Efficiency of Using Different Designs of Working Wheels in the Flow Path of a Turbomolecular Vacuum Pump

The determination of optimal parameters of turbomolecular vacuum pumps is an urgent problem of the modern vacuum machine building. Since vacuum pumps are typically included in the most diverse facilities, it is necessary to estimate the influence of external conditions on the exhaust units, which undoubtedly affects the pump parameter optimization to be provided. One of the methods to resolve the problem is the reasonable formation of the flow path of a vacuum turbomolecular pump with optimal parameters of working wheels. Now the diversified designs of working wheels are known which are applied in turbomolecular vacuum pumps. They differ not only in parameters but also in operating characteristics. Therefore the application of particular types of working wheels in the created turbomolecular pumps is an important task, the results offulfillment of which will have an effect upon the efficiency ofthe pump itself. A technique is considered for choosing designs ofworking wheels in the flow path of turbomolecular vacuum pumps operating in a broad pressure range. The influence of different factors on basic parameters of turbomolecular pumps is analyzed, which will allow the pump efficiency to be increased. Recommendations on using the blade and disc wheels under various conditions of the pump operation are given. The application of the recommendations in practice will make it possible to improve main characteristics of turbomolecular vacuum pumps.

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