空气冷却器降温工艺分析

空冷器是降温系统末端传冷的关键设备,其类型、布置方式和工作参数对制冷效果影响显著。阐述了空冷器的分类及选择标准,分析了空冷器在采煤工作面和掘进工作面的布置形式:在采煤工作面中空冷器可以布置在进风巷始端、工作面进风口处、工作面和回风巷内;在掘进工作面中空冷器可以放置在距掘进迎头50 m的区域内,并将空冷器出风风筒进行隔热处理。介绍了空冷器布置在巷道内风流的处理过程和计算方法,分析了空冷器处理风流的热力学特征,得出空冷器单位产冷量的计算公式。     

高温矿井采煤工作面进风巷空冷器有效位置的确定

进风巷空冷器的位置对工作面的降温效果和降温效率的高低有重要影响。论文提出了空冷长度的概念,确定了空冷长度的计算方法,根据工作面允许的进风温度,确定了工作面进风巷空冷器的有效位置。采用有限元分析方法,建立了空冷器在进风巷不同安装位置下的采煤工作面热力学模型,并对其进行了模拟。根据计算和有限元分析的结果,对某矿采煤工作面进风巷空冷器不同位置时的风流热力参数进行了测定,现场测定结果与模拟效果表明:进风巷空冷器有效位置的确定方法合理,模型结果能够满足模拟要求,可以用来对工作面进风巷空冷器有效位置进行设计。     

掘进工作面揭露空巷时瓦斯分布规律研究

为研究残煤复采工作面布置轨道运输平巷时工作面揭露空巷时的瓦斯涌出分布规律,文章以山西潞安某煤矿1204复采工作面在掘轨道运输平巷为研究背景,通过运用FLUENT数值模拟软件研究掘进工作面揭露空巷时的瓦斯涌出分布规律,研究结果表明:风筒出风口风速在22 m/s,出风口距离掘进工作面10 m的设置是合理的,掘进工作面在风流的有效射程之内;当空巷内瓦斯浓度为3.5%时,掘进工作面揭露空巷后,工作面处的最大瓦斯浓度为2.2%左右,120 s之后工作面以及空巷内的瓦斯浓度降到0.5%以下,达到安全生产条件,且空巷内两端的风流速度为0.5 m/s左右,完全可以将空巷端部处瓦斯带出空巷内。     

高温采煤面空冷器的布置优化

为解决采煤工作面冷损大,提出在采煤工作面液压支架上布置空冷器;基于射流理论和采煤工作面温湿度变化关系,对采煤工作面空冷器进行了非均等距离布置,得到该布置方式下所需空冷器数量;为进一步优化所设计空冷器的节能性,提出了矩阵优化方案。     

超长采煤工作面坚硬顶板强制放顶技术实践

一八九○煤矿是焦煤集团生产骨干矿井之一,原设计采煤工作面平均倾斜长度为120m,工作面搬家次数较频繁,为提高矿井原煤产量,对采煤工作面巷道布置进行优化设计,采煤工作面倾斜长度由120m增加至250m。为此需要解决超长采煤工作面坚硬顶板处理技术,经过合理设计掘进一条深孔巷,在深孔巷、运输巷和回风巷采取布置长距离老顶孔和端头孔,实施深孔预裂爆破技术处理坚硬顶板。     

综放工作面旋转下巷改造方案分析与应用

通过对扇形旋转工作面下巷采煤设备布置的特点与回采巷道掘进施工顺序分析研究,从现场具体情况出发,适当调整巷道适合的施工方位,改善采煤设备的布置空间,解决了下巷转载设备布置存在的难题。     

扇形旋转工作面下巷改造方案探讨与应用

通过对扇形旋转工作面下巷采煤设备布置的特点与回采巷道掘进施工顺序分析研究,从现场具体情况出发,适当调整巷道适合的施工方位,改善采煤设备的布置空间,解决了下巷转载设备布置存在的难题。     

掘进巷道双风筒降温措施的研究

在非人工制冷降温的掘进工作面,利用双风筒供风是降低工作面风流温度的一个有效措施。根据风筒内、外内流相互制约的特点,分析了双风筒布置掘进巷道内的风流热力变化,并提出了计算方法和原理,依此编 制了计算机程序。利用该计算机程序分析了掘进工作面风筒内、外风流温度的变化规律,为高温掘进工作面的热源计算和通风降温提供了可靠的计算工具。     

高位巷一巷两用瓦斯抽采技术研究与应用

为了解除煤巷掘进期间的煤与瓦斯突出危险和解决工作面回采时的瓦斯超限问题,在松河矿井1031工作面顶板上方布置高位巷,从高位巷内向下施工穿层钻孔在掘进前预抽掘进条带瓦斯,利用高位巷在工作面回采时抽采采空区上部卸压瓦斯。采用一巷两用的高位巷抽采瓦斯方法后,巷道掘进时无煤与瓦斯突出发生,工作面回采时回风流最高瓦斯体积分数不超过0．8％、上隅角最高瓦斯体积分数不超过0．96％。     

采掘集中区域生产系统优化研究

在不改变3下1105采煤工作面通风系统的前提下,施工掘进回风通道,专供3下1101里面掘进工作面回风流通过,避免掘进工作面的回风流进入采煤工作面的进风流之中,有效避免串联风。系统优化后,可以同时施工3下1101里面工作面,有效地缓解紧张接续,确保了矿井正常接续。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

2014 second batch of rare earth quota released

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矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586