外投料式滚筒筛分骨料的效率研究

为了提高外投料式滚筒筛分骨料的效率,对其筛分过程进行研究。以(10~40)mm粒度范围的骨料为研究对象,基于离散元理论,利用EDEM建立筛分模型并结合其筛分过程进行模拟仿真,得到在一定条件时,其转速和进料角度对滚筒筛分效率的影响规律:骨料筛分的最佳转速为15rpm,最佳进料角度为150°;通过正交实验模拟,得到了外投料式滚筒筛的滚筒转速、进料角度、进料量三因素对骨料筛分效率的显著性和最佳取值。仿真研究结果可以为外投料式滚筒筛的结构设计及其工艺参数优化提供借鉴和参考,具有较强的工程应用价值。

Radial mixing and segregation of granular bed bi-dispersed both in particle size and density within horizontal rotating drum

Taking simultaneous variations in both particle volume and density into account, the radial mixing and segregation of binary granular bed in a rotating drum half loaded were investigated by a 3D discrete element method. Then, based on the competition theory of condensation and percolation, radial segregation due to differences in particle volume and/or density was analyzed. The results show that if either percolation effect induced by volume difference or condensation effect induced by density difference dominates in the active layer of moving bed, separation will occur. Controlling the volume ratio or density ratio of the two types of particles can achieve an equilibrium state between percolation and condensation, and then homogenous mixture can be obtained. When the percolation balances with the condensation, the relationship between volume ratioand density ratiopresents nearly a power function. Scaling up a rotating drum will not affect the mixing degree of the granular bed so long as the volume ratio and density ratio are predefined.

模块化滚筒好氧发酵反应器设计与试验

针对现有滚筒式好氧发酵反应器存在腔体容积固定不可调、运行能耗高、尾气余热回用难等问题,基于模块化设计理念,研发了一种模块化滚筒好氧发酵反应器,主要由滚筒、曝气系统、余热回用装置、驱动系统和密封连接件等模块单元组成。对模块化滚筒好氧发酵反应器进行堆肥性能试验,结果表明:高温期持续9 d,发酵持续15 d后种子发芽指数达90%以上,各项指标均满足堆肥腐熟和无害化要求。该设计提高了滚筒好氧发酵反应器加工组装效率,扩大了滚筒好氧发酵反应器适用范围,具有规模可调、分段驱动、分级发酵、精准曝气等优点,可为滚筒好氧发酵反应器堆肥技术发展和应用提供支撑。

带式输送机驱动系统的分析与比较

带式运输机在起停运行时存在着刚性撞击和负载起动等情况,会对带式输送机造成损伤,针对此现象,文中采取在大规模的带式输送机上应用软起动驱动系统解决,软起动驱动系统主要采用永磁直驱滚筒、液黏传动、变频器、可控启动传动系统CST和柔性驱动系统FDS等方案。对5种驱动装置的柔性启动机理进行了较为详尽的阐述;通过比较5种驱动系统,分析其优缺点,并对应用于带式输送机的软起动驱动装置所带来的经济效益进行了分析。

投喂频率对陆基圆桶养殖大口黑鲈生长及水体水质的影响

【目的】研究不同投喂频率对陆基圆桶养殖大口黑鲈(Micropterus salmoides)生长性能、水体水质及其微生物群落结构的影响。【方法】本研究开展了2次/天和3次/天两种投喂频率实验。【结果】3次/天组的终末体质量和特定生长率高于2次/天组。投喂频率对水体中氨氮(TAN)、亚硝酸盐(NO_(2)-N)、悬浮物量(SS)和化学需氧量(COD)等指标的浓度均有显著性影响(P<0.05),且2次/天组高于3次/天组。两组养殖水体的细菌群落结构相似,其优势菌门均为变形菌门(Proteobacteria)和拟杆菌门(Bacte-roidetes),优势菌属均为邻单胞菌属(Plesiomonas)和红细菌属(Rhodobacter);对大口黑鲈养殖过程中常见致病菌丰度进行统计,发现3次/天组豚鼠气单胞菌(Aeromonas caviae)的平均丰度(0.08%)显著低于2次/天组(0.14%)(P<0.05)。环境因子与细菌群落结构关联分析结果显示,氨氮(TAN)、总氮(TN)和总磷(TP)对水体细菌群落结构均有显著性影响(P<0.05)。【结论】大口黑鲈陆基圆桶养殖模式中,3次/天投喂频率较2次/天投喂频率具有生长快、养殖水体关键水质指标水平低以及致病菌丰度低的优势。本研究结果可为陆基圆桶养殖大口黑鲈的科学投喂提供实际支持。

器以载道:铜鼓文化在铸牢中华民族共同体意识中的价值逻辑及实践路径

铸牢中华民族共同体意识是习近平总书记提出的重大原创性论断,是维护各民族根本利益和实现中华民族伟大复兴的必然要求。中华民族共同体意识厚植于中华优秀传统文化之中。具有两千多年历史的中国铜鼓不仅是中华民族历史文化变迁的“见证者”,也是中华民族交往交流交融的“记录者”。中华民族共享的文化符号、共生的历史记忆、共有的价值观念都在铜鼓文化中可见一斑。为全面体现、充分发挥铜鼓文化这一中华优秀传统文化在铸牢中华民族共同体意识中的价值和功能,应积极彰显共享文化符号,维系中华民族情感纽带;增进文化互鉴融通,强化中华民族文化认同;打造铜鼓文旅品牌,推动各民族共同富裕。

打辊工艺对翠碧一号上部烟叶打叶质量和出片率的影响

为提高翠碧一号上部烟叶打叶质量和出片率,明确打辊工艺对打后片烟结构、叶中含梗率和出片率的影响,采用均匀试验设计不同打辊转速组合,在打叶复烤生产线开展打叶实验,应用回归分析构建一至四级打辊转速与片烟结构、叶中含梗率和出片率的数学模型,利用模型对四级打辊转速参数进行了优化和验证。结果表明:大片率、中片率、大中片率和碎片率与打辊转速线性回归模型均在P<0.01水平显著,叶中含梗率与打辊转速线性回归模型在P<0.05水平显著,出片率与打辊转速线性模型相关系数为0.83,但在P<0.05水平不显著;在其他工艺条件恒定时,大片率、中片率、大中片率受一级打辊转速和二级打辊转速影响较大,碎片率受一级打辊转速和三级打辊转速影响较大,叶中含梗率受一级打辊转速影响较大,出片率受一级打辊转速、二级打辊转速和四级打辊转速影响较大;优化后一至四级打辊转速分别为585 r/min、590 r/min、680 r/min和690 r/min,较现行工艺大片率降低了9.59%、中片率提高了17.41%、出片率提高了1.33%,有效提升了翠碧一号上部烟叶的打叶质量。

带式输送机传动滚筒强度分析及结构优化

以DTL180型带式输送机为例进行分析,利用ANSYS软件构建了带式输送机传动滚筒的强度分析模型。结果发现,传动滚筒结构设计方面存在较大冗余,实际应力和位移变形量比许用值低很多。以传动滚筒轴直径、筒壳厚度、辐板厚度三个结构参数为优化对象开展优化改进工作,在确保滚筒强度的基础上,使得上述三个结构尺寸大幅度减小,传动滚筒总重量降低了22.57%。将结构优化后的带式输送机传动滚筒应用到新景煤矿中进行工程应用,发现其整体运行良好,使得结构件的加工成本降低,经济效益显著。

湖南花鼓戏女性群像服饰设计研究

文章旨在探讨湖南花鼓戏女性群像服饰的历史演变、艺术表现形式以及在数字艺术领域的应用。通过文献综述和案例分析的方法,文章探究了湖南花鼓戏女性服饰从早期的简洁实用风格到中期的高档面料和精致装饰,再到近代的时尚化与修身化设计的演变过程。湖南花鼓戏女性群像服饰不仅展现了传统与现代元素的融合,还体现了不同社会阶层和性格特征的女性形象。此外,文章还探讨了花鼓戏服饰在数字艺术领域的应用,包括数字化再现与复原、创意设计与创新、互动体验与传播以及数字艺术教育等方面,展示了如何通过现代技术手段保护和传承这一传统艺术形式。

转炉处置废金属油桶废油燃烧特性试验

废金属油桶作为废钢加入转炉时,其内部附着的废油在转炉高温气氛下的燃烧反应特性及机理尚不明确。利用热重分析仪和高温管式炉试验台等,对废油在不同温度、不同空气通量、不同燃烧时间等条件下,热重、吸放热特性和气固相产物等进行研究。试验证明,空气充足的情况下650℃时废油已燃尽,燃尽时间在转炉加废钢与兑铁水的时间间隔内,转炉内部高温环境足以使废金属油桶附着的废油充分燃烧。

高应力大巷底鼓机理及其稳定性控制方法

针对余吾煤业1号回风大巷在高应力扰动下出现的巷道底鼓严重问题,综合运用理论分析、数值计算和现场试验相结合的方法,系统研究了高应力大巷底鼓机理及其稳定性控制方法。理论计算结果表明,高应力巷道底板破坏深度达1.35 m,底板滑移面受到的滑动力达3.11 MPa,超过了底板砂质泥岩极限抗拉强度,导致巷道底板发生底鼓。从高应力巷道底鼓控制角度出发,提出了高应力巷道顶底板加强锚索与巷道两帮锚杆联合支护的巷道底鼓控制技术,数值模拟结果表明巷道底鼓量可降低67%,有效控制底鼓的同时,也可为巷道整体稳定提供支撑。通过现场试验,研究提出的巷道底鼓控制方法可使回风大巷顶板下沉值降低37%,底鼓值降低72%,两帮变形量降低53%,有效保证了回风大巷的稳定。研究结果对于指导深部矿井高应力环境下巷道底鼓控制具有重要实践意义。

双折线卷筒上钢丝绳卷绕状态的力学分析

钢丝绳偏角直接影响钢丝绳在双折线卷筒上的卷绕整齐性。因此本文以双折线卷筒的钢丝绳截面单元微元体为分析对象,建立了双折线卷筒在均速转动条件下钢丝绳卷绕状态的力学模型。通过该力学模型分析表明,卷筒均速转动下钢丝绳后偏时钢丝绳随着钢丝绳偏角增大受到挤压力增大,但“骑绳”现象很难发生;当钢丝绳前偏时钢丝绳偏角超过绳槽螺旋角时“跳绳”现象可能会发生,并且钢丝绳偏角越大“跳绳”越容易发生。其次,通过所建的力学模型对工程实例进行了计算分析;结果表明,平行线绳槽段的钢丝绳偏角是决定“跳绳”发生的关键,同时钢丝绳张力越大越容易发生“跳绳”。本文建立的双折线卷筒力学分析模型可以为提升绞车的参数设计和钢丝绳的选择提供了的理论依据。

广西瑶族长鼓舞文化英译研究

瑶族长鼓舞是中国国家级非物质文化遗产之一,流传于湖南、广东、广西等地。本文以广西瑶族长鼓舞为研究对象,通过实地调查与翻译实践相结合,探讨瑶族长鼓舞的发展现状,以便提高瑶族长鼓舞的知名度,促进其传承和发展。在苏珊·巴斯特内文化翻译观的指导下,译者根据文本特点选择归化与异化的翻译策略,采用、意译、音译、省译、增译等翻译方法,增强国外读者对广西瑶族长鼓舞文化的理解,促进广西瑶族长鼓舞文化的对外宣传。

Kinematics and Path Following Control of an Articulated Drum Roller

Automatic navigation of an articulated drum roller, which is an articulated steering type vehicle widely used in the construction industry, is highly expected for operation cost reduction and improvement of work effi- ciency. In order to achieve the path following control, considering that its steering system is articulated steering and two frames are articulated by an active revolute joint, a kinematic model and an error dynamic state-space equation of an articulated drum roller are proposed. Besides, a state- feedback control law based on Lyapunov stability theory is also designed, which can be proved to achieve the purpose of control by the analysis of stability. What＇s more, to evaluate the performance of the proposed method, simu- lation under the MATLAB/Simulink and experiments using positioning algorithm and errors correction at the uneven construction site are performed, with initial dis- placement error （-1.5 m）, heading error （-0.11 tad） and steering angle （-0.19 rad）. Finally, simulation and exper- imental results show that the errors and steering angle can decrease gradually, and converge to zero with time. Meanwhile, the control input is not saturated. An articu- lated drum roller can lock into a desired path with the proposed method in uneven fields.

薄板烘丝机筒内结垢程度对设备工艺性能的影响

为揭示薄板烘丝机筒内结垢对设备工艺性能的影响,利用涂层测厚仪结合数理统计分析技术、热成像分析技术对比两台薄板烘丝机结垢严重程度、过程参数批间运行值、热风控制稳定性、料尾延迟特性、蒸汽消耗量、壁面温度分布均匀性等差异。结果表明:制丝一区和制丝二区的烘丝机壁面污垢层厚度平均值分别为1.5 mm、0.4 mm;不同结垢程度的烘丝机,批间物料流量和工艺热风流量运行值存在显著性差异;与污垢层厚度为0.4 mm的烘丝机相比,当壁面污垢厚度为1.5 mm时,烘丝机工艺热风流量和温度的波动增大,料尾延迟时间增加了30 s,蒸汽消耗量增加了65 kg/h;壁面颗粒污垢的附着与积聚,影响了筒壁温度分布均匀性,局部温度极差达8℃。

Performance of rotating drum biofilter for volatile organic compound removal at high organic loading rates

Uneven distribution of volatile organic compounds （VOCs） and biomass, and excess biomass accumulation in some biofilters hinder the application of biofiltration technology. An innovative multilayer rotating drum biofilter （RDB） was developed to correct these problems. The RDB was operated at an empty bed contact time （EBCT） of 30 s and a rotational rate of 1.0 r/min. Diethyl ether was chosen as the model VOC. Performance of the RDB was evaluated at organic loading rates of 32,1, 64.2, 128, and 256 g ether/（m^3·h） （16.06 g ether/（m^3·h） ≈ 1.0 kg chemical oxygen demand （COD）/（m^3·d））. The EBCT and organic loading rates were recorded on the basis of the medium volume. Results show that the ether removal efficiency decreased with an increased VOC loading rate. Ether removal efficiencies exceeding 99% were achieved without biomass control even at a high VOC loading rate of 128 g ether/（m^3·h）. However, when the VOC loading rate was increased to 256 g ether/（m^3·h）, the average removal efficiency dropped to 43%. Nutrient limitation possibly contributed to the drop in ether removal efficiency. High biomass accumulation rate was also observed in the medium at the two higher ether loading rates, and removal of the excess biomass in the media was necessary to maintain stable performance. This work showed that the RDB is effective in the removal of diethyl ether from waste gas streams even at high organic loading rates. The results might help establish criteria for designing and operating RDBs.

全钢轻型载重子午线轮胎胎体脱层病疵改善分析

分析全钢轻型载重子午线轮胎胎体脱层病疵产生的原因,并提出相应的解决措施。通过使用较厚三角胶、调整成型鼓边端曲线使其趋于平滑、胎体使用弯曲刚度较小的1+5×0.18ST钢丝帘线,无批量胎体脱层病疵发生,改善效果明显。

Fatigue behaviour of coke drum materials under thermal-mechanical cyclic loading

Coke drums are vertical pressure vessels used in the delayed coking process in petroleum refineries. Significant temperature variation during the delayed coking process causes damage in cracking. There were some studies on coke drums in the form of bulging and the fatigue life estimation for the coke drums, but most of them were based on strain-fatigue life curves at constant temperatures, which do not consider simultaneous cyclic temperature and mechanical loading conditions. In this study, a fatigue testing system is successfully devel- oped to allow performing thermal-mechanical fatigue （TMF） test similar to the coke drum loading condition. Two commonly used base and one clad materials of coke drums are then experimentally investigated. In addition, a comparative study between isothermal and TMF lives of these materials is conducted. The experimental findings lead to better understanding of the damage mechanisms occurring in coke drums and more accurate prediction of fatigue life of coke drum materials.

Reliability modeling of hydraulic system of drum shearer machine

The hydraulic system plays an important role in supplying power and its transition to other working parts of a coal shearer machine. In this paper, the reliability of the hydraulic system of a drum shearer was analyzed. A case study was done in the Tabas Coal Mine in Iran for failure data collection. The results of the statistical analysis show that the time between failures （TBF） data of this system followed the 3-parameters Weibull distribution. There is about a 54% chance that the hydraulic system of the drum shearer will not fail for the first 50 h of operation. The developed model shows that the reliability of the hydraulic system reduces to a zero value after approximately 1 650 hours of operation. The failure rate of this system decreases when time increases. Therefore, corrective maintenance （run-to-t^ailure） was selected as the best maintenance strategy for it.

Particle breakage of sand subjected to friction and collision in drum tests

This paper presents a laboratory experimental study on particle breakage of sand subjected to friction and collision,by a number of drum tests on granular materials(silica sand No.3 and ceramic balls)to investigate the characteristics of particle breakage and its effect on the characteristics of grain size distribution of sand.Particle breakage increased in up convexity with increasing duration of drum tests,but increased linearly with increasing number of balls.Particle breakage showed an increase,followed by a decrease while increasing the amount of sand.There may be existence of a characteristic amount of sand causing a maximum particle breakage.Friction tests caused much less particle breakage than collision tests did.Friction and collision resulted in different mechanisms of particle breakage,mainly by abrasion for friction and by splitting for collision.The fines content increased with increasing relative breakage.Particle breakage in the friction tests(abrasion)resulted in a sharper increase but with a smaller total amount of fines content in comparison with that in the collision tests(splitting).For the collision tests,the fines content showed a decrease followed by an increase as the amount of sand increased,whereas it increased in up convexity with increasing number of balls.The characteristic grain sizes D_(10) and D_(30) decreased in down convexity with increasing relative breakage,which could be described by a natural exponential function.However,the characteristic grain sizes D50 and D60 decreased linearly while increasing the relative breakage.In addition,the coefficients of uniformity and curvature of sand showed an increase followed by a decrease while increasing the relative breakage.