共查询到19条相似文献,搜索用时 140 毫秒
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射流管在气力输送中的应用 总被引:2,自引:0,他引:2
对物料气力输送的各种供料方式的性能、特点和使用场合进行了比较 ,重点讨论了传统文丘里供料器实际应用中存在的问题 ,介绍了几种国内外新型的文丘里供料器结构及其特点和用途。指出采用组合式供料器 ,即将文丘里供料器与机械旋转式连续供料器进行组合使用 ,可以同时改善它们两者单独使用时存在的问题。文中介绍了LAVAL管密相输送气量控制方面的应用 ,指出LAVAL管在气力输送中主要起稳定空气流量和压力的作用 ,使输送过程稳定、均匀 ,并简要介绍了气力输送系统的设计方法和步骤 相似文献
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介绍了为某型舰艇滑油系统而设计的控制压力低、流通能力大和稳定性好的插装式减压阀;建立了插装式减压阀的数学模型,通过Matlab仿真分析了插装式减压阀的稳态特性,并与试验测试结果进行了比较,验证了设计的结果是准确的. 相似文献
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结合某型盾构机特点,提出盾构机推进系统的闭环控制容积调速技术.其工作原理是通过液压缸的反馈信号,调节比例变量泵的输出流量和比例减压阀的出口压力,满足系统的推进速度和压力要求,实现连续控制.在AMESim环境下对系统的比例变量泵、比例减压阀和液压缸进行模型构建,并对推进系统进行动态特性仿真分析.通过仿真结果验证仿真模型的正确性,同时说明该系统适应特性和响应特性良好,为实际工程需要提供依据. 相似文献
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提出了气力输送闭式管路系统这一新的思路,给出了气力输送闭式管路系统除法特性的计算方法,分析结果表明,气力输送闭式管路系统较 开式管线系统具有能循环利用气流功能、不需高效除尘器、总排尘量大幅度减少等优点。 相似文献
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分析了炭黑在气力输送过程中的破碎机理。通过实验,介绍了气力输送系统中炭黑的种类和炭黑的物性对炭黑的破碎的影响,指出气力输送系统的输送管路长度和布置以及输送参数如输送压力和输送速度等的变化直接影响着炭黑的破碎率的大小。为更好地解决炭黑在气力输送中存在的问题,优化炭黑气力输送系统的设计提供了依据。 相似文献
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Fei Yan PanPan Tu Xin Li Yun Chen Yan Zheng Rui Zhu 《Advanced Powder Technology》2021,32(5):1399-1409
The pneumatic system is frequently operated in the high air velocity region, which aggravates the power consumption and erosion of bend, and the dynamic analysis of particles in bends with different radius of curvature in a horizontal-vertical pneumatic conveying system is necessary. This experimental study focuses on the particle motion characteristic of bend on the horizontal-vertical pneumatic conveying in terms of on pressure drop, particle velocity, power spectral characteristics of particle fluctuation velocity, the energy distribution of the proper orthogonal decomposition (POD) modes, time coefficients of POD, and spatial mode of POD mode during flowing through bends. The results indicate that the particle rope is the large-scale motion of particles containing high energy, which dominates the motion of particles in the bend, and the suppression of small-scale motion leads to the low pressure drop in a large radius ratio of the bend. 相似文献
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Although attrition during pneumatic conveying is a common problem, very few publications can be found in the open literature on this subject. The particle-to-wall impact is perhaps the predominant cause of degradation since the particle impinges the wall surface at high velocities in dilute phase pneumatic conveying. The most important factors appear to be the conveying air velocity and moisture content. This article presents the experimental findings of a study on degradation of maize starch during pneumatic conveying process. The tests were carried out in a conveying setup having a pipe length of approximately 50 m and a pipe inner diameter of 50 mm in order to find out the breakage of particles under various airflow velocity conditions and temperatures. Dehumidified air was used during the experimentation, and the air temperatures used during these test were 100°C and 25°C. The experimental results indicated that for a given air temperature condition, the variation of attrition rate was a complex function of air velocity and solids loading ratio. Further, for any start pressure condition, the attrition rate was found to increase substantially with increase in air temperature. 相似文献
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正压浓相气力输送系统是目前国内火电厂应用最为广泛的气力输送系统,该系统对运行的控制流程要求高、逻辑性强;其关键输送技术指标均采用模拟量进行检测,并实时控制.本文介绍的恒压输送系统,除了以上特点外,其独具的输送压力的动态实时调控功能,更是对控制系统提出更高的要求;阐述了DCS用于正压浓相恒压输送系统的典型设计. 相似文献
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Although attrition during pneumatic conveying is a common problem, very few publications can be found in the open literature on this subject. The particle-to-wall impact is perhaps the predominant cause of degradation since the particle impinges the wall surface at high velocities in dilute phase pneumatic conveying. The most important factors appear to be the conveying air velocity and moisture content. This article presents the experimental findings of a study on degradation of maize starch during pneumatic conveying process. The tests were carried out in a conveying setup having a pipe length of approximately 50 m and a pipe inner diameter of 50 mm in order to find out the breakage of particles under various airflow velocity conditions and temperatures. Dehumidified air was used during the experimentation, and the air temperatures used during these test were 100°C and 25°C. The experimental results indicated that for a given air temperature condition, the variation of attrition rate was a complex function of air velocity and solids loading ratio. Further, for any start pressure condition, the attrition rate was found to increase substantially with increase in air temperature. 相似文献
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Hui Li 《Particulate Science and Technology》2000,18(3):187-198
In order to prevent flow blockage phenomenon and to reduce the impact of particles on the wall of the bend, an experimental study of the swirling flow pneumatic conveying system with a horizontal curved pipe was carried out in this work. The experiment was performed in a 90-deg pipe bend with pipe diameter 75 mm and centerline curvature ratio 12. The straight pipes with 75 mm inside diameter at the upstream and downstream of the bend were 1.3 m and 4.0 m in lengths, respectively. The initial swirl number was varied from 0.22 to 0.60, the mean air velocity from 10 to 20 m/s, and the solid mass flow rate from 0.07 to 0.68 kg/s. It is found that in the lower air velocity range, the overall pressure drop of the swirling flow pneumatic conveying shows a lower tendency than that of axial flow pneumatic conveying. The minimum air velocities can be decreased by using the swirling flow pneumatic conveying. From the visualization of particle flow patterns, the impact of particles on the wall of the bend can be reduced using the swirling flow. 相似文献
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The minimum transport or capacity limitation boundary for low-velocity slug-flow pneumatic conveying affects the design and operation of conveying systems. Unfortunately, the relevant mechanisms involved with this boundary still lack full understanding and assessment. Investigations have been carried out to model the capacity limitation for the low-velocity slug-flow pneumatic conveying of poly granules through horizontal pipes. Pipeline diameter, air mass flow rate, and operating pressure have been found to affect the maximum slugging capacity of this material. A semiempirical equation has been established to predict the maximum solids mass flow rate for a given air mass flow rate and conveying pipeline. Good agreement has been achieved between the model predictions and the experimental results over a wide range of airflows and pressures. 相似文献
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The minimum transport or capacity limitation boundary for low-velocity slug-flow pneumatic conveying affects the design and operation of conveying systems. Unfortunately, the relevant mechanisms involved with this boundary still lack full understanding and assessment. Investigations have been carried out to model the capacity limitation for the low-velocity slug-flow pneumatic conveying of poly granules through horizontal pipes. Pipeline diameter, air mass flow rate, and operating pressure have been found to affect the maximum slugging capacity of this material. A semiempirical equation has been established to predict the maximum solids mass flow rate for a given air mass flow rate and conveying pipeline. Good agreement has been achieved between the model predictions and the experimental results over a wide range of airflows and pressures. 相似文献