Project Background

Experimental project for AOA process renovation of two oxidation ditches in the north and south of a sewage treatment plant in Jiaxing, Zhejiang Province. As the first AOA process transformation test project in Zhejiang Province with a processing capacity of 40000 tons per day, it is also a core demonstration project for the technical transformation of the factory area.

The key part of this project - the supply of core mixing equipment - is undertaken by Chuanneng Carbon and. With its professional knowledge and technical strength in the field of environmental protection equipment, Chuanneng Carbon provides a solid guarantee for the successful implementation of the project, helps to improve the efficiency and quality of sewage treatment, and promotes the development of environmental protection.

Problem Analysis

Faced with the challenges brought by the super large structure of the north-south double ditch (with a single ditch size of 80.5m × 43.25m × 4.9m), such as incomplete flow field coverage caused by the ultra long ditch width, sludge deposition, interruption of flow connection, and fluctuations in nitrogen and phosphorus removal efficiency.

Solution

The technical team utilizes advanced flow field simulation technology to iteratively calculate and optimize impeller parameters based on process characteristics and mixing intensity requirements, ensuring the overall mixing effect of the flow field. Finally, 14 MJN full flow mixing systems were customized, achieving stable operation of the AOA process renovation project.

Flow field simulation

Technical Features

Adopting variable cross-section and variable twist angle blade design, axial flow mixing design ensures uniform flow field and covers the entire length of the oxidation ditch (single unit service range of 3-20m, 14 units linked to achieve no dead angle mixing), solving the problem of local settlement. Three dimensional modeling of propeller blades, formed by cold pressing in one go, for more stable mixing.

7 units of 5.5kW: installed in anaerobic section, anaerobic/aerobic section, and anoxic section respectively

7 units of 2.2kW: installed in anaerobic section, anaerobic/aerobic section, and aerobic/anoxic section respectively

Both types of equipment are designed with motors installed above the liquid level, without the need for bottom bearings and maintenance free underwater. The equipment adopts a high-strength double support frame, which increases the stability and service life of the equipment.

Mixing effect