Industrial Glass-melting Furnaces Research Articles

INTEGRATION OF OPERATION OF REGENERATORS OF GLASS FURNACES

The material of the article relates to the glass industry, namely to equipment for cooling the roof of regenerators of glass melting furnaces and can be used in the construction of new or reconstruction of existing regenerators.
 When the refractories of industrial glass melting furnaces are destroyed, an intensive decrease in the wall thickness of the melting basin occurs, which leads to a significant increase in the temperature of the outer surface of the walls and, accordingly, an increase in heat losses. The maximum destruction of the refractory masonry of the walls of the melting basin is observed at the level of the mirror of the melted glass. There is uneven wear along the height and perimeter of the pool. The rate of destruction of the masonry is determined by the stability of the used refractories, the temperature regime of glass melting, and the design features of the units.
 The technical task of the article is: to increase the service life of the refractory masonry of the glass furnace regenerator roof; utilization of the heat of the outer masonry surface of the regenerator roof, as well as improvement of its cooling system by using water cooling of the outer surface of the regenerator roof; saving fuel consumed to heat the same amount of coolant in boiler equipment.
 The proposed cooling of the outer surface of the regenerator roof makes it possible to: reduce the temperature of the outer surface of the roof to the level of 30 °C and at the same time make the most of the heat of the outer surface of the regenerator roof, which has not been used before, for example, to obtain hot water from a heat supply system, and this makes it possible to save fuel costs, which are necessary for the operation of boiler equipment to heat the same amount of coolant; to ensure a more uniform distribution of temperature fields over the entire plane of the regenerator roof by using flat collectors of a special design, which, in turn, makes it possible to slow down the process of destruction of the refractory lining of the regenerator roof. The thermocouples installed in the pipelines make it possible to monitor the change in the temperature of the coolant in the collectors, and in the event of an increase in the surface temperature of the collectors, the automation increases the flow of the coolant in the pipelines. The collectors are equipped with pressure valves, when the temperature of the coolant in the collector is above 100 °C, it can boil in the collector and then the pressure valve equalizes the pressure in the collector.

Detailed comparison of physical fining methods in an industrial glass melting furnace using coupled CFD simulations

Melting and primary fining represent the most essential steps in the glass manufacturing process. Electric boosting and bubbling are common methods used to optimize these processes by improving the product quality and energy efficiency. However, a structured overview of their impacts on the operation of the total melting furnace has not previously been published. The present paper provides a thorough comparison of these technologies applied to an industrial melting furnace, including the effects on temperatures, melt flow patterns, glass quality, as well as the heat fluxes and process efficiency. In this work, extensive numerical simulations were performed. Unlike other studies described in the literature, a validated CFD model of exceptionally high accuracy was employed. Furthermore, the entire melting furnace was considered, such that the glass tank was coupled to detailed simulations of the turbulent gas-phase combustion. A novel method for combustion modeling in glass manufacturing was applied, and user-defined functions supported an analysis of glass quality. Substantial differences were observed between the furnaces with electric boosting and bubbling. For the first time, interrelated effects could be described in detail, providing a comprehensive overview of the entire operation. Based on the presented results, the targeted use of both electrodes and gas nozzles is suggested for future melting processes.

A Glimpse of the Evolutionary Studies on Glass Tank Furnace in Terms of Raw Materials, Melting Process, Refractories, and Energy Efficiency

This paper discusses the raw materials used in ancient glasses. Following a consideration of some archaeological reasons for studying glass, the discussion concentrates on the evidence provided by the chemical analysis of the glass and focuses on glass from later prehistoric Western Europe. Consideration of the major, minor, and trace components of the glass leads to the conclusion that prehistoric glass artisans were able to closely control the addition of small quantities of colorants, opacifiers and clarifiers to the glass melt. Some possible ways of introducing such small quantities of these substances are suggested. Reduction of fuel consumption in glass melting furnaces can cut the cost of production, and tackle the global warming. The paper presents three independent solutions to reduce the fuel consumption in industrial glass melting furnaces. The solutions include air preheating, raw material preheating, and improving the insulation of combustion space refractory. Energy balance equations are derived and used to identify the effects of each solution. The results indicate that the three solutions reduce the fuel consumption by 9.5%, 17%, and 34% respectively. An insight into the refractory usage is shown for different sections of the glass tank furnace.

ОПТИМІЗАЦІЯ КОНСТРУКЦІЙНИХ ХАРАКТЕРИСТИК КІНЦЕВОГО РЕКУПЕРАТОРА ДЛЯ СКЛОВАРНИХ ПЕЧЕЙ

Studies have been carried out on the choice of optimal design characteristics of membrane panels for various parameters of flow turbulence on the inner surface of the pipes, from which the heat exchange surface of the heat exchanger is assembled, designed to increase the efficiency of fuel use in industrial glass melting furnaces due to the cooling of flue gases exhausted after furnace regenerators.

Arc melting plant for synthesizing and producing fusion-cast refractories

Data are given on arc melting plant for synthesizing and producing fusion-cast refractories. The technical characteristics of experimental plant type EDP-600 with moving electrodes are such as to allow one to synthesize fused materials on the basis of the oxides Al2O3, MgO, Cr2O3, and ZrO2, and also allows one to produce refractory components for industrial glass-melting furnaces. The DSPM-1.5 arc furnace is recommended for the industrial production of fusion-cast baddeleyite-corundum, high-alumina, and chromium-bearing refractories.

Modeling of thermal processes in the packing of regenerative heat exchangers in industrial glass-melting furnaces

Amathematical model of regenerative heat exchangers (regenerators) with stationary refractory packing used for heating incoming air for combustion in the high-temperature melting units of glass works is examined. The calculation package developed with the model can be used to model operation of the regenerators in tank glass-melting furnaces using modern types of packing with a different packing chamber configuration for glass-melting furnaces with horseshoe and transverse flames in consideration of the features of their operation.

Numerical simulation and experimental analysis of an industrial glass melting furnace

This paper presents a three dimensional study of a gas-fired, regenerative, side-port glass melting furnace. The furnace is divided into three regions: combustion space, glass tank and batch blanket. The combustion space is simulated separately, while the glass tank and the batch blanket are coupled together as a whole. To couple the three regions, a new method is proposed that is more flexible and faster than the existing conventional methods. The melting process of the batch blanket, the natural convection vortices of the glass tank and the turbulence and the chemical reactions of the combustion space are all simulated. The simulation was preformed using Gambit-2 and Fluent-6 software. The calculated temperatures are compared with actual values measured at different locations on the furnace surfaces. Results indicate that the maximum relative error is less than 7.6%. This work can form the basis for the parametric analysis of the furnace to reduce its fuel consumption.

The effect of mechanical agitation on convective homogenization of glass melt

Experimental data are supplied on the specifics of glass melt flows in the beginning of the chilling part of the tank, behind the barrier, and in front of the working zone, when using agitators in industrial glass-melting furnaces. It is established that in order to eliminate coarse cords and layers, the velocity gradient of glass melt flows ought to be increased by 2 orders of magnitude, compared to the natural homogenization. This purpose can be accomplished most simply and efficiently through mechanical agitation of the glass melt.

Improvement of Operation of Open-Flame Glass-Melting Furnaces (A Review)

The paper summarizes the experience of more than ten years of research performed by the authors on industrial glass-melting furnaces of various designs and is based on the analysis of mathematical modeling of heat exchange processes in the flame space of these furnaces. The mathematical modeling is based on the most adequate zonal method for heat exchange calculation. Recommendations for rational organization of combustion of various types of fuel in glass-melting furnaces are supplied.

The Krylov accelerated SIMPLE(R) method for flow problems in industrial furnaces

Numerical modeling of the melting and combustion process is an important tool in gaining understanding of the physical and chemical phenomena that occur in a gas- or oil-fired glass-melting furnace. The incompressible Navier–Stokes equations are used to model the gas flow in the furnace. The discrete Navier–Stokes equations are solved by the SIMPLE(R) pressure-correction method. In these applications, many SIMPLE(R) iterations are necessary to obtain an accurate solution. In this paper, Krylov accelerated versions are proposed: GCR-SIMPLE(R). The properties of these methods are investigated for a simple two-dimensional flow. Thereafter, the efficiencies of the methods are compared for three-dimensional flows in industrial glass-melting furnaces. Copyright © 2000 John Wiley & Sons, Ltd.

96/05349 Combustion measurements in an industrial glass-melting furnace

This paper describes the results of an experimental study undertaken in an industrial regenerative 'horseshoe'-flow-type oil-fired furnace for the production of glass containers. The data reported include in-flame gas species concentrations of O 2 , CO, CO 2 and NO x , and gas temperatures, for one of the furnace operating conditions. The results reveal: a) in-flame peak temperatures of about 1690 °C; b) exhaust-gas temperatures of about 1520 °C; and c) exhaust levels of CO at 0.1%vol and NO 2 at 580 ppm. The data presented are especially useful for evaluation and development of 3-D mathematical models.

Mathematical and Experimental Modeling of the Circulation Patterns in Glass Melts

Natural convection currents in a rectangular two-dimensional enclosure representative of the longitudinal section of an industrial glass-melting furnace have been established by both model experiments and numerical calculation. For the latter a finite-difference method has been employed to solve the time-dependent coupled flow and energy equations. The highly generalized mathematical model makes allowance for buoyancy, temperature-dependent viscosity, and diffusive radiation. Generalized boundary conditions are employed to permit specification of any combination of temperature, flux, or mixed thermal boundary conditions. Representative temperature and flow contour maps obtained from the calculations are shown to agree well with experimental results obtained with a 1/20 scale model in which glycerine was employed as the modeling fluid.