轮胎胎圈打褶和胎里窝气的原因分析及解决措施

对造成轮胎胎圈打褶和胎里窝气缺陷的原因进行分析并提出相应解决措施。轮胎胎圈打褶问题主要通过调整机械手伸张直径公差范围、调整内套高度、增加“呼吸”动作、控制装胎高度和换用光面胶囊等方式进行解决;胎里窝气问题主要通过调整定型时间和增加定型排放的方式进行解决。采取改进措施后胎圈打褶和胎里窝气缺陷轮胎数量明显减少,节约了生产成本。     

全钢载重子午线轮胎胎圈出边的原因分析和解决措施

从工艺方面分析全钢载重子午线轮胎胎圈出边的原因,并提出相应解决措施。通过采取调整内衬层、过渡层与气密层的宽度和厚度、恢复硫化机机械手强制定中装置、确保机械手转动盘中心套筒和胶囊上卡盘立柱与套筒直径匹配、避免中心机构内芯子杆偏歪和弯曲、将变形后的椭圆形胎圈恢复为圆形以及调整机械手张开直径等措施,成品轮胎胎圈出边质量缺陷率由0. 063%降低至0. 015%。     

全钢载重子午线轮胎胎侧蛇形弯曲原因分析及解决措施

对全钢载重子午线轮胎胎侧蛇形弯曲的产生原因进行分析,并提出相应解决措施。通过采取胎侧在恒温恒湿环境下停放、调整挤出机温度匹配性、合理设定混炼胶门尼粘度标准、优化耐磨胶配方及改进胎侧终口型系数等措施,有效解决了胎侧蛇形弯曲问题,降低了胎侧部件返工率,使成品轮胎胎圈类质量缺陷的理赔率由0.66%下降至0.21%。     

全钢载重子午线轮胎胎坯胎圈内径偏大的解决措施

探讨采用一次法成型的全钢载重子午线轮胎胎坯胎圈内径偏大的解决措施。钢丝圈底部增添胶片对胎坯胎圈内径有明显影响,胎圈宽度也增大,不能解决成品轮胎胎圈质量问题;成型机机头宽度调整对胎坯胎圈内径影响不大,对解决成品轮胎胎圈质量问题也无效;成型鼓撑块直径与胶囊厚度配合调整,可有效降低成品轮胎胎圈质量发生率。     

23.5-25 16PR横向花纹工程机械轮胎胎肩泡产生原因及解决措施

分析23．5－2516PR横向花纹工程机械轮胎胎肩泡的主要形态及其产生的原因,通过采取调整胎面设计尺寸、水胎冠部和肩部厚度、增添正包装置等措施,使该规格轮胎合格率从87．7％上升为98．5％,经济效益明显提高。     

半钢子午线轮胎胎圈变形原因分析及解决措施

分析半钢子午线轮胎胎圈变形的原因并提出相应解决措施.硫化胶囊固定套高度不合适或上卡盘与钢棱圈配合过紧、启模时活络模花纹块不能及时完全打开和轮胎粘上模、脱下模方式不当、抽真空不当或硫化胶囊粘连、卸胎支臂位置不当以及运输不当均会导致胎圈变形,采取相应解决措施后,半钢子午线轮胎胎圈变形废品率由0.12%降至0.01%,胎圈变形废品占总废品比例由22.60%降至2.46%.     

全钢载重子午线轮胎胎肩气泡产生原因及解决措施

对全钢载重子午线轮胎胎肩气泡产生原因进行分析,并提出相应的解决措施。从结构设计、半成品部件和成型方面分析胎肩气泡产生原因,通过采取重新设计胎面和垫胶尺寸,调整带束层宽度;严格控制车间温度和湿度,保证物料存放条件,增大胎面基部胶宽度;根据不同胎面调整压合压力,校正后压辊精度等措施,有效解决了全钢载重子午线轮胎胎肩气泡问题。通过加强现场工艺监控措施,明显减小了胎肩气泡发生几率。     

全钢载重子午线轮胎胎圈包布宽度优化分析

采用哈尔滨工业大学开发的轮胎专用三维非线性有限元分析软件TYSYS建立全钢载重子午线轮胎有限元分析模型,对不同胎圈包布宽度及匹配三角胶调整进行对比分析.结果表明,适度加大胎圈包布宽度并减小下三角胶高度,同时调整三角胶断面形状,可有效减小胎圈部位钢丝材料端点应力集中,大幅度提高轮胎的使用性能.     

白胎侧轮胎生产工艺控制

根据白胎侧结构及白胎侧胶自粘性差和气密性高等特点,从混炼、挤出、成型、硫化到白字打磨和成品轮胎送检全面介绍白胎侧轮胎生产工艺控制应注意的问题.生产工艺技术完善和改进后,白胎侧轮胎的外观质量和使用性能得到明显改善,废品率由2.75%降至0.37%,动平衡性能优级品率由83.18%升至94.19%.     

载重斜交轮胎胎圈钢丝包胶配方的改进

对载重斜交轮胎胎圈钢丝包胶配方进行改进,通过调整生胶体系,降低胎圈钢丝包胶中填料的用量,适当提高炭黑用量,采用间-甲-白和钴盐并用的粘合体系等途径,提高了胎圈钢丝包胶的强度,改善了与钢丝的粘合性能,减小了载重斜交轮胎胎圈爆破和胎圈钢丝刺出等缺陷,成品轮胎的胎圈问题退赔率由原来的1.3%降为0.1%以下,显著提高了轮胎的实际使用寿命。     

八字山风井主要风机选型及风量优化研究

主要通风机是矿井通风系统中最核心、最关键的设备,合理的风机型号选择和通风风量的匹配对于保障矿井通风安全、降低通风成本具有重要意义。以镇城底矿八字山回风井为研究对象,采用理论分析和现场实践结合的方法,对风机选型和风量分配进行优化研究。研究表明,八字山回风井通风容易时期,回风井回风量115.4m3/s,通风负压1 870Pa;通风困难时期,回风井回风量169.5m3/s,通风负压2 890Pa;确定选择风机型号为2台DBK54-8No.30防爆对旋轴流式通风机。现场实测各处用风地点,风流稳定,风阻合理,未有瓦斯超限等现象,说明风机选择合理,风量分配满足生产要求。     

Energy transfer in hydrogen/air and methane/air mixtures

This article presents gas kinetic calculation methods for the energy transport in hydrogen/ air and methane/ air mixture. The total molecular heat conductivity as well as its various shares are calculated and discussed for a temperature range of 400 to 3500 K and for a pressure of 10⁵ Pa. The variation of the air/ fuel ratio under the conditions of chemical equilibrium is also investigated. As opposed to our previous article, an extension of the Chapman-Knskog method which goes beyond the classical 1st approximation for elastic collisions is applied for the evaluation of suitable calculation methods. This is carried out following the method for strong relaxing thermal nonequilibrium according to Brun. The equations applied in this work are simplified formulations for the proximity to equilibrium. The method for the evaluation of the parameters of the inelastic collision and some chosen results are presented. A discussion of the various shares of the molecular heat conductivity emphasizes the considerable influence of the diffusion and the thermal diffusion processes in fuel/ air mixtures compared to the Fourier heat conductivity.     

Mass- and momentum transfer in hydrogen/air and methane/air mixtures

In this article we present results for the viscosity and the mass transfer rates of hydrogen/air, hydrogen/oxygen, methane/air and methane/oxygen mixtures in the temperature range from 1000 to 7000 K and a pressure range from 10³ to 10⁶ Pa. In addition, the combustion ratio is varied from 0 to ∞. The transport properties are calculated from the first order solution of the Chapman Enskog approach to the Boltzmann equation, assuming chemical equilibrium composition. An extensive literature study was performed to derive experimental and/or theoretically based data for the respective binary interaction potentials. The values of the collision integrals, as derived from a complex numerical integration procedure, are correlated to an approximation formula. In addition, the exact solutions of the kinetic theory are compared to frequently used empirical mixture rules. For the mixture viscosity an easy approximation formula is deduced from the gas-kinetic theory.     

回转式空气预热器漏风的危害与治理

通过分析中国石化扬子石化股份有限公司烯烃厂乙烯装置辅锅一级过热器在高负荷情况下容易出现超温现象的隐患，引出了回转式空气预热器漏风的问题。对其漏风危害和原因进行了分析，提出了漏风治理的详细措施。     

地下水曝气过程中空气流场的数学模拟

地下水曝气（AS）过程中空气流场的数学模拟是现场过程研究的必要手段。利用饱和度与相对渗透率、毛细压力间的关系建立了AS二维非稳态流场的数学模型，用有限元法模拟了复杂流场非稳态二维气相饱和度场、速度场和稳态压力场分布，结果显示气相饱和度随着曝气时间和距曝气井位置的不同而变化。在曝气5 h左右，流场区域稳定。由饱和度的分布确定了空气在地下水中流型为下部U形，上部水平。在本模拟条件下，单井AS的影响区半径为9 m，若修复大面积污染的地下水，宜采用多井曝气的方式，增大其影响区半径。     

Polytetrafluoroethylene decomposition in air and nitrogen

The kinetics of the thermal decomposition of polytetrafluoroethylene (PTFE) have been studied using dynamic TG‐DTG at heating rates between 1 and 25°C/min at atmospheric pressure. Two different atmospheres were used: on the one hand, an inert atmosphere (N₂)in order to study the pyrolysis of the material, and on the other hand an oxidative atmosphere (synthetic air) to study the combustion of the polymer. The same kinetic model has been applied simultaneously to runs performed at different heating rates and different atmospheres allowing a good correlation of the weight loss data. The kinetic model considers that the overall decomposition of the PTFE is done via two different parallel processes. Dynamic measurements were performed by combined thermogravimetry mass spectrometry (TG‐MS) in order to determine the decomposition products. The evolution of ₂F₄, CF₄, COF₂, HF, hydrocarbons, benzene and some other compounds has been also analyzed.     

碳化硅泡沫陶瓷空气吸热器性能数值模拟

基于Dymola软件平台,建立了以碳化硅泡沫陶瓷为吸热体的塔式太阳能热发电用空气吸热器一维动态仿真模型。模型结合了Rosseland辐射传递方程,并考虑了空气物性随温度及压强的变化。使用Modelica语言编写程序,并由该语言对代数微分方程自动求解。通过分析仿真结果,剖析空气吸热器工作过程的传热特性,得出投入辐射能热通量、吸热体厚度、平均孔径等参数对空气、吸热体温度及系统达到稳定所需时间的影响,为该类空气吸热器的设计提供了理论依据。