Experimental Study And Optimization Of Structural Components Of Fan Filter Units

Along with development of science and technology, Production of Microelectronics, pharmaceutical, biotechnology and other industries require production, miniaturization.While manufacturing process require better production process which also promote the rapid development of clean technologies. Over the last decade, because of construction and installation convenience, space saving, vacuum sealing, etc, Fan Filter Unis(referred to FFU) has been used widely in clean room. However, there is a big difference in terms of aerodynamic performance, power consumption and noise between different products of FFU on the market. Because performance difference of FFU is caused by different internal structure, therefore, to improve the performance of FFU, the research of internal structure shall be considered first. At present, some scholars have made some experimental research of structural components of different FFU, but there is the lack of simulation and optimization of FFU internal flow field through CFD software.In order to evaluate and research the performance of FFU products, this paper test the performance parameters of FFU by FFU Performance Test Bench. First, uniformity of the air supply of different modulus FFU are compared, then aerodynamic performance of variety of FFU are tested, then the rotational speed and bezel forms impact of FFU performance is studied. Comparative results indicate that there is huge differences between different FFU. Single FFU is significantly affected by structural components.To improve the diversion effect of airflow which leaving the fan and flow to the lower plenum inside the FFU, According to the centrifugal fan volute design method, the constant cross-sectional of its diffuser outlet is designed to avoid swils and reflux caused by ordinary snail-shaped flow path. After carrying out CFD simulation of modeling, comparison results show that, the performance of 45o tongue disposement of snail shaper flow path is optimal, which has a high static pressure and total pressure efficiency under the same frontal velocity. Then the structural parameters of centrifugal impeller is changed and simulated. Comparison results show that increasing the the number of blades to 11, changing the entry angle of 15o can improve the aerodynamic performance and total pressure efficiency.To reduce production costs and production cycle of the centrifugal impeller. This paper study the plaster casting of centrifugal impeller. Simulation by ProCast shows that bottom gating system with riser can complete filling. Based on four factors and three levels orthogonal test, The best process parameters is pouring temperature of 690℃,cast iron temperature of 130℃, pouring speed of 1.0m?s-1, plaster mold preheat temperature of 200℃.