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。     

建筑瓷砖辊道窑窑体主要尺寸优化初探

近年来辊道窑在我国发展迅猛,尤其是生产建筑瓷砖的企业几乎都采用辊道窑作为烧成设备。而且随着辊道窑技术日益成熟,辊道窑是越做越长、越做越宽:窑长有的已超过200米,窑内宽已达3米以上。本文以热平衡为依据,用VB编程探讨了窑炉主要结构尺寸大小对产量、能耗的影响,初步探讨了建陶工业辊道窑主要结构尺寸的合理范围。     

PRODUCER GAS FOR BURNING REFRACTORIES1

History of installations in the United States of producer gas for burning fire brick. Causes of failure or abandonment of producer gas firing. Continuous regenerative kiln necessary for successful burning at high temperatures with producer gas. The compartment kiln, fired with producer gas, best adapted for general refractories. Advantages of the compartment kiln over the car tunnel kiln. Essential features of continuous kilns for the successful burning of refractories. Special features of gas producers for ceramic kilns. Temperatures from producer gas. Economy of producer gas as compared with natural gas, oil and powdered coal. Investigation of designs and methods of operating gas producers.     

Technological features of Renaissance pottery from Deruta (Umbria, Italy): An experimental study

This work is focused on the assessment of the basic technological features of the pottery production in Deruta in the Renaissance period. For this purpose, clay samples and two kinds of ceramic products (tiles and wares) dating back to the XVIth century were characterized using different analytical techniques: optical, cathodoluminescence and electron microscopy on thin sections, X-ray fluorescence and X-ray diffraction on the bulk powdered samples. Then two clays best representing the chemical composition of the ceramic products underwent laboratory experimental firing tests at different conditions following the procedure of firing applied in the XVIth century as reported in the ancient historical documents. The firing products underwent textural, chemical and mineralogical characterization by the same analytical techniques in order to be compared with the clays and the shards. Archaeometric investigation of the ceramic bodies led to the identification of two different clay raw materials, both of local provenance, for the tile and the ware production. Archaeometric investigation of the glazes showed some differences between the wares from different workshops. In this respect the typology and the quality of the glaze resulted to be much more effective than the texture and composition of the ceramic body in characterizing the wares from different coeval workshops. Results of the experimental tests evidenced the firing products result from a complex mix of physical and chemical variables strictly correlated to one another. Above all, the heating rate and the amount of calcite in the clay raw material are crucial driving forces of the kinetics of firing. Comparison between the original and the experimental ceramic products indicated ranges of biscuit firing temperature of 850–1050 °C and of 950–1050 °C for the tiles and the wares, respectively, and a low heating rate in both cases.     

Spectroscopic and porosimetry studies to estimate the firing temperature of some archaeological pottery shreds from India

The present study aims to estimate the firing temperature of archaeological pottery shreds collected from the three archaeological sites namely Maligaimedu, Thiruverkadu and Palur in Tamilnadu state, India. The spectroscopic method Fourier Transform Infrared Spectroscopy (FT-IR) has been employed to find the lower limit of firing temperature of the archaeological pottery shreds by refiring the samples to four different temperatures from 200 °C to 800 °C. From the observation of the hydroxyl band and appearance/disappearance of octahedral sheet structure the firing temperature of the shreds has been estimated. The samples from Maligaimedu site named as MM1, MM3 and MM5, Thiruverkadu and Palur samples were fired to a temperature above 800 °C and the samples of Maligaimedu MM2, MM4 and MM6 were fired below 800 °C. Additionally, porosimetry measurements such as water absorption and mercury intrusion (MIP) were also carried out. The samples MM1, MM3, TK2–TK6, PL3 and PL5 were fired to a temperature less than 900 °C and the other samples to less than 1000 °C.     

PLC在辊道窑故障报警系统中的应用

辊道窑是生产建筑瓷砖的现代化窑炉，烧成时间缩短，截面上下温度均匀。具备其他工业窑炉无法比拟的优点。但也会经常出现故障，如油泵、风机停机等等，因此对辊道窑故障报警显得尤为重要。结合目前的辊道窑故障报警的现状。提出了用PLC实现辊道窑故障报警系统的设计方案，给出了报警系统的硬件结构和梯形图。     

FIRING OPEN TERRA COTTA KILNS WITH GAS1

Experiments conducted with a small kiln in firing terra cotta without the use of a muffle giving satisfactory results, the large kilns at this plant were equipped for gas firing, the muffles being removed. The equipment for gas firing is described and alterations made in the kilns are explained. The general operation of the kilns is discussed. Savings obtained are enumerated. The consideration of gas as a fuel in the ceramic industry is recommended.     

Gas release during clay firing and evolution of ceramic properties

Gas release, crystalline structure and ceramic properties were analysed during firing of clay raw materials and extruded bricks. Carbon monoxide, carbon dioxide, nitrogen oxides, and methane emissions were measured during the firing cycle. Ammonia and sulphur dioxide were not observed within the detection limits. The evolution of crystalline phases, open porosity, volumetric shrinkage, rupture tension and apparent density were correlated to the amount of gases produced at different temperatures, ranging from 300 to 1200 °C. These results can be applied for optimising the production process.     

Removal of the persistent pollutant chlorobenzene by adsorption onto activated montmorillonite

The potential of activated bentonite was assessed for adsorption of chlorobenzene from aqueous solution. The bentonite used was treated by chemical and thermal activation over 100–500 °C. The thermal activation increased the adsorption capacity more strongly than chemical activation which consists to acid and hydrogen peroxide treatment. The removal is dominated by adsorption at low initial concentrations and low temperatures and favourable in acidic media. The dependence of the adsorption on pH appears to be related to the solubility of chlorobenzene. Thermodynamic parameters such as ΔH°, ΔS°, ΔG° and Ea have been calculated. The adsorption process is spontaneous and exothermic in nature. The Freundlich isotherm described the adsorption data over the concentration range (20–270 °C).     

Annealing effects on the mechanical properties of near-frictionless carbon thin films

In this work, the near-frictionless carbon (NFC) thin films developed at Argonne National Laboratory were annealed at 100 °C, 150 °C, 200 °C, 400 °C, and 600 °C in nitrogen atmosphere. The changes of the NFC mechanical properties were measured with both static and dynamic nanoindentation methods. It was found that the Young's modulus and hardness decreased with increasing annealing temperatures. Raman spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM) were used to characterize the film's structural change before nanoindentation testing. Raman characterization indicated that the G peak shifted upwards as the annealing temperature was increased above 150 °C, which indicated decreasing sp³ content. The intensity of the D peak was shown to increase with annealing temperature indicating that the NFC film became more graphite-like. AFM analysis showed an increase of sp² clustering with annealing temperature, which resulted in an increase in surface roughness. SEM characterization indicated that as the films were annealed large cracks and numerous pinholes were generated. The characterization results were in good agreement with the measured mechanical properties.     

智能微型电热辊道窑设计开发

通过智能微型电热辊道窑的研发,介绍该窑设计、施工主要关键技术,进而说明其低蓄热、烧成热效高、温差小、控制稳定简便、烧成周期灵活可调等特点,可满足多品种、小批量功能陶瓷的生产方式。     

Microstructural evaluation of a clay ceramic incorporated with petroleum waste

In this work an extensive SEM/EDS microstructural investigation associated with technological properties was carried out on kaolinitic clay bodies incorporating different amounts, up to 20 wt.%, of a bentonite-treated petroleum waste. The clay bodies were fired at temperatures from 850 to 1100 °C and then bend tested until rupture. Fracture surface observation revealed the existence of relatively small BaSO₄ particles that do not significantly contribute to the rupture process. By contrast, larger clay matrix embedded particles and voids exert more influence on the ceramic rupture. Since these particles are also normal features in waste-free clay bodies, the incorporation of bentonite-treated petroleum waste cannot be directly related to the rupture process. Exception occurred above 10 wt.% added waste and temperatures higher than 1000 °C, at which the comparatively higher amount of non-plastic quartz particles plays a role in the decrease of strength.     

建筑瓷砖烧成缺陷监测预报专家系统的初探

本文对专家系统用于辊道窑焙烧建筑瓷砖工况监测进行了探索,采用基于可信度的带有阈值的不确定推理方法,建立了一个建筑瓷砖烧成缺陷监测预报仿真专家系统,仿真结果表明系统能够及时预报建筑瓷砖某些烧成缺陷的产生。     

陶瓷纤维在辊道窑中高温粉化过程的初析

本文综述了陶瓷纤维分类、主要成份及性能,结合辊道窑的结构特点及陶瓷烧成的工艺特点,分析了热应力、气氛制度、坯釉烧成及燃料燃烧所产生的有害成份、窑内的速度场及窑体结构等对陶瓷纤维粉化的影响,并提出了应用模拟研究的方法探讨陶瓷纤维粉化与各影响因素之间的定量关系,探讨了陶瓷纤维使用寿命的预测方法和在辊道窑使用中的抗粉化方法。     

THE HEAT-BALANCE STUDY OF CERAMIC KILNS1

The elements of the heat-balance study and calculation of the thermal efficiency of ceramic kilns are summarized, and an outline of a heat-balance method is given. The CO₂ in the flue gases of the kilns studied was measured automatically and continuously by an electric CO₂ meter making use of the thermal conductivity method, and some of the resulting CO₂percentage curves are given and interpreted. A complete heat-balance of a 30-foot round downdraft facebrick kiln fired with wood is given, together with various data and conclusions on the use of wood in firing ceramic kilns. A complete heat-balance of a Hoffman continuous coal fired kiln is given, together with temperature-gradient curves and other data of this and two other Hoffman kilns.     

陶瓷窑炉墙体新型砌筑结构与节能解析

陶瓷辊道窑是陶瓷工业的新型窑炉,具有很多优点,它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、热耗大。本文通过对窑墙散热计算,试图通过改变耐火材料及保温材料的砌筑方法,来优化辊道窑的窑墙结构。     

Surfactant-modified bentonite as adsorbent for the removal of humic acid from wastewaters

The effectiveness of surfactant-modified bentonite (SMB) in removing humic acid (HA) from wastewaters was evaluated. Hexadecyl trimethylammonium (HDTMA) chloride was used to modify the surface of the clay mineral. The SMB exhibits very high adsorption potential for HA and at pH 3.0 more than 99% removal was achieved from an initial concentration of 25 μmol/L. The experimental kinetic data were analyzed using the pseudo-first-order kinetic model. Adsorption occurs through film diffusion at low as well as at higher concentrations and temperatures. The adsorption of HA using SMB was an exothermic process. HA adsorption was found to decrease with increase of ionic strength due to the formation of outer-sphere surface complexes on SMB. The equilibrium isotherms were determined and data were analysed using the Langmuir isotherm model. The maximum adsorption capacity, Q° was 73.52 μmol/g with binding constant, b = 0.155 L/μmol at 30 °C and pH 3.0. The adsorbent was suitable for repeated use (more than 3 cycles) without any noticeable loss of capacity.     

不同温度制度下不同产品单位产量烧成能耗的对比方法

针对陶瓷烧成窑炉提出了一种在改造前后不同温度制度下不同产品时节能率的计算方法,并描述了具体的测试步骤,对陶瓷窑炉的测定具有一定的指导意义。     

Effects of sand addition on production of lightweight aggregates from Tunisian smectite-rich clayey rocks

Smectite-rich claystone–marlstone samples from 12 outcrops located in the Southern Atlas domain of Tunisia were investigated with regard to manufacture of lightweight aggregates (LWAs). The clayey materials mainly consist of smectite, kaolinite and illite, together with quartz, calcite, dolomite and feldspars as accessory components. 10–12 mm pellets were prepared from wet paste and initially heated to 600 °C, 700 °C or 800 °C (depending on the raw material) for at least 2 h in order to avoid any explosion of the aggregate. The pellets were then subjected to a quick firing process at 1180 °C. The addition of 15% of quartz sand (< 250 μm grain size) to the raw materials was found to improve some required pre-treatments and give better expansion properties to some of the aggregates. The addition of 1% used automobile oil to the clay and quartz sand mixtures caused the formation of more gas and a drop in bloating temperature. The obtained LWAs were characterized by physical properties such as apparent density, mechanical resistance, water absorption and expansion. The laboratory results were comparable to those of two commercial LWAs from France (Argidécor®) and Portugal (LECA®) and provide new openings for the utilization of Tunisian claystone in civil engineering work or in agricultural applications.     

钧瓷釉的仿制实验

本文采用仿制实验的方法,用现代陶瓷生产用普通原料和现代窑炉烧成技术,再现宋代钧瓷釉的窑变艺术效果。实验结果证明,钧釉窑变效果的产生,主要与釉料的化学组成而产生的液一液分相结构和乳浊现象,以及釉中铁、铜的呈色有关,而分相结构和乳浊现象及呈色又与烧成温度和气氛相关。