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161.
阐述了在隔膜法烧碱生产过程中,因氯气含水多、干燥塔板积液和塔板上无泡沫层等造成氯气干燥效果不好导致酸流量调节困难,并影响设备使用寿命的问题。提出了具体有效的整改措施。  相似文献   
162.
Drying-induced stresses in elastic and viscoelastic saturated materials   总被引:1,自引:0,他引:1  
The paper presents a theoretical analysis of stresses generated during convective drying of kaolin, based on elastic and viscoelastic models. The equations of these models were solved analytically for a cylindrically shaped sample; the distribution and evolution of the radial and circumferential stresses are illustrated in diagrams. The acoustic emission method was used in experimental tests for identification on line of the time period during which the stresses reach their maximal values. A better correlation has been found between the experimental tests and the theoretical predictions obtained on the basis of the viscoelastic model.  相似文献   
163.
The presented study describes the processes and mechanisms of batch fluidized bed drying. The influencing factors of hot air drying are theoretically and experimentally examined, in order to present the relations between temperature and humidity profiles and all other drying parameters. A physical model is presented to facilitate the calculation of the drying processes under defined conditions. Three succeeding drying stages are therefore modeled. Mass and energy balances including all components taking part in the process are formulated. The model clarities the drying process under the assumption of pure heat transfer mechanisms. It does not contain adaptive parameters and takes into account an inactive bypass fraction of the fluidization and drying medium. The evaluation of the model was successful for two fluidized bed plants with nominal widths of 100 mm and 400 mm. The experiments showed sufficient accuracy and transferability of the model to equipment of application‐oriented dimensions.  相似文献   
164.
介绍了共沸蒸馏脱水的基本原理和置换剂的选择条件,综述了共沸蒸馏脱水技术在纳米材料制备中的应用,探讨了共沸蒸馏脱水在纳米粉体制备过程中的防团聚机理,指出了共沸蒸馏脱水技术目前还存在的问题和今后的研究方向.  相似文献   
165.
The thermal properties of amorphous gelatin films and gelatin films with renatured structural order were measured by using conventional and temperature modulated differential scanning calorimetry (DSC). Different amounts of gelatin structural order associated with a melting enthalpic change in the DSC measurement were prepared based on different gelatin drying conditions. Two consecutive heating and cooling DSC measurements on the gelatin films showed that there was no change in the glass‐transition temperature (Tg) for the amorphous gelatin but there was a decrease in the Tg for the structural gelatin on the second DSC scan. This decrease was attributed to the plasticizing effect from the release of originally hydrogen‐bonded water associated with the structural gelatin. In addition, a reversing endotherm observed upon melting of the structural gelatin during a temperature modulated DSC measurement indicated that the transition of bound water to free water occurred as the partial triple‐helix gelatin melted. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1795–1801, 2006  相似文献   
166.
谐振筒式密度计的测量原理为谐振筒的谐振频率会随筒内液体密度的变化而变化,从而通过测量其谐振频率来达到测量其密度的目的。但由于低品质因数谐振筒在谐振频率附近的幅度与其他频率的幅度区分度太小,导致谐振难以实现。因此如何使低品质因数谐振筒达到谐振状态并测得其谐振频率,是谐振筒式燃油密度传感器激励系统的关键问题。激励系统以DSP为主控芯片,运用椭圆拟合的方法解决了低品质因数谐振筒式密度计激励系统的关键技术问题-增益测量和相位测量,运用原位计算节省了DSP大量的内存空间,同时运算量又较小。仿真结果表明,增益测量精度优于0.05%,相位测量精度优于0.05%,高于实际需要。系统在测量并记录了增益、相位差之后,利用相关算法实现了自动增益调节和自动相位调节,并实现了谐振筒的谐振,测得了其谐振频率。  相似文献   
167.
脲醛树脂乳液干燥成粉末的试验研究   总被引:2,自引:0,他引:2  
进行了用惰性粒子流化床干燥器将脲醛树脂乳液干燥成粉末的试验研究,产出了品质好的干粉,得出了在试验条件下的干燥强度和热效率,并作了经济性评价。  相似文献   
168.
A laboratory scale spray dryer was used to encapsulate vildagliptin (VLG), an antihyperglycemic drug, into different polymers such as poly(dl-lactide) (PDLA), poly(dl-lactide-glycolide)-50:50 (PLGA 50:50), and poly(dl-lactide-glycolide)-75:25 (PLGA 75:25). Response surface methodology (RSM) was employed to evaluate the effects of process and formulation factors on the encapsulation efficiency (EE). The physicochemical properties of the drug-loaded micro-/nanoparticles, mainly the drug loading (DL), particle size distribution, surface morphology, drug–polymer compatibility, and release rate were investigated. % EE of drug-loaded micro-/nanoparticles were in the range of 57.10% to 76.44%. PLGA50:50 micro-/nanoparticles showed highest EE as compared to PDLA and PLGA75:25 micro-/nanoparticles. The mean particle size of the micro-/nanoparticles containing PLGA 50:50, PLGA 75:25, and PDLA polymers were 428?nm, 640?nm, and 1.22 µm, respectively. Surface morphology study revealed smooth, spherical and nonporous surface structures of the micro-/nanoparticles. Fourier transform infrared spectroscopy studies confirmed the drug–polymer compatibility. Powder X-ray diffraction analysis of micro-/nanoparticles revealed that VLG was present in the amorphous form within the micro-/nanoparticles formulations. In vitro release study demonstrated that VLG is slowly released from micro-/nanoparticles for 12?h and the drug release rate was influenced by type and viscosity of polymers used. This work suggests that PDLA, PLGA 50:50, and PLGA75:25 polymers are able to sustain the VLG release rates from micro-/nanoparticles.  相似文献   
169.
Abstract

Sewage treatment can be classified into three phases: liquid, gaseous, and solid. Treatment of solids is performed in several steps, and the greatest difficulty in removing water from sewage sludge is due to the bound water present in the sludge. Thus, biodrying, a drying method that can be classified as biological, has been recently applied to treat this type of waste. This review paper aims to report and compile data from 49 biodrying assays of sewage sludge found in the literature (through the present, 2019) into one synthesis table, to discuss and compare the numerous variables found in these papers and their implications for biodrying, and to suggest possibilities for future research. This paper additionally intends to improve knowledge of biodrying and to consequently contribute to the monitoring and understanding of the process.  相似文献   
170.
采用二次回归正交设计方法,对“胶乳法“氯化天然橡胶(CNR)进行薄层干燥试验.分析了热风温度、风速和物料的粒径等因素对干燥速率、干燥后物料性能的影响规律,确定了影响物料薄层干燥速率各因素的主次,提出了较佳的干燥工艺和合理的性能参数.  相似文献   
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