Cellular Glass Manufactured by Microwave Irradiation of Residual Glass, Eggshell and Borax

The paper presents an improved method of manufacturing cellular glass using residual glass (91 %), sodium borate (5 %), eggshell waste (4 %) and added water (9 %). Compared to methods using eggshell as an expanding agent producing cellular glass with low compression strength, the technique adopted by the authors is original by the addition of sodium borate, which contributes to increasing the compression strength and the use of the unconventional electromagnetic wave heating method, which ensures very economical specific energy consumption. The optimal variant of cellular glass had the following characteristics: density of 0.40 g/cm3, porosity of 81 %, heat conductivity of 0.086 W/m·K, compression strength of 4.3 MPa and the cell dimension between 0.3-0.9 mm. The specific energy consumption of the process was 0.80 kWh/kg. The product has adequate features for using as a heat insulation material under conditions of quite high mechanical loading.

Research and Application for In Situ Blend of Infrared Opacifiers Titanium Oxide in Silica Aerogel

As its much lower thermal conductivity than other usual materials, Silica aerogel is a potentially efficient heat insulation material with the lowest bulk density. However, it is transparent for infrared light when used in high temperature. Herein, titanium oxide was added in the silica aerogel by in-situ blending. The dispersion property of titanium oxide particles, microstructure mechanical property, thermal conductivity, and thermal insulation were investigated. The results of this in-situ blending process indicated a potential application value in aerospace thermal protection industry.

The Prediction of Drying Uniformity in Dryer Chamber System Using Computational Fluid Dynamics (CFD)

The Dryer Chamber System is the most commonly used one because of its simple and economical design. The present article reviews the process of drying a heat insulation material, manufactured in a flat form with various thicknesses. The flat material is arranged on pallets with a distance between each other. The disadvantage of this Dryer Chamber System is the non-uniformity in the moisture distribution in the final product due to the poor organization of the airflow in the dryer chamber. The goal of this study is to analyze the conditions for improving the uniformity of drying in the currently existing Dryer Chamber System for heat insulation materials. The factors influencing the uniformity of the humidity of the material at the outlet of the dryer are studied: the way the air moves around the material and the distribution of its speed as well as the method of its supply. The influence of the situation of the material in the drying chamber on these factors was studied. The method of computational fluid dynamics (CFD) was used to determine the velocity distribution. As a result of the numerical simulation, a scheme for organizing the space of the drying chamber has been proposed, with which to improve the distribution of the speed field. An experiment was performed to verify the results of the simulations. The performed analyzes show that the proposed scheme for improving the organization of the air movement in the drying chamber leads to the improvement of the uniformity of drying of the material.

SAWMILCOBETONE ON NON-CEMENT COMPOSITE BINDER

The role and advantages of products based on a non-cement binder using wood waste compared to other types of materials and technologies are considered. The purpose of this work was to obtain a heat insulation material based on wood processing waste and non-cement binder. The cement-free binder material using sawdust as an aggregate is effective under real-world production conditions.