工艺参数对惰性代料高压熔铸成型质量的影响

为减少熔铸炸药的装药缺陷、提高装药密度，设计制造了一套高压熔铸成型系统，采用与典型TNT基和DNAN基熔铸炸药物理性质相近的惰性代料开展高压熔铸成型试验，研究加载压力、保压时间和加压时机对代料药柱相对密度和装药质量的影响。结果表明，高压熔铸成型过程中，除液相补缩作用被增强外，还存在糊状补缩和固相补缩作用，从而显著减少药柱的装药缺陷，提高相对密度；加载压力应在药柱的三轴压缩屈服强度和三轴压缩抗压强度之间；保压时间应超过药柱的凝固耗时；加压时机的温度应保证模具内壁尚未出现凝固层；加载压力25.45MPa、保压时间60min、加压时机80℃工况下制得的药柱无装药缺陷，相对密度高达99.90%。     

DNAN基高致密熔铸炸药装药安全性研究

文章从熔铸炸药的一般性质入手,分析了以球形化RDX/DNAN为基的高致密熔铸炸药装药的可行性与优越性;通过制备一定量的RDX/DNAN和RDX/TNT熔铸炸药药柱,采用GJB炸药试验方法,进行密度和冲击波感度测试。试验结果表明,相同配比下使用球形化RDX的TNT基高致密熔铸炸药相对于使用普通RDX的TNT基高致密熔铸炸药,其密度更高,冲击波感度略有降低。而相同RDX含量下,将载体由TNT改为DNAN,其冲击波感度又降低了超过15%,安全性得到了极大的提升。     

炸药熔铸过程缩孔和缩松的形成与预测

采用工业CT对熔铸成型TNT及RHT(熔黑梯)药柱内部的缩孔和缩松情况进行检测,分析了炸药熔铸成型过程中内部缩孔缩松产生的模式和机理.采用有限元法对炸药熔铸成型过程中缩孔缩松的形成过程进行了数值模拟.结果表明,熔铸炸药内部缩孔缩松的形成主要是由于其凝固过程中结晶收缩、固体收缩及气体析出形成的,采用临界固相率和补缩距离相...     

破甲战斗部精密装药基础及实验研究

论述了影响破甲战斗部精密药柱压制成型的基础因素,对压制过程进行力学分析,利用塑料粘结炸药,针对影响装药密度的因素进行了实验研究。     

复合载荷作用下TATB基PBX炸药药柱的损伤试验研究

为研究损伤炸药的安全性,在温度载荷和机械载荷的复合作用下,对TATB基PBX炸药药柱进行了较轻微和较强烈两种不同程度的损伤试验。测试了损伤前后PBX药柱的密度、超声波声速和增益值变化,采用隔板试验测试了冲击波感度。结果表明,经两种复合载荷作用后药柱的密度分别减小0.15%和2.16%,超声波声速减小0.97%和7.87%,增益值增加43.32%和49.07%;50%爆轰隔板厚度分别增加约2.08%和30.21%,表明复合载荷作用越强烈,药柱密度和声速值减小越明显,损伤越严重,冲击波感度越高。     

炸药模拟环境温湿度试验技术研究

介绍了炸药模拟环境试验的装置、温度和湿度范围、循环程序、周期及失效判据的选择，对十几种炸药进行了环境适应性试验，取得大量数据，对炸药的环境适应能力进行评估，在此基础上研究建立了炸药模拟环境试验技术。该技术不但能判断炸药药柱是否合格，而且能发现药柱相互间差异，排出优劣顺序，为炸药性能的评价提供了一个较好的试验方法     

一种工业CT定量检测炸药装药密度的方法

为了定量检测炸药的装药密度,提出了一种工业CT测量炸药装药密度的线性换算法。用蒸馏水制备已知密度的盐溶液作密度标准件,对该方法进行了验证。用该方法测量了某战斗部产品实际装药密度和某种炸药药柱的密度。结果表明,该法与排水法测量装药密度或药柱密度之间的误差为1%。认为线性换算法简单、实用,能用于检测结构简单样品的装药密度。     

主体炸药RDX对CH-6炸药药柱特性的影响

用药柱特性试验和X射线探伤测定了分别由压煮RDX与丙精RDX制成的两种CH-6混合炸药的药柱特性。结果表明．由压煮RDX制成的CH-6混合炸药．其药柱特性优于由丙精RDX制成的CH-6混合炸药。确定了造成这种结果的原因。     

JBO-9021炸药初始密度对爆轰波阵面曲率效应的影响

采用高速扫描相机及电探针,在室温环境下对不同初始密度(1.894~1.901g/cm3)、不同半径(5.0、7.5、15.0mm)的钝感炸药JBO-9021药柱开展了曲率效应实验,获取了拟定态爆轰波阵面形状及波速,分析了其随炸药柱密度及半径的变化。结果表明,随着炸药JBO-9021的初始密度由1.894g/cm3增至1.901g/cm3,3种不同半径JBO-9021药柱的爆轰波拟定态波速均增大,拟定态波阵面形状变得更为平坦,波阵面中心点与边界点之间的波到达时间差降低;在小曲率范围内(κ0.2mm-1),JBO-9021药柱爆轰波波阵面法向波速Dn与当地曲率κ的关系(Dn(κ)关系)不受药柱半径及密度的影响,当曲率κ0.2mm-1时,Dn(k)关系随药柱半径及炸药密度呈现离散趋势,药柱半径及初始密度共同影响爆轰波波阵面大曲率的Dn(κ)关系。     

高温暴露试验对PBX药柱的影响

对Ｒ８５２。Ｈ７８１、Ｈ８７２、Ｈ８７１８、ＨＭＸ－１５９、８０２１等炸 药进行高温暴露试验，考究其药柱在高温暴露条件下，不可逆尺寸变化和密度变化，并用Ｘ光衍射法研究了试验闪后主体炸药的晶体结构变化。     

Fabrication of High-Density Homogeneous ThO2-UO2 Fuel Pellets

Thorium oxide and uranium oxide pellet fuel development activities leading to a process fohd fabrication of high density, homogeneous fuel pellets are described. Conventional dry ball-milling was used to comminute commercially available powders. After separate milling, these ThO₂-UO₂mixtures were co-milled, pressed, and sintered to 95 % of theoretical density with a homogeneous distribution of the components. An intimate mix of highly active powders promotes solid solution formation and yields high density pellets.     

Optimization of preparation of matrix pellets containing ethylcellulose

The aim of this study was to investigate the effects of the parameters of the spheronization and the nature of the wetting liquid on the properties of matrix pellets prepared by extrusion and spheronization. Ethylcellulose was used as a matrix former, microcrystalline cellulose as a filler, atenolol as a model active agent, and water and a water–ethanol mixture as liquids. The formation of the pellets and the interactions of the components were evaluated via mechanical, dissolution and morphological studies on the pellets. A factorial design was used to determine the effects of the evaluated factors. It was concluded that significant effects were exerted not only by the operational parameters, but also by the nature of the liquid. The breaking hardness and the dissolution revealed that the ethanol in the liquid caused changes in the wettability of the components and consequently in the matrix structure. This was explained by a comparison of the relative importance of the factors. The alterations induced by ethanol were preferable in the dissolution, because the possibility of the burst effect in the first phase of dissolution can then be avoided. However, it is not favourable as concerns the sphericity and the mechanical properties of the pellets.     

Effects of raw material moisture content,densification pressure and temperature on some properties of Norway spruce pellets

In order to study the pelletising process, Norway spruce sawdust pellets were produced under strictly controlled conditions on a laboratory scale. The aim of the work was to investigate how the moisture content of raw material and the densification parameters, pressure and temperature, affect compression strength, dry density and moisture uptake of the formed pellets. In the experiments performed, temperature (26–144 °C), moisture content (6.3–14.7 wt.% of d.b.) and pressure (46–114 MPa) were the factors which varied according to a prescribed central composite design. The relationships between the factor settings and the responses (dry density, moisture uptake and compression strength) were evaluated by multiple linear regressions.In the present study, it was found that high compression strength was strongly correlated with the density of the pellets. High temperature (at least up to 144 °C) and low moisture content at the start of compression (down to 6.3 wt.% of d.b.) increased the dry density of the pellets. Remarkably, compression force had very little effect in the tested range of 46–114 MPa, indicating that pressure in the die does not need to be higher than 50 MPa.Similarly, compression force had very little effect on moisture uptake in the pellets. The least moisture uptake occurred when the pellets were produced at 90 °C.     

Effects of raw material moisture content,densification pressure and temperature on some properties of Norway spruce pellets

In order to study the pelletising process, Norway spruce sawdust pellets were produced under strictly controlled conditions on a laboratory scale. The aim of the work was to investigate how the moisture content of raw material and the densification parameters, pressure and temperature, affect compression strength, dry density and moisture uptake of the formed pellets. In the experiments performed, temperature (26–144 °C), moisture content (6.3–14.7 wt.% of d.b.) and pressure (46–114 MPa) were the factors which varied according to a prescribed central composite design. The relationships between the factor settings and the responses (dry density, moisture uptake and compression strength) were evaluated by multiple linear regressions.In the present study, it was found that high compression strength was strongly correlated with the density of the pellets. High temperature (at least up to 144 °C) and low moisture content at the start of compression (down to 6.3 wt.% of d.b.) increased the dry density of the pellets. Remarkably, compression force had very little effect in the tested range of 46–114 MPa, indicating that pressure in the die does not need to be higher than 50 MPa.Similarly, compression force had very little effect on moisture uptake in the pellets. The least moisture uptake occurred when the pellets were produced at 90 °C.     

Fe-Cr高变催化剂的模压成型和机械强度的动态研究

引　言目前国内绝大多数工业催化剂的成型过程工艺都是由经验决定的 ,往往缺乏催化剂成型基础理论的系统研究 .近年来 ,科学家对于催化剂成型进行了一些有益的研究和探索 .朱洪法[1] 对催化剂成型过程进行了论述 .李永丹[2 ] 研究了铁氧化物催化剂的机械强度和模压成型过程 ,认     

加氢裂化循环气支链爆炸形态的区划与应用

对加氢裂化循环气与相关可燃性气体支链爆炸的特性及其应用进行了系统的研究.探索了浓度爆炸极限、爆炸形态与波形及其影响因素;根据爆炸形态与波形的不同,提出了对加氢裂化循环气爆炸形态科学区划的新理念;在爆炸极限内,可以进一步区划4种爆炸形态(冷焰、爆燃、爆轰、爆燃向爆轰转化),与7个爆炸区域（上、下冷焰区,上、下爆燃区,上、下爆燃向爆轰转化区,爆轰区）,并探讨了不同爆炸形态压力波的发展机制.对进一步研究相关的多元支链爆炸体系,促进多元支链爆炸理论的发展,具有一定的理论价值.实验测得了爆炸危险度、火焰蔓延极限、最小点火能等特性参数;引进了“关键组分”的概念,指出加氢裂化循环气的多元体系,引发爆炸的物质是关键组分H₂和氧化剂O₂;探讨了制订防爆安全指标的依据与方法.对于预防混合气体支链爆炸事故的发生、指导防爆电气设备与阻火器的设计、指导支链燃烧与支链爆炸的实践,具有参考价值.     

Pelletization kinetics of an earthy iron ore and the physical properties of the pellets produced

The iron ore sample used in this investigation was brought from the El-Gedida iron ore deposit, Baharia Oasis, Egypt. This ore is porous, earthy, hard, and has a relatively high specific surface area.The batch balling kinetics of this ore show that the ball growth rate increased by increasing the moisture content. The water content required for pelletizing this ore ranged between 16 and 19% of the dry weight of the charge. As expected, increase in bentonite content retarded the ball growth. Finer feed produced by more dry grinding increased the ball growth rate.The average drop number of pellets was improved by increasing the moisture content to a certain limit, after which the quality of the pellets decreased. The drop number also went up as the amount of bentonite was increased. Increasing the degree of fineness of ore improved the level of drop number.The crushing strength of dried pellets improved with increasing water content to a certain limit, then the trend reversed. Bentonite addition slightly improved the crushing strength of pellets. Increasing the degree of fineness of the ore decreased the crushing strength of dry pellets.The bulk density of pellets increased with higher moisture content to a certain limit and then the trend reversed. Small amounts of bentonite addition decreased the bulk density, but when bentonite exceeded 0.5% the bulk density slightly increased with increasing amount of bentonite. Denser pellets were produced when finer feed was used.     

TATB/HMX共晶炸药的制备及性能研究

采用溶剂/非溶剂法,在超声辅助的情况下,制备了TATB/HMX共晶炸药;探究了TATB/HMX共晶技术的影响因素;计算了TATB/HMX共晶炸药的理论密度和理论爆速;采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)和差示扫描热量法(DSC)对其进行表征和热分析,并测试了其撞击感度。结果表明,制备TATB/HMX共晶的最佳工艺条件为:以[Emim]Ac/DMSO为复合溶剂,TATB和HMX投料比(摩尔比)为3∶7,温度为80℃,搅拌速率为500r/min;与原料相比,TATB/HMX共晶分子在结构上发生改变;TATB/HMX共晶炸药颗粒大小约为2μm,形貌为六边形晶体;共晶炸药的热安定性优于原料HMX,其特性落高比原料HMX高74cm,撞击感度明显降低;理论密度为1.891g/cm~3,理论爆速为8.758km/s,表明其爆炸性能良好。     

木块微波裂解及产物组成分析

使用2 450 MHz/12 kW微波裂解装置裂解木块并对不同裂解条件下气、液产物进行了分析。结果表明,木块微波裂解生成了极具价值的生物油、合成气等产品;裂解功率对液体产品收率及主要组分的种类产生影响;裂解温度对液态产品各组分相对含量及气态产品的成分构成产生影响。     

Effect of process parameters on pelletisation of herbaceous crops

Straw, sawdust and other herbaceous crops benefit from pelletisation, as the process increases the materials bulk density therefore reducing transportation and storage costs; providing better material feeding with less dust formation. This study investigated a pressure pelletisation method of switchgrass for five types of material preparation: raw cut switchgrass, raw shredded switchgrass, torrefied switchgrass, switchgrass combined with heavy pyrolysis oil and wheat straw. The effects of pelletisation pressure and temperature on the quality of pellets were evaluated in terms of density, mechanical strength and durability. Temperature had a greater effect than pressure on pellet quality, where at elevated temperatures, the lignin present in the biomass softened and acted as a binding agent. The cut switchgrass produced more desirable pellets over shredded switchgrass due to an additional binding effect of intertwined fibres. The torrefaction of grass was not an attractive pre-process as the pellets were very brittle and possessed little mechanical strength and reduced bulk density. At elevated temperatures, with a grass to tar ratio of 2:1, the pellets were twice as strong as pellets made by cut switchgrass. The increased durability was a result of lignin present in the biomass and the heavy oil dispersing inside the pelletiser, which filled in the gaps between the switchgrass fibres upon heating. Finally, the pellets were burnt in a fixed bed combustor and the ignition rate and average burning rates were evaluated. The results have provided an indication to how the pellets would perform compared to other fuels. Future work should focus on the standardisation of herbaceous crop pelletisation and in particular, upper and lower bound limits for the moisture content should be investigated, as moisture was found to have a significant impact on pellet quality.