Optimization Of Inner Structure And The Development Of Performance Testing Apparatus For Fan-filter-unit

The fan-filter-unit (FFU) is widely used in cleaning engineering because of its so many advantages, such as simpleness of construction, flexibility of alteration, space saved and negative pressure seal. In practical applications, there are some problems existing due to lots of FFUs running at the same time. For instance, total noise level is high and the power consumption of the unit is too much, also the uniformity of air velocity at the outlet of FFU is not good enough. There are more and more FFU manufacturers, but the performance of the FFU from various manufacturers is different. Due to the lack of unified test standard, the FFUs'performances of various manufacturers are gotten in different ways. As a result, the same types of FFU from various manufacturers have different performances. And the testing method needs researched. Research scholars at home and abroad have researched and gained some information about the testing method, however, no unified test standard is formed. Furthermore, there is no standard performance testing apparatus or relative standard for FFU in the world at the moment.In the purpose of evaluate various kinds of FFU's performance, performance testing apparatus for FFU has been developed thanks to predecessors'research achievement and related standards domestic and overseas. Also the testing method is provided. The soft of FLUENT was conducted in order to research FFU's inner structure and then problems of FFU exiting now can be solved. The performances, such as air volume, air velocity at the section and overbottom pressure, of the FFU which is 1175mm long and 575mm wide has been tested. According to the real size, correct physical model was established and proper mathematical model was determined. Taking increasing air volume as to be optimization objective, numerical simulation was conducted for various baffle construction. The numerical data are compared with experimental data in good agreement.After the actual testing of FFU, the data which is obtained from the FFU performance testing apparatus is stable and reliable. Results show that baffle types affect FFU's performance greatly. The air volume of the FFU with opposite-angle baffle and quadrangle baffle is nearly unchanged. The air volume of the FFUs, including the FFU without the boards at the bottom, the FFU with inward baffle and the FFU with oblique upward baffle in the shell, increases a lot. When the same air volume is reached, the rotating speed of the three types of FFU above can be turn down and the purpose of saving electricity can come true.