**Technical specifications and application guidelines for 7.5kW Roots blower**
1、 Core performance parameters
|* * Parameter Category * * | * * Standard Type * * | * * High Voltage Type * * | * * Vacuum Type * *|
|--------------------|--------------------|--------------------|--------------------|
|* * Rated power * * | 7.5kW (10HP) | 7.5kW | 7.5kW|
|* * Flow range * * | 8-35m3/min | 6-25m3/min | 10-40m3/min|
|* * Work pressure * * | 9.8-49kPa | 49-78.4kPa | -20~-40kPa|
|* * Speed * * | 1450rpm (4-pole) | 1750rpm (6-pole) | 1450rpm|
|* * Noise level * * | 75-82dB (A) | 78-85dB (A) | 72-78dB (A)|
|* * Inlet and outlet diameter * * | DN80 (3 inches) | DN65 (2.5 inches) | DN100 (4 inches)|
2、 Structural reinforcement design
1. * * High voltage version upgrade configuration**
```mermaid
graph TB
A [thickened shell] -->B [25mm wall thickness]
C [Reinforced rotor] -->D [QT600-3 material]
E [Bearing System] -->F [22315+Hydraulic Preloading]
```
2. * * Vacuum type special design**
-Double lip type air seal
-Large volume exhaust chamber
-Anti backflow automatic valve
3、 Typical application scenarios
|* * Industry * * | * * Purpose * * | * * Recommended Model * * | * * Supporting Equipment * *|
|---------------|--------------------------|-------------------|--------------------|
|Wastewater treatment | Aeration and oxygenation (water depth 3-4m) | Standard type | Micro porous aeration tube+DO instrument|
|Pneumatic conveying | Grain/plastic particle conveying | High pressure type | Cyclone separator|
|Vacuum packaging | Food production line vacuum pumping | Vacuum type | Buffer tank+filter|
|Aquaculture | Intensive fish pond oxygenation | Standard frequency conversion type | Nano aeration disc|
4、 Selection calculation template
**Case: Aeration system for medium-sized sewage treatment plant**
1. Basic conditions:
-Processing capacity: 5000m3/d
-BOD load: 200mg/L
-Water depth: 3.5m
2. Calculation process:
\[
\begin{align*}
\Text {Oxygen Demand}&=5000 \ times 0.2 \ times 1.2=1200kgO2/d\\
\Text {standard gas demand}&=\ frac {1200} {0.28 \ times 24} ≈ 178m3/h\\
\Text {Selection Result}&=2 units of 7.5kW (15m3/min), one for use and one for backup
\end{align*}
\]
5、 Energy Efficiency Management Plan
1. Energy saving effect of frequency conversion control**
|Frequency (Hz) | Flow () | Power () | Energy saving rate|
|------------|----------|----------|--------|
| 50 | 100 | 100 | - |
| 45 | 90 | 72.9 | 27.1 |
| 40 | 80 | 51.2 | 48.8 |
2. * * Thermal energy recovery system**
-Recyclable heat: ≈ 5.5kW (at oil temperature of 60 ℃)
-Recycling purpose: sludge drying/space heating
6、 Maintain standards
|* * Project * * | * * Cycle * * | * * Tools * * | * * Allowable Deviation * *|
|----------------|----------|---------------------|------------------|
|Adjustment of rotor clearance | 1 year | feeler gauge (0.02-1mm) | ± 0.05mm|
|Gear meshing inspection | 2 years | Red lead powder | Contact surface ≥ 60|
|Coupling alignment | 6 months | Laser alignment instrument | ≤ 0.05mm/m|
7、 Quick troubleshooting
1. * * Abnormal Pressure Diagnosis Tree**
```mermaid
graph TD
A [Insufficient pressure] -->B {Normal current}
B -->| Yes | C [Check for pipeline leaks]
B -->| No | D [Check rotor clearance]
C -->E [Sealing Failure]
D -->F [Gear wear]
```
2. * * Common problem handling**
|Fault Symptoms | Priority Checkpoints | Professional Tools|
|---------------|---------------------|-------------------|
|Abnormal vibration | Tightening torque of anchor bolt | Torque wrench (80N · m)|
|High oil temperature | Cooling fan speed | Infrared thermometer|
|Current fluctuation | Voltage stability | Power quality analyzer|
8、 Mainstream models in the market
|Brand | Standard Model | High Voltage Model | Vacuum Model | Reference Price|
|------------|-----------|------------|------------|------------|
|| -75 | -75H | -75V | 18000 to 25000|
|| -75 | -75G | -75Z | 22000-30000|
|| BG-7.5 | BG-7.5HP | BG-7.5V | 16000 to 22000|
9、 Selection suggestions
1. * * Conventional aeration * *: Choose standard type+variable frequency control (energy efficiency)
2. * * Dusty gas * *: optional cyclone separator+wear-resistant coating rotor
3. * * Corrosive Environment * *: Designated 316L stainless steel material (cost+35)
**Attention:**
It is strictly prohibited to operate beyond the rated pressure (valve set value 1.1 times the working pressure)
The lubricating oil must be replaced after the first 200 hours of operation
Oil viscosity should be checked daily in winter (ISO VG68)
The 7.5kW Roots blower, with its moderate power range and excellent cost-effectiveness, has become a power equipment for medium-sized environmental protection projects and industrial processes. When selecting, it is necessary to focus on verifying the matching degree between actual working pressure and flow rate. It is recommended to configure an intelligent control system to achieve energy efficiency performance.
