双管板换热器的结构设计

双管板换热器为管壳式换热器的一种特殊结构被广泛应用于换热器管程和壳程介质严禁混合的场合。双管板换热器的管板有普通型双管板和整块式双管板两种型式,由于整块管板加工难度大、成本高,而且在防止管壳程介质串流方面也不如普通型双管板,所以在实际设计制造中普通型双管板较为普遍。随着新型化工产品的研究开发,双管板换热器的用量逐年增加,而由于双管板换热器的特殊结构要求,在设计和制造过程中各细节必须充分考虑,产品质量才能保证。现以我公司在多晶硅项目上设计制造的一台固定双管板式换热器为例对双管板换热器的结构设计和强度计算进行阐述。     

双管板换热器的设计和制造

介绍双管板换热器的结构设计、材料选择和制造、胀接、水压试验等,阐述双管板换热器在设计计算和制造等方面应注意的问题。     

双管板换热器在设计和制造等方面的问题分析

双管板换热器在制造中管板的加工以及强度胀接是难点,因此要制造出高质量的双管板换热器要严格按照工艺要求,同时借鉴先进的技术经验,从选材,设计,制造等方面来保证产品的质量。     

双管板换热器的结构及制造工艺合理设计

双管板换热器主要适用于壳程与管程介质严格禁止混合使用的场所。另一种认为双管板换热器可用于管、壳程间介质压差很大的场合,设计在内外管板之间的空腔中加入一种介质,来减小管壳程间介质的压差,。目前双管板换热器在防止管、壳程介质串流的问题上有着明显的优势。论述双管板换热器的壳体、管板、折流板等的制造工艺方法、管板预装、管板与换热管的连接方法,并且在制造生产中值得注意的几个关键问题。     

分离式双管板列管换热器的设计与制造

论述了双管板换热器材料选择、管板胀管槽等结构的设计、双管板检漏设计、最佳胀管压力计算等 ,以及双管板制造中内侧管子管板液压强度胀接、外侧管子管板强度焊接、双管板间空腔内和管子管板焊接接头气密性试验的要求     

双管板换热器的设计与制造要点

根据双管板换热器的结构特点,论述了双管板换热器关键结构设计与制造过程关键质量控制的要点。     

双管板换热器胀接试验研究

对于双管板换热器,其换热管和内管板的连接只能采用胀接连接结构形式,胀接质量的优劣决定换热器制造的成败。通过胀接试验确定合适的胀接工艺,是保证双管板换热器制造质量的技术关键点。     

运用SW6进行双管板换热器管板的计算

由于ＳＷ６－９３（ＳＷ６－１９９８）软件包没有双管板换热器管板的计算模块，因此在设计计算时，我们将双管板换热器分成几个单管板换热器进行计算。几年来设计了数十台固定双管板换热器（卧式、立式）和Ｕ形管双管板换热器，下面介绍分解模式。     

脱高塔再冷器的双管板设计

双管板是管壳程之间的换热介质不允许相互渗漏的情况下,可靠而有效的结构形式.以某有机硅单体工程甲基单体分离框架单元中的脱高塔再冷器的设计实例阐述了双管板换热器的运用场合、结构特点,介绍了脱高塔再冷器的结构设计及管板的计算,并分析了双管板换热器的制造要点及操作中应该注意的问题,从而保证装置的安全运行.     

双管板换热器的设计

通过一设计实例介绍了双管板换热器的机理、结构形式和材料选择。阐述了内、外管板间隙和管板厚度的设计计算,以及制造、验收等方面应注意的问题。     

2,3,6-三甲基苯酚一步氧化制备2,3,5-三甲基-1,4-苯醌研究进展

2,3,6-三甲基苯酚一步氧化制备2,3,5-三甲基-1,4-苯醌相对于传统的磺化-氧化法具有产品收率高、过程简单、条件温和以及环境友好等特点。本文针对2,3,6-三甲基苯酚一步氧化制备2,3,5-三甲基-1,4-苯醌的均相催化氧化和非均相催化氧化工艺进行了综述,对两种工艺的发展过程及研究现状进行了评价及总结。详细讨论了不同方法和路线在催化活性、选择性以及产品分离和催化剂回收等方面的优缺点,简要分析并总结了2,3,6-三甲基苯酚一步氧化研究的发展规律和最新动态,展望了以非均相催化反应机制为重点的微观机理研究和以提高催化剂循环稳定性、降低制备成本为重点的工业化探索两个潜在的发展方向。     

Biosorption: critical review of scientific rationale,environmental importance and significance for pollution treatment

Biosorption may be simply defined as the removal of substances from solution by biological material. Such substances can be organic and inorganic, and in gaseous, soluble or insoluble forms. Biosorption is a physico‐chemical process and includes such mechanisms as absorption, adsorption, ion exchange, surface complexation and precipitation. Biosorption is a property of both living and dead organisms (and their components) and has been heralded as a promising biotechnology for pollutant removal from solution, and/or pollutant recovery, for a number of years, because of its efficiency, simplicity, analogous operation to conventional ion exchange technology, and availability of biomass. Most biosorption studies have carried out on microbial systems, chiefly bacteria, microalgae and fungi, and with toxic metals and radionuclides, including actinides like uranium and thorium. However, practically all biological material has an affinity for metal species and a considerable amount of other research exists with macroalgae (seaweeds) as well as plant and animal biomass, waste organic sludges, and many other wastes or derived bio‐products. While most biosorption research concerns metals and related substances, including radionuclides, the term is now applied to particulates and all manner of organic substances as well. However, despite continuing dramatic increases in published research on biosorption, there has been little or no exploitation in an industrial context. This article critically reviews aspects of biosorption research regarding the benefits, disadvantages, and future potential of biosorption as an industrial process, the rationale, scope and scientific value of biosorption research, and the significance of biosorption in other waste treatment processes and in the environment. Copyright © 2008 Society of Chemical Industry     

振动丝法测定常压和加压下液体的黏度和密度

介绍了自行研制的高温高压振动丝黏度密度仪的构造和测定原理,并以正戊烷作为实验流体对仪器的可靠性和准确性进行了测试.测定了环己烷在323.15～413.15 K温度范围内、正辛烷在313.15～393.15 K温度范围内、苯在303.15～445.15 K温度范围内压力分别为常压和6.10 MPa、正庚烷和异辛烷在298.15～403.15 K温度范围内压力分别为常压和5.10 MPa下的黏度与密度,并分别对不同压力下的黏度、密度数据进行了关联.     

木质素/热塑性塑料复合材料界面增容的研究进展

将木质素作为一种有机颗粒填料添加到热塑性塑料中,可解决造纸黑液资源化利用、石油原料日渐紧张以及环境污染加剧等严峻问题。而木质素与热塑性塑料之间相容性直接影响木质素在塑料工业中的应用与发展。首先简要概述了木质素结构与性质和木质素/热塑性塑料复合材料的性能分析,然后系统地阐述国内外研究木质素/热塑性塑料复合材料界面增容方法及其原理;增容方法按添加相容剂、改性木质素和改性塑料进行归类,并对3种增容方法进行比较分析;接着综述了木质素复合材料中增容方法的交叉复合使用;最后对未来木质素/热塑性塑料复合材料界面增容的研究方向以及思路进行了展望。     

Characterization of chlorophyll pigments present in canola seed,meal and oil

Chlorophyll pigments present in canola seed, meal and crude and degummed oils were analyzed by high-performance liquid chromatography (HPLC) with a fluorescence detector. Chlorophylls a and b, low levels of pheophytin a, and occasionally traces of pheophorbide and its methyl ester were present in canola seed. Meals and oils contained magnesium-deficient chlorophyll pigments such as pheophorbide a, methylpheophorbide a, pheophytins a and b, and pyropheophytins a and b but not chlorophyll a or b. The amounts of chlorophyll pigments were oil > seed >> meal. Both crude and degummed oils contained pheophytin a and pyropheophytin a as main components, but the ratio of pyropheophytin a to pheophytin a was markedly higher in degummed oils. No pheophorbides were detected in degummed oils. These results suggest that oil processing steps such as extraction and degumming affect the composition of chlorophyll pigments. Publication No. 678 Canadian Grain Commission.     

塑料挤出机螺杆,机筒耐磨损,耐腐蚀的强化与应用

对塑料挤出机,注塑机螺杆,机筒的磨损,腐蚀原因及提高螺杆,机筒耐磨损,耐腐蚀的方法、制造与应用作了较详尽的介绍。     

工业生产中物位测量的探讨与研究

在工业生产中常常会遇到常温,常压和一般介质的液位,料位和界面的测量,也会遇到高温,高压,易燃易爆,腐蚀性较强的液位,料位和界面的测量。在工业生产中物位测量有接触式和非接触式测量。但应根据生产工况及技术要求来合理选用。     

A Simulation Model for Heat Pump Dryer Plants for Fruits and Roots.

Dryer design requires food properties, drying rate and mass-heat transfer coefficients. These values change continuously during drying due to changes in food fractions, particularly the water fraction. The high energy demand and costs allied to inefficient devices, creates a great need for new processing equipment. Along these guide-lines, several heat pump drying research projects were established at the Norwegian University of Science and Technology. The heat pump dryer provides high quality final product as its drying conditions can be controlled. Its efficiency and non-polluting operation come from closed air-refrigerant circuits and from its ability to fully recover the latent heat of moist air as it exits the drying chamber. Most of the above features are quite the opposite of the conventional dryer characteristics. Several experiments were made on heat pump drying of fruits and roots at temperatures from -22.5 to 40°C to obtain data and correlations on thermophysical properties, specific enthalpy and rehydration. Also, tests were done on drying rate, moisture content, drying constant, effective mass diffusivity and heat and mass transfer equations. The next important phase is the development of a simulation model to predict the performance and characteristics of the heat pump dryer plant. The objectives of the present work are to develop and lo test a heat pump dryer simulation model. The simulation provides results on the characteristics of both plant and components which are integrated by heat and mass transfer equations. The program has menus with click-on icons, input and output pop-up dialogue boxes. The usual commands such as, file-open, file-save, edit-delete are available in this program simply called Hpdryer. The model contains moist air psychrometric. natural and conventional refrigerant property libraries. Ammonia is a time-tested, self-alarming and natural refrigerant. It has been used extensively in the past, and it has better thermodynamic and transport properties than halocarbons. Safety is easily attained by design and its restrictive standards have helped increase its use in several countries. There are 36 ammonia installations in Norway and in the United Kingdom, including a drying plant. Ammonia has zero Odp, zero Gwp and the recent R&D has led to viable small-sale heat pump plants. Ammonia and dichlarodifluoromethane refrigerants were used in the test cases simulated by Hpdryer madel.     

The Body’s Cellular and Molecular Response to Protein-Coated Medical Device Implants: A Review Focused on Fibronectin and BMP Proteins

Recent years have seen a marked rise in implantation into the body of a great variety of devices: hip, knee, and shoulder replacements, pacemakers, meshes, glucose sensors, and many others. Cochlear and retinal implants are being developed to restore hearing and sight. After surgery to implant a device, adjacent cells interact with the implant and release molecular signals that result in attraction, infiltration of the tissue, and attachment to the implant of various cell types including monocytes, macrophages, and platelets. These cells release additional signaling molecules (chemokines and cytokines) that recruit tissue repair cells to the device site. Some implants fail and require additional revision surgery that is traumatic for the patient and expensive for the payer. This review examines the literature for evidence to support the possibility that fibronectins and BMPs could be coated on the implants as part of the manufacturing process so that the proteins could be released into the tissue surrounding the implant and improve the rate of successful implantation.     

Intricate Connections between the Microbiota and Endometriosis

Imbalances in gut and reproductive tract microbiota composition, known as dysbiosis, disrupt normal immune function, leading to the elevation of proinflammatory cytokines, compromised immunosurveillance and altered immune cell profiles, all of which may contribute to the pathogenesis of endometriosis. Over time, this immune dysregulation can progress into a chronic state of inflammation, creating an environment conducive to increased adhesion and angiogenesis, which may drive the vicious cycle of endometriosis onset and progression. Recent studies have demonstrated both the ability of endometriosis to induce microbiota changes, and the ability of antibiotics to treat endometriosis. Endometriotic microbiotas have been consistently associated with diminished Lactobacillus dominance, as well as the elevated abundance of bacterial vaginosis-related bacteria and other opportunistic pathogens. Possible explanations for the implications of dysbiosis in endometriosis include the Bacterial Contamination Theory and immune activation, cytokine-impaired gut function, altered estrogen metabolism and signaling, and aberrant progenitor and stem-cell homeostasis. Although preliminary, antibiotic and probiotic treatments have demonstrated efficacy in treating endometriosis, and female reproductive tract (FRT) microbiota sampling has successfully predicted disease risk and stage. Future research should aim to characterize the “core” upper FRT microbiota and elucidate mechanisms behind the relationship between the microbiota and endometriosis.