The search for optimum solutions for melting insulator glass

The effect of the temperature conditions of melting and the design features of the glass melting furnaces on the increase in the specific removal of glass melt in processing quenched insulating parts of high-voltage suspension insulators is demonstrated. Designs are proposed for glass melting furnaces and glass melting temperature regimes whose use will increase the economy of manufacturing insulators.     

Catalytic activities and properties of mesoporous sulfated Al2O3–ZrO2

Mesoporous sulfated Al₂O₃–ZrO₂ (MSAZ) catalysts with large surface areas and pore volumes after calcination at high temperature (650 °C) and with higher Al₂O₃ content than 20wt% were successfully prepared from a template of block copolymer (P84). The MSAZ catalysts were characterized by X-ray diffraction (XRD), N₂ adsorption, transmission electron microscopy (TEM), ²⁷Al magic-angle spinning nuclear magnetic resonance (MAS NMR), thermogravimetric analysis (TG–DTG), temperature-programmed desorption of ammonia (NH₃-TPD) and infrared spectra (IR) of adsorbed pyridine. It is shown that the resulting mesostructured sulfated Al₂O₃–ZrO₂ samples have a well-developed textural mesoporosity. The number of acid sites present on MSAZ catalysts is higher than that on conventional sulfated zirconia, and the former catalysts are more active than the latter one for various acid-catalyzed reactions.     

Ignition and Combustion of Dust-Gas Suspensions

The ignition and combustion of dust-gas suspensions are considered. It is shown that the ability of these systems to accumulate heat is determined not only by their kinetic and thermal properties but also by the relation between their reaction surface and the heat-removal surface (f). Experimental information on flame temperatures, ignition delays, and flame propagation over gas suspensions is processed using the parameter f, and the postulate on the stimulating role of the developed reaction surface in activating these processes is validated. It is shown that during overall burning, diffusion combustion of particles occurs only for rather small values of f. The ambiguous effect of the parameter f on the ignition and combustion processes leads to the necessity of optimizing the fuel size distribution and concentration for the effective operation of the power devices. The role of the macroparameters of two-phase flames of refractory metals in the synthesis of combustion nanoproducts is analyzed. __________ Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 6, pp. 3–14, November–December, 2005.     

Preparation and Photoluminescence of Partially Filled ZnO Microtubes Using Block Copolymers

Partially filled ZnO microtubes were synthesized in large scale using block copolymers. The growth mechanism of this unique construction is proposed on the basis of adsorption of block copolymers on {0002} plane of wurtzite ZnO. The photoluminescence property of these unique ZnO microtubes is also studied using a Xe lamp as the excitation source at room temperature. Blue emission band at 425 nm is a much stronger ultraviolet emission band, which is due to laminar structure of ZnO microtubes.     

Interrelationship of the baric index for the normal burning velocity of gas—Air mixtures and the kinetics of trimolecular reactions in a flame front

Through numerical simulation of flame propagation through a methane- and hydrogen-air mixture, with consideration given to the transfer and chemical reactions, we have investigated the relationship between the kinetics of trimolecular reactions and the baric index of the normal burning velocity. It has been demonstrated that the lower the constants of the trimolecular reaction rates, the higher the magnitude of the baric index. In the case of methane the baric index, although it grows, it nevertheless remains negative, while in the case of hydrogen this index changes sign.Balashikha. Translated from Fizika Goreniya i Vzryva, No. 2, pp. 46–49, March–April, 1991.     

Product composition of the dynamic conversion of brown coal in supercritical water

The product composition of the dynamic conversion of brown coal, which was continuously supplied as a water-coal slurry to a flow reactor at 30 MPa, was studied. The temperature of water and coal particles was increased from room temperature to 400°C (top part of the reactor). The conversion of the organic matter of coal was ～48%, and the products collected at the reactor outlet consisted of solid tar components, substances dissolved and emulsified in water, and volatile substances, whose major constituent was CO₂. The composition of solid tar components and oils was determined.     

High-temperature rheological properties of clay bodies and bodies plasticized with clay

Conclusions We determined the rheological properties of clay materials at elevated temperatures. With an increase in the temperature and pressure the structural-mechanical constants diminish, and the plasticity increases. The total proportion of elastic and plastic deformations reaches significant values (92–95%) in kaolins at 1450°C, and in Chasov-Yar clay at 1200–1250°C. It is in these conditions precisely that we obtain the densest thermal-pressed products.With optimum thermoplastic pressing temperatures the various clay materials have the closest viscosity and maximum yield point values.The best natural raw material for thermoplasticizing is Chasov-Yar clay, but it is possible to use other clay materials. It is possible to regulate the rheological properties of bodies by varying the compositions (filler + thermoplasticizer) of the bodies, the pressing temperature, and pressure.The rheological properties of mixtures of zircon and thermoplasticizer (10% Chasov-Yar clay) at 1450–1480°C facilitate the production of especially dense products for continuous steel casting. Tests carried out on continuous casting plant were successful.Translated from Ogneupory, No. 6, pp. 43–51, June, 1973.     

The manufacture of lightweight,heat-insulating refractory goods with an operating temperature up to 1750°C

Conclusions The possibility is shown of obtaining lightweight refractories with an operational temperature of 1750°C and having a wide range of properties. The use of these refractories depends on the particular requirements and the conditions of service.Translated from Ogneupory, No. 3, pp. 24–28, March, 1986.     

直纺长丝工艺中聚酯熔体端羧基值控制的工业研究

本文从工业生产的实践出发对杜邦聚酯技术直接纺工艺中端羧基控制进行了研究。通过对熔体端羧基值对无油长丝端羧基、粘度及纺丝加工影响的分析 ,阐明了聚酯端羧基控制范围 ;通过摸索三个反应釜工艺条件对端羧基值的影响 ,找出了端羧基工业控制的有效途径 ,为同类技术装置生产提供了依据