中频感应热处理线处理石油套管的实验研究

中频感应热处理线有投资少、见效快、生产成本低、设备维护成本少,维护量小等多种特点。文章介绍了用中频感应热处理线处理石油套管的试验研究。     

钢管感应热处理中频电源装置控制系统嫁接改造

阐述了鲁宝钢管感应热处理扫频式零压软启动中频电源装置存在的问题及控制系统嫁接改造的必要性,对负载预充磁(电)—附加振荡启动、扫频式零压软启动、自激—零电压启动三种中频电源装置启动方式优缺点进行了对比。详细介绍了鲁宝钢管感应热处理中频电源装置自激—零电压启动主回路和控制回路改造的具体内容及工作原理,改造后自激—零电压启动中频电源装置调试步骤、调试注意事项及调试数据结果;对比感应热处理中频电源装置改造前后运行数据,对感应热处理中频电源装置控制系统嫁接改造达到的效果进行了分析。     

晶闸管在国产双频淬火机上的应用

介绍了共昌双频（低中频）感应淬火机的晶闸管将工频电能变频为低中频电能的变频过程,并成功地应用在共昌双频（低中频）感应淬火机冷轧工作辊热处理的情况。通过与比利时OSB双频（工中频）感应淬火机的对比分析,证实其达到了进口设备的性能,获得了冷轧辊所需工艺质量目标,开辟了一条高效率、低投入的国产化新路。     

粉末热锻密封环的中频感应加热淬火工艺

介绍了中频感应加热在粉未热锻密封环热处理中的应用及效果。     

卷板焊接表面中频感应淬火镀铬辊的研制

介绍了采用卷板焊接工艺制作冷轧工艺线辊,基材选用45钢,通过中频感应热处理方式获得硬化层,再进行表面毛化处理及电镀铬。该类辊的研制处于国内先进水平,研制的淬火镀铬辊达到预期技术水平。     

超紧凑型钢管感应调质热处理线的研究应用

通过ARE产线钢管感应调质热处理线研究应用项目的开展,对现有感应热处理线进行改造。现有的ARE钢管感应热处理线整体布局不变,整流变压器、上料台架、上料装置、下料装置、双向链式冷床、下料台架及液压站等利旧,输送辊道部分利旧、局部改造,淬火电源、回火电源及感应圈根据产品方案按照淬火+回火工艺要求重新设计并更新,补齐相应的水淬及配套的水循环系统,配套相应仪表、自动化、计算机系统,实现温度闭环控制。通过改造将现有感应热处理线打造成一条超紧凑型钢管感应调质热处理线,使其具备年淬火+回火热处理管线管、接箍料、石油套管等3万t的生产能力,弥补ARE产线热处理的缺口,提高产线的盈利能力。     

钢管感应热处理工序的节能措施

阐述了钢管感应热处理设备的组成,介绍了中频电源装置的工作原理,找出了影响钢管感应热处理工序电能消耗的主要因素：钢管热处理温度、装置加热效率、装置谐波影响以及装置附加损耗等。从合理设计钢管热处理温度、提高装置加热效率、消除装置谐波影响、减少装置附加损耗、避峰用谷五个方面对如何降低钢管感应热处理工序电能消耗、节省电费进行了详细分析与探讨,提出了改进的可行性方案以及需现场落实的具体措施,对实施后达到的效果进行了分析。     

振吴电炉--电磁感应加热热处理技术创新与运用

利用中频电源的电磁感应加热原理来进行石油专用管的淬火、回火或正火和圆钢透热，在美国等发达国家已经属于一种成熟的工艺技术，并且在石油专用管的制造领域得到了广泛的应用。20世纪70年代。国外感应加热热处理炉在钢管尤其是石油钢管的强化和调质热处理中得到了应用与发展。美国LONGSTAR公司、无限制管公司以及日本川崎钢铁公司都用中频感应热处理炉，对石油套管进行调质处理。在法国和日本的许多工厂均采用中频感应加热炉来对焊管进行热处理。     

扫频式零压软启动中频电源的调试及应用

以钢管感应热处理设备低温炉、中温炉、高温炉中频电源装置为例,阐述了扫频式零压软启动中频电源装置的组成及工作原理;详细介绍了扫频式零压软启动中频电源装置的调试步骤、调试要点、现场调试遇到的问题及调试数据记录;介绍了扫频式零压软启动中频电源装置的使用情况、常见故障及存在问题。     

矿用高强度圆环链的热处理

结合矿用高强度圆环链的使用条伯对其不同的热处理方式进行了分析，特别是对中频感应加热淬、回火的规律进行了较详细的测试和分析，分析结果为选用最佳的热处理制度提供了依据。     

Relation of platelet abnormalities to thrombosis and hemorrhage in chronic myeloproliferative disorders

A single cohort of small individuals (31 mm mean shell length, 112 mg mean dry flesh weight) of the marine bivalve mollusc Mytilus galloprovincialis Lmk. was held sequentially for 2 wk at each of four food levels equivalent to ingested rations of less than 0.1%, 2.6%, 3.1%, and 7.4% of dry body weight per day. Growth rate reached a maximum at the highest ration level and was strongly correlated, amongst individuals, with mean heterozygosity measured across nine enzyme loci. Rates of energy expenditure were analysed separately as maintenance metabolic rate and the energy costs of growth (J mg-1 dry tissue). The maintenance metabolic rate correlated with traits of protein metabolism (protein synthesis, deposition, and breakdown), and the separate energy costs of both maintenance and growth correlated with the efficiency of protein deposition (protein growth as a proportion of synthesis). The energy costs of growth also varied in negative relation to mean individual heterozygosity. In a multiple regression analysis, the energy allocation to the costs of growth, body size, mean heterozygosity, and the efficiency of protein deposition together explained 90% of the variance amongst individuals in observed rates of growth. The results support the hypothesis that individual variability in the energy costs of protein turnover and in the efficiency of protein deposition during rapid growth are significant factors providing a link between individual genotype and its phenotypic expression as growth.     

Cost-Estimating Tools for Low-Impact Development Best Management Practices: Challenges, Limitations, and Implications

Tools were developed for estimating costs of vegetative roofs, rainwater catchment systems, and bioretention facilities. These tools provide a detailed framework to facilitate cost estimation for capital costs, operation and maintenance costs, and life-cycle net present value. The tools can provide users with planning-level cost estimates and serve as a format for cost-reporting for past, current, and future projects. Very little cost data was available in the public forum, and prolific inconsistencies of supporting details were found in the available cost data. To address this, design assumptions were established for each facility type and professionally prepared cost estimates based on these design assumptions were used. Electives in design, such as plant selection and media depth, also greatly affected costs. To make the user aware of these effects, the model separates each option into line items that can be elected or excluded as appropriate. To facilitate collecting future cost data, best management practice (BMP) designers and builders should use these tools to record actual costs and report them to a clearinghouse such as the BMP Database.     

District nebuliser compressor service: reliability and costs

BACKGROUND: There is little information on the costs of maintaining a district nebuliser compressor service. This retrospective study examines the issue, reliability, and maintenance costs of electrical compressors to assist the prediction of future costs, taking into account recent safety legislation. METHODS: Records of issue, repair, and replacement for the period 1982-91 were reviewed. The current policy of repairing and replacing as necessary, and three other theoretical costings, were considered. RESULTS: The number of compressors being issued is increasing. Repaired compressors are less reliable and frequency of repair is a function of compressor age. The current policy is the most cost effective. CONCLUSIONS: To repair and replace nebuliser compressors as necessary is the most economical policy under the present terms offered by the manufacturers, but changes in safety legislation will affect the provision of such services.     

Integrated Model for Optimizing Strategic Overhaul Planning of Distributed Pump Stations

An important part of the lifecycle costs for pump stations are the support costs associated with energy and preventive maintenance of the pumps. Both cost terms are interrelated because a trade-off exists between maintaining pumps frequently (with increased pump efficiency, reduced energy costs and increasing maintenance costs, and pump unavailability) and extending the intervals between the overhauls (increased loss of efficiency, increased energy costs, and decreased maintenance costs). The planner needs to forecast pump overhaul demands to determine budget levels because economic resources are limited. This process is assisted by using mathematical programming methods to prioritize funding for equipment requiring renewal in consideration of limited resources in a strategic time horizon (several years). This work proposes an efficient model to define an overhaul maintenance program for a pump network with a large number of pumps (a few hundred in the case study). The model minimizes the discounted total (energy+overhaul) cost by selecting and scheduling pumps for overhaul subject to budget constraints. The formulation uses 0–1 integer programming.     

Capabilities of modern systems for monitoring and diagnosing equipment

The cost of maintenance and repair is one of the most important service characteristics of any technical system. It is almost impossible to minimize such costs without efficient monitoring of the condition of the system. In modern monitoring and diagnostic instruments—at least those used on rotating equipment—vibration is the main type of process that is analyzed and takes precedence over all other processes, thermal processes included. This is not only because vibration diagnostics is more efficient and is rapidly becoming less costly to perform, but also because it can be done at any time—including after several years of equipment operation, when the costs of preventive maintenance and repairs are usually no longer economically justifiable. VAST Company, St. Petersburg. Translated from Metallurg, No. 11, pp. 33–36, November, 1998.     

Economical vacuum degassing of steel with the use of mechanical pumps

If greater use is to be made of vacuum technologies in out-of-furnace treatments of steel within Russia, more stringent requirements will have to be met in regard to the reliability, productivity, and efficiency of the pieces of equipment used to create the vacuum-the vacuum pumps. Unfortunately, Russian-made vacuum pumps do not presently meet these requirements. The equipment traditionally used to create a vacuum in units designed to treat steel outside the steelmaking furnace is based on steam-jet ejectors. This article compares the operating costs of a vacuum-degassing unit for 90-ton heats when the unit is equipped with mechanical pumps and when it has a steam-jet-ejector station. In the latter case, liquid-ejector pumps are used as the starting stage. It was found that the costs of the material resources and maintenance of the auxiliary equipment of a vacuum-degassing unit with mechanical pumps are roughly 10 times less than the analogous costs of a vacuum system with steam-jet ejectors. Another important advantage of vacuum-degassing units with mechanical pumps is that they are environmentally safe. __________ Translated from Metallurg, No. 4, pp. 58–61, April, 2007.     

36室焙烧炉的运行与维护

阳极预焙烧是炭素生产及电解铝使用必不可少的生产环节,而焙烧炉是预焙阳极生产的关键设备之一,它不仅造价高,维修费用大,且维护的难度也很大。焙烧炉运行是否良好,维护是否及时,直接影响预焙阳极的质量、成本、焙烧炉的使用寿命及尾气排放等诸多问题,故焙烧炉的运行与维护非常重要。     

Arc heating in the tundish with a graphite electrode in comparison to a metallic plasma torch

Since 1991, BGH Edelstahl, Siegen, operated a 0.4 MW tundish heater equipped with a DC metal plasma torch containing a tungsten electrode. Due to cost considerations, the metal torch has recently been replaced by a 100 mm diameter hollow graphite electrode. After 6 months of operational experience first results are now available on graphite wear rates, carbon pickup and running costs as compared to the metal torch system. The average wear rate was 0.46 kg/h or 0.03 kg/t steel. Carbon pickup under normal conditions was below 10 ppm for all steel grades investigated ranging from 0.015 to 0.455% C. The case of accidental direct contact between melt and graphite has also been investigated. The normal carbon pickup to be expected can be correlated to the tip wear rate of the graphite electrodes. From this correlation, carbon pickup would increase with power from 3 over 10 to 25 ppm for 0.3, 1 and 2 MW. The running costs proved to be lower than with metal torches due to less water cooling, less wear parts like nozzles and starting electrodes, and less personnel for maintenance.     

The Second Canadian Gastroesophageal Reflux Disease Consensus: moving forward to new concepts

Gastroesophageal reflux disease (GERD) is a disease with serious consequences that may result in significant impairment in quality of life and disease morbidity. Across all grades of severity of symptoms and severity of underlying esophageal disease, proton pump inhibitors (PPIs) provide therapeutic gains over prokinetics (PKs) or H2 receptor antagonists (H2RAs). The potential cost effectiveness of using medications with higher acquisition costs that may lower health care costs overall is often disregarded when conducting cost comparisons with medications having lower 'up-front' costs. Limiting therapy to less effective agents condemns many patients to protracted suffering, repeated physician visits and needless reinvestigation of symptoms that could have been resolved by appropriate initial therapy. Based on current data, use of any classification of symptom severity as a basis for selecting one class of therapeutic agents over another for first line therapy (i.e. PKs, H2RAs for 'mild' GERD, versus a PPI for 'severe' disease) is unwarranted.