Computer Aided Design of a Paper Pulp Sieve

• Main Authors: Jih-Hung Chang, 張日鴻
• Other Authors: Yung-Sheng Liu
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/39332680153140554207

碩士 === 逢甲大學 === 機械工程學所 === 94 === The subject of this thesis is to improve the design of a waste paper pulp sieve so as to increase the pulp productivity and keep the sieve screen clean. Waste paper pulp sieve includes a rotor with series airfoils and a stationary screen; between them is thick waste paper pulp. Waste paper pulp is pressurized by rotor airfoils, and impurities are separated from waste paper pulp by the screen, so that fine pulp flows out of the sieve through screen. On the increasing of pulp productivity, a helical sieve mesh is to be used instead of traditional straight mesh. Then different helical angles of the sieve mesh will be analyzed to optimize pulp productivity. On the cleanness of screen, the pressure difference of the airfoil shaped rotor will be analyzed to insure the proper negative pressure at the rear part of airfoil. The algorithm employed in the thesis is computer simulation. The software used is FLUENT 6.2Ò. Computer model of rotor and the screen are built up, and the rotor rotates under 375 rpm to simulate the motion of paper pulp sieve. Fine pulp flow out of the screen will be analyzed by FLUENTÒ. The result shows that helical screen mesh opening is more productive then straight mesh opening, and the best helical angle is 25°. Most work done in this thesis is improving the paper sieve screen design. Future work might be improving the rotor design so that the rotor will regulate the pressure of waste paper pulp to be uniform from top to bottom in the sieve. The results of the improvement will be more fine pulp flowing out from screen top to bottom, cleaner screen opening, raise the productivity of conversion waste paper to fine paper pulp, and reduce the energy consumption.