Numerical Study Laminar Flow in static mixer with helical Element

• Main Authors: Teng-Chuan Lai, 賴登傳
• Other Authors: Kuo-Tung Chang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/21878619745033334365

碩士 === 明志科技大學 === 機電工程研究所 === 98 === Helical static mixer has now been widely used in the petrochemical, chemical, medical, food processing industries. Nowadays, state of the art requires more improved patterns for the actual requirements and also meets several challenges in the design of this type of mixers. This study focuses on the fluid characteristics comparison between the Kenics static mixer popularly applied in the market and the novel Tri-helical static mixer under the same laminar condition by numerical simulation, which proceeds by using a commercial package STAR-CD of computational fluid dynamics. For the mixer design, the radial speed of a fluid can improve the fluid speed gradient as well as the spiral deformation and extension of the flow. From the simulation result analysis, the radial velocity of the Kenics static mixer is lower than that of the Tri-helical static mixer, which improves about 1.2 multiples of the radial speed of the Kenics type. Meanwhile, the friction factor through the Tri-helical static mixer can cause approximately 1.24 times of the Kenics static mixer. The effect of aspect ratio of mixing element and spacing of mixing element have been investigated though numerical simulation. The radial velocity increase a AR decreases. In turns, pressure difference increase. Increase in spacing of mixing element. Mixing efficiency by 90% compared to baseline, Tri-helical static mixer more Kenics static mixer to improve the efficiency of mixing 1.1 times, proved Tri-helical static mixer and Kenics static mixer can effectively improve the flow of fluid in the static mixer blend. Keyword: Helical static mixer, Friction factor, Reynolds number(Re), Aspect ratio (AR), mixing efficiency