A New Solution for Energy Saving in Wastewater Treatment Plants: Technical Advantages and Applicatio

Energy conservation and consumption reduction have always been important goals in wastewater treatment plant operations. In addition to optimizing treatment processes, selecting energy-efficient mechanical equipment is equally important. Among all equipment, blowers used in aeration systems are one of the major energy consumers and play a critical role in energy-saving upgrades.

Traditional Roots blowers and multistage centrifugal blowers are widely used. However, they generally have disadvantages such as mechanical friction losses, high noise levels, and considerable maintenance requirements. With technological advancements, air suspension centrifugal blowers and magnetic bearing centrifugal blowers have gradually become new options for energy-efficient upgrades in the wastewater treatment industry. This article focuses on air suspension centrifugal blowers.

1. What Is an Air Suspension Centrifugal Blower?

An air suspension centrifugal blower is a high-speed centrifugal blower that uses aerodynamic foil bearing technology. When the rotor rotates at high speed, a high-pressure air film forms between the rotor and the bearing foils through aerodynamic pressure effects. This allows the rotor to operate in a suspended, non-contact state.

In wastewater treatment plants, these blowers are mainly used to supply air to biological aeration tanks, providing oxygen for aerobic microorganisms and promoting the degradation of organic pollutants. Aeration can also facilitate the oxidation of substances such as iron and manganese and help remove gases such as carbon dioxide and hydrogen sulfide, depending on the treatment process.

2. Main Components and Technical Advantages

An air suspension centrifugal blower mainly consists of a centrifugal impeller, air foil bearings, a high-speed permanent magnet synchronous motor, a variable frequency drive (VFD), and an intelligent control system. Air foil bearing technology and high-speed motor control technology are its core technologies.

Compared with traditional blowers, its main advantages include:

1. High Energy Efficiency

The high-speed permanent magnet motor and air suspension bearings reduce mechanical contact friction and transmission losses. Combined with variable-speed control, the blower can adjust airflow according to the actual oxygen demand of the biological treatment system, helping avoid energy waste caused by excessive aeration.

2. Low Noise and Compact Design

The integrated structure is compact, requires less installation space, and is relatively easy to install. Non-contact operation reduces mechanical friction and vibration. Together with an acoustic enclosure, it helps lower operating noise and improve the working environment in blower rooms.

3. Intelligent Control

The blower generally integrates a variable frequency drive and intelligent control system. It can monitor operating parameters such as motor speed, outlet pressure, airflow, temperature, and power consumption in real time. It can also be connected to the wastewater treatment plant's central control system for remote monitoring and automatic adjustment.

4. Easy Maintenance and Lower Operating Costs

The motor and impeller are directly connected, eliminating the need for a speed-increasing gearbox and conventional lubrication oil system. This reduces mechanical transmission components and lubrication maintenance requirements, helping lower routine maintenance workloads and operating costs.

5. Flexible Airflow Adjustment

Variable-speed control allows airflow to be adjusted according to changes in influent flow, water quality, and dissolved oxygen levels in biological tanks. This helps match air supply with actual aeration demand and improves overall system efficiency.

3. Application Case in a Wastewater Treatment Plant

After completing an upgrading and expansion project, a wastewater treatment plant adopted an A/A/O-MBR process. Its existing Roots blowers could no longer meet the increased aeration requirements.

The plant originally had three Roots blowers operating in a two-duty, one-standby configuration. After nearly nine years of operation, their performance had gradually deteriorated. Two blowers were required to operate simultaneously under normal conditions. Motor temperatures could reach approximately 100°C, causing lubricant deterioration and increasing equipment failures and maintenance frequency.

In addition, the noise level in the blower room was approximately 110 dB, significantly affecting the working environment.

To ensure stable biological treatment while reducing energy consumption and noise, the plant replaced the existing Roots blowers with air suspension centrifugal blowers in a one-duty, one-standby configuration. Airflow was adjusted according to actual wastewater flow, water quality, and aeration requirements.

The upgrade achieved several improvements:

First, fewer blowers were required. Previously, two Roots blowers were needed to meet aeration demand. After the upgrade, one air suspension centrifugal blower was sufficient under the corresponding operating conditions.

Second, noise levels were significantly reduced. With air suspension bearing technology and acoustic enclosures, blower room noise decreased from approximately 110 dB to below 70 dB, considerably improving the working environment.

Third, energy savings were achieved. Under relatively stable wastewater treatment capacity and water quality conditions, the upgraded air suspension centrifugal blower achieved approximately 20% energy savings compared with the original Roots blowers.

Fourth, effluent quality remained stable. Although the aeration system operating mode changed, the effluent quality showed no significant variation and continued to meet treatment requirements.

4. Conclusion

As the wastewater treatment industry moves toward green, low-carbon, and intelligent operations, aeration system upgrades have become an important way to reduce operating costs.

With advantages such as high energy efficiency, low noise, easy maintenance, and intelligent control, air suspension centrifugal blowers offer a new option for replacing traditional blower equipment.

However, equipment selection should not rely solely on energy-saving specifications. Actual airflow and pressure requirements, operating loads, and standby capacity must also be considered.

Only by combining high-efficiency equipment with scientific operation and management can wastewater treatment plants fully realize energy-saving benefits and achieve greener, more economical, and sustainable development.

Air Suspension Centrifugal Blower information

Web: http://www.greentechblower.com  (Group Web)  ‖  http://www.zqblower.cn  (Chinese)  ‖ http://www.ringblower.cn/ (Ring blower)  ‖  http://www.china-blower.com  (Roots Blower)  ‖  https://www.zibovacuumpump.com(Vacuum Pump)