风流扰动支架架间高压喷雾降尘雾滴粒度实验

为确定风流扰动综采工作面液压支架架间高压喷雾降尘雾滴粒度变化规律,选用3种喷嘴,基于自主设计的高压喷雾雾滴粒度测量系统进行了模拟实验,并进行了风流扰动架间高压喷雾雾滴降尘应用试验.结果表明:速度为1.2m/s的风流扰动后,雾滴场的雾滴粒径平均值有所增大,迎风侧雾滴粒径小于背风侧;随着喷嘴迎风安设角度α增大,雾滴场的整体雾滴粒度先减小后增大,α=10°时最小,3种喷嘴中喷嘴Ⅰ在8MPa喷雾压力时的雾滴粒度最小;风流扰动后,随着α增大,各测点粉尘质量浓度、全尘与呼尘降尘率平均值的差值均先减小后增大,降尘率平均值反之,α=10°时降尘效果最佳,全尘、呼尘的降尘率平均值分别为80.11%,78.04%,结合实验结果,确定最优α为10°.     

喷雾压力影响采煤机外喷雾喷嘴雾化特性变化规律

基于喷嘴雾化特性测定实验装置,对4种应用效果较优的实心圆锥形雾场喷嘴在2~8MPa喷雾压力时的宏观及细观雾化特性进行了测定.结果表明:随着喷雾压力增大,喷嘴的宏观雾化特性雾化角不断减小、射程不断增大,细观雾化特性雾滴粒径不断减小,在雾场中,雾滴粒径随距喷嘴轴向距离的增大而增大,随距横截面中心距离的减小而增大.结合现场及实验结果,优选了适于中短距离、大面积降尘且雾滴粒径较小的喷嘴Ⅲ为采煤机外喷雾喷嘴,并进行了现场试验.结果表明:随着喷雾压力增大,各测点的粉尘浓度、全尘与呼尘降尘率差值均不断减小,降尘率不断增大,喷雾压力为8MPa时雾化降尘效果最优,全尘、呼尘降尘率平均值分别为81.82%,79.96%.     

煤矿高压喷雾雾化粒度的降尘性能研究

从理论、实验和现场试验3个方面对高压喷雾雾化粒度的降尘性能做了深入的研究;对高压喷雾降尘机理进行了分析,提出了雾化粒度D50的计算式和雾化粒度捕捉最小粉尘粒度的相互关系式;利用测试范围在5～2 000 μm的Winner313激光粒度分析仪和喷嘴雾化测试系统,对煤矿常用的5种压力式喷嘴进行了4,6,8和10 MPa共4个压力下的雾化粒度测定,得到了喷嘴雾场不同位置的D10,D50,D90,D[3,2],D[1,3]平均粒径分布和650 μm以下的粒径分布,雾场位置(150-9)处的粒径随压力增加雾化粒度变小;根据理论、实验数据和综放工作面煤尘实际测定的粒径分布,确定了该面的喷雾降尘压力和喷嘴型号,通过现场应用,煤机外喷雾和支架喷雾压力从2 MPa提高到8 MPa后,移架工序的全尘由536.2 mg/m3降到97 mg/m3.     

螺旋滚筒喷嘴内流场数值模拟研究

为提高螺旋滚筒的喷雾降尘效果,改善井下作业环境,基于流体动力学理论,建立喷嘴内部流场模型。对不同喷嘴口径、旋流芯中心孔口径以及喷雾压力的喷嘴喷雾过程进行数值模拟,得到不同参数条件下流体速度的分布规律:喷嘴口径在一定范围内适当增大能够增加内部湍流区域,进而提高出口位置流体的流出速度;旋流芯中心孔直径的增大虽然在一定程度上增加中心孔射流对旋流场的扰动,但是对流体喷出速度影响不大;随着喷雾压力提高,流体内部湍流动能得到加强,喷嘴出口流速得到提高。对工业性试验中工作面粉尘质量浓度进行测定,在滚筒喷雾系统开启后降尘率达到90%以上,工作面粉尘质量浓度得到了有效降低。     

高炉渣气雾粒化性能试验研究

针对高炉熔渣的粒化环节,在气淬的基础上加入喷雾射流,通过实验研究了不同气压、水流量和出渣温度对熔渣粒化性能的影响,包括熔渣颗粒的飞行轨迹、粒径分布、成珠率等。结果表明：气量和水量的增大有助于提供给渣流更多的动量,使渣粒的飞行时间越长,渣粒落地粘壁的比例越小;喷雾射流的加入在水流量小于1.5 L/min时,在一定程度上可以强化熔渣的破碎过程,使渣粒平均粒径减小,随着喷雾量的持续增加,熔渣的粒径分布整体呈先减小后增大的趋势,熔渣成珠率先增大后减小;随着气流速度的增大,渣粒的平均粒径先逐渐减小,后趋于稳定,渣粒的成珠率随着气体流速逐渐增大后逐渐趋于稳定值,最大约83%;渣流温度的不同导致其具有不同的黏度,渣流温度越大,黏度越低,成珠率越好,粒径越小,熔渣的粒化性能越好。     

间接蒸发冷却用气水雾化喷嘴特性实验研究

为了提高间接蒸发冷却器换热效率,提出了将气-水雾化喷嘴应用于间接蒸发冷却器改进换热器表面水膜的均匀性,实验研究了扇形两相(气-水)喷嘴在不同空气压力和水压下的特性,测出了不同压力时喷嘴雾化角和气水质量流量值,得出了其变化规律,确定出了最佳的喷雾气水压力比和雾化角等参数.     

压风射流添加发泡剂装置性能实验研究及应用

根据井下掘进面风量大、水压低的特点,提出了压风射流添加发泡剂的理念.实验表明,压风射流器吸液量随出口压力减小而增大,当出口压力减小到一定值后,吸液量达到最大值并维持不变;进口压力升高,吸液量增大,但增大的程度减小,且出口压力越高,达到超临界吸液所需的进口风压越大;射流器在超临界吸液时,吸液量越小,临界出口压力越大,装置驱动性能越强;压风射流器应用于煤矿井下泡沫降尘时,确保了发泡剂的小流量稳定添加,降低了泡沫成本,简化了系统操作,尤其适用于高强度硬岩巷道掘进降尘,泡沫降尘效率可达82.3%~87.9%,远高于水雾降尘效率,取得了理想的降尘效果.     

在线加湿压力和加湿流量对PM_(10)排放的影响

利用实验室粉体物料自由下落在线加湿模拟试验装置,研究气水两相喷嘴中的加湿压力和加湿流量对不同粉体物料中PM10排放的影响.通过实验,获得的最佳加湿压力为0.30MPa,最佳加湿流量为2.4 L/h.利用最佳加湿压力和最佳加湿流量可以优化在线加湿条件,达到最佳的降尘效果和节约降尘成本.     

在线加湿压力和加湿流量对PM_(10)排放的影响

利用实验室粉体物料自由下落在线加湿模拟试验装置,研究气水两相喷嘴中的加湿压力和加湿流量对不同粉体物料中PM10排放的影响。通过实验,获得的最佳加湿压力为0.30MPa,最佳加湿流量为2.4 L/h。利用最佳加湿压力和最佳加湿流量可以优化在线加湿条件,达到最佳的降尘效果和节约降尘成本。     

管道内喷雾蒸发冷却的数值模拟及优化设计

为研究雾滴粒径、喷头间距、风速和喷雾比等参数的改变对管内喷雾降温蒸发效率的影响,采用DPM模型方法对送风管道内喷雾直接蒸发冷却进行数值模拟和分析.通过单因素和多因素正交试验模拟,得到各参数最佳工况.模拟结果表明:粒径、风速和喷雾比越小时,蒸发效率越高;喷头间距的最佳值,应根据饱和水气比、空气流速、喷头的喷出速度和喷射角度确定.根据模拟结果,考虑系统经济性,对雾滴粒径小于30μm、风速1 m/s以下的工况,喷雾比下限为0.7,蒸发效率最高可达92%,饱和效率可达65%以上.     

Controlling the coal dust at transshipment point: A study of the foam-sol foaming device

In order to effectively control the dust at the transshipment point with foam-sol, this paper attempted to study the characteristics of dust diffusion at transshipment point and the foam-sol foaming device with diffusion outlet was also designed in this paper. To study the diffusion rules of coal dust, fluent discrete phase model was utilized in the numerical simulation, as the coal dust was thrown down at a horizontal velocity of 2.5 m/s. A foam-sol foaming device was designed, through which foaming agent could be automatically sucked into the Venturi by the negative pressure. The automatic controller was also equipped, which could transform the energy of the compressed air into the constant pressure difference so that the gelling agent could be qualitatively added into the gel container. The diffusion outlet that could spray out foam-sol in a continuous, conical and 3D manner was also designed. Moreover, this paper also carried out the contrast experiments on dust removal efficiency among water, aqueous foam and foam-sol. The results clearly show that the symmetrical whirlpools appeared below the inlet where the largest whirlpool diameter was 0.52 m, and the horizontal distance from swirl range to the inlet was approximately 0.69 m. By using the self-designed foaming device, the foaming was multiplied by 30 times and the volume ratio with water and foaming agent reached 95%:5%. In this context, the gas pressure was controlled at 0.3 MPa, with gas flow at 15 m³/h and water flow at 0.5 m³/h, with water pressure controlled between 0.34 and 0.36 MPa. The foam-sol has the highest dust removal efficiency than other agents.     

Effects of atomization parameters of dust removal nozzles on the de-dusting results for different dust sources

In order to obtain appropriate spray pressure and enhance the spraying and dust removal efficiency, various factors including the dust characteristics, nozzle spraying angle, effective spraying range, water consumption and droplet size are taken into account. The dust characteristics from different mines and atomization parameters of different pressure nozzles were measured. It was found that the internal pressure of coal cutters and roadheaders should be kept at 2 MPa, which could ensure large droplet size, large spraying angle and low water consumption and hence realizing a large-area covering and capture for large particle dusts. However, the external spray pressure should be kept at 4 MPa for smaller droplet size and longer effective spraying range, leading to effective dust removal in the operator zone. The spray pressure of support moving, drawing opening, and stage loader on a fully mechanized caving face and stage loader on a fully mechanized driving face should be kept at 8 MPa, under which the nozzles have long effective spraying range, high water flow and small droplet size for the rapid capture of instantaneous, high-concentration and small size dust groups. From the applications on the caving and driving faces in the coal mines, it is indicated that the optimization of spray pressure in different spraying positions could effectively enhance dust removal efficiency. Selecting appropriate nozzles according to the dust characteristics at different positions is also favorable for dust removal efficiency. With the selected nozzles under optimal pressures, the removal rates of both total dust and respirable dust could reach over70%, showing a significant de-dusting effect.     

提高湿法烟气脱硫喷淋塔脱硫和除尘效率的探讨

分析了现代大型喷淋塔为提高脱硫与除尘效率在设计上所作的改进及存在的问题。通过一个曾经设计过的喷淋塔实例,结合烟气和吸收液两相逆向流动和两相间的化工传质过程,剖析了喷淋层覆盖率的实质,提出弱效喷淋覆盖和多重喷淋覆盖对喷淋塔脱硫和除尘效率的影响,给出喷淋覆盖率的选择、喷淋层和喷嘴布置的设计方法,对改善烟气脱硫和除尘效率均有明显效果。     

A new design of foam spray nozzle used for precise dust control in underground coal mines

In order to improve the utilization rate of foam,an arc jet nozzle was designed for precise dust control.Through theoretical analysis,the different demands of foam were compared amongst arc jets,flat jets and full cone jets when the dust source was covered identically by foam.It is proved that foam consumption was least when an arc jet was used.Foam production capability of an arc jet nozzle under different conditions was investigated through experiments.The results show that with the gas liquid ratio(GLR)increasing,the spray state of an arc jet nozzle presents successively water jet,foam jet and mist.Under a reasonable working condition range of foam production and a fixed GLR,foam production quantity increases at first,and then decreases with the increase of liquid supply quantity.When the inner diameter of the nozzle is 14 mm,the best GLR is 30 and the optimum liquid supply quantity is0.375 m~3/h.The results of field experiments show that the total dust and respirable dust suppression efficiency of arc jet nozzles is 85.8%and 82.6%respectively,which are 1.39 and 1.37 times higher than the full cone nozzles and 1.20 and 1.19 times higher than the fiat nozzles.     

Dust removal efficiency of high pressure atomization in underground coal mine

To master theoretical calculation for dust removal efficiency of high pressure atomization in an underground coal mine, the corresponding atomization characteristics and dust removal efficiency were both comprehensively studied in theory by virtue of related theories of hydromechanics and aerosol.According to actual measurements of flow coefficients and atomization angles of X-type swirl nozzle,computational formula was derived for atomized particle sizes of such a nozzle in conjunction with relevant empirical equation. Moreover, a mathematical model for applying high pressure atomization to dust removal in underground coal mine was also established to deduce theoretical computation formula of fractional efficiency. Then, Matlab was adopted to portray the relation curve between fractional efficiency and influence factors. In addition, a theoretical formula was also set up for removal efficiency of respirable dust and total coal dust based on dust size and frequency distribution equations. In the end,impacts of dust characteristic parameters on various dust removal efficiencies were analyzed.     

操作参数对生物质再燃脱硝特性的影响

以稻壳（RH）、木屑（SD）和生物质炭（BC）3种生物质为对象,利用携带流脱硝试验装置,研究了再燃区反应温度（T2）、再燃区化学计量比（SR2）、停留时间（τ）、NO初始浓度（CNO,in）、水蒸气含量、生物质种类及添加剂等对生物质再燃脱硝效果的影响.结果表明：在T2=850℃-1150℃范围内,随着T2升高,再燃脱硝效率呈现逐渐上升的趋势.在SR2=0.5-1.0范围内,生物质再燃脱硝效率随着SR2降低而逐渐上升.在τ=0.5-1.3 s范围内,生物质再燃脱硝效率随着τ增加呈现先上升后趋于稳定的趋势.在CNO,in=300-600μL/L范围内,生物质再燃脱硝效率随着CNO,in增加逐渐增加,但当CNO,in〉400μL/L时,脱硝效率增加不明显.随着烟气中水蒸气含量增加,生物质再燃脱硝效率呈现先增加后降低并逐渐趋于平稳的趋势,模拟烟气中含有4%水蒸气时的脱硝效率最大.不同生物质的再燃脱硝效率显著不同,RH和SD的脱硝效率明显高于BC.添加剂对脱硝效果有一定的促进作用,其中, NaCl促进作用最为显著.添加剂（Fe2O3）浓度（50-150μmol/mol）对生物质再燃脱硝效率的影响不大.     

综采工作面割煤时煤尘污染状况的现场实测研究

在对平沟煤矿综采工作面采煤机割煤时煤尘浓度和分散度现场实测和分析的基础上,得出了综采工作面采煤机割煤时煤尘的污染特征.在一定风速条件下采煤机割煤时,距底板和煤壁较近处煤尘的总粉尘浓度沿程分布曲线出现2个极大值,然后随着煤尘运移距离的增加,煤尘的总粉尘浓度沿程分布曲线趋向于1个稳定值;距顶板和液压支架较近处煤尘的总粉尘浓度沿程分布曲线仅出现1个极大值,然后随着煤尘运移距离的增加,煤尘的总粉尘浓度沿程分布曲线也趋于1个稳定值.     

一种喷射型粉尘预荷电器的实验研究

研制了一种以金属拉伐尔管为阳极，管喉部装针状放电阴极的粉尘预荷电装置。由于含湿空气通过该装置的电晕放电场时急剧膨胀，产生大量的带电冰气溶胶。实验测定了用于产生带电冰气溶胶的有效电流和冰气溶胶对粉尘预荷电的效果。并探讨了将这项技术用于除尘实践的可能性。     

基于气-水界面电晕放电效应脱硫实验模型的研究

以治理大气污染为目的,依据气-水界面电晕放电机理,提出了一种气-水协同电晕放电效应的烟气净化法,本着除尘与脱硫脱硝一体化的新设想,对这一模型和它的实验系统进行了设计,并进行了脱硫实验模拟．结果表明,利用这一模型,在电晕电压为5kV、烟气流量为1．85m^3/h、水流量为3L／min时SO2脱除率达99％．