射流喷射器用于干渣气力输送的实验研究

针对燃煤电厂的锅炉干渣气力输送系统,采用气-固射流喷射器进行干渣气力输送实验,通过改变射流喷射器的结构参数和运行操作参数,分析各结构尺寸和运行参数对下料特性的影响,并通过数值模拟计算,对实验结果进行验证。结果表明,通过优化射流喷射器的结构尺寸和运行参数,在下料口可形成负压,提高落料均匀性及给料机运行可靠性。     

论正压浓相气力输送技术在CFB中的应用

CFB的除灰方式及除灰系统对全厂的安全经济运行及环境保护有着重大的影响,正压浓相气力输送系统具有明显的节约能源减少维修费用改善环境和利于综合利用等优点。     

气力输送在锅炉飞灰回燃技术中的应用

以山东省内几家热电厂75、130t/h循环流化床锅炉飞灰回燃、热效率提高为例,介绍气力输送系统在热电厂飞灰回燃过程中的应用,对热电厂飞灰含碳量高的原因进行分析,详细分析飞灰回燃系统的工艺流程,并对飞灰回燃前后的含碳量及成本进行对比。结果显示:飞灰回燃技术能够显著提高煤炭的燃烧率,提高锅炉的热效率。     

炭黑在气力输送系统中的破碎原因的分析

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．     

炭黑在气力输送系统中的破碎原因的分析

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。     

气力输送片冰技术及其在三峡工程施工中的应用

气力输送片冰技术为生产预冷混凝土提供了一种输送能力大、速度快、冷耗少、输送距离长、系统布置灵活、装备简单、安装方便、运行可靠、经济性好的新的片冰输送工艺。文章总结了本项技术的研究试验成果；介绍了南一水库和三峡工程混凝土施工中应用本项技术所显示的优越性和良好的社会经济效益。     

粒子群算法在气力输送管道压降预测中的应用

管道压降是气力输送系统设计的一个重要参数,传统的求解方法比较复杂.本文提出了以气体流速、颗粒浓度、混合比等作为神经网络输入,建立管道压降网络模型的方法.为进一步提高管道压降预测准确度,以预测误差作为适应度值,采用粒子群算法对网络权值和阈值寻优,优化神经网络,并利用样本数据训练出了有效的压降预测网络.通过将预测数据和粉料气力输送实验装置的实测数据相比较,结果表明,该方法预测误差小,准确度高,有较高的实用价值.     

气力输送在连续膨化硝铵炸药生产线上的应用刍议

文章阐述了气力输送的原理及设计计算方法,分析了气力输送技术在连续膨化硝铵炸药生产线上应用的可行性和优越性。     

HDPE管在市政排水工程中的应用

本文探讨了HDPE管的主要特点及工程应用实例,介绍了HDPE管的一些常用做法,对于其性能与传统管材进行了比较。     

Investigating Straight-Pipe Pneumatic Conveying Characteristics for Fluidized Dense-Phase Pneumatic Conveying

This article presents results from an investigation into the pneumatic conveying characteristics (PCC) for horizontal straight-pipe sections for fluidized dense-phase pneumatic conveying of powders. Two fine powders (median particle diameter: 30 and 55 µm; particle density: 2300 and 1600 kg m^?3; loose-poured bulk density: 700 and 620 kg m^?3) were conveyed through 69 mm I.D. × 168 m, 69 mm I.D. × 148 m, 105 mm I.D. × 168 m and 69 mm I.D. × 554 m pipelines for a wide range of air and solids flow rates. Straight-pipe pneumatic conveying characteristics obtained from two sets of pressure tappings installed at two different locations in each pipeline have shown that the trends and relatively magnitudes of the pressure drops can be significantly different depending on product, pipeline diameter and length and location of tapping point in the pipeline (indicating a possible change in transport mechanism along the flow direction). The corresponding models for solids friction factor were also found to be different. There was no distinct pressure minimum curve (PMC) in any of the straight-pipe PCC, indicating a gradual change in flow transition (change in flow mechanism from dense to dilute phase). For total pipeline conveying characteristics, the shapes of the PCC curves and the location of the PMC were found to be significantly influenced by pipeline layout (e.g., location and number of bends) and not entirely by the dense-to-dilute-phase transition of flow mechanism. Seven existing models and a new empirically developed model for PMC for straight pipes have been evaluated against experimental data.     

石灰长距离气力输送系统的试验研究

基于气力输送理论,通过石灰的长距离输送试验系统的建立,研究输送过程中耗气量、管道压力损失、物料输送前后的状态等重要输送特性。结果表明,将气力输送应用在长距离的石灰输送上是完全可行的,可解决钢铁行业的高粉尘污染问题,极大地改善工作环境。     

Pneumatic Conveying for Snow Storage Plants

In Japan, the number of snow storage plants has been increasing for the purpose of storing agricultural products and for the air-conditioning of buildings in summer. In order to gather snow into the snow storage room, a rotary snow plow is often used, but it is difficult to pile up snow within the room from inside out. To overcome this limitation, a pneumatic snow conveying system was developed in order to transport snow to the snow storage plant. The system consists of a blower, snow feeder, cyclone separator, and pipeline. The pressure type of the conveying system incorporates both negative and positive pressures, with a capacity to convey wet snow at 10 t/h a distance of 40 m. For snow with free water content below 15%, the system conveyed wet snow without sticking to the inside walls of the pipeline.     

粉体性能对浓相气力输送特性的影响

气力输送过程中物料性能是确定输送特性的重要因素,因此,粉料气力输送技术的实现要以对粉料的性能研究为基础。文中对影响气力输送的粉体基本性能及其相关参数做了较全面分析,其中粒子尺寸、粒径分布、形状是影响粉料是否可适用于浓相气力输送的关键参数,其它特性都与这3种特性相关联。介绍了几种应用广泛的粉料气力输送特性分组方法,并进行了简要评述,同时指出了今后的研究方向。     

密相气力输灰管道的设计与应用

对气力输灰工程中密相输灰管道的设计和计算确定管内压力和速度的公式进行整理 ,同时可以得到较合理的管径和不同管径的长度。运行参数当已知时 ,给出的计算公式可作为设计的依据     

密相气力输送系统中几种气量控制方式的比较

从调压范围、压力特性和流量特性方面介绍了减压阀的主要性能,讨论了气力输送交流中减压阀的选择和调节,分析了密相气力输送系统中各种气量控制方法,对其各自的优缺点进行了详细讨论,重点分析减压阀及减压阀与拉法尔联合气量控制系统的优、缺点,表明可调式拉法尔管是今后气力输送气量控制发展的方向。     

Particle Trajectories in Dilute Phase Pneumatic Conveying

A nonintrusive cross-correlation method to measure the particle velocities in dilute phase pneumatic conveying is described. The cross-correlation function generated gives information about the time it takes for a particle to travel between two optimally placed measurement planes. Experiments and CFD simulations are used to estimate an optimal inter-plane distance for various flow conditions.     

A Pressure Drop Model for Positive Pneumatic Conveying of Flour Through a Vertical Pipeline

A differential equation of motion for gas-flour two-phase flow in a vertical pipe was first derived based on the momentum conservation and by adopting two empirical expressions for the velocity ratio of flour to gas and frictional coefficient between flour and pipe wall, and then a pressure drop model for dilute positive pneumatic conveying of flour through a vertical pipeline was developed by employing the continuity and state equations for gas. The conveying tests were conducted on a positive pneumatic conveying system of flour in a flour mill. Under each of the six different flow conditions, the conveying parameters, such as the flour and gas mass flow rates and the pressure drop between two selected cross sections on the vertical pipeline were measured. The pressure drop between the two selected cross sections was evaluated using the pressure drop model for each of the six flow conditions. The calculated values of pressure drop agree well with the measured data, and it is demonstrated that the model is applicable to vertical positive pneumatic conveying systems of flour.     

不规则宽粒径石灰石粉脱硫及气力输送技术

通过分析干法脱硫技术及其影响因素,如石灰石性能和石灰石颗粒直径等,提出脱硫剂的选择及气力输送的方式,同时分析了气力输送中的问题,如透气性差和保气性差引起的不易流化等,并相应提出解决办法和输送设计方案。针对不规则宽粒径石灰石粉粒具有的特殊颗粒学特性和复杂气固两相流场,提出了解决方案,为更好地设计石灰石粉气力输送系统提供参考。