**Selection and usage guide for Roots blower for aeration**
Roots blower is the core equipment of the sewage treatment aeration system, used to provide stable oxygen to the biochemical tank and promote microbial degradation of pollutants. The following are the key selection points, usage techniques, and common problem solutions for aeration applications.
---
**1、 Why choose Roots blower for aeration? **
1. * * Stable flow rate * *: not affected by pressure changes, ensuring uniform dissolved oxygen (DO).
2. * * Suitable for medium and low pressure * *: The required pressure for aeration is usually * * 19.6~58.8kPa * * (2-6 meters of water depth), which perfectly matches the performance of Roots blower.
3. Oil free design: Avoid lubricating oil contamination of activated sludge.
4. * * Easy maintenance * *: Low failure rate, suitable for 24-hour continuous operation.
---
**2、 Calculation of key parameters for selection**
**1. Determine air volume (Q)**
-* * Formula * *:
\[
Q \, (\ text {m3/min})=\ text {sewage volume} \, (\ text {m3}) \ times \ text {gas water ratio} \, (3:1 \ sim 15:1)
\]
-Example * *: 1000m3/d sewage, air to water ratio 10:1 → required air volume * * 7m3/min * *.
-* * Experience score * *:
-Ordinary activated sludge process: * * 3~5m3 air/m3 sewage * *.
-High load process (such as A/O): * * 8-15m3 air/m3 sewage * *.
**2. Calculate pressure (P)**
-* * Formula * *:
\[
P \, (\ text{kPa})=\ text{water depth} \, (\ text{m}) \ times 9.8+\ text{pipe resistance} \, (5 \ sim 10 \ text{kPa})
\]
-Example: 4 meters of water depth+pipeline resistance of 8kPa → required pressure of 47.2kPa.
**3. Matching power (kW)**
|* * Pressure (kPa) * * | * * Required power (kW/m3/min) * *|
|----------------|--------------------------|
| 19.6~29.4 | 0.15~0.25 |
| 39.2~58.8 | 0.25~0.35 |
-Example: Air volume 10m3/min @ 49kPa → Select a 30kW fan.
---
**3、 Recommended model of aeration specific Roots blower**
|* * Power (kW) * * | * Airflow (m3/min) * * | * * Applicable water depth * * | * * Typical model * *|
|--------------|------------------|-------------|-------------------|
|7.5 | 3~8 | 2~3 meters | JG-SR50, -50|
|15 | 8~15 | 3~4 meters | JG-SR80, BST-100|
|22 | 15~25 | 4~5 meters | JG-SR125, -125|
|37 | 25~40 | 5~6 meters | JG-SR150, BST-200|
---
**4、 Design of supporting aeration system**
1. * * Fan * *: Roots blower (variable frequency control optional).
2. * * Pipeline * *: UPVC or galvanized steel pipe, designed with a flow rate of * * 10~15m/s * *.
3. * * Aerator * *:
-Micro porous aeration disc: high oxygen utilization rate (≥ 25), but prone to clogging.
-Spin mixed aerator: anti clogging, suitable for high SS wastewater.
4. * * Auxiliary equipment * *:
-Check valve: prevents sewage backflow during shutdown.
-* * Muffler * *: reduces noise to<75dB.
-* * Air filter * *: protects the fan from dust damage.
---
**5、 Key points of operation and maintenance**
**1. Energy saving techniques**
-Variable frequency control: automatically adjusts the speed according to the DO value, saving 20-40% of electricity costs.
-Regularly clean the aerator: Blockage can lead to increased pressure and energy consumption.
**2. Common problem solving**
|* * Problem * * | * * Reason * * | * * Solution * *|
|------------------|------------------------|-------------------------|
|Insufficient DO | Blockage of aerator and insufficient air volume | Clean the aerator and check the air volume of the fan|
|Fan overheating | Overpressure operation, poor cooling | Check system resistance, clean heat sink|
|* * Abnormal vibration * * | Unbalanced impeller, loose foundation | Re calibrate impeller, tighten bolts|
---
**6、 Roots blower vs other aeration equipment**
|* * Comparison item * * | * Roots blower * * | * * Centrifugal blower * * | * * Screw blower * *|
|----------------|----------------------|----------------------|--------------------|
|* * Applicable pressure * * | Medium and low pressure (<98kPa) | Ultra low pressure (<15kPa) | High pressure (>200kPa)|
|* * Energy consumption * * | Medium | Low (at low pressure) | High (at high pressure)|
|* * Maintenance cost * * | Low | Medium | High|
|* * Applicability of Aeration * * | ★★★★★ | ★☆ (shallow water only) | ★★★ (high energy consumption in deep water)|
---
**7、 Summary**
-* * Selection formula * *: Air volume=sewage volume x air water ratio, pressure=water depth x 9.8+pipeline resistance.
-* * Recommended model * *: Choose a Roots blower (such as JG-SR125) with a power of 15~37kW for water depths within 5 meters.
-* * Energy saving key * *: Variable frequency control+regular maintenance of aerator.
**Tip * *: If the sewage contains corrosive gases (such as HS), choose * * stainless steel material * * fan!
