| Title |
Evaluation of Pressurized Water Mixing of Big Pipe with CFD at Water Treatment Process |
| Authors |
조영만 ( Young-man Cho ) ; 유현철 ( Hyun-chul Yu ) ; 장경혁 ( Gyeong-hyuk Jang ) ; 정용준 ( Yong-jun Jung ) |
| DOI |
https://doi.org/10.15681/KSWE.2021.37.3.168 |
| Keywords |
Computational Fluid Dynamics; CFD; Mixing degree; Pressurized water; Water treatment process |
| Abstract |
Mixing is a very important unit in water treatment process. A mechanical stirring method is generally used for mixing, but recently, the use of pressurized water mixing method (pump diffusion flash mixer) has gained interest because it is more advantageous in terms of mixing time, noise, energy consumption, and maintenance. The following conclusions were obtained from the study of pressurized water mixing method by Computational Fluid Dynamics. Firstly, the mixing degree in the pipe increased as the density of water increased. Secondly, even if the relative velocity between flow rate in the pipe and the pressurized water was constant, the mixing degree decreased as the flow velocity in the pipe increased. Thirdly, the stronger the injection energy the higher the mixing degree. It was also found that the mixing degree was greatly affected by the injection velocity as compared to the injection flow amount. Finally, the required energy to achieve 95% mixing degree at the distance of 10 times diameter in big pipes of 500 mm to 3000 mm was 0.3 to 4.5 kJ. The result of this study could be used in the process design of injection with water purification chemicals, such as, ozone, chlorine, and coagulant. |