不同化学组成的熟料混合粉磨增强效应的非线性统计模型

应用活性矿物掺料增强效应模型,建立了定量分析不同化学组成熟料混合磨 水泥时质量较差的熟料在混磨水泥中的增强效应的非线性统计模型,并将该模型方法推广到不同窑型熟料混合粉磨制备水泥的情况,验证了该模型的合理性和有效性,在给定两种熟料的情况下,依据此模型可以快捷的判断这两种熟料的混合粉磨的可行性,并确定最佳增强效应时的混合比例,从而可以指导生产实践。     

不同KH值熟料混合粉磨的效果

本文运用机械力学活化的理论,结合高KH熟料的显微结构和粉磨特性,以及熟料中fCaO的存在形态和水化特点,探讨了KH对不同窑型熟料混合粉磨效果的影响。研究表明,KH不同的各窑型熟料混合粉磨,因熟料粉磨性能上的差异,一方面改善了水泥的粒度分布,细颗粒含量增加,另一方面促进了熟料的机械力化学活化,熟料矿物产生了较多晶格缺陷,从而提高了水泥的强度,并在一定程度上减轻了fCaO对水泥安全性的不良影响。     

熟料混合粉磨试验研究

由于旋窑与立窑窑型不同，熟料的形成条件不同，因此，所生产的熟料的化学组成、矿物组成、晶体结构及物理性能上都存在着差异。当它们混合粉磨的时候，相互间会产生一定的作用，从而对水泥的性能产生影响。故有必要对此进行研究分析。     

水泥熟料与第二组分混合粉磨特性研究

研究了水泥熟料与石灰石、矿渣、火山灰等材料以及立窑熟料与回转窑熟料双组分物料的分别与混合粉磨特性。通过测定分别与混合磨产物的粒度分布、比表面积和筛余值,以及熟料与石灰石混合粉磨产物各粒级范围两组分的相对含量,分析了易磨性不同的两组分物料之间的相互作用,揭示了混合粉磨过程中常发生选择性粉磨,一组分物料可能对另一组分物料的粉磨起促进或阻碍作用。恰当利用这种相互作用可以改善双组分物料易磨性,从而促进了整体的粉磨过程,并改善水泥粒度分布与性能。     

立窑熟料与立波尔窑熟料混合粉磨的水泥特征

0 引言 立窑熟料和立波尔窑熟料因煅烧方式不同,岩相结构和矿物组成及易磨性存在差别。若二者以不同的比例混合粉磨,制得的水泥颗粒及其物理性能有何特点呢?平顶山水泥厂原有两条Φ4×60m的立波尔窑生产线,年产硅酸盐熟料60万t,1998年扩建一条Φ3×10m的机立窑生产线,年产熟料8万t。为了研究两种不同窑型生产的熟料混合磨制的水泥的性能,我们利用本厂生产的立窑熟料和立波尔窑熟料,按不同的比例相混合,磨制成不同编号的水泥,分析其颗粒特     

湿法回转窑熟料和立窑熟料混磨对水泥性能的影响

将湿法回转窑熟料和立窑熟料按不同比例混合磨制水泥,测定了水泥的物理性能。结果表明：混合磨制水泥的稠度、凝结时间、安定性等与单独粉磨水泥相比没有明显变化,但各龄期抗压强度比立窑水泥有很大的提高。立窑热料反碍不超过４０％时,混磨水泥的强度与湿法窑水泥也相当或略有增长。运用灰色关联度方法研究表明,混合粉磨改善了水泥颗粒级配,有利于强度的发展。两种熟料单独粉磨至同一细度再混合后得到了与混合粉磨一致的结论。     

不同窑型水泥熟料共同粉磨对水泥性能的影响

实验室测试了共同粉磨不同窑型熟的水泥物理性能、颗粒级配和水化放热速率。结果表明,回转窑和立窑熟料混合,改善了水泥熟料的易磨性,水泥的标准稠度用水量随着立窑熟料掺入量和粉磨时间的延长而增大。泌水性得到明显改善,颗粒级配更加合理,水泥强度提高,特别是３ｄ的抗压、抗折强度,它并不是两种水泥强度的简单加权,而是表现出增强作用,混合水泥熟料放热量、放热速率界于两者之间。     

立窑与回转窑熟料混合粉磨提高水泥质量的探讨

立窑与回转窑熟料混合粉磨提高水泥质量的探讨潘永礼辽宁省铧子新生水泥厂（１１１３１２）我厂于１９５７年建厂，有机械化立窑３台：Φ２．５×１０ｍ、Φ２×８ｍ、Φ２×７．８ｍ；生料磨２台：２×Φ２．２×６．５ｍ；水泥磨４台：３×Φ１．８３×６．１２ｍ３台，...     

玻璃电熔窑的数学模拟研究

从最基本的流体力学及传热公式出发,结合玻璃电熔窑的实际情况,确定了高温下熔融玻璃物理性质系数的计算公式;根据实验数据建立了电导率、密度随温度变化的数学式;用Lakoatos法确定了Fulcher粘度公式的计算系数;在电熔窑作业温度范围内把导热系数近似看作常数.从而建立了玻璃电熔窑工作时的基本数学方程式;同时在切合生产实际的条件下,制定了熔炼玻璃的温度、流速和电位的边界条件;并把这些基本公式用SIMPLE法在二维空间上进行离散,用Line-by-Line法对离散方程进行求解,求解时应用分块修正法加快收敛速度,得出的结果与捷克的Staněk的物理模拟研究结果情况一致,对玻璃电熔窑设计操作有重要价值.     

耦合工况下回转窑热工过程综合数学模型

从回转窑的结构特点及物料运动特性出发,针对回转窑热工过程中所涉及的对流、辐射、传导多种热交换方式及复杂的物理化学反应,应用区段法建立了反映回转窑热工过程特点的综合数学模型。结果表明:大部分区段烟气、料床、窑壁温度分布规律基本相同,但烟气温度高于料床、窑壁温度;在距窑头约10 m处,烟气温度达到最高值1 524℃,随后烟气温度沿轴向下降,到窑尾,烟气温度下降到最低值383℃;料床温度随窑体转速的增加而减低,温度愈高,窑体转速对料床温度的影响愈显著。     

Conjugate mathematical model of ignition of magnesium samples

A distributed mathematical model of ignition of a magnesium particle with allowance for the heterogeneous chemical reaction and the region of the thermal influence of the particle on the gas is developed. A solution of the problem in a steady formulation is found, which allows expanding the classification of the thermal history of the particle-gas system. A numerical model for solving the considered class of boundary-value problems of magnesium-particle ignition is proposed, and the mathematical model is verified in terms of the ignition delay as a function of the Nusselt number. A limiting size of the gas layer near the particle, which determines the ignition mode, is identified. Stability of some heating regimes to finite and infinitesimal disturbances is demonstrated. It is shown that the ignition process can be controlled by a high-frequency thermal action on unstable states of the particle-gas system. __________ Translated from Fizika Goreniya i Vzryva, Vol. 42, No. 3, pp. 57–63, May–June, 2006.     

A mathematical modeling approach for supply chain management under disruption and operational uncertainty

In this work, we proposed a two-stage stochastic programming model for a four-echelon supply chain problem considering possible disruptions at the nodes (supplier and facilities) as well as the connecting transportation modes and operational uncertainties in form of uncertain demands. The first stage decisions are supplier choice, capacity levels for manufacturing sites and warehouses, inventory levels, transportation modes selection, and shipment decisions for the certain periods, and the second stage anticipates the cost of meeting future demands subject to the first stage decision. Comparing the solution obtained for the two-stage stochastic model with a multi-period deterministic model shows that the stochastic model makes a better first stage decision to hedge against the future demand. This study demonstrates the managerial viability of the proposed model in decision making for supply chain network in which both disruption and operational uncertainties are accounted for.     

Linear segmented polyurethanes. II. A mathematical model for the prepolymerization stage

In the first part of this sequel, an experimental investigation on the synthesis of linear segmented polyurethanes was presented, that included estimation of the kinetic constants at 60°C for the prepolymerization and finishing stages. This work presents two comprehensive mathematical models that simulate the mentioned prepolymerizations, in reactions between two poly(tetramethylene oxide) PTMO macrodiols and an excess of methylene diphenyl diisocyanate. The models require to input the molar mass distribution (MMD) of the initial macrodiol. The single-phase (or homogeneous) model calculates a final MMD of approximately 40,000 different molecular species, and somewhat underestimates the observed molar mass dispersities. The double-phases (or heterogeneous) model produces a better fit of the observed MMDs by simulating two independent polymerizations carried out in parallel. The double-phases model contains three adjustable parameters: the reaction imbalances into both phases, and an “effective” rate constant. In part III of this sequel, the presented models will be extended to simulate the finishing stages. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46946.     

水平同心型料管道输送的数学模型

在假设条件下,参照管道水力学理论,分别引入运动型料表面和静止管道壁面的摩阻系数,建立水平同心型料管道流的简易数学模型。该模型较好地描述了型料管道的流动特性,能快速计算型料管道输送参数,其计算值和实验测试值非常吻合,适用于型料管道输送原理的研究和管道工程系统的设计。     

再生纺涤纶短纤维优化配料模型研究

根据约束线性规划原理及涤纶短纤维生产过程中物理变化的内在联系,建立了中空涤纶短纤维配料的数学模型,该模型充分考虑了再生涤纶短纤维生产的工艺要求,得到了适合生产需要的配料结果。通过实例模拟配料计算,该模型比常规配料计算更科学。     

Experimental determination and mathematical modeling of the drying kinetics of a single droplet of colloidal silica

ABSTRACT

Colloidal silica has been used frequently as a model material of drying in the past two decades. Several models of single droplet drying have been validated against the sole experimental evidence by Ne?i? and Vodnik (Kinetics of droplet evaporation. Chemical Engineering Science 1991, 46(2), 527–537), in which relatively scattered experimental data on drying of single droplet of colloidal silica were provided. Due to the importance of this sort of data, the drying of single droplet of colloidal silica was determined more accurately under more extensive conditions in this work. The effect of air temperature on the drying of single droplet of colloidal silica was probed as well as the evolution of particle morphology. The droplet of colloidal silica was found to shrink irregularly during drying due to uneven exposure of droplet surface to air stream. The moisture within the droplet appears to transfer freely to the surface, keeping the surface highly moist. For a large part of drying process, drying of single droplet of colloidal silica is similar to the evaporation of water droplet, which can be predicted well using a simple mathematical model.     

Extraction of toluene and n-heptane mixture using ionic liquid Aliquat 336 and mathematical modeling for solvent selection

Liquid–liquid equilibrium data for the system consisting of toluene, n-heptane and Aliquat 336 ionic liquid was obtained at 303.15 K and atmospheric pressure. The values of distribution coefficient and selectivity were evaluated. Mathematical model relating distribution coefficient and dispersion, dipolar interaction and hydrogen bonding has been developed. Hansen’s solubility parameters were used to determine the parameters. The model was applied for various ionic liquids as solvents. The model predicted the trends similar to the trend reported in the literature. Thus model can predict better solvent for the given extraction application. This methodology has great potential to act as a knowledge-based framework to aid development of new tailor-made solvents. This will save cost and time in experimentation and analysis.     

纤维湿热表面涂覆数学模型的建立及其应用

建立了纤维湿热表面涂覆的数学模型及衡算方程 ,讨论了其在项目设计和工程应用中的适应性。结果表明 ,在约束条件下 ,该数学模型具有较好的适用性 ,其衡算结果与实验结果相吻合。