)
3. * * Equipment protection**
-* * Third level filtration system * *:
|Filter level | Precision | Protected object|
|----------|---------|-------------------------|
|Coarse filtration | 1mm | Prevent large particles such as leaves from entering|
|Medium filter | 180 μ m | Protection rotor clearance (0.1-0.3mm)|
|Fine filtration | 50 μ m | Avoid bearing wear|
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**2、 Special function of export muffler**
1. * * Pressure pulsation**
-Helmholtz resonator: Design a tuning cavity for fundamental frequency noise (such as the typical pulsation frequency of 87Hz for a 37kW fan)
-Expansion chamber design: When the volume ratio is ≥ 3:1, the pulsation amplitude can be reduced by more than 60%
2. * * Thermal protection**
-Temperature resistant structure:
-Conventional type: -30 ℃~150 ℃ (glass wool sound-absorbing layer)
-High temperature type: up to 450 ℃ (ceramic fiber+stainless steel lining)
-* * Thermal expansion compensation * *: The corrugated tube structure can absorb an axial expansion of 5mm
3. * * Protection**
-Explosion relief device: When the instantaneous pressure is greater than 1.5 times the rated pressure, the bursting disc will first rupture
-* * Condensation drainage * *: Automatic drain valve is installed at the bottom (processing capacity ≥ 0.5L/min)
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**3、 System level synergy effect**
1. * * Energy consumption optimization**
-High quality mufflers can improve overall efficiency by 2-3 (by reducing intake and exhaust resistance)
-Typical pressure loss control value:
|Operating conditions | allowable pressure drop|
|-------------|---------|
|Imported | ≤ 300Pa|
|Export | ≤ 500Pa|
2. * * Extended maintenance cycle**
-Combined use can enable:
-Extended bearing life by 30 (by reducing particle ingress)
-The oil change cycle of the gearbox has been extended from 2000 hours to 3000 hours
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**4、 Selection technical specifications**
1. Acoustic matching principle**
-The frequency of the muffler should cover 1.5 times the characteristic frequency of the fan
-Example: Three blade Roots blower with a speed of 980rpm:
```
Fundamental frequency=(980 × 3)/(60 × 2)=24.5Hz
The effective frequency band of the muffler should cover up to 36.75Hz
```
2. * * Structural integrity requirements**
-Vibration tolerance: 4.5mm/s (compliant with ISO10816-3 standard)
-Blasting pressure: ≥ 2 times the working pressure (ASME Sec.VIII requirement)
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**5、 Innovative technology application**
1. * * Intelligent noise reduction system**
-Real time acoustic monitoring: built-in MEMS microphone (50-10kHz frequency response)
-Adaptive adjustment: dynamically adjust the resistance chamber volume through an electric valve
2. * * Composite function design**
-Integrated noise reduction and heat exchange: By utilizing cooling water from the shell side, the exhaust temperature can be reduced by 30 ℃
-Modular quick release structure: filter replacement can be completed within 15 minutes (patented buckle design)
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**6、 Industry application differences**
|Industry | Key points of imported mufflers | Key points of exported mufflers|
|------------|--------------------------------|--------------------------------|
|Wastewater treatment | Moisture proof design (IP55 protection) | Hydrogen sulfide corrosion resistance (316L stainless steel)|
|Pneumatic conveying | Wear resistant lining (ceramic coating 3mm) | Anti static design (surface resistance<10 Ω)|
|Food and Medicine | Aseptic Structure (Steamable) | Zero Dead Angle Design (Meets FDA Certification)|
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**7、 Maintain technical indicators**
1. * * Performance degradation warning**
-When the pressure difference increases to twice the initial value (such as inlet>600Pa)
-When the insertion loss is reduced by more than 3dB (sound absorbing material needs to be replaced)
2. * * Key maintenance nodes**
-Every 3 months: Check the integrity of the filter screen (damage rate<5)
-Every 2 years: Replace the sound-absorbing material (if the density changes by more than 15, it needs to be replaced)
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By scientifically configuring the inlet and outlet silencers, the noise of the Roots blower system can be controlled below 85dB (A) (measured at a distance of 1m from the equipment), while improving the overall operational efficiency of the equipment. It is recommended to use CFD simulation to assist in design, ensuring a balance between airflow organization and acoustic performance.
