Papers by Keyword: Drying Process

Abstract: The determination of drying period, compressive strength, and air-dry density represent crucial parameters for assessing the quality and performance of earthen construction materials. This paper explores the possibilities of using the ultrasonic method as a non-destructive testing technique applied to earthen materials (specimens, elements, or structures) to determine these properties. The method relies on the measurement of ultrasonic pulse velocity (UPV), which is influenced by factors such as density, elasticity, and curing process. By analyzing the propagation of ultrasonic waves through earthen samples, valuable insights can be gained regarding their drying period, compressive strength, and density. The drying period of earthen samples can be determined using the ultrasonic method by monitoring the changes in pulse velocity over time. As the moisture content decreases during the drying process, the velocity of ultrasonic waves increases due to the reduced presence of water. This allows for the estimation of the drying period without the need for time-consuming and destructive testing methods. Compressive strength is also a critical parameter in assessing the structural integrity of earthen materials. The UPV method offers a non-destructive approach to determine the compressive strength of earthen samples. This provides a valuable tool for quality control and assessment of earthen construction materials. Density is another important property that influences their performance and the UPV method can be used to determine the density of earthen materials by measuring the ultrasonic pulse velocity and analyzing its relationship with density. This non-destructive approach allows for quick and efficient estimation of the compactness and quality of earthen mixes. Overall, the ultrasonic method offers a non-destructive and efficient approach in determining the drying period, compressive strength, and density of various soil compositions. By measuring the pulse velocity and analyzing its relationship with these properties, valuable insights can be gained regarding the quality and performance of earthen construction materials. This method has the potential to significantly improve the assessment and quality control processes in earthen construction, leading to more sustainable and reliable structures associated with the earthen techniques.

Abstract: The process of silicon carbide producing (SiC) in a resistance furnace is accompanied by moisture movement in the batch. An important consideration is the accounting of moisture transfer in the preparation of the mathematical description of the process. The aim of the article is to improve the existing model of heat and mass transfer in SiC production.

Abstract: The collapse of high aspect ratio features is a daunting challenge facing the semiconductor industry. The complex physics and dynamics that govern this process are not entirely understood. Through the use of optical video imaging we have observed pattern collapse in real time. It was found that the liquid meniscus reconfigures itself laterally along the length of the structure as opposed to the expected top-to-bottom drying. Herein, we report on our observations and the physics of drying high aspect ratio structures.

Abstract: The work focuses on an important scientific problem of modeling thermal processes of thermal technology, which are complicated with non-isothermal chemical reactions during the thermal preparation of raw materials in a dense layer. A mathematical model is presented for heat and mass transfer in a dense layer. The firing phosphate pellets parameters analysis calculated according to the model and performed on a kiln machinery in the scheduled mode was conducted. The features of the course of processes of drying, agglomeration and dissociation of carbonates in the pellets are revealed at their heat treatment. The received results, allow defining the temperature and gas dynamic condition of roasting the pellets for achievement of the required moisture content, necessary extent of dissociation of carbonates and the acceptable durability.

Abstract: Using cement kiln dispose sludge from sewage plants can achieve the sludge stabilization, harmless, reduction and resource comprehensive utilization purposes. This is Not only to solve the problem of sludge treatment which is difficult to solve by sewage treatment plant, but also to make full use of the sewage treatment plant sludge to replace part of cement clinker production materials. And it makes full use of sludge incineration emitted in the process of low calorific value. Municipal sludge contains more moisture. It is necessary to dry the sludge outside the kiln before entering kiln process. As cement kiln co-processing, it should be combined with the characteristics of NSP clinker production, it is necessary to not only consider the total energy consumption of the drying process, but also the re-use of dried sludge heat value, as well as consider the total of water into the kiln by drying sludge affecting the whole clinker production process. In this paper, with the initial solid content 20%, dry heating value 3400 cal/g sludge as a research object, the moisture morphology, thermal characteristics, drying technological parameters and composition of water after drying in sludge were analysed. This issue combines sludge drying with cement kiln disposal, which can not only solve the heat and odor problem during the individual sludge drying process, but also provide a theoretical basis for cement kilns co-disposal of municipal sewage sludge to achieve the purposes of sludge stabilization, harmless, minimization and resource utilization.

Abstract: The presented article deals with the influence of the drying process on the micro-mechanical properties of the composite middle lamella. The purpose of the composite middle lamella is to connecti individual cells. Micromechanical properties were obtained using nanoindentation and directly continuous stiffness measurement technique. Indentation modulus of tested samples was 11.45 GPa for natural dried wood and 12.51 GPa for artificial dried wood.

Abstract: The effect of drying temperatures on the quality of dried Mopan persimmon was studied in this paper. The drying temperatures were selected at 50℃, 55℃and 60℃ respectively. The moisture content, soluble tannin content, total sugar content and total acid content were determined for evaluating the quality of dried samples. The result showed that the drying temperature at 55℃ was the optimal temperature for drying Mopan persimmons. Under the condition, the drying process took for 92 hrs, the final moisture content was 33.71%, the soluble tannin content was 3.02%, the total sugar content and total acid content were 4.83% and 0.24% respectively.

Abstract: In order to describe the internal moisture rate and to take all different mechanisms of moisture movement into account, it is suitable to use effective diffusivity as a measure of moisture rate, irrespectively of the mechanisms really involved. This means that all different mechanisms and driving forces for internal moisture transport are lumped together and introduced into effective moisture diffusivity. Hence, diffusion equations are retained and reused with the effective diffusivity coefficient as a measuring parameter of internal moisture ratio. In our previous studies we have presented the calculation method which assumed constant diffusivity. The next goal was to estimate effective diffusivity at various moisture contents, in a real case of non-linear drying curves, and to predict drying kinetic. In our last study we have developed a model for determination of the variable effective diffusivity and identification of the exact transition points between possible drying mechanisms. In this paper we have tried to develop more accurate tool for determination of time dependent effective moisture diffusivity. An analytical model and computing procedure were developed to evaluate mass transfer properties and describe drying kinetic of clay tiles having less clay fraction. The proposed procedure was validated with experimental drying data. Presented results have demonstrated that the proposed dying model can be applied for the accurate description of experimental drying kinetics and a reliable estimation of effective diffusivity.

Abstract: Gelcasting is a widely
used method for manufacturing ceramic components. Currently the research on drying process is limited to qualitative analysis for drying process. In order to reveal the mechanism of the gelcast bisque’s drying process, the one-dimensional dynamics model for drying process has been formulated, based on the microscopic quantitative description of the evaporation process and mass transferring process through the gelcast bisque. Then the model has been modified with the consideration of the capillarity effect and the bisque’s drying shrinkage influence. By comparing with the experimental results the one-dimensional dynamic model of drying process can be proved to accurately describe the bisque’s drying process.

Abstract: This paper represents the upgrade of our previous study in which we have presented a model for simulation of the drying kinetic and estimation of the effective moisture diffusivity of clay tiles using a constant diffusivity model. The main objective of this study is to determine the time - dependent effective moisture diffusivity of shrinkable clay tiles. Experimental investigations were carried out, on clay tiles, in a laboratory recirculation dryer in which drying parameters (humidity, temperature, and velocity) could be programmed, controlled and monitored during drying. Results presented in this study have shown that the proposed drying model describes and correlates accurately drying kinetics and gives a reliably estimation of the time - dependent effective moisture diffusivity.