The roots blower previously used in Shanxi Yicheng Sewage Treatment Plant has high operating energy consumption, heavy daily maintenance workload, high noise, inconvenient flow regulation, and with the increase of service life, the performance of the blower has decreased significantly, and the aeration volume can no longer meet the treatment requirements. The original 3 Roots blowers will be upgraded and replaced with magnetic suspension centrifugal blowers of MagnetoValley Technology.

The nameplate parameters and actual operating parameters of roots blower are shown in the following table:

According to the site survey, the depth of the on-site sewage pool is 5.5m, and the actual water depth is 5m. According to the survey of the on-site sewage situation, the daily required air volume of the fan is 60-90 m ³/ Min, normally start one Roots blower to meet the working conditions, and start two when the air volume demand is large.

According to the working conditions, one CG-B105 maglev centrifugal blower of Cigu Technology can be used for daily use. The specific parameters are as follows:

（CG/B105磁悬浮离心式鼓风机性能曲线图）

To sum up, under the same operating conditions, compared with a single Roots blower, the single maglev centrifugal blower of Cigu Technology can save 30.2 kWh of electricity, with a power saving rate of about 29%. The annual power saving of one machine is 259720 kWh (8600 h/year), and the annual power saving income is 168818 yuan (0.65 yuan/kWh). The actual operation of the magnetic suspension fan can be adjusted in real time according to the site conditions, and the actual power saving rate is better.

(1) Energy saving and high efficiency: the high-speed motor and impeller are directly coupled and driven, friction-free, realizing high speed stepless speed regulation, saving more than 30% energy than the traditional Roots blower.

(2) Low noise: magnetic bearing adopts self-balancing technology, and its vibration is one order of magnitude smaller than traditional bearing; Active damping design, stable operation, low body vibration, and fan noise of about 80dB.

(3) It can realize intelligent control: it can monitor the operation status of the fan in real time, and realize intelligent regulation and manual regulation and multi-mode control of air volume, air pressure, speed, etc; "Cigu Cloud" realizes remote maintenance and debugging.

(4) Maintenance-free: the magnetic suspension blower is friction-free, 100% oil-free and maintenance-free. Only the filter cotton and filter must be replaced.

Due to the excellent performance of the magnetic suspension centrifugal blower, the operation cost has been significantly reduced and the system stability has been improved. At present, it has been widely used in hundreds of municipal projects such as Beikong Water, China Water, Shenzhen Water, Tongfang Water, Nanjing Water Group, Chongqing Kangda Water, Gaoke Water, Jining Water and so on. Since the establishment of Cigu Technology in 2006, thousands of maglev blowers have been used in the country and some overseas countries and regions with high efficiency and energy saving, and continue to reduce costs and increase efficiency for customers in various industries, which has been highly praised by users and industry experts.