乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

Coefficient of optimality of linings of heating units

The efficiency of the use of various refractories is estimated by an objective factor, namely, the coefficient of optimality of linings of heating units.Translated from Ogneupory, No. 12, pp. 26 – 27, December, 1994.     

Stability of granules of solid solutions of poly-pehnyleneterephthalamide

Conclusions Studies of starting solutions of PPTA in sulfuric acid and of granules obtained under pressrue at low temperature, and of granules stored in a hermetic package, have been carried out by the methods of differential thermal analysis, turbidity spectrum and viscometry.On granulation of a solidified PPTA solution, short-term storage of the granules in a hermetic package, or short contanct of the granulated mass with air, no appreciable change in melting point or of the intrinsic viscosity of the system takes place.Long storage of a granulated solution, even in hermetic packages, can lead to a considerable decrease in the melting point of the crystal solvates, caused by an increase in defectiveness of crystal structure under the effect of moisture.Translated from Khimicheskie Volokna, No. 3, pp. 25–26, May–June, 1986.     

Model of diffusion-limited combustion of assembly of droplets

Omsk. Translated from Fizika Goreniya i Vzryva, Vol. 26, No. 1, pp. 67–73, January–February, 1990.     

气化给煤系统故障分析

气化给煤装置自投运以来,出现了气化煤仓堵煤、称重给煤机输送皮带因跑偏而损伤以及清扫装置故障频繁等问题,多次造成气化系统减负荷运行。通过对出现的各种问题进行分析,找到了产生这些问题的原因,并有针对性地采用配煤和改进清扫链等措施,使出现的问题得到了极大的改善。     

Process of acceleration of filtration of viscose

Conclusions It is significant that the purification on a single passage of viscose through porous ceramic corresponds to the result of a two-stage filtration of it in industrial filter-presses with standard fillings.Kiev Combine. Kiev Technological Institute of Light Industry. Translated from Khimicheskie Volokna, No. 3, pp. 20–22, May–June, 1969.     

Theory of thermohydrodynamic instability of the front of filtration combustion of gases

Based on the filtration equations with account of heat transfer in the heating region, the problem of instability of small perturbations of the wave front of filtration combustion of a gas is solved. Expressions for the growth decrement and critical transverse size of a perturbation are obtained. The problem of the wave-front stability is solved with account of the macroscopic redistribution of filtration in the system. The solution includes macroscopic characteristics such as the transverse size, the width of the high-temperature zone, etc. A method is proposed for taking into account the influence of the characteristics of the system on the evolution of perturbations. It is shown that small deformation perturbations of the front always increase to a certain amplitude; their subsequent development— continuation of their growth or stabilization—is determined by the characteristics of the system. Translated fromFizika Goreniya i Vzryva, Vol. 35, No. 5, pp. 3–5, September–October 1999.     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

氯碱生产中的资源循环利用改造总结

介绍了海化氯碱树脂公司对淡盐水、电石泥、氯气、废水、余热及冷凝水的回收综合利用情况。     

Exchange Behavior of Kaolins of Varying Degrees of Crystallinity

Particle-size fractions of several Georgia kaolins, which were prepared by sedimentation procedures, were examined from the standpoint of crystallinity, cation-exchange capacity, and surface area. Crystallinity was studied using X-ray techniques, exchange capacities were measured using the manganese saturation method, and surface areas were determined using glycerol adsorption techniques. A linear relation was obtained between surface areas and exchange capacities when areas were increased by decreasing the particle size or by changing from well-crystallized to poorly crystallized kaolins. In most cases, the empirically determined crystallinity ratios indicated a change in crystallinity with change in particle size, the crystallinity generally increasing with decreasing particle size in individual samples. Unlike, however, the relation noted for exchange, the crystallinity did not consistently correlate with area changes both among the various samples and within the various particle-size fractions of a single sample. These results suggest that the relatively high cation-exchange capacity of poorly ordered kaolins is more directly a result of high surface area with crystallinity playing, at most, a very minor role.     

Analysis of products of high-temperature pyrolysis of various hydrocarbons

Ethane, ethylene, acetylene, propane and neopentane have been pyrolyzed at 1173 K, and methane at 1372 K in a flow system, and the volatile pyrolysis products analyzed. Eleven aromatic hydrocarbons, containing 14 or fewer carbon atoms, accounted for 98 + % of the liquid products recovered in each case. Benzene was the main product, followed by naphthalene. No compounds with branched chains or multiple substituents were present, and compounds containing even numbers of carbons comprised 93–99% of each mixture. Acetylene was a major component of the gaseous effluent from each of the initial hydrocarbons. The effect of temperature on the composition of the gaseous effluent during pyrolysis of methane, ethane and ethylene was determined. Carbon film deposition from methane commenced at about 1273 K; from ethane at 1015 K and from ethylene at 1100 K, in each instance coinciding with the appearance of acetylene in the effluent. As the temperature was raised, at first the increase in the rate of carbon deposition closely followed the increase in the concentration of acetylene in the effluent. It is proposed that acetylene may be a common factor in the pyrolysis of aliphatic hydrocarbons, perhaps acting as the precursor of both surface carbon and aromatic hydrocarbons by a process of head-to-tail linkage of two-carbon units at active surface sites to form chains that then undergo dehydrogenation to carbon or cyclization and desorption as aromatic species.     

Phase behavior of homologous series of monoesters of polyols

Phase behavior of anhydrous monopalmitates and stearates and of most laurates, myristates and behenates of ethylene glycol, erythritol, xylitol, sorbitol, and mannitol has been studied. The compounds, substantially free of diesters, are mostly not isomerically pure but are predominantly primary esters. Also studied were the (nonisomeric) palmitate and stearate of pentaerythritol (Pe) and the oleate of erythritol. Mesomorphism, absent in anhydrous monoglycerides unless of short chain length and symmetrical, is a prominent feature of the members of the present group of compounds containing at least three unesterified hydroxyls. In general, crystal melting points rise with length of polyol, and mesomorphic melting points rise faster. Crystal melting points rise with acyl chain length while mesomorphic melting points run through a maximum. Heats of fusion are of the order 40 cal/g for crystal melting and 0.5 cal/g for melting of mesomorphic states. In the range explored, mesomorphic values fall with both polyol length and acyl length. At higher acyl chain length, notably with behenates, there are new features of mesomorphic behavior. Crystalline phase, from solvent, melts to a neat or lamellar phase, which in turn melts to liquid with subsequent appearance of higher melting middle or cylindrical phase. Polymorphism is general among the crystal states and tends to be complex. In a brief study of solvent crystallized 50–50 binary mixes of xylitol stearate with other xylitol esters and other stearates, considerable evidence of solid solution in Form I crystals (of xylitol stearate type) was observed with very modest eutectic lowering of crystal melting point. Mesomorphic points were almost linearly intermediate between those of components. Of particular interest were mixtures of xylitol stearate and 1-monostearin (50–50 and 25–75), for which mesomorphic melting points were realized, and for which an extrapolation to 100% monostearin leads to a hypothetical mesomorphic melting point far below any monoglyceride crystalline melting point. A brief examination of an aqueous xylitol palmitate system explored to a maximum temperature of 165 C shows extensive occurrence of aqueous mesomorphic state somewhat after the manner of monoglyceride systems. Mesomorphic melting level rises rapidly from the value for anhydrous ester.     

Approximation of temperature dependence of the modulus of elasticity of glass

A refined nonlinear value of the main parameter of a material, i.e., the elongation modulus versus the instant temperature value, was suggested for introduction into the computational algorithm of tempering stresses.     

A study of the rate of formation of polysulfides of tetramethylthiuram disulfide

The rate of formation of tetramethylthiuram polysulfides (TMTP), that play an important role in vulcanization, was studied. After a short induction period (<30 s), tetramethylthiuram disulfide (TMTD) and TMTD-sulfur mixes, heated to 130–150°C in the absence of rubber, rapidly form a series of TMTPs. The concentrations of TMTPs of lower sulfur rank increase most rapidly, indicating that sulfur atoms are added to the accelerator sequentially. The incorporation of sulfur molecules to give TMTPs, which subsequently desulfurate, does not occur. Equilibrium concentrations of the various TMTPs are achieved in about 2 min. Little tetramethylthiourea is formed below 200°C. Tetramethylthiuram monosulfide (TMTM) is stable, but TMTM-sulfur mixes form TMTPs. A mechanism is proposed to account for the large amount of TMTM formed on heating TMTD in the absence of sulfur and the correspondingly higher TMTP concentrations in the presence of sulfur. © 1995 John Wiley Sons, Inc.     

塑料密度温度系数的测定

对HDPE、LDPE、PP、PS、ABS、EVA、PVC等常见塑胶粒的密度温度系数进行了测定。采用本文所测得的密度温度系数值,将常温下测得的密度值校正到指定温度下的密度值,这种方法可以满足塑料密度常规检验的要求。     

浅谈安全中的“以人为本”

在安全生产系统中,人的素质是占主导地位的,人的行为贯穿生产过程的每一个环节。企业安全要以人为核心,树立人本观念。安全管理必须重视人的因素,提高人的素质,从精神上、物质上关心人尊重人,以有效的手段约束和激励人,加大安全投入、落实有效措施,保障个人的利益,使大家找到归属感,保护员工身体健康和生命安全,最终形成安全管理＂命运共同体＂,推动企业发展和提高。     

光度法测定甲醛的研究进展

本文综述了近年来光度法测定甲醛的研究进展,分别从非动力学光度法、动力学光度法进行归纳,并从反应介质、检出限、线性范围和应用等方面进行叙述。     

Model of Cellular Instability of Flames of Ternary Mixtures

A simple phenomenological diffusive-thermal model of cellular instability of premixed flames of ternary mixtures is developed and presented. The model shows that preferential diffusion can alter stoichiometry of the mixture, i.e., the ratio of the fuel and oxidizer concentrations, and also its effective dilution by an inert. Key parameters of the model are estimated using numerical modeling of burning velocities. Laminar burning velocities are calculated for hydrogen-oxygen-nitrogen, methane-oxygen-nitrogen, and propane-oxygen-nitrogen mixtures. Conditions for the appearance of cellular instability in ternary mixtures are determined and compared with experiments. In good agreement with experimental observations, the diffusive-thermal instability is predicted in hydrogen flames with equivalence ratios φ ≲ 1.45, in lean methane flames with φ ≲ 1.02, and in rich propane flames with φ ≳ 1.03. The magnitude of the change in the local flame velocity due to preferential diffusion is evaluated. It is demonstrated that nitrogen diffuses faster than oxygen in hydrogen-air and methane-air flames, while oxygen diffuses faster than nitrogen in flames of propane and other heavier hydrocarbons. In mixtures of air with propane or heavier hydrocarbons, the transition between stable and unstable regimes is predicted in mixtures that are leaner than the mixture corresponding to the peak of the burning velocity curve, in agreement with experimental observations. __________ Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 5, pp. 14–22, September–October, 2005.