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1.
超声波防除积垢节能技术及设备开发   总被引:6,自引:0,他引:6       下载免费PDF全文
传热设备的积垢问题一直是人们急于解决的一大难题,不仅影响热能利用和生产正常运转,而且会降低产品质量,增加生产成本。通过机理研究、室内试验和工厂试验,揭示了超声波防除积垢的机理,筛选出最佳的声场参数,研制出一种新型的超声波防除积垢设备,室内试验和工厂试验结果表明,超声波技术不但可以防止新垢的产生,而且可以有效地去除已有积垢,显著地提高蒸发系统传热系数和生产能力,可停止使用化学清洗剂,从而延长传热设备使用寿命,避免污染环境,该技术有可能广泛地应用于制糖工业、化肥工业、制浆造纸工业等诸多领域。  相似文献   

2.
建立表征离心压气机叶轮积垢分布的粗糙度模型,在叶片表面生成三维、非均匀分布的粗糙带,数值研究干净和积垢状态下叶轮的气动性能和内部流场,并通过敏感性分析,找到对叶轮气动性能影响最大的积垢区域。结果表明:积垢叶轮的多变效率和总压比较干净叶轮均有显著下降;随着流量增大,性能衰减愈发明显;离心压气机叶片前缘靠近叶顶部位为气动性能对积垢的最敏感区域.研究工作为离心压气机的鲁棒设计优化奠定了理论基础。  相似文献   

3.
《物理》2002,(2)
特约专稿我的研究生涯 (黄昆 ) .研究快讯表面三维纳米结构在衰变过程中的层间质量传输机制 (李茂枝等 ) ;LaFe1 1 2 Co0 7Si1 1 合金在室温区的巨大磁熵变 (胡凤霞等 ) .评  述物质的新状态———玻色 -爱因斯坦凝聚——— 2 0 0 1年诺贝尔物理奖介绍 (陈徐宗等 ) .知识和进展芯 -壳结构复合纳米颗粒 (阚彩侠等 ) ;BN纳米管———一种新型的纳米材料 (邢光建等 ) ;新型压电单晶PMNT的生长、性能及其应用研究 (罗豪等 ) ;受控核聚变两大途径的对比与结合 (谭宝林 ) .物理学和高新技术物理场防除积垢节能技术 (丘泰球等…  相似文献   

4.
针对换热设备积垢与能源浪费问题,建立了水力空化防除垢实验测试平台,并以加热器和铜片试件为结垢表面进行了实验研究。采用显微放大摄影系统详细观测了水力空化防除垢现象与效果,系统研究了液体流量对防垢效果及积垢沉积的影响规律。研究结果表明:水力空化作用能使溶液中的成垢物质细化、破碎,减小垢层与试件表面的附着力并且将已有垢层粉碎、破坏;存在最佳的溶液流量使试件表面的防垢率达到最大,而积垢脱除速率随着流量的增大而降低。  相似文献   

5.
《应用光学》2007,28(1):I0009-I0012
一、光电侦察技术 中国历史就有“耳听是虚,眼见为实”的说法。目视侦察曾是获取战场信息最主要的方法,现在依然是重要的方法之一。现代光电技术延展了目视侦察的距离,拓展了信息的内容和含量,它是以可见光和红外光作为载体的信息获取手段,其主要的技术有光学技术、激光技术、红外技术、微光技术、紫外技术、照相技术、电视摄像技术等。  相似文献   

6.
弹性管束汽-水换热器强化传热试验研究   总被引:2,自引:0,他引:2  
本文设计了一种新的传热元件-弹性管束,它对管内外流体流动具有良好的振动响应特性。利用传热表面振动提高管外对流换热系数的同时,利用振动变形减少积垢,降低污垢热阻,实现了复合强化传热。在汽水换热条件下,对流作诱导振动强化传热规律进行了试验研究,得到了管外对流换热的准则方程式。  相似文献   

7.
无污染物理采油新技术   总被引:1,自引:0,他引:1  
路斌  关继腾 《物理》2002,31(4):235-239
无污染物理采油技术是继化学采油技术之后发展起来的一种油层处理新技术,具有化学采油方法所有具备的许多优点。文章介绍了目前物理技术在采油工程中的应用状况,论述了各种物理采油技术的作用机制和工作原理,并对目前该项技术在我国的发展状况进行了分析,指出了一些需要注意的问题。  相似文献   

8.
王长顺  邹义夫 《物理实验》1994,14(3):135-136
一种快速的实用低温温度计定标方法王长顺,邹义夫,郭加平,余保龙(河南大学物理系开封475001)低温物理实验是近代物理学的重要课题,作为低温实验技术的基础实验,我们开设了实用低温温度计定标实验.在教学中,我们改进了低温均温体,利用快速的测量技术,使实...  相似文献   

9.
表面热透镜技术测试光学薄膜特性研究   总被引:1,自引:0,他引:1  
在薄膜特性的研究工作中,激光引起的表面形变是一种广泛应用的技术。在这种技术中,薄膜的形变(热包高度小于0.1nm)一般是采用光热偏转技术来探测的。介绍了一种通过光学衍射效应来研究薄膜表面形变的新技术即表面热透镜技术,它是研究薄膜特性的一种灵敏且易于控制的方法。探讨了其理论模型及在薄膜的吸收测量和缺陷特性测试方面,该方法相对于传统方法的优点和潜力。  相似文献   

10.
先进光学制造技术发展研究   总被引:6,自引:1,他引:5  
本文报告了高技术的牵引和市场需求推动是先进光学制造技术发展的动力。研究了先进光学制造技术分类方法。讨论了先进光学制造技术的概念,指出了继承和集成是先进光学制造技术主要特点。一大一小,一长一短,一刚一柔是其主要发展方向。  相似文献   

11.
A study of dry cleaning methods for plasticized PVC has been undertaken using three commercial cloths recommended for plastics artworks, in addition to cotton swabs traditionally used in art conservation. The evaluation of the cleaning has focussed on the efficiency of the cleaners, and the physical and chemical damages caused by the cleaning. The physical and chemical modifications of the PVC surface have been studied by optical microscopy, non-contact profilometry and ATR-FTIR spectroscopy, while spectrocolorimetry and non-contact profilometry have been used for evaluating the cleaning efficiency. The results have shown that the cleaner's composition and the cleaning time play an important role in damaging the plasticized PVC surface. On the contrary, it has not been completely determined if the texture of the cleaning agents’ surface had an influence on the cleaning efficiency.  相似文献   

12.
Paper is one of the most important materials in cultural heritage given its extensive use as the data carrier for religious, artistic and scientific records. For both aesthetic and conservation reasons, cleaning of these materials is often needed. Current paper cleaning methods using conventional means are not always sufficient, e.g. for the local cleaning of paper in the vicinity of sensitive media. In this respect a ns-pulse laser provides a valuable tool for solving difficult cleaning problems. The influence of various laser wavelengths (355 nm, 532 nm, and 1064 nm) and the ageing status of modern paper test systems were studied. Colorimetric measurements, the determination of the average molecular mass of cellulose, and chemiluminescence analysis proved to be useful for the characterization of the laser-treated paper. Treatment with green laser light at =532 nm below the paper ablation threshold fluence gave the most promising results on pure papers, with no discolouration and no other visible alteration, nor detectable chemical changes. PACS 06.60.J; 78.60.Ps; 81.65.Cf  相似文献   

13.
Ultrafiltration (UF) of whey is a major membrane based process in the dairy industry. However, commercialization of this application has been limited by membrane fouling, which has a detrimental influence on the permeation rate. There are a number of different chemical and physical cleaning methods currently used for cleaning a fouled membrane. It has been suggested that the cleaning frequency and the severity of such cleaning procedures control the membrane lifetime. The development of an optimal cleaning strategy should therefore have a direct implication on the process economics. Recently, the use of ultrasound has attracted considerable interest as an alternative approach to the conventional methods. In the present study, we have studied the ultrasonic cleaning of polysulfone ultrafiltration membranes fouled with dairy whey solutions. The effects of a number of cleaning process parameters have been examined in the presence of ultrasound and results compared with the conventional operation. Experiments were conducted using a small single sheet membrane unit that was immersed totally within an ultrasonic bath. Results show that ultrasonic cleaning improves the cleaning efficiency under all experimental conditions. The ultrasonic effect is more significant in the absence of surfactant, but is less influenced by temperature and transmembrane pressure. Our results suggest that the ultrasonic energy acts primarily by increasing the turbulence within the cleaning solution.  相似文献   

14.
Modern scanning transmission electron microscopy (STEM) enables imaging and microanalysis at very high magnification. In the case of aberration-corrected STEM, atomic resolution is readily achieved. However, the electron fluxes used may be up to three orders of magnitude greater than those typically employed in conventional STEM. Since specimen contamination often increases with electron flux, specimen cleanliness is a critical factor in obtaining meaningful data when carrying out high magnification STEM. A range of different specimen cleaning methods have been applied to a variety of specimen types. The contamination rate has been measured quantitatively to assess the effectiveness of cleaning. The methods studied include: baking, cooling, plasma cleaning, beam showering and UV/ozone exposure. Of the methods tested, beam showering is rapid, experimentally convenient and very effective on a wide range of specimens. Oxidative plasma cleaning is also very effective and can be applied to specimens on carbon support films, albeit with some care. For electron beam-sensitive materials, cooling may be the method of choice. In most cases, preliminary removal of the bulk of the contamination by methods such as baking or plasma cleaning, followed by beam showering, where necessary, can result in a contamination-free specimen suitable for extended atomic scale imaging and analysis.  相似文献   

15.
Ultrasound is a sound wave with a frequency above the human audible range of 16Hz to 16kHz. In recent years, numerous unit operations involving physical as well as chemical processes are reported to have been enhanced by ultrasonic irradiation. There have been benefits such as improvement in process efficiency, process time reduction, performing the processes under milder conditions and avoiding the use of some toxic chemicals to achieve cleaner processing. These could be a better way of augmentation for the processes as an advanced technique. The important point here is that ultrasonic irradiation is physical method activation rather than using chemical entities. Detailed studies have been made in the unit operations related to leather such as diffusion rate enhancement through porous leather matrix, cleaning, degreasing, tanning, dyeing, fatliquoring, oil-water emulsification process and solid-liquid tannin extraction from vegetable tanning materials as well as in precipitation reaction in wastewater treatment. The fundamental mechanism involved in these processes is ultrasonic cavitation in liquid media. In addition to this there also exist some process specific mechanisms for the enhancement of the processes. For instance, possible real-time reversible pore-size changes during ultrasound propagation through skin/leather matrix could be a reason for diffusion rate enhancement in leather processing as reported for the first time. Exhaustive scientific research work has been carried out in this area by our group working in Chemical Engineering Division of CLRI and most of these benefits have been proven with publications in valued peer-reviewed international journals. The overall results indicate that about 2-5-fold increase in the process efficiency due to ultrasound under the given process conditions for various unit operations with additional benefits. Scale-up studies are underway for converting these concepts in to a real viable larger scale operation. In the present paper, summary of our research findings from employing this technique in various unit operations such as cleaning, diffusion, emulsification, particle-size reduction, solid-liquid leaching (tannin and natural dye extraction) as well as precipitation has been presented.  相似文献   

16.
Numerical simulation and automated optimization of Langevin-type ultrasonic transducers are investigated. These kind of transducers are standard components in various applications of high-power ultrasonics such as ultrasonic cleaning and chemical processing. Vibration of the transducer is simulated numerically by standard finite element method and the dimensions and shape parameters of a transducer are optimized with respect to different criteria. The novelty value of this work is the combination of the simulation model and the optimization problem by efficient automatic differentiation techniques. The capabilities of this approach are demonstrated with practical test cases in which various aspects of the operation of a transducer are improved.  相似文献   

17.
Economic application of atmospheric pressure plasma technology for industrial pollution control requires fulfilling two propositions: First application of pollution control technologies needs to result in clear environmental, health, or safety benefits motivating political measures. Second plasma technology needs to be competitive as compared to other available pollution control technologies. Thus in this article methods for the evaluation of atmospheric plasma application for industrial pollution control are reviewed: Examples of emission regulations and emission control technologies are given. Requirements of industrial scale emission control and of thermal and non‐thermal exhaust gas treatment technologies are described. The potential of various non‐thermal plasma reactor concepts for cost effective treatment of industrial scale gas flows is analyzed, and methods for the evaluation of plasma energy balance and plasma chemical kinetics are given for them. How to deal with shortcomings of atmospheric pressure plasmas such as lack of plasma‐chemical selectivity is addressed in a section about plasma‐catalytic hybrid processes. Further the progress made recently in electrostatic precipitation is reviewed, and the importance of electro‐hydrodynamic effects for the reactor design both for electrostatic precipitation and for plasma chemical pollution control is considered. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

18.
This paper deals with dust particle elimination on industry plastic foils in industry environment and with technical air cleaning for this environment. We describe electro-physical processes that are in progress during electric charge neutralization. These charges arise during foil manufacturing process. We describe a method for electric parameter measurement for such foils, surface charge measurement on foils and methods of their neutralization. We describe an unconventional type of contamination separator for various technical areas. The application of negative or positive unipolar discharge is used in area of air cleaning in medical and other environments.  相似文献   

19.
Cleaning of paper objects represents one of the most complex cases of laser ablation, since low volumes of dispersed material phases are evaporated while a sensitive and fragile fibrous organic matrix has to be preserved. Conventional chemical and mechanical cleaning methods suffer from the common phenomenon that the foreign matter is diluted into the substrate rather than removed. The application of a laser beam allows highly localized and optically specific interaction. However, the occurrence of extreme temperatures and light intensities may cause irreversible alteration of the paper matrix. Further, incomplete removal and/or chemical conversion of contaminations may result in insufficient cleaning or affect the ageing behaviour. Laser treatments were performed by Q-switched Nd:YAG lasers at three wavelengths (355 nm, 532 nm, and 1064 nm). Papers contaminated with inks and adhesive-tape remnants served as model samples. Multispectral imaging and colorimetric results served to quantify and systematize the results. PACS 81.05.Lg; 81.65.Cf; 81.70.Fy  相似文献   

20.
随着物联网的兴起,数据的积累速度、维度以及体积等也越来越大,成了真正的大数据范畴。在农业温室大棚中部署的大量各种各样的传感器产生了大量多源异构的传感数据,而且这些数据中存在需要清洗的各种脏乱数据。本文按照数据清洗,模型构建和模型应用三个部分进行详述,首先介绍数据清洗技术和多源异构数据的融合技术,然后列举了常见的预测模型构建方法并分别指出了每种方法的适用情况,最后对常见的应用领域进行了综述和总结,并提出了目前还存在的问题,以及对未来的展望。  相似文献   

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