Implementation And Applications Of Liquid Permeability Evaluation Method Of Porous Metal Material

Porous metal material is a kind of special metal material, which consists of metal frames and pores. It is widely used for filtering, separating, absorbing sound, distributing gas, exchanging heat and so on in aeronautics and astronautics, atomic energy, petrochemical industry, metallurgy industry, environment protection industry and so on. The most uses of porous metal material are filtering and separating. Liquid permeability is the most important quality index in filtration and separation for porous metal media, which can provide reference for selection, design of filter and filtration process. At present, flow rate—pressure drop curves have been used for evaluating liquid permeability on porous materials in overseas but in domestic. It is not necessary to take fluid state into account for this kind of evaluation method which can actually reflect the liquid permeability on porous materials. Comparing with characterizing relative permeability coefficient, this evaluation method is more visual, more simple and more accurate, so for evaluating liquid permeability on porous materials this method in future will be adopted. In order to have a liquid permeability unified technical index at home and abroad and improve international competitiveness of domestic porous materials, State Key Laboratory of porous metals materials proposed this subject. Implementing this subject, water permeability test platform on porous materials had been made, by which flow rate-pressure drop curves can be plotted. Moreover, because it is used to use the relative permeability coefficient for engineering large application fields, a function for calculating relative permeability coefficient was designed for the test platform. By controlling flow rate with overflow valve, the measurement rang of test platform had reached 0.006～3m~3/h, which is suitable for almost all kinds of common porous metal material. By designing software, the flow rate-pressure drop curves in rectangular coordinate system and dual-logarithm coordinates system can be plotted and the relative permeability coefficients calculated. By means of designing three sets of clamps, the test platform met the requirement of measurement for common porous metal material and had higher measurement efficiency. Drying samples before measurement, the measuring repeatability comes to well enough. Forcheimar formula was used to check rationality of flow rate-pressure curves. The result showed that flow rate—pressure curve could actually reflect the change of flow rate with pressure drop.Flow rate—pressure drop curves of powder porous metals, fiber porous metal and mesh porous metals were measured by the test platform. After processing flow rate and pressure drop data by origin software, the new flow rate—pressure drop regression curves could provided reference for making permeable metal porous material and filter application. In this paper, the changing rule of liquid permeability of three kinds of porous metals with porosity was obtained. The relations between relative gas permeability and relative water permeability were obtained in statistics, which the customers can understand water permeability from gas permeability. The relations between relative gas permeability and relative water permeability is:K_气=80.5×K_水+97.3...