13 Space heating and cooling

in the centre of the tube because of insufficient thermal feedback. The results are presented and were found to be quite different from those for conventional combustion.

97/04094 Macroscopic modelling of the reaction bonding of aluminum oxide Gaus, S. P. J. Eur. Ceram. Sot., 1997, 17, (S), 971-975. The paper presents the reaction-bonded aluminium oxide (RBAO) process, a novel method to produce monolithic alumina-base ceramics. In order to gain some insight into the process, a macroscopic model, which considers the interaction of oxygen diffusion and reaction within a porous body, has been developed. The model facilitates prediction of the effects of parameters such as heat-treatment cycle, atmosphere, and scale to a first approximation, as well as important consideration for industrial applica- tions. Thermogravimetric (TG) curves predicted by the model show reasonable agreement with experimental data and indicate that a combina- tion of reaction and diffusion controls the process.

97104095 Manufacture of ceramic from coal ash as filtering materials Ogawa, K. Jpn. Kokai Tokkyo Koho JP 09,156,998 [97,156,998] (Cl. C04B35/00), 17 Jun 1997, Appl. 951334,057, 29 Nov 1995, 5 pp. (In Japanese) Ceramic products can be manufactured with coal ash microparticles having particle size l-10 ,rm, that have been shaped and sintered. In these products, coal ash particles are bound together giving a porous micro- structure through the entire product. They are useful as filtering materials and adsorbents.

97104096 Production of ceramic building materials in Russia from anthracite tailings Siefke, C. Kernm. Z., 1997, 49, (5), 362-364, 366-367. (In German) Methods of producing thermal insulating ceramic bricks from anthracite tailings with a high C content, allowing the excess energy to be used for other purposes are reported.

97104097 Silica bricks after fifteen years in service. Critical study Zamboni, L. A. et al. lnterceram, 1997, 46, (3). 162-164, 166. Various refractory bricks were selected for examination after used 15 years of operation in coke oven batteries. The SiOz bricks at the fire side showed a mechanical and chemical resistant microstructure. The coke side showed fissures due to stress resulted from gas formation by air entrance and coal combustion, and thermal shock during operation. Its vitreous phase quality, quantity, and distribution made the coke side microstructure weak.

97104096 Sol-gel synthesis of lanthanum chromite powder. Bilger, S. et al. J. Eur. Ceram. Sot., 1997, 17, (8), 1027-1031. A ceramic material with conduction characteristics satisfactory for the interconnector of solid oxide fuel cells (SOFC) is alkali earth-doped LaCr03 For the synthesis of highly sinterable LaCr03 powders, spray- drying of adequate precursors like solutions based on alkoxides has been used. Lanthanum chromium hydroxide solution was prepared by hydrolysis and chromium hydroxide solution was prepared by hydrolysis of synthesised methoxide complexes. The chemical reactions during hydrolysis and peptization of the precursors are described. The crystal-phase formation during the heat treatment of spray-dried amorphous gel consisting of hydroxide and contaminant chloride ligands was characterized by thermal analysis methods (TG, DTG, DTA) and X-ray diffraction analysis. The progressive oxidation of Cr(II1) by thermal dehydroxylation transforms the powder into fine crystal La(II1) Cr(V) hydroxo-oxychloride at 450°C. A thermal treatment permits complete chlorine removal forming sinterable crystal LaCrOJ perovskite powder at temperatule above 720°C. The same sol-gel process can be applied to chlorine-free nitrate-containing alkoxide solutions. The properties of sinterable lanthanum chromite powders obtained from these sols are compared with powders made by direct spray-drying of lanthanum-chromium nitrate solutions.

97104099 Specific heat capacity of new porous carbon materials: Woodceramics Kano, M. et al. Thermochim. Acta, 1997, 292, (l-2), 175-177 ‘Woodceramics’ are new carbon porous materials developed by carbonizing wood or woody materials impregnated with thermosetting resin. The carbonization takes place in a vacuum furnace at high temperature. Woodceramics have superior characteristics from the point of view of engineering and ecological materials: they are hard and strong, have porous structure and low density, are made from natural resources, do not cause environmental pollution, and are cheap to manufacture. Differential scanning calorimetry was carried out to determine the heat capacity at high temperature.

97104100 Specific heat capacity of new porous carbon materials: Woodceramics Kane, M. et al. Thermochin. Acto, 1997, 292, (l-2), 175-177. Wood or woody materials impregnated with thermosetting resin are carbonized in a vacuum furnace at high temperature to produce ‘Woodceramics’. These have superior characteristics from an engineering and ecological point of view: they are hard and strong, have porous

structure and low density, are made from natural resources, do not cause environmental pollution, and are cheap to manufacture. Differential scanning calorimetry has been employed to determine their heat capacity at high temperature.

97lO4101 Spray repairing materials for refractory linings Mitsui, H. et al. Jpn. Kokai Tokkyo Koho JP 09,132,470 [97,132,470] (Cl. C04B35/66), 20 May 1997, Appl. 95/317,194, 10 Nov 1995, 5 pp. (In Japanese) Metallic Si 10-30, coke having particle diameter ilOO ,lrn 0.5-5.0 wt%, and balance fired refractory powder comprise the spray repairing materials. The materials are fed at hot state into an 02 stream to melt the refractory powder by the combustion heat of the metallic Si, to repair the refractory linings.

97104102 Study of the synthesis of ammonium dawsonite. Part II. Characterization Sakamoto, R. G. Ceramica, 1996, 42, (278), 776-779. The paper describes the preparation of ammonium aluminium hydroxy carbonate (AAHC) known as ammonium dawsonite by precipitation from ammonium aluminium sulfate (AA) and ammonium hydrogen carbonate (AHC). The precipitate was washed three times and its purity degree was determined after each washing. X-ray diffractometry, SEM, thermal analysis, as well as qualitative and quantitative chemical analyses of the impurities present were implemented to characterize the material after each step. The results showed that the obtained AAHC had high purity and its grain size was l-3 pm dimension.

97104103 materials]

Thermochemistry and kinetics [of ceramic

Flagan, R. C. Carbide, Nitride Boride Mater. Synth. Process., 1997, 275-306. Edited by Weimer, A. W., Chapman & Hall, London, UK. The thermochemical and kinetics of vapour-phase synthesis of ceramic materials are investigated.

13 SPACE HEATING AND COOLING

97104104 Applicability of zeolite for CO* storage in a CaO- CO* high temperature energy storage system Kyaw, K. et al. Energy Cowers. Mgmt, 1997, 38, (lO-13), 1025-1033. This paper reviews reversible thermal dissociation reactions for application in thermal energy storage at very high temperatures. Among them, dissociation of CaCOJ seems very promising as the material can dissociate at 1098 K under atmospheric condition and the reactants involved are free from toxicity. One of the dissociation products, CO2 gas, requires a storage system. Three CO2 storage systems are being considered and the thermal operating efficiencies, COP, of the respective CaO-CO2 energy storage systems are evaluated. The system with a zeolite adsorbent for CO2 storage can compete with the other systems when the adsorptivity of the adsorbent increases to higher values. The CO2 adsorption characteristics of zeolite 13X and super activated carbon under a temperature range 303-573 K are studied. Zeolite 13X adsorbent was found to be suitable as a CO2 storage medium in a CaO-CO2 high temperature thermal energy storage system.

97104105 temperature

The comfort zone and the oscillation of the driving

Morillbn, D. et al. Applied Energy, 1997, 57, (l), l-l I. For the purpose of calculating the heating and cooling loads of a single room, a Fourier-analysis based method is proposed. The method includes the effects of thermal inertia and climate. Two situations are studied: firstly when the driving outdoor-temperature fluctuates within the comfort zone and secondly when this temperature fluctuates out of the comfort zone. Some experimental measurements were performed at different locations in order test the validity of the method.

97104106 Design and testing of current leads made from Ag- Au sheathed 81-2223 superconducting wires Sasaoka, T. et al. Cryogenics, 1997, 37, (S), 409-415. The paper describes the manufacture of a pair of current leads consisting of spirally assembled Ag-Au sheathed Bi-2223 superconducting wires. The heat leak into liquid helium (LHe) was measured in a vapour cooler under a self-cooling condition. The heat cycle of the fabricated superconducting current lead had no influence on the characteristics of both super- conducting and joint parts. The paper presents the findings from the tests.

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