Selection of the structures of tunnel kiln suspended roof thermal insulation

Conclusions A method has been developed for thermal calculation of suspended roofs taking into consideration the three-dimensional geometric configuration of the roof, the temperature relationship of the thermal conductivity of the materials, and the mutual irradiance of the projecting elements of the structure. An engineering program for calculation of suspended, and, as a particular case, of nonsuspended roofs was developed for Fortran IV algorithm language.With use of the program for thermal calculation of the roof at temperatures in the working channel from 1100 to 1900°C variations were developed of structures of the thermal insulation of tunnel kiln suspended roofs making it possible to substantially (up to 30%) reduce heat losses in comparison with those observed in existing kilns.Translated from Ogneupory, No. 6, pp. 40–44, June, 1983.     

陶瓷窑炉墙体新型砌筑方法与节能

辊道窑是陶瓷工业的新型窑炉,其具有很多优点。有利于实现烧成工序的机械化与自动化,是快速烧成较理想的窑炉,但由于辊子长度的限制。窑墙结构较薄;但无论窑炉多先进,耗热大还是陶瓷窑炉的重要课题。笔者曾对窑墙散热计算时发现。在不改变耐火材料及保温材料的厚度及种类。只改变耐火材料及保温材料的砌筑方法,得到不同保温性能,从而可进一步探讨改进辊道窑窑墙结构的方案。     

Performance Comparison of Two Solar Kiln Designs for Wood Drying Using a Numerical Simulation

The predicted performances of the two different timber-drying solar kiln designs (Oxford and Boral kilns) have been compared by using the climatic and geographical conditions of Brisbane (27.46°S) in Australia. The dimensions of the original Boral kiln have been scaled down in order to compare the kilns’ performances on the basis of same load capacity. The comparison was made in terms of the key performance indicators, including drying rates, drying qualities (i.e., the level of strains developed within the timber boards during drying), energy gains, and major elements of the energy losses (i.e., the convection and radiation losses) while drying timber from an average initial moisture content of 53% (dry basis) to a final moisture content of 15% (dry basis) in both kilns. The relative performances for the two designs were discussed in more detail by using the typical climatic conditions (spring season 2013), when the days and nights are of approximately equal length. Finally, an analysis of the seasonal effects on the kiln performances was also carried out in this article. More effective orientation of the solar absorbers with respect to sun, together with faster heat transfer rates between the circulating air and the timber stack for the Oxford design, were likely to give consistently better predicted performance for the Oxford design than for the Boral kiln throughout the year.     

Operating high-temperature tunnel kilns with a 700-mm-high charge

Conclusions In low tunnel kilns, periclase-spinel brick should be fired in columns about 700 mm in height in an arrangement which leaves an effective cross section of 47–48%.Injectors for feeding air at low pressure to the burners serve no useful purpose. A 45-m-long firing zone (15 positions) is not required.Ways must be found of further improving the heat insulation properties of the lining of the kiln trucks.Translated from Ogneupory, No. 2, pp. 12–15, February, 1976.     

Use of fibrous materials for heat insulation of bottom tubes of continuous soaking pits

Conclusions A system for two-layer heat insulation of bottom tubes of continuous soaking pits has been developed; it consists of shaped refractory blocks made by vibrocasting and insulating sleeves of high-alumina wool. Tests on a model reveal that the insulation is very stable and that scale does not penetrate it; the heat losses through the insulation were reduced by 78% below those from an unprotected tube.Translated from Ogneupory, No. 5, pp. 24–27, May, 1979.     

CLAY SEWERPIPE MANUFACTURE1 VI. Heat-Balance Determinations

Heat-balance determinations were conducted on a number of sewerpipe kilns and the kiln efficiencies were found to vary from 14.97% to 29.03%. The method of calculating the heat balance is described in detail. Kiln efficiencies for individual periods range higher for the second period in most cases with some of the kilns reaching upward of 40% efficiency. In general as the kiln reaches higher temperatures the kiln efficiency decreases due to increasing stack and kiln structure losses. In all, thirty-four kiln tests were conducted in six plants in various sections of the country, in twenty-six of which heat-balance calculations were made, the remainder being auxiliary tests giving only general operating data such as tonnage of ware, fuel consumption, temperature schedule, and ware analysis.     

The thermodynamic efficiency of tunnel kilns

Refractories and Industrial Ceramics - An in-depth thermodynamic analysis of modern high-temperature tunnel kilns showed that the principal exergy losses in the kilns are due to the irreversibility...     

热辐射涂料在陶瓷辊道窑中的节能机理与应用

基于辐射传热原理,本文详细分析了热辐射涂料在陶瓷辊道窑中应用的节能机理,理论分析和实际应用都表明在辊道 窑中应用热辐射涂料后可以有效地增强炉膛中的辐射传热,从而提高辊道窑的热效率,节能效果显著。     

回转窑传热过程数学模型的研究现状及其发展

介绍了各种回转窑传热过程数学模型的概况及其特点,并综述了国内外有关回转窑传热过程数学模型的研究现状及其发展。结合当前的实情,对回转窑传热过程数学模型研究领域中需进一步改进和完善的方面提出了一些建议,并展望了回转窑传热过程数学模型的发展趋势。     

在陶瓷梭式窑中应用高效热辐射强化剂的节能实践

基于辐射传热原理，本文详细分析了高效热辐射强化剂在陶瓷梭式窑中应用的节能机理，理论分析和工业试验都表明在梭式窑中应用高效热辐射强化剂后可以有效地增强窑内的辐射换热，从而提高梭式窑的热效率，达到显著的节能降耗效果。     

Effect of Heat Losses on Fire Resistance Test Results for Metal

The effect of heat losses on the fire resistance of a flat metal plate tested in a standard fire regime is examined. The dependence of the temperature dynamics of the plate with and without a coating on the thermophysical properties of the insulation on exposure to fire heat loading is studied numerically. The results of the study indicate the need for using a coupled formulation of the problem and standardizing the type and thermophysical properties of the thermal-insulation material for a correct modeling and testing of the heat and fire protection of the metal plate, especially in the case of a small plate thickness. Integral criteria are proposed to characterize the heat losses and insulation efficiency on the rear surface of the plate.__________Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 3, pp. 98–105, May–June, 2005.     

热管在陶瓷工业窑余热回收工程中的应用初探

介绍了工业窑炉烟气余热回收工程中所广泛应用的热管技术;并结合陶瓷窑炉,对热管换热器在陶瓷工业中的应用进行了初步探索。     

Influence of the secondary air parameters on the combustion conditions of a tunnel kiln

Conclusions The operating effectiveness of the cooling zone has a significant influence on the fuel consumption in a tunnel kiln, which increases with an increase in the temperature level of firing of the refractories. Acceleration of heat exchange in the cooling zone with improvement in its thermal and gas insulation is an important step in reducing the fuel consumption in kilns.With identical effectiveness of the thermal operation of the cooling zone the parameters of the secondary air supplied for combustion do not have a significant influence on the total fuel consumption in the furnace but do determine to a significant degree the operating conditions of its burners.Translated from Ogneupory, No. 3, pp. 41–43, March, 1987.     

陶瓷工厂能源管理及综合利用

通过对窑炉热排放的有效检测,并合理控制利用,可使企业清楚了解生产设备的能耗,并可有效利用余热,减少能耗,直接或间接降低生产成本。经过对各种工况下的充分考察、计算,分析了热能耗的可控因素及控制可行性,并对系统在实际应用中易出现的问题和缺陷进行了研究。经过在有效工况下的实际应用,充分验证了合理利用有效的控制手段,通过对窑炉热排放的控制进而达到节能减排的目的是切实可行的。     

APPLICATION OF THE DOWNDRAFT PRINCIPLE TO TUNNEL KILNS1

Down draft is established as best for producing even heat distribution in periodic and chamber kilns. Methods of applying down draft to tunnel kilns are described and illustrated.     

Drehrohrreaktoren in der Chemietechnik

Rotary kiln in chemical engineering. This review stresses the importance of rotary kilns in industry. After a brief account of design considerations, the following processes are treated: particle and product motion, longitudinal and transverse transfer of solids, mass- and heat transfer, as well as chemical reactions. Common models used for rotary kilns are discussed. Typical industrial processes employing rotary kilns are presented. The present status of control and automation of these plants are discussed.     

陶瓷隧道窑热耗的定量分析

利用陶瓷燃料隧道窑热耗数学模型及计算机模拟方法,得出了９种重要因素对热耗定量影响的模拟结果,并对模拟结果进行了分析,由此寻求陶瓷资料隧道窑节能的较好途径。     

多孔球形莫来石基浇注料的制备及性能研究

为制备保温性能及机械性能均较优异的高温窑炉用隔热耐火材料,以多孔球形莫来石、矾土细粉、α-Al₂O₃微粉、硅微粉和Secar71水泥为主要原料,制备了多孔球形莫来石基浇注料,研究了矾土细粉掺量对多孔球形莫来石基浇注料机械性能、导热系数、抗侵蚀性能及热震稳定性的影响。结果表明,改变矾土细粉的掺量,可使多孔球形莫来石基浇注料在保持较高机械性能的基础上提高保温性、热震稳定性和抗侵蚀性能。随着矾土细粉掺量的增加,多孔球形莫来石基浇注料的机械性能变化不大,但导热系数小幅降低,抗侵蚀性能出现较大差异,热震稳定性先提高后降低。当矾土细粉掺量为28%(质量分数)时,多孔球形莫来石基浇注料的机械性能、热震稳定性及抗侵蚀性能良好,在1 000 ℃时导热系数为0.905 W·m^-1·K^-1。多孔球形莫来石基浇注料的导热系数低于中间包和钢包永久层用高铝浇注料,可替代中间包、钢包永久层用高铝浇注料以减少热损失。