Porous Refractory Ceramics for High-Temperature Thermal Insulation - Part 1: The Science Behind Energy Saving

2021 ◽  
Vol 70 (3) ◽  
pp. 38-45
Author(s):  
Rafael Salomão ◽  
Katherine S. Oliveira ◽  
Leandro Fernandes ◽  
Paulo Tiba ◽  
Ulisses S. Prado
Author(s):  
D. R. Clarke ◽  
G. Thomas

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.


Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 588
Author(s):  
Eiji Kamio ◽  
Hiroki Kurisu ◽  
Tomoki Takahashi ◽  
Atsushi Matsuoka ◽  
Tomohisa Yoshioka ◽  
...  

Forward osmosis (FO) membrane process is expected to realize energy-saving seawater desalination. To this end, energy-saving water recovery from a draw solution (DS) and effective DS regeneration are essential. Recently, thermo-responsive DSs have been developed to realize energy-saving water recovery and DS regeneration. We previously reported that high-temperature reverse osmosis (RO) treatment was effective in recovering water from a thermo-responsive ionic liquid (IL)-based DS. In this study, to confirm the advantages of the high-temperature RO operation, thermo-sensitive IL-based DS was treated by an RO membrane at temperatures higher than the lower critical solution temperature (LCST) of the DS. Tetrabutylammonium 2,4,6-trimethylbenznenesulfonate ([N4444][TMBS]) with an LCST of 58 °C was used as the DS. The high-temperature RO treatment was conducted at 60 °C above the LCST using the [N4444][TMBS]-based DS-lean phase after phase separation. Because the [N4444][TMBS]-based DS has a significantly temperature-dependent osmotic pressure, the DS-lean phase can be concentrated to an osmotic pressure higher than that of seawater at room temperature (20 °C). In addition, water can be effectively recovered from the DS-lean phase until the DS concentration increased to 40 wt%, and the final DS concentration reached 70 wt%. From the results, the advantages of RO treatment of the thermo-responsive DS at temperatures higher than the LCST were confirmed.


2012 ◽  
Vol 476-478 ◽  
pp. 1589-1595
Author(s):  
Yi Ping Zhu ◽  
Xi Liao ◽  
Shu Yun Wu ◽  
Jing Luo ◽  
Yuan Jiang ◽  
...  

Based on indoor thermal environment test and questionnaire surveys, the paper studies on thermal insulation capacity and indoor thermal environment of the vernacular dwellings in Wei-he Plain of Shaanxi Province, China, and analyses their heating methods and application status. Besides, the popularity of sustainable techniques in local area has been evaluated and summarized. Moreover, the paper discusses the present problems in local indoor thermal environment and energy-saving status.


2021 ◽  
pp. 79-86
Author(s):  
V.G. Babashov ◽  
◽  
N.M. Varrik ◽  

Based on the analysis of recent publications of scientific and technical literature, data on the production of zirconium oxide fibers used for the manufacture of high-temperature thermal insulation materials are presented. Information is provided on various methods of obtaining zirconium oxide fibers (methods of impregnation of the template and molding of the mixture, sol-gel method of spinning a fiber-forming precursor solution), as well as on the technique of fiber molding (manual pulling, dry and wet spinning, blowing and electrospinning). The use of such fibers for the production of thermal insulation materials (felts, cords and blocks) instead of currently existing materials made of aluminum oxide-based fibers can significantly increase the operating temperatures of the thermal protection systems.


Author(s):  
Mariana E. Ghica ◽  
Cláudio M. R. Almeida ◽  
Laura S. D. Rebelo ◽  
Gabriel C. Cathoud-Pinheiro ◽  
Benilde F. O. Costa ◽  
...  

2018 ◽  
Vol 140 ◽  
pp. 376-386 ◽  
Author(s):  
Haoyuan Ren ◽  
Dafang Wu ◽  
Junning Li ◽  
Wenjun Wu

2016 ◽  
Vol 35 (2) ◽  
pp. 195-200 ◽  
Author(s):  
Ling-zhi Yang ◽  
Rong Zhu ◽  
Guo-hong Ma

AbstractAs a large number of energy was taken away by the high temperature furnace gas during the EAF smelting process, a huge economic and environmental benefits would obtained to recycle and utilize. In this paper, the energy of the EAF was analyzed theoretically with the hot metal ratio of 50%. Combined with the utilization of the gas waste heat during the scrap preheating, electricity generation, production of steam and production of coal gas processes, the effect of the energy saving and emission was calculated with comprehensive utilization of the high temperature furnace gas. An optimal scheme for utilization of the waste heat was proposed based on the calculation. The results show that the best way for energy saving and carbon reduction is the production of coal gas, while the optimal scheme for waste heat utilization is combined the production of coal gas with the scrap preheating, which will save 170 kWh/t of energy and decrease 57.88 kg/t of carbon emission. As hot metal ratio in EAF steelmaking is often more than 50%, which will produce more EAF gas waste heat, optimizing EAF gas waste heat utilization will have more obvious effect on energy saving and emission reduction.


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