CONTROLLING AND MONITORING THERMOTE NICAL PARAMETERS OF GLASS MELTING FURNACE

According to the characteristics of the ther-motechnical parameters such as temperature pressure and glass level for glass melting furnace, the design method for monitoring and controlling these parameters is introduced in this paper based on MACROMAX-2 concentrated and dis-tributedcontrol system. The configuration of management information and control loop is described, and research tests were performed to check the functions of system.

TWO-DIMENSIONAL MATHEMATICAL MODEL OF COMBUSTION SPACE IN GLASS MELTING FURNACES

Under some assumptions and dividing the combustion space into several isothermal zones and isothermal surface elements, a two-dimensional mathematical model for combustion space in cross-fired glass melting furnaces was constructed. The finite element method and the Gauss integration were used to calculate direct ex-change areas, and a inverse matrix was used to obtained the total ex-change areas. The temperature distributions were obtained by itera-tions. Some results were presented to show the effects of the fire tem-perature distribution, the convective -heat transfer coefficients and the heat losses through crown surfaces on the temperature distributions.

Innovation of Regenerator Checkerwork for Glass Melting Furnaces

Regenerator checkerwork for glass melting furnaces should have high resistance against thermal stress and chemical attack,high mechanical stability,high efficiency to recover the heat from waste gas and low tendency for clogging.This article reviews the innovation of the regenerator checkerwork from the past decades.The state of the art for optimised material choice and optimised checker shapes will be reported.

Fireclay Refractory Bricks for Glass Melting Furnace

This standard is applicable to fireclay refractory bricks with unit weight ≥ 50 kg for glass melting furnaces.

Sintered AZS Bricks for Glass Melting Furnace

1 Scope This standard specifies the brand, technical requirements, test methods, inspection rules, marking, packing, transportation, storage, and quality certificate of sintered AZS bricks for glass melting furnace. This standard is applicable to sintered AZS bricks for glass melting furnace.

Fused Cast Alumina Refractory Products for Glass Melting Furnace

JC/T 494-92(96) 1 ScopeThis standard specifies the technical requirements, test methods, inspection rules, marking, packing, transportation, and storage of fused cast alumina refractory products for glass melting furnace. This standard is applicable to the fused cast alumina refractory products for glass melting furnace (called products for short).2 Normative ReferencesGB 2997 Test method for apparent porosity, water absorption, bulk density and true porosity of dense shaped refractory productsGB 5072 Test method for cold crushing strength of dense shaped refractory productsGB 5989 Test method for refractoriness under load of dense shaped refractory products (Differential, with rising temperature)GB 7320 Test method for thermal expansion of refractory productsGB 10204 Test method for corrosion resistance of refractories for glass melting furnace to molten glassGB 10325 Stacking, sampling, acceptance, storage and transportation of shaped refractory productsGB 10326 Inspections of dimension, appearance and section of refractory productsGB/T 14351 Chemical analysis method of fused cast alumina refractoriesYB 4015 Sample preparation for testing of refractory products for glass melting furnaceYB 4016 Sampling and inspection of refractory products for glass melting furnaceJC 493 Fused cast zirconia corundum refractory products for glass melting furnace

Silica Refractory Bricks for Glass Melting Furnace

1 Scope This standard specifies the classification, technical requirements, test method, inspection rules, marking, packing, transportation, storage and quality certification of silica refractory bricks for glass melting furRaces.

High Quality Silica Bricks for Glass Melting Furnace

This standard specifies the classification, technical requirements, test method, inspection rules, marking, packing, transportation, storage and quality certification of high quality silica bricks for glass melting furnace.

Low Porosity Fireclay Bricks for Glass Melting Furnace

This standard specifies the classification, technical requirements, test methods, inspection rules, marking, packing, transportation, storage and quality certificate of low porosity fireclay bricks for glass melting furnace.

Investigation of Microstructure and Phase Composition of Chromic Oxide, AZS/Cr and High-alumina Refractories after Exposure of Basalt and Aluminaboronsilicate Glasses Melts

The microstructure and phase composition of high-alumina,chromic oxide,and AZS/Cr refractories containing 30%and 60%(by mass)Cr_(2)O_(3) after exposure to aluminaboronsilicate glasses and basalt melts depending on the type of melts and temperature have been studied.The mechanisms of refractory corrosion by the used melts and the factors contributing to the inhibition of corrosion development have been investigated by the method of petrographic analysis.On the basis of obtained results,the use of high-alumina,chromic oxide,and AZS/Cr refractories in the sections of glass furnace linings,experiencing the intensive impact of aluminaboronsilicate glasses and basalt melts,has been confirmed and scientifically substantiated.

Numerical Simulation of Induced Alterations of Flow Patterns Within Glass Melts using External Lorentz Forces

A common way to produce glass is to use melting tanks that work continually with several hundred tons per day.The process of efficiently melting,refining,and homogenizing the glass melt is strongly dependent on the flow patterns within the melting tank.In order to improve the quality of glass products and the efficiency of the melting process,it is necessary to control the flow patterns and to optimize the temperature distribution within the melting tank.Using Lorentz force to create additional flow components based on electric current density distributions and externally generated magnetic fields is an excellent method to obtain targeted and tailored flow influences.In order to evaluate this method,it is necessary to simulate the induced alterations of the melt flow.Such numerical simulations require the coupling of the electromagnetic and flow field calculations including the energy equation because the electrical conductivity of the molten glass is strongly dependent on the temperature.The idea is to include the calculation of the magnetic field completely into FLUENT using the so-called User Defined Scalars(UDS)and User Defined Functions(UDF).

Structure of Bi_2O_3-ZnO-B_2O_3 system low-melting sealing glass

Bi2O3-ZnO-B2O3 system glass is a kind of lead-free low melting sealing glasses.The structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass was investigated by DSC,FT-IR,XRD and SEM.The results show that with the increase of B2O3 content,the transition temperature Tg and softening temperature Tf of Bi2O3-ZnO-B2O3 system low-melting sealing glasses increase,which leads to the liquid phase precipitation temperature increasing and promotes the structure stability in the glass.With increasing the heat treatment temperature,a large number of liquid phases appear in samples and the sinter efficiency of the samples increases.The FT-IR spectra of the glasses show the presence of some bands that are assigned to vibrations of Bi-O bond from [BO3] pyramidal and [BiO6] octahedral units and B-O from [BO3] and [BO4] units.With the decrease of B2O3 content,the crystallization tendency of the glass increases.In glass samples B1 and B2,crystallization starts at 460℃ and 540℃,respectively.Both of them precipitate Bi24B2O39 phases.

Glass melt inclusion in clinopyroxene from Linqu Cenozoic basalt,Shandong Province,China

Cenozoic basalts from the Linqu County, Shandong Province, China entrain some clinopy- roxene crystals, of which many contain abundant glass melt inclusions. These melt inclusions are ex- tremely irregular in shape with most grain sizes in a range of 10-50 μm and coexist with low-Mg# olivines, labradorites and Ca-rich potassium feldspars. In-situ major and trace element analyses show that the glass melt inclusions are high in alkalis (Na2O+K2O > 10 wt%), SiO2 (>54 wt%), CaO and FeO (>4 wt%), but low in MgO (Mg# < 20), and have LREE enrich- ments ((Ce/Yb)cn = 11.6-16.4) and apparently posi- tive Eu anomalies (Eu/Eu* > 2), thus having phonoli- tic compositions. The compositional features of cli- nopyroxene crystals, glass melt inclusions and their coexistent minerals suggest that these melt inclu- sions were exotic melts in clinopyroxenes trapped prior to their entrainment in the host basalt. The dis- covery of these melt inclusions provides a new ap- proach to further investigating the evolution of Meso- zoic lithospheric mantle beneath the southeastern North China Craton.

Melting, sintering and wetting properties of ZnO–Bi_2O_3–B_2O_3 sealing glass

Glasses based on ZnO-Bi_2O_3-B_2O_3 system are expected to be a new kind of sealing glasses because of their low melting temperature and other properties.In order to reveal the effect of B_2O_3 on the rheological behavior of ZnO-Bi_2O_3-B_2O_3 system glass melt,the properties of viscosity,thermal expansion,fluxion property and wetting process between cylinder samples and stainless steel were investigated with the rotating crucible viscometer,dilato meter and high-temperature microscope.The structure of sintered glass samples was investigated with scanning electron microscope.The results show that the B_2O_3 content increasing in B_1-B_3 at the given temperature between 400 ℃ and 500 ℃ leads to the increasing of the sample viscosity.When the amount of B_2O_3 increases from 5.24%to 9.24%(mass fraction),the coefficients of thermal expansion of glass samples decrease smoothly from 10.94×10^(-6) to10.71×10^(-6) and 10.38×10^(-6) ℃^(-1) respectively.In the case of sealing temperature,its value increases from 453 ℃ to 494 ℃.ZnO-Bi_2O_3-B_2O_3 system low-melting glass powder sintering was with viscous liquid to participate,which could make the densification of glass sample more effective and more efficient.With the content of B_2O_3 increasing,the wetting angle between the glasses samples and stainless steel could also increase,and the resulting appropriate sealing temperature range is 460-490 ℃.

Glass-ceramics made from arc-melting slag of waste incineration fly ash

Grate fly ash and fluidized bed fly ash mixed with glass cullet additive respectively were melted in the electronic arc-furnace. The product, arc-melting slag, was further treated by crushing, pressing and heat treatment in order to make the glass-ceramics. The crystallization behaviors of the produced glass-ceramics were examined by differential thermal analysis (DTA), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Results show that main crystalline phase of the glass-ceramics from grate fly ash is wollastonite (CaSiO3) with small amount of diopside (Ca(Mg,Al)(Si,Al)2O6), and that from fluidized bed fly ash is diopside (Ca(Mg,Al)(Si,Al)2O6). It is found that the glass-ceramics sintered at 850 °C and 1 000 °C from grate fly ash and fluidized bed fly ash respectively have the optimal physical, mechanical and chemical characteristics. Glass-ceramics samples, produced from incinerator fly ash with desirable properties and the low leaching concentration of heavy metals, can be the substitute of nature materials such as marble, granite and porcelain tiles.

Preparation and Characterization of Low-melting Glasses Used as Binder for Protective Coating of Steel Slab

The low-melting phosphate glass was prepared for production of glass binders for protective coating of steel slab. Effects of different O/P ratios on glass structures and properties were analyzed. Differential thermal analysis （DTA） and infrared spectroscopy （IR） techniques were applied for low-melting glass binder. It was found that the glass transition temperature（T） was about 300 ℃ and softening temperature（T1） was about 480 ℃. The choice of O/P ratio was very important to the glass transition and softening temperatures. When more P=O bonds existed in the glass networks, P-O-P bond angle was deformed with decreasing of the ratio of O/E The coatings could adhere to the substrates instantaneously at 800 ℃ when the content of binder exceeded 3wt%. The optimal content of glass binder was 5wt%.

THE EFFECT OF MELTING TEMPERATURE ON THE PROPERTIES OF PbBr _2-PbCl_2-P_2O_5 GLASSES

A series of PbBr 2 PbCl 2 P 2O 5 glasses have been prepared and characterized to research the effect of melting temperature on the properties of glasses. The glass forming regions have been explored and the stability of the glasses against crystallization studied. The density, characteristic temperatures, chemical analysis compositions, and infrared absorption spectra of the glasses were measured. Results show that the PbBr 2 PbCl 2 P 2O 5 ternary system melted at 530～540℃ has a broader glass forming region which extended to the side of PbBr2 than that melted at 450～470℃. The glass transition temperature is more than 200℃ and the density is more than 5 5 g·cm 3 . Both the chemical analysis composition and the infrared absorption spectra of some glasses melted at 530～540℃ show that the decomposition of NH 4H 2PO 4 is more complete than that of glasses melted at 450～470℃.