两种混合单元混合机理的数值模拟

为了研究SV型和SX型混合单元在全静态乳化器的混合机理,使用群体平衡模型对乳化器内部流场进行模拟分析。结果表明,SV型与SX型混合单元的混合机理是油相与水相材料通过混合单元时其空间流动方向改变,在流场内形成大量的漩涡,从而达到乳化的目的;通过比较流体在经过SV型和SX型混合单元后的水相索特平均直径(d_(32)),得出SV型混合单元的乳化效果更强,但同时消耗更多的能量,压降更大。     

现场混装乳化炸药静态敏化器混合特性研究

为了研究现场混装乳化炸药静态敏化器的混合特性以及安全性,采用数值模拟和试验相结合的方法,分析了设计的静态敏化器的混合机理、参数变化对混合流场特性的影响规律以及其混合安全性,对比分析了两种混合单元组合方式下乳化基质与敏化剂的混合效果.研究表明:两种不同结构的混合单元能起到让乳化基质与敏化剂初步混合和强化混合的作用;当乳化基质、敏化剂混合流流经静态混合单元时,压力值在乳化基质管路安全泵送的压力范围内,应用安全;在两个缩径混合单元中间加一个网状结构混合单元组成的静态敏化器具有良好的混合敏化效果.     

现场混装乳化炸药静态敏化器混合特性研究

为了研究现场混装乳化炸药静态敏化器的混合特性以及安全性,釆用数值模拟和试验相结合的方法,分析了设计的静态敏化器的混合机理、参数变化对混合流场特性的影响规律以及其混合安全性,对比分析了两种混合单元组合方式下乳化基质与敏化剂的混合效果。研究表明:两种不同结构的混合单元能起到让乳化基质与敏化剂初步混合和强化混合的作用;当乳化基质、敏化剂混合流流经静态混合单元时,压力值在乳化基质管路安全泵送的压力范围内,应用安全;在两个缩径混合单元中间加一个网状结构混合单元组成的静态敏化器具有良好的混合敏化效果。     

一级乳化工艺制备长储存期乳化炸药的试验研究

研究了一级乳化工艺条件下,乳化剂种类、油相配方及不同乳化器对乳化炸药爆炸性能和储存稳定性的影响,采用高低温循环试验考察制备乳化炸药的储存稳定性。试验研究表明:一级乳化(CYJ型乳化器)时,LZ27011乳化剂制备的乳化炸药储存稳定性、爆炸性能和微观结构均优于S/T乳化剂制备的乳化炸药;乳化剂为LZ27011时,CYJ型乳化器较JWL-YR乳化器的乳化效果更好;乳化剂(Span80和LZ27011的质量比为0.51.5)和乳化器确定时,油相配比对乳化炸药的储存稳定性有显著的影响,当油相组成复合蜡和150SN的质量比为3.21.0时,所制得的乳化炸药经34个高低温循环后,爆炸性能仍符合标准要求。     

乳化炸药全静态乳化器流场数值模拟分析

分析了国内外乳化炸药乳化器的发展现状及趋势。设计了乳化炸药全静态乳化器。对全静态乳化器的流场数值进行了模拟分析,对水相射入速度为10、15、20 m/s和25 m/s时内部流场情况进行了仿真对比和生产试验。结果表明:采用水相对射的方式,有利于油水相的混合;随着水相射入速度的提高,湍动能强度逐渐增大,油相分散得也更加均匀,有利于乳化。     

敞开式大产能乳化器在乳化炸药生产中的应用

论述了AE-HLC-Ⅲ型敞开式大产能乳化器在乳化炸药连续化生产线上进行的工业化安全验证及应用。观察乳化器运行状况,测试其生产的乳化炸药爆炸性能,并跟踪测试其贮存性能。结果表明,该乳化器基本满足了生产对大产能、高安全的要求,并结合生产应用情况对乳化器的设计提出建议。     

井下乳化炸药混装车连续敏化器结构优化

为了使连续敏化器在较低的压降下实现乳化基质与敏化液的混合,以井下乳化炸药混装车的连续敏化器为研究对象,通过正交实验对不同结构的连续敏化器的内部流场进行数值模拟。结果表明连续敏化器的分流口直径对压降影响最明显,汇流口直径对混合效果影响最大,优化后的连续敏化器结构参数为分流口角度30°,分流口直径4 mm,汇流口直径6 mm,分流口数量4个。通过现场实验验证,优化后的连续敏化器满足乳化基质与敏化液的混合要求,相对于现有结构还降低了25%的流体压降。     

静态乳化器

为提高乳化炸药生产过程的安全性,开发新的本质安全的静态乳化器势在必行。静态乳化器由敞口、低转速的粗乳器和精乳器组成,精乳器为静态混合器,两者之间由螺杆泵衔接。通过理论计算和试验研究,确定了静态乳化器的主要技术参数。目前,静态乳化器已成功用于乳化地面站,产品性能稳定,完全满足有关国家标准的要求。静态乳化器的研发可以大大改善乳化炸药生产过程中的安全性,避免因设备自身设计缺陷引起的爆炸等恶性安全事故,提高炸药生产企业的安全生产水平,提升我国工业炸药的生产技术水平。     

静态乳化器

为提高乳化炸药生产过程的安全性,开发新的本质安全的静态乳化器势在必行。静态乳化器由敞口、低转速的粗乳器和精乳器组成,精乳器为静态混合器,两者之间由螺杆泵衔接。通过理论计算和试验研究,确定了静态乳化器的主要技术参数。目前,静态乳化器已成功用于乳化地面站,产品性能稳定,完全满足有关国家标准的要求。静态乳化器的研发可以大大改善乳化炸药生产过程中的安全性,避免因设备自身设计缺陷引起的爆炸等恶性安全事故,提高炸药生产企业的安全生产水平,提升我国工业炸药的生产技术水平。     

乳化器中搅拌结构及参数对乳化作用的影响

文章从乳化机理入手，论述了各种搅拌结构的工作原理及特征，综合其优点，设计了新型高效乳化器，从结构上强化湍流脉冲，选择最佳转速、功率及乳化时间。     

Effect of water supply pressure on atomization characteristics and dust-reduction efficiency of internal mixing air atomizing nozzle

As a new type of nozzle, the internal mixing air atomizing nozzle has been widely used in the field of dust reduction via spraying. In this study, the effect of water supply pressure on the atomization characteristics and dust-reduction efficiency of the internal mixing air atomizing nozzle was investigated. Firstly, the FLUENT software was used to simulate the flow field inside and outside the nozzle under different water supply pressures. The numerical simulation results showed that as the water supply pressure increased, the internal pressure and water flow velocity in the mixing chamber of the nozzle increased while the air flow rate decreased sharply, resulting the continuous decrease in the relative velocity between gas and liquid. Meanwhile, as the water supply pressure increased, the fragmentation scale of the liquid jet at the outlet of the nozzle was prolonged and the atomization of the liquid was limited. Secondly, based on the custom-developed dust reduction experimental system via spraying, the atomization characteristics of the nozzle were investigated. According to the experimental results, when the water supply pressure increased, the water flow rate and air flow rate of the nozzle had exponential increase and decrease, respectively. As the water supply pressure increased, the range, droplet volume fraction, droplet size, and velocity all increased, while the atomization angle first increased and then decreased. Finally, the dust reduction experiment via spraying was performed under different water supply pressures. The results showed that with the increase of water supply pressure, the dust-reduction efficiency for both the total dust and the respirable dust first increased and then decreased.     

Measuring mixing dynamics of transparent fluids with electronic speckle pattern interferometry

Electronic speckle pattern interferometry (ESPI) combined with phase-shifting techniques is used for studying the mixing dynamics of transparent fluids. The potentials of the technique for studying fluid mixing are illustrated for simple examples of water flow and moving water droplets in water. With ESPI we could actually follow water droplets moving in water and water flowing in water on a television monitor at the video rate. A He-Ne laser (lambda(0) = 632.8 nm) was used as the light source, and phase stepping was applied, giving an interferometric sensitivity better than lambda(0)/10. The observed phase changes are due to changes in the refractive index caused by small temperature differences between the droplets and the surrounding water. Temperature differences of less than 0.1 K are detectable for droplets of a diameter of 4 mm.     

Optimized particle engineering of fluticasone propionate and salmeterol xinafoate by spray drying technique for dry powder inhalation

Asthma is one of the most common respiratory diseases that can be efficiently managed through combined treatment of fluticasone propionate (FP) and salmeterol xinafoate (SX). In this study, we challenged the use of both spray drying and mixing techniques in sequential combination of lactose or mannitol with FP and SX as two steps in development of inhalable powder formulation of the drugs. Leucine was used as a dispersibility enhancer. The formulations were optimized using the Design-Expert software. The effects of three independent variables namely the type of carrier, percentage of spray-dried carrier and the amount of leucine were investigated on in vitro deposition. The results showed that the maximum fine particle fraction (FPF) and the minimum particle size was belonged to formulation in which the percentage of leucine was 20% with respect to the total solid content and 50% of mannitol was used during spray drying, while the remaining 50% of it was applied in the physical mixing process. This study showed that not only the choice of carrier and additives for every drug combination, but also an optimized ratios of them during both spray drying and physical mixing can be crucial in developing suitable inhalable dry powder formulations.     

正应力支配下混合顺序对PA6/HDPE/CNTs体系结构及性能的影响EI北大核心CSCD

利用自行研制的叶片式混炼装置,实现了正应力支配下聚合物复合体系的熔融共混。实验研究了混合顺序以及混合时间对高密度聚乙烯(HDPE)/尼龙6(PA6)/碳纳米管(CNTs)共混物的微观结构、流变特性、热性能及宏观力学性能的影响。结果表明:正应力支配作用能在短混合时间内实现PA6粒子和CNTs的均匀分散,分散效率高;相比于将HDPE,PA6,CNTs三者同时共混或者是先将PA6与CNTs混炼制成母料,再与HDPE共混这两种混合顺序,先将HDPE与CNTs混炼制成母料,再与PA6共混制得的共混物中分散相PA6粒径最小,分散更均匀,共混物的热性能以及力学性能更好。     

Rapid microfluidic mixing.

A preformed T-microchannel imprinted in polycarbonate was postmodified with a pulsed UV excimer laser (KrF, 248 nm) to create a series of slanted wells at the junction. The presence of the wells leads to a high degree of lateral transport within the channel and rapid mixing of two confluent streams undergoing electroosmotic flow. Several mixer designs were fabricated and investigated. All designs were relatively successful at low flow rates (0.06 cm/s, > or = 75% mixing), but had varying degrees of success at high flow rates (0.81 cm/s, 45-80% mixing). For example, one design operating at high flow rates was able to split an incoming fluorescent stream into two streams of varying concentrations depending on the number of slanted wells present. The final mixer design was able to overcome stream splitting at high flow rates, and it was shown that the two incoming streams were 80% mixed within 443 microm of the T-junction for a flow rate of 0.81 cm/s. Without the presence of the mixer and at the same high flow rate, a channel length of 2.3 cm would be required to achieve the same extent of mixing when relying upon molecular diffusion entirely, while 6.9 cm would be required for 99% mixing.     

Statistical anisotropy in free turbulence for mixing layers at high Reynolds numbers

A lateral shearing interferometer was used to measure the slope of perturbed wave fronts after propagating through free turbulent mixing layers. Shearing interferometers provide a two-dimensional flow visualization that is nonintrusive. Slope measurements were used to reconstruct the phase of the turbulence-corrupted wave front. The random phase fluctuations induced by the mixing layer were captured in a large ensemble of wave-front measurements. Experiments were performed on an unbounded, plane shear mixing layer of helium and nitrogen gas at fixed velocities and high Reynolds numbers for six locations in the flow development. Statistical autocorrelation functions and structure functions were computed on the reconstructed phase maps. The autocorrelation function results indicated that the turbulence-induced phase fluctuations were not wide-sense stationary. The structure functions exhibited statistical homogeneity, indicating that the phase fluctuations were stationary in first increments. However, the turbulence-corrupted phase was not isotropic. A five-thirds power law is shown to fit orthogonal slices of the structure function, analogous to the Kolmogorov model for isotropic turbulence. Strehl ratios were computed from the phase structure functions and compared with classical estimates that assume isotropy. The isotropic models are shown to overestimate the optical degradation by nearly 3 orders of magnitude compared with the structure function calculations.     

固体环氧树脂水分散体的制备和性能

用中等分子量的固体双酚A型环氧树脂ER-1和环氧乙烷/环氧丙烷的嵌段共聚物Lutrol F68合成了一种活性非离子型乳化剂F68-E,对乳化剂F68-E的结构以及合成过程进行了分析。用乳化剂F68-E对环氧树脂ER-1进行乳化,探讨了使用相反转法乳化时,乳化剂浓度、乳化温度和溶剂种类对环氧树脂水分散体的粒径和力学稳定性的影响。此外,将环氧树脂水分散体制成中温固化体系,对其干膜固化物进行了吸水率测试和动态热机械分析。结果表明,引入12%的乳化剂F68-E后,固化体系的吸水率由1.38%降至0.97%,玻璃化转变温度由102.5℃降至82.6℃。