The single-channel Al2O3-based porous ceramic membrane tubes (PCMT) were prepared with different grain size of Al2O3 powders by extrusion molding process, combing the traditional solid-phase sintering method. The effects of raw grain size and sintering temperature on the microstructure, phase structure, density, and porosity were investigated. The results revealed that with further increase in sintering temperature, the density of porous ceramics increases, while the porosity decreases, and the pore size decreases slightly. The pore size and porosity of porous ceramics increase with the increase in raw grain size, while the density decreases. Future, in order to study the water filtration of PCMT, the effect of porosity on the pressure distribution and flow velocity different cross-sectional areas with constant feed mass flow was analyzed using Fluent 19.0. It was found that an increase in the porosity from 30% to 45% with constant feed mass flow influenced transmembrane pressure, that varied from 216.06 kPa to 42.28 kPa, while the velocity change at the outlet was not obvious. Besides, it was observed that the surface pressure is almost constant along the radial direction of the pipe, and the velocity of water in the PCMT is increasing with the decreasing of distance to the outlet. It was also verified that the porosity being 39.64%, caused transmembrane pressure reaching to 77.83 kPa and maximum velocity of 2.301 m/s. These simulation and experimental results showed that the PCMT have good potential for water filtration.
Keywords: extrusion molding process; grain size; porous Al2O3 ceramic membrane tube; sintering temperature.