预蒸处理对辐射松脱脂效果及干燥质量的影响

采用预蒸与常规干燥结合的方式对辐射松(Pinus radiata)锯材进行脱脂和干燥处理,分析预蒸处理对辐射松边材和心材含水率、脱脂率和干燥质量的影响。结果表明:预蒸处理可以缩短心材的干燥时间,对边材的影响不大。由于边材含脂率低、渗透性好,预蒸处理对边材的脱脂率影响不大,预蒸与常规干燥结合以及常规干燥两种工艺处理边材的脱脂率均在60%左右;对于心材,预蒸处理促进松脂迁移,预蒸组的脱脂率大于对照组,但心材初含水率低、渗透性差,导致心材脱脂率低于边材。预蒸组和对照组工艺处理的试材均表现出良好的抗松脂渗出效果,预蒸组表观质量更好。预蒸处理对辐射松边材和心材的干燥质量基本无影响,但需注意防范心材螺旋纹理造成的木材干燥过程中扭曲变形缺陷的发生。

浅谈豆饼预蒸用于高短法蒸料的重要性

浅谈豆饼预蒸用于高短法蒸料的重要性董其武，陈菊英（银川市酱制品厂）银川地处西北边题．过去或酿造酱油技术比较落后，仅原料消化率一项一直徘Ｍ在６０％～７０％之间。提高原料消比率意味着在不增加原料的基础上可提高产负。ｉｆ）ｌ）０年底我厂引进酱油高短法连续拓...

预蒸煮膨化工艺研制婴幼儿营养米粉

淀粉与水混合并加热至超过临界温度(50～70℃)时便形成凝胶。利用各种工艺提供充足的热能,保持足够的温度对淀粉进行预处理,可得到熟化度高、溶解速度快的预糊化淀粉。

间歇式蒸呢机的创新与开发

为了更好地改进蒸呢工序的效果,开发新的蒸呢机械,总结了呢绒一般疵点的形成原因和预防方法,分析了影响蒸呢质量的因素和注意点,本着设备为工艺服务的理念,开发出CM0106间歇式蒸呢机。对CM0106间歇式蒸呢机的主要机构、蒸辊动态蒸呢、精细控制、创新工艺和技术参数进行了详细的介绍,具体说明了预蒸、旋转蒸等新技术功能的操作步骤,对设备先进特点进行了全面的阐述并与其他蒸呢机性能进行了对比。CM0106间歇式蒸呢机操作简单,人机效率高,整理后产品品质高、匀透性更好。通过系统研究蒸汽常压蒸呢工艺的技术及装备,借助传承、创新、思考,促进行业设备的更新换代。

红麻预水解碱法蒸煮制溶解浆的研究

采用预水解碱法蒸煮工艺制取红麻溶解浆,可以达到去除半纤维素、降低灰分和铁质、提高α-纤维素含量的目的,所得成品浆粕甲纤含量达到95%。而且,红麻经预水解后的水解液中的木糖醇可以提取利用,降低了蒸煮黑液排污COD总量。

解决空气预热器出口温度偏低的措施方案

针对用户反映“垃圾焚烧锅炉蒸汽空气预热器出口空气温度偏低”的问题,分析了蒸预器的结构工作原理及出口空气温度偏低的影响因素,阐述了解决其出口空气温度偏低应采取的技术措施及处理方法,从而满足蒸汽空气预热器出口温度不低于180℃性能要求,也为该类装置的疏水、配管及应用提供了参考依据。

不同织物数码喷墨印花的工艺实践

介绍了奥地利Zimmer公司的Chromjet喷墨印花的工艺流程,并分别以涤纶织物、改性涤纶织物和锦纶织物、羊毛织物数码喷墨印花生产工艺为例,详细介绍了染化料的选择、色浆黏度的调节、预蒸条件的选用、喷印车速的控制,并分析了喷墨印花在生产中关键技术问题的解决方法。指出了数码喷墨印花具有环保、低耗等优势且印制织物立体感强、清晰度高。

The effect of ethanol on the performance of CrO_x/SiO_2 catalysts during propane dehydrogenation

The effects of ethanol vapor pretreatment on the performance of CrOx/SiO2 catalysts during the dehydrogenation of propane to propylene were studied with and without the presence of CO2.The catalyst pretreated with ethanol vapor exhibited better catalytic activity than the pristine CrOx/SiO2,generating 41.4% propane conversion and 84.8% propylene selectivity.The various catalyst samples prepared were characterized by X-ray diffraction,transmission electron microscopy,temperature-programmed reduction,X-ray photoelectron spectroscopy and reflectance UV-Vis spectroscopy.The data show that coordinative Cr^3＋ species represent the active sites during the dehydrogenation of propane and that these species serve as precursors for the generation of Cr^3＋.Cr^3＋ is reduced during the reaction,leading to a decrease in catalytic activity.Following ethanol vapor pretreatment,the reduced CrOx in the catalyst is readily re-oxidized to Cr^6＋ by CO2.The pretreated catalyst thus exhibits high activity during the propane dehydrogenation reaction by maintaining the active Cr^3＋ states.

Measurement and Prediction of Vapor Pressure for H20 ＋ CHaOH] C2HsOH ＋ [BMIM][DBP] Ternary Working Fluids

The ionic liquid, 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP]) was prepared and the vapor pressures of three set of binary solutions H2O(1)/CH3OH(1)/C2H5OH(1) + [BMIM][DBP](2) were measured at different temperature and in the ILs mole fraction range from 0.1 to 0.6 with a static equilibrium apparatus. The measured vapor pressures were correlated with Non-Random Two Liquid (NRTL) activity coefficient model and the average relative deviations (ARD) between experimental and correlated vapor pressures for these binary solutions were 3.19%, 2.42% and 2.95%, respectively. Then, the vapor pressures of two set of ternary solutions H2O(1) + CH3OH(2)/C2H5OH(2) + [BMIM][DBP](3) were measured with an inclined boiling apparatus and further predicted with NRTL activity coefficient model based on the binary interaction parameters coming from fitting the vapor pressures of the binary solutions. The results indicated that the ternary solutions containing [BMIM][DBP] were shown a strong negative deviation from Raoult's Law when the mole fraction of [BMIM][DBP] was larger than 0.2, which meant that ternary solutions could absorb the refrigerant vapors at the same or below solution temperature. Meanwhile, the average relative deviations between experimental and predicted vapor pressures for ternary solutions were 2.92% and 3.06%, respectively. Consequently, the NRTL active coefficient model used for non-electrolyte solutions was still valid for predicting vapor-liquid equilibrium of binary or ternary solutions containing ILs.

THE VARIATION OF EVAPORATION OVER SOUTH CHINA AND ITS RELATIONSHIPS TO PRECIPITATION

The evaporation rate over South China is estimated based on the Climate Prediction Center Merged Analysis of Precipitation(CMAP)data and the NCEP/DOE reanalysis II data from 1979 to 2007. The temporal variation of evaporation over South China and its relationship to precipitation are discussed. Climatologically,the evaporation rate over South China is the largest in July and smallest in March.In spring and summer,the evaporation rate is approximately one half of the precipitation rate.However,the evaporation rate is approximately equal to the precipitation rate in fall and winter.The year-to-year variation of the evaporation rate over South China is quite in phase with that of the precipitation rate in the period from February to May but out of phase with that of the precipitation rate in early winter.Over South China there is a pronounced decreasing trend in the evaporation in colder seasons and a positive correlation between the evaporation variation and the rainfall variation in spring.In summer,the abnormality of rainfall over South China is closely related to the anomalous evaporation over the northeastern part of the South China Sea and its eastern vicinity.In winter,the rainfall variation in South China has a close linkage with the evaporation variation in a belt area covering the eastern Arabian Sea,the Bay of Bengal,the southeastern periphery of the Plateau,the southern part of South China Sea and the central part of Indonesia.

Projected Changes of Palmer Drought Severity Index under an RCP8.5 Scenario

The potential change of drought measured by the Palmer Drought Severity Index （PDSI） is projected by using a coupled climate system model under a Representative Pathway 8.5 （RCP8.5） scenario.The PDSI changes calculated by two potential evapotranspiration algorithms are compared.The algorithm of Thomthwaite equation overestimates the impact of surface temperature on evaporation and leads to an unrealistic increasing of drought frequency.The PM algorithm based on the Penman-Monteith equation is physically reasonably and necessary for climate change projections.The Flexible Global Ocean-Atmosphere-Land System model,Spectral Version 2 （FGOALS-s2） projects an increasing trend of drought during 2051-2100 in tropical and subtropical areas of North and South America,North Africa,South Europe,Southeast Asia,and the Australian continent.Both the moderate drought （PDSI ＜-2） and extreme drought （PDSI ＜-4） areas show statistically significant increasing trends under an RCP8.5 scenario.The uncertainty in the model projection is also discussed.

Study on Regeneration of MDEA Solution Using Membrane Distillation

Treating acid gases contained in natural gas by MDEA is used widely. But the efficiency of regeneration of the MDEA solution limited the development of this technology. An optimal temperature is necessary for regeneration of the MDEA solution using membrane distillation. The experiment results showed that the regeneration rate of MDEA rose with an increasing temperature. But the rate increased slowly after the regeneration temperature arrived at a certain value. This study can confirm that regeneration of the MDEA solution using membrane distillation is feasible. This technology provides more advantages as compared to conventional regeneration process.

Effect of thermodynamic parameters on prediction of phase behavior and process design of extractive distillation

Extractive distillation was investigated for separation of the minimum azeotrope of n-propanol/water, via the Aspen Plus simulation platform. Experimental data of n-propanol/water, which could pass the thermodynamic consistency test, were regressed to get suitable binary interaction parameters(BIPs) by the UNIQUAC thermodynamic model. The azeotrope system was heterogeneous in the simulation with built-in BIPs, which was contrary to the experimental data. The study focused on the effect of thermodynamic parameters on the prediction of phase behavior, and process design of extractive distillation. N-methyl-2-pyrrolidone(NMP) and ethylene glycol were used as solvents to implement the separation. Processes with built-in and regressed BIPs were explored,based on the minimum total annual cost(TAC). There were significant differences in the phase behavior simulation using different thermodynamic parameters, which showed the importance of BIPs in the design and optimization of extractive distillation.

Pretreatment of lead anode slime with low silver by vacuum distillation for concentrating silver

The feasibility of separation of lead anode slime with low silver by vacuum distillation was analyzed theoretically. The volatilization rates and mass fractions of elements, influenced by distillation temperature, heat preservation time and material thickness, were investigated under laboratory conditions. The experimental results indicate that almost all of lead and bismuth can be separated from silver-contained multicomponent alloy at 1 223 K for 45 min when the chamber pressure maintains at 10-25 Pa. Silver can be easily enriched in the residue and its mass fraction increases from 3.6% to 27.8% when the distillation temperature is between 1 133 K and 1 373 K. Due to the forming ofintermetallic compounds Cu2Sb, Cul0Sb3 and Ag3Sb, the antimony could not be evaporated completely during the vacuum distillation. EDS analysis indicates that the condensate has a columnar crystal structure.

Prediction of Boiler Drum Pressure and Steam Flow Rate Using Artificial Neural Network

Numerical simulation of complex systems and components by computers is a fundamental phase of any modern engineering activity. The traditional methods of simulation typically entail long, iterative processes which lead to large simulation times, often exceeding transient real time. Artificial neural networks （ANNs） may be advantageous in this context, the main advantage being the speed of computation, the capability of generalizing from the few examples, robustness to noisy and partially incomplete data and the capability of performing empirical input-output mapping without complete knowledge of underlying physics. In this paper, the simulation of steam generator is considered as an example to show the potentialities of this tool. The data required for training and testing the ANN is taken from the steam generator at Abott Power Plant, Champaign （USA）. The total number of samples is 9600 which are taken at a sampling time of three seconds. The performance of boiler （drum pressure, steam flow rate） has been verified and tested using ANN, under the changes in fuel flow rate, air flow rate and load disturbance. Using ANN, input-output mapping is done and it is observed that ANN allows a good reproduction of non-linear behaviors of inputs and outputs.

Gradient Step Method to Predict the Ozone Solubility in Water

In this work it presents a strategy to obtain the ozone solubility in water by gradient step method. In this methodology, the ozone in mixture with oxygen is bubbling in a reactor with distilled water at 21℃ and pH 7. The ozone concentration on gas phase is continually increased after the saturation is reached. The method proposed is faster than conventional method （isocratic method）. The solubility from the gradient method is compared with that values obtained from correlations founded in the literature.

Influence of intermetallic Al-Mn particles on in-situ steam Mg-Al-LDH coating on AZ31 magnesium alloy

The influence of intermetallic Al-Mn particles on the corrosion behavior of in-situ formed Mg-Al layered double hydroxide(Mg-Al-CO32--LDH)steam coating on AZ31 Mg alloy was investigated.The alloy was pretreated with H3PO4,HCl,HNO3or citric acid(CA),followed by hydrothermal treatment,for the fabrication of Mg-Al-LDH coating.The microstructure,composition and corrosion resistance of the coated samples were investigated.The results showed that the surface area fraction of Al-Mn phase exposed on the surface of the alloy was significantly increased after CA pretreatment,which promotes the growth of the Mg-Al-LDH steam coating.Further,the LDH-coated alloy pretreated with CA possessed the most compact surface and the maximum coating thickness among all the coatings.The corrosion current density of the coated alloy was decreased by three orders of magnitude as compared to that of the bare alloy.

Corncobs as Substrate for Oleaginous Yeast-Pretreatment via Steam Explosion and Hydrolysis

Corn cobs are a promising lignocellulosic substrate for the production of biofuels like bioethanol via conventional yeast or biodiesel via oleaginous yeast. Pretreatment of the substrate is essential for further hydrolysis and fermentation steps. This study focused on the steam explosion method as pretreatment. Therefore, different steam explosion severities were evaluated. The content of glucan, xylan and Klason lignin was examined. Xylan degraded with increasing severity from 412.7 g·kg-1 （untreated） to a minimum of 127.3 g-kg1 dry matter （190 ℃/30 min）. Glucan concentrations increased from 315.1 g·kg1 （untreated） to a maximum of 371.6 g·kg-1 dry matter （200 ℃/20 min）. For soluble lignin, an increase could be observed at rising severity, from 145.3 g·kg-l （untreated） to a maximum of 214.9 g·kg-1 dry matter （190 ℃/30 min）. Furthermore, the mass recovery was calculated. At harsher pretreatment conditions, a significant mass loss was observed, estimated by the ash content in the recovered dry matter. The lowest recovery rate was observed for SF = 4.13 （190 ℃/30 min） with 68.39%. The produced inhibitors were evaluated.