Proper aeration and fan selection are the two most important considerations in sewage treatment plants.Aeration energy consumption at wastewater treatment plants typically consumes 60％ of all electrical usage.Blowers can offset some of the energy requirements.To ensure the most effective results, we can help you select the proper size, type and layout of blower equipment.
Blower of basic knowledge
The blower produces air flow （speed）.The total blower system creates pressure （back pressure） through resistance to air flow.By combining flow rate and back pressure, you can identify the actual working airflow. When the pressure in the manifold is just enough to overcome the static pressure, the optimal energy use can be achieved. Because many sewage plant operators tend to set pressure points too high, too much blower pressure will occur – which wastes electricity.
Main Components of Blower System
Generators and Engines
Valves and accessories
Instruments and switches
Control and tools
While the purpose of the blower is to create additional air flow, the purpose of blower controls is to provide the correct air flow at any time, which in turn provides enhanced aeration efficiency. In addition to matching the air flow with the existing requirements in the most efficient way, the blower control system monitors and further adjusts, such as running the minimum number of machines and operating them within their optimal efficiency range.
Providing for the correct oxygen level at any moment requires automatic flow adjustments.Therefore, the fan system must be the most effective, stable and adaptable to the changing conditions. Various solutions can address these fluctuations, including throttling suction, adjusting speed to drive or circulate different blowers.
Some aeration systems allow each blower to circulate for different lengths of time and use the oxygen retention capacity of wastewater to regulate oxygen feed.
The overall goal is to offer adaptive oxygen supply at an affordable energy cost.
Air flow efficiency
Proper air supply is critical to various functions in wastewater treatment facility:
1.Keep bacterial suspension
3.Supplies sufficient oxygen transfer for BOD removal and nitrification
The essential function of an aeration control system is to fulfill oxygen demands and maintain the treatment process at the lowest possible costs.A common measurement of proper air flow for the treatment process is to check the DO （Dissolved Oxygen） Concentration.Finding the correct level is a key step in optimizing the efficiency of your Aeration System.
Too low – too low DO concentration does not provide sufficient process performance and promote unnecessary biological development
Excessive-excessive dissolved oxygen concentration may hinder normal stability, promote the growth of unwanted microorganisms, lead to “oxygen poisoning“ and waste power.
Consideration of bolwer Energy Efficiency
Matching of blower air flow to process requirements
Optimize the blower to operate in the most efficient range
Run the minimum number of blower （closed blower does not consume energy）
Minimize system discharge pressure and inlet losses
Provide flexibility and adequate turndown for loading variations
Avoid idling operation and air loss
Arrange fan operation to maximize service life and maintenance interval
For wastewater treatment plants that use different submersion depths, it may be more beneficial to use separate blowers for the various depths of aeration.