Numerical Simulation And Experimental Research Of Centrifugal Filtration Process For Copper Alloy Melts Using Ceramic Foam Filters

Copper alloy is a kind of important nonferrous metal material, it is widely applied in the national defense and electric power industries. With the continuous advance of science technology and industrial production, the purity of the copper alloy have been put forward higher requirements. Ceramic foam filtration technology as an effective method to remove nonmetallic inclusions in alloy melt has been proved. When using the small aperture, large thickness foam ceramic filter to filter the smaller inclusions, but it is difficult to accomplish the filtration process, because the increased of the filtration resistance could seriously affect the filtration velocity.Ceramic foam filtration technology under the centrifugal field is a new filtration purification approach, it can make the alloy melt through the smaller cell size, larger thickness of ceramic foam filter, so as to improve the filtration efficiency and filtration velocity.In this study, Centrifugal filtration process for copper alloy melt using ceramic foam was carried out by experimental and numerical simulation methods. the influence of filtration process parameters, such as filtering temperature, centrifugal rotational speed, aperture and thickness of foam ceramic filter on the filtration efficiency were studied by experiment. Geometric structure parameters of foam ceramic were obtained by scanning electron microscope, A 3D model close to the actual structure of foam ceramics was constructed with Weaire-Phelan foam model, the change laws of filtration resistance and filtration efficiency were studied by using the numerical simulation method when the copper alloy melt at different filter parameters.Through the experimental study and numerical simulation, The main research content is as follows:(1)The results of filtration experiment and numerical simulation showed that compared with gravity filtration,centrifugal filtration by means of centrifugal force can through smaller aperture and lager thickness of foam ceramic filter,which was conductive to improve the cleanliness of copper alloy melt and filtration velocity,and then improve mechnical properties of copper alloy.(2)The result of numerical simulation showed that the structure parameters of foam ceramic is the main factor which can effect the filtration efficiency and the filtration resistance.the effect pecking order of various factors on filtration efficiency was that:aperture of foam ceramic filter>thickness of foam cetamic filter>centrifugal rotational speed>filtering temperature; the effect pecking order of various factors on filtration resistance was that: aperture of foam ceramic filter>thickness of foam cetamic filter.and to improve centrifugal rotational speed is conducive to overcome flow resistance,while to improve filtering temperature is conducive to overcome thermal resistance.(3)Weaire Phelan model is recognized as one of the most representative foam geometry model, how to accurately obtain the structural parameters of foam ceramic and Plateau border processing are the key factors to construct three-dimensional foam ceramic which basic skeleton is weaire phelan geometri model.(4)The results of numerical simulation basically agree well with filtration experiment laws,it also shows that the reasons for the deviation is not taked into account the interface behavior among the alloy melt, inclusions and ceramic foam, and scouring action of melt on captured inclusions.The result of numerical simulation has certain guiding significance to optimize Centrifugal filtration process for copper alloy melt using ceramic foam.