A Micro Vacuum Pump Based On Diffusion And Jet Pumps

With a rapid progress of micro-electro-mechanical systems, a demand for micro vacuum pump is increasing. However, the existing micro vacuum pumps can not meet the requirement of the micro-apparatus such as micro mass spectroscopy.Based on the mechanism of diffusion and eject pumps, the miniaturization of the vacuum pump has been investigated in the paper. The stricture and geometric parameters of the micro vacuum pumps were optimized using computational fluid dynamics (CFD). A small jet vacuum pump was fabricated using electric discharge machining and diffusion bonding. The performance of the micro vacuum pump was studied by a developed testing facility using the mediums of steam, oil and argon. The experimental results showed that a pressure difference of9000Pa was achieved using argon. Designed another single-stage jet pump which base on silicon materials, finished the manufacturing process designing. And a testing system has been designed.It was found that, for small or micro vaccum jet pump, the velocity at the exit of the spray increased and leveled off with an increase in the divergent angle. For the micro vacuum pump, the distance between the interior wall and spray exhibited an important influence on the velocity distribution at the exit of the pump. The properties of the medium for the micro vacuum pump obviously affected the performance of the micro vacuum pump.The above experimental results are important to the miniaturization on vacuum pumps.