Simulation of Drying for Multilayer Membranes

Abstract

In ceramic membrane preparation, drying variables and its phenomena are very important to ensure no defects and failures in membrane layers. Generally, ceramic membrane consists of several layer with the top structure or layers possesses a very hygroscopic zone that acting as a separator while next two layers are non hygroscopic zone. Combination of these two different multilayer systems that exhibit different properties always associated to the failure of ceramic consolidation structure during the drying and sintering process. Therefore,controlling of drying behavior is very important to ensure a consistent shrinkage exist between these two layers system. Thus in this present work, the drying process of multilayer materials was studied and observed via simulation technique. A two dimensional mathematical model that coupled mass, heat and gas transfer was employed. Finite element method was used to solve the model and numerically compute using Skyline solver to capture highly nonlinear and transient process. The results showed that drying of multilayer material for membrane structure is obviously different from drying of single layer system. Separation zone that acting as hygroscopic zone does play its roles towards effecting higher pore water pressure and gas pressure. Thus, different drying factors can be seen in the layering system. Hence, understanding those drying factors that may cause inhomogeneous shrinkage due to the existence of different porous network in membrane layers is essential to avoid ceramic membrane failure.

An overview on recent approaches on drying of natural rubber materials

“…Understanding the relationship between moisture transfer and its microstructure helps to avoid changes in the quality of products [34]. The porous model technique is used to explain moisture transport [35][36][37][38]. The basis of this method is the existence of two different regions-hygroscopic and non-hygroscopic.…”

“…The basis of this method is the existence of two different regions-hygroscopic and non-hygroscopic. According to reports, the hygroscopic zone consists exclusively of bound water [35,36]. According to research, the non-hygroscopic zone contains free liquid water that fills most of the pores of the medium and is held in place by capillary forces [34,[39][40][41].…”

A Review of the Parameters Related to the Rubber Sheets Production: Major Constituents of Rubber Latex, Rubber Particles, Particle Interaction of Rubber Latex, Rubber Porous Structure, Rubber Drying Kinetics and Energy Consumption

“…This technique is based on the existence of two different regions (nonhygroscopic and hygroscopic). For the hygroscopic region, the report of Sanavia et al, [102]; Harun et al, [103] and Goyeneche et al, [104] presented that this region was characterized by the exclusive presence of bound water. For the non-hygroscopic region, the report of the report of Harun et al, [103]; Venil et al, [105] and Chen et al, [106] presented that this region had free liquid water occupied the major portion of the pores in the medium and this water was retained by capillary forces.…”

“…For the hygroscopic region, the report of Sanavia et al, [102]; Harun et al, [103] and Goyeneche et al, [104] presented that this region was characterized by the exclusive presence of bound water. For the non-hygroscopic region, the report of the report of Harun et al, [103]; Venil et al, [105] and Chen et al, [106] presented that this region had free liquid water occupied the major portion of the pores in the medium and this water was retained by capillary forces. Note: the bound waters were adsorbed on the walls of the solid structure by EF and VWI under the form of multi-molecular layers for both regions (non-hygroscopic and hygroscopic).…”