Hydrocyclone design and energy requirement for treating storm water runoff from bridge

Abstract

A design methodology was proposed for the hydrocyclone used for solids separation from runoff. The design approach was validated by performing experiments on an in situ hydrocyclone with a diameter of 7.5 cm. The performance of the hydrocyclone was evaluated based on monitoring work, with the results indicating that the observed average pressure inside the collection pipe was proportional to the rainfall intensity. When the respective average observed pressure was 1.5 and 5.0 m water head, the volume fraction of underflow was estimated as 16 and 12%, respectively. The solids separation efficiency was proportional to the pressure, and it was in the range of 20–90% ,while the pressure ranged from 0.5 to 9 m water head. For the hydrocyclone in the test bed, the operation energy was directly provided by the pressure generated inside the collection pipe. In the case of the potential energy being unavailable, a pump can be applied to support the required energy. While the respective flow rates were 0.8, 2.4, and 3.6 m³/h, the total required energy was 1.7, 6.7, and 10.7 m water head, respectively.

Keywords:

• Hydrocyclone design
• Bridge runoff
• Energy requirement

Acknowledgements

The data of this paper was provided by the “Eco-star Aquatic Ecosystem Restoration Research Program” in Korea. The preparation of the this paper was supported by the Scientific Research Foundation of Nanjing University of Information Science and Technology and a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.