For sewage treatment, Roots blower is a suitable choice. The following is a detailed analysis of its applicability:
1、 Working principle and characteristics
Roots blower belongs to the positive displacement blower and is a type of rotary blower. It uses two or three leaf shaped rotors to make relative motion inside the cylinder to transport gas. This type of fan has a simple structure, operates smoothly and reliably, has high mechanical efficiency, and is easy to maintain and upkeep. At the same time, it is insensitive to dust, droplets, and fibers contained in the transported gas, and has strong adaptability.
2、 Application in sewage treatment
1. Aeration process: Roots blower is mainly used for aeration process in sewage treatment. By providing sufficient oxygen for biochemical reactions and promoting microbial activity, the efficiency of wastewater treatment can be improved. Its stable flow output and high pressure characteristics make the sewage treatment process more reliable.
2. Capacity and pressure: Roots blowers have a wide range of applications, with volumetric flow rates typically between 0.25~80m3/min, power between 0.75~100kW, and pressures up to 20~50kPa. These parameters enable Roots blowers to meet the sewage treatment needs of different scales.
3、 Advantages and disadvantages
Advantages:
1. Simple structure, smooth and reliable operation.
2. High mechanical efficiency, easy to maintain and upkeep.
3. Not sensitive to impurities in the transported gas, with strong adaptability.
4. It performs well in situations where the resistance of the pipeline network is variable and the air volume requires basic stability.
Shortcoming:
1. The noise is relatively high and corresponding noise reduction measures need to be taken.
2. There is a disadvantage of lubricating oil leaking into the cylinder, which requires regular inspection and maintenance.
3. The air volume can only be adjusted by adjusting the speed method (but the Roots blower has a constant torque load and the speed cannot be adjusted) or the bypass vent valve method, the latter of which will cause waste. However, the Roots blower after frequency conversion transformation has higher efficiency at low and variable flow rates.
4、 Comparison with other fans
Compared to centrifugal fans, Roots blowers are cheaper in price but may be slightly less efficient. Especially when the flow rate exceeds 100m3/min, the power consumption of Roots blower is relatively high. However, Roots blowers are still widely used in small-scale municipal and factory wastewater treatment due to their stability and reliability.
In summary, Roots blowers have significant advantages and applicability in wastewater treatment. Although there are some shortcomings, through reasonable selection, maintenance, and upkeep, it can fully play its role in sewage treatment.
