The following is a detailed technical guide for the 7.5kW Roots blower, covering the entire process of parameters, selection, application, and maintenance:
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**1、 Core parameters of 7.5kW Roots blower**
|* * Parameter Item * * | * * Standard Range * * | * * Explanation * *|
|------------------|----------------------|--------------------------|
|* * Model Example * * | -80/100/125 | Number represents imported caliber (mm)|
|* * Airflow * * | 3.5-8.5m3/min | Depending on pressure (see table below)|
|* * Rated pressure * * | 0.02-0.06MPa | Commonly used for aquatic products is 0.03MPa, pneumatic conveying is 0.05MPa|
|* * Speed * * | 1450rpm (4-pole motor) | Variable frequency control adjustable to 800-1800rpm|
|* * Noise * * | 75-85dB (A) (with muffler) | 90-100dB without muffler|
|* * Weight * * | 250-350kg | Cast iron body, heavy-duty design|
---
**2、 Selection and Adaptation Table**
**1. Airflow output under different pressures**
|Pressure (MPa) | Airflow (m3/min) | Applicable scenarios|
|----------------|----------------|------------------------|
|0.02 | 7.5-8.5 | Shallow water oxygenation (1-1.5m)|
|0.04 | 5.0-6.0 | Deep water aquaculture/pneumatic conveying|
|0.06 | 3.5-4.5 | High pressure transmission (short distance)|
**2. Coverage area calculation (aquatic)**
-* * Formula * *:
\[
Breeding area (mu)=\ frac {actual air volume} {1-1.5m3/min · mu}
\]
-Example: Airflow of 6m3/min → Can cover 4-6 acres (water depth of 2m)
**3. Pneumatic conveying capacity**
|* * Material * * | Conveying distance | Pipeline diameter | Remarks|
|----------------|----------|----------|-----------------------|
|Flour/feed powder | ≤ 40m | DN80 | Requires cyclone separator|
|Plastic pellets | ≤ 25m | DN100 | Recommended pressure 0.05MPa|
---
**3、 Typical system configuration**
**1. Aquatic oxygenation plan**
-* * Host * *: 7.5kW Three leaf Roots blower (-100)
-* * Attachment * *:
-Silencer (1 inlet/1 outlet)
-Check valve (DN100)+pressure gauge (0-0.1MPa)
-Aeration pipeline network:
-Nano tubes (Φ 12mm) or aeration discs (Φ 250mm, 4-6 per acre)
**2. Pneumatic conveying scheme**
```plaintext
Fan → Rotating feeder → DN100 wear-resistant pipeline → Cyclone separator
↓
Bag filter (emission ≤ 20mg/m3)
```
---
**4、 Operation and maintenance**
**1. Daily inspection items**
-Oil level (at 1/2-2/3 of the window)
-Pressure gauge reading (≤ 0.06MPa)
-Abnormal noise/vibration (no numbness when touching the shell by hand)
**2. Regular maintenance schedule**
|* * Project * * | Cycle | Operating Standards | Consumables/Tools|
|----------------|----------|------------------------|--------------------|
|Air filter | Weekly | Compressed air blowback | Air pressure gun|
|Gear oil replacement | First 500 hours, last 3000 hours | ISO VG220, draining old oil | Oil pump+waste oil drum|
|Belt adjustment | monthly | deflection 10-12mm/10kg pressure | tension meter|
|Rotor clearance detection | Annual | Gauge measurement ≤ 0.20mm | Gauge (0.02-1.00mm)|
---
**5、 Quick Troubleshooting Checklist**
|* * Fault * * | Cause | Solution | Emergency Response|
|----------------|---------------------|------------------------|---------------------|
|Decreased air volume | clogged filter element/leaking pipeline | cleaned filter element+sealed inspection | closed faulty branch|
|Motor overheating | Voltage instability/overload | Measure three-phase voltage (± 10) | Stop immediately to cool down|
|Abnormal vibration | Loose foundation/damaged bearings | Tighten bolts or replace bearings | Add temporary shock-absorbing pads|
---
**6、 Selection Comparison Suggestions**
|* * Scenario * * | Recommended Configuration | Comparison of Alternative Solutions|
|------------------|---------------------|------------------------|
|Fish pond oxygenation | 7.5kW+nanotubes | 35% more energy-efficient than 3 3kW turbine engines|
|Feed mill conveying | 7.5kW+anti-static pipeline | 50% lower cost than screw fan|
|Small scale sewage treatment | 7.5kW+frequency converter | more resistant to impurities than centrifugal fans|
---
**7、 Economic analysis**
|* * Project * * | 7.5kW Roots blower | Comparative reference|
|----------------|---------------------|------------------------|
|Purchase cost | 15000-22000 yuan | 20% lower than the same power centrifuge|
|Operating cost | 5.25 yuan/h (0.7 yuan/kWh) | Annual electricity savings of approximately 12000 yuan (vs impeller)|
|Lifespan | 8-10 years (rotor lifespan of 5 years) | Gear oil needs to be replaced regularly|
---
**Precautions**
1. * * No idling without water * *: Manually turn and lubricate before the first start.
2. Anti corrosion requirements: SS304 stainless steel model should be selected for seawater aquaculture.
3. * * Standardization * *:
-The pneumatic conveying system must be equipped with a pressure relief valve (set to start at 0.07MPa)
-The motor junction box requires an IP55 protection level
If selection is required, please provide parameters such as gas medium, working pressure, and ambient temperature. For special gases such as biogas and corrosive gases, explosion-proof or anti-corrosion models need to be customized.
