连续式低粘度粉浆料真空脱气系统的设计

针对蒸浆用的低粘度粉浆料，提出自吸进料-喷淋脱气-分级间歇出料的脱气工艺；由此设计出的连续式真空脱气系统，可解决现有真空摘抄设备存在的不适应问题，简化了设备结构，并便于设备维护，延长整机寿命。     

果实饮料的脱气及相关设备

本文论述了可用于果实饮料的四种脱气方法的原理及其相关设备,并对这四种脱气方法进行比较。     

真空冷冻干燥草莓粉工艺研究

以冻干草莓粉为研究对象,对其湿法生产工艺和真空冷冻干燥条件进行了研究.通过U8(81×41)均匀设计和L9(34)正交设计试验,确定了湿法生产冻干草莓粉的最佳工艺条件为将草莓浆在-25℃下预冻5 h,装料厚度6 mm,冻干室工作压力65 Pa,升华温度55℃,解析温度70℃.     

真空冷冻干燥板栗粉的可行性研究

本文介绍我国板栗产量大,将低价原料通过冻干工艺加工成冻干板栗粉,提高产品附加值的同时论述产品特点、生产规模、工艺设备以及经济效益。     

菠萝粉真空冷冻干燥工艺研究

以菠萝为原料,利用真空冷冻干燥将菠萝果肉制作成为菠萝粉。通过正交实验,对菠萝粉真空冷冻干燥工艺作初步研究,探讨真空冷冻干燥不同的干燥温度、真空度、物料厚度对菠萝粉干燥特性的影响,得到最优菠萝粉成品的最佳干燥工艺为:干燥温度为65℃,真空度为40Pa,物料厚度为4mm,菠萝粉干燥品质的影响因素主次是物料厚度>真空度>干燥温度。     

低粘度磷酸酯淀粉浆料与递质pH的依赖关系

在pH值为2．0～7．0范围内,制备不同的样品,以粘度、粘度稳定性、浆膜性能及浆液粘附性能为量化指标,研究了磷酸酯淀粉粘度与制备递质的pH依赖关系．结果表明,起始pH值对粘度的影响较显著,pH值范围不同,影响程度和方式也不同,当pH≤4．0时,粘度降低较快,主要发生淀粉链水解,浆膜性能及浆液粘附性较差;pH≥6．0,淀粉开始发生交联,粘度逐渐增加、稳定性降低;4．8≤pH≤5．4,淀粉水解适中,能获得粘度、浆膜性能及浆液粘附性较好的磷酸酯淀粉,尤以pH=5．2为优;在该pH值范围内,未观察到粘度稳定性与pH较明显的规律性变化关系．     

真空系统工艺设计合理性的思考

真空系统是制盐生产中的关键工序，它直接影响制盐生产中的总有效温差的高低，影响单位时间内的产盐量。真空系统工艺合理，能促进整个蒸发系统运行经济．产盐量增高，各种能耗低，反之，对制盐生产危害极大。本文围绕我厂１５万，屯真空系统工艺的合理性谈几点看法。     

喷雾干燥和真空干燥制备豆酱粉的比较研究

以豆酱为原料,采用真空干燥和喷雾干燥制备豆酱粉,确定最佳的工艺条件.相对于真空干燥豆酱粉,喷雾干燥豆酱粉感官指标、理化指标更好,所以选择喷雾干燥制粉,优化后的喷雾干燥条件为:进口温度180℃,出口温度80℃.制得的豆酱粉口味良好、运输方便、保存期长,具有一定的市场前景.     

连续式微波真空干燥设备的设计与试验

阐述连续式微波真空干燥设备的结构特点和设计要点,分析并确定微波馈口、微波干燥室、微波密封及连续送料系统的结构和相关参数。试验表明,整机结构合理、操作方便、性能稳定、安全可靠,能快速低温干燥出高品质的苹果脆片,产量能满足工厂化生产要求。     

变压吸附气体分离技术在食品工业中的应用

简要介绍变压吸附气体分离技术的原理、优点,重点列举该技术在食品工业中的应用。     

A new method for separating HFC-134a from gas mixtures using clathrate hydrate formation

A new separation method using gas hydrate formation is proposed for separating HFC-134a from gas mixtures containing N2 and HFC-134a. The feasibility of this separation method was investigated from various points of view. First, to determine the mixed hydrate stability region, three-phase equilibria of hydrate (H), liquid water (Lw), and vapor (V) for HFC-134a + N2 + water mixtures with various HFC-134a vapor compositions were closely examined in the temperature and pressure ranges of 275-285 K and 0.1-2.7 MPa, respectively. Second, the compositions of the hydrate and vapor phases at a three-phase equilibrium state were analyzed for identical mixtures at 278.15 and 282.15 K to confirm the actual separation efficiency. Third, kinetic experiments were performed to monitor the composition change behavior of the vapor phase and to determine the time required for an equilibrium state to be reached. Furthermore, X-ray diffraction confirmed that the mixed HFC-134a + N2 hydrates were structure II. Through an overall investigation of the experimental results, it was verified that more than 99 mol % HFC-134a could be obtained from gas mixtures after hydrate formation and subsequent dissociation processes. Separation of HFC-134a using hydrate formation can be carried out at mild temperature and low-pressure ranges. No additive is needed to lower the hydrate formation pressure.     

Influence of polyols and bulking agents on flavour release from low-viscosity solutions

The release of four volatile flavour compounds (cis-3-hexen-1-ol, benzaldehyde, ethyl butanoate and butyl isovalerate) from pure water and various low-viscosity aqueous solutions (sucrose, maltitol, erythritol, polydextrose and oligofructose, each at 20% (w/w)) was investigated. Dynamic headspace concentrations of the flavour compounds at thermodynamic equilibrium were monitored by proton-transfer-reaction mass spectrometry (PTR-MS). The rheological properties of the solutions were characterised by their viscosity. Flavour release from pure water increased with increasing hydrophobicity and volatility of the flavour compounds. The highly volatile compounds were retained more extensively in the presence of sucrose, polyols and bulking agents, compared to in pure water, whereas an increase in the release of the less volatile cis-3-hexen-1-ol was observed. All aqueous solutions had similar viscosities, although bulking agent solutions tended to have higher viscosities than polyol solutions of the same concentration. A correlation between viscosity and flavour release in the low-viscosity solutions was not evident.     

豆奶分离机差速器的设计

根据豆奶分离机的特点，选定三级行星差速变速器作为豆奶分离机的差速器。对三级行星差速器从参数选择到各级的传动做了详细的计算。     

Cycle development and design for CO2 capture from flue gas by vacuum swing adsorption

CO2 capture and storage is an important component in the development of clean power generation processes. One CO2 capture technology is gas-phase adsorption, specifically pressure (or vacuum) swing adsorption. The complexity of these processes makes evaluation and assessment of new adsorbents difficult and time-consuming. In this study, we have developed a simple model specifically targeted at CO2 capture by pressure swing adsorption and validated our model by comparison with data from a fully instrumented pilot-scale pressure swing adsorption process. The model captures nonisothermal effects as well as nonlinear adsorption and nitrogen coadsorption. Using the model and our apparatus, we have designed and studied a large number of cycles for CO2 capture. We demonstrate that by careful management of adsorption fronts and assembly of cycles based on understanding of the roles of individual steps, we are able to quickly assess the effect of adsorbents and process parameters on capture performance and identify optimal operating regimes and cycles. We recommend this approach in contrast to exhaustive parametric studies which tend to depend on specifics of the chosen cycle and adsorbent. We show that appropriate combinations of process steps can yield excellent process performance and demonstrate how the pressure drop, and heat loss, etc. affect process performance through their effect on adsorption fronts and profiles. Finally, cyclic temperature profiles along the adsorption column can be readily used to infer concentration profiles-this has proved to be a very useful tool in cyclic function definition. Our research reveals excellent promise for the application of pressure/vacuum swing adsorption technology in the arena of CO2 capture from flue gases.     

木糖渣木质素的提取工艺研究

应用碱溶方法提取木糖渣木质素液,经正交试验确定了优化的工艺条件为:固液比1∶9、Na OH溶液浓度2.5%、反应时间3h、提取温度85℃,木质素的提取率达到96.7%。再经连续膜浓缩技术将木质素液的干物浓度由2%浓缩至10%以上,最后经喷雾干燥技术得到碱性木质素产品,或者经酸析分离工序制备酸性木质素产品,为木糖渣的高值化利用提供了新途径。     

TBJ型透平真空泵在纸机真空系统的应用

简述了国产TBJ型透平真空泵的性能、结构及特点,介绍了不同真空泵的选用和工艺管线布置,及真空系统的节能情况。     

皮革真空转鼓的设计研究

对皮革在真空机制下的湿加工机理进行了分析与研究 ,为增加皮革鞣制及鼓滚摔软效果 ,提出了集真空、温度和机械摔滚机制于一体的机构及结构设计方案 ,研制出了一种生产效率高、使用范围广、少污染的皮革真空转鼓。     

基于S7-300PLC果蔬真空预冷机控制系统的设计

以果蔬真空预冷机的控制系统为例,分析其结构和工艺原理,采用小型PLC代替传统的继电器控制,进行了PLC选型和程序设计,实现了果蔬真空预冷机的PLC自动控制,从而提高了预冷机的可靠性和自动化程度,对通用真空预冷控制系统的设计具有借鉴意义。     

基于PLC的燃气计量仪表校准系统设计与开发

设计了基于PLC和IPC技术的仪表校准系统.该系统包括3路校正系统,通过西门子S7-200的PLC以及I/O模块,完成底层设备的测试过程,并将测试数据和过程状态通过网络通信的方式,在上位机的IPC系统中进行监控和处理.该系统能可靠地完成对燃气计量仪表校准的自动控制任务,具有推广价值.