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Gas Quenching Small Components
Gas quenching is an environmentally friendly and effective way of quenching components. However it has not been possible to apply it to small components because of the difficulties of jigging. A method of gas quenching such small components is described in which they are levitated in a confined gas stream. The method is suitable for quenching low alloy steel components that weigh between 1 and 10g....
2020-09-13 23:35:02浏览：38
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Simulation research on carbon dioxide as cushion gas in gas underground reservoirs
Aimed at the problem of mixing working gas and cushion gas in carbon sequestration technology, the feasibility of using cation dioxide as the cushion gas in reservoirs is discussed firstly. At the usual condition of reservoirs, carbon dioxide is a kind of supercritieal fluid with high condensability, high viscosity and high density. Secondly, this article studies the laws of formation and development of mixing zone by numerical simulation and analyses the impact on mixing zone brought by different injection modes and rational ratios of cushion gas in reservoirs. It is proposed that the appropriate injection ratio of cushion gas is 20% - 30%. Using carbon dioxide as cushion gas in gas reservoirs is able to make the running of natural gas reservoirs economical and efficient....
2020-09-13 23:35:02浏览：49
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THE VACUUM IN NONISENTROPIC GAS DYNAMICS
We investigate the vacuum in noniscntropic gas dynamics in one space variable,with the most general equation of states allowed by thermodynamics. Wc recall physical constraints on the equations of state and give explicit and easily checkable conditions under which vacuums occur in the solution of the Riemanu problem.We then present a class of models for which the Riemann problen admits unique global solutions without vacuums....
2020-09-13 23:35:02浏览：31
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On cyclic oscillation in granular gas
In a Maxwell's demon experiment on a dilute granular gas made up of two species of particles placed in two closely connected containers, a cyclic oscillation similar to the chemical oscillations is recognized that the two species of particles cluster alternately in the two containers. Then the nonlinear behavior is qualitatively explained based on a flux model....
2020-09-13 23:35:02浏览：41
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环形加热炉燃料结构的改造
环形加热炉原以天然气为燃料,为节省燃料费用成本,同时充分利用煤气厂生产的富裕焦炉煤气,故将环形炉1～3区燃料由天然气改为焦炉煤气.建立焦炉煤气阀站及分区管路,更换烧嘴及烧嘴砖,更换调节阀、流量孔板等现场电气设备,建立全新燃烧控制程序及HMI画面.对改造后环形炉运行带来的经济效益进行了分析比较....
2020-09-13 23:35:02浏览：37
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松木屑催化热解及热解油分析
以松木屑为原料，选取无水Na2CO3、无水Al2O3、凹凸棒土、ZSM-5共4类催化剂，利用管式炉实验及色质联用(GC-MS)分析仪进行热解特性研究，探索了热解产物产率和组分特性的变化规律．实验结果表明，松木屑在热解温度为550,℃时，产油率达到最大值51.47%(质量分数)；无催化剂条件下松木屑热解油主要成分为酸类化合物，加催化剂条件下松木屑热解油主要成分为酸类和酮类化合物，催化剂的加入主要影响了呋喃类、醇类、糖类和含氮类化合物的质量分数．ZSM-5催化剂的催化性能最佳，其能够提高热解油产率，其对应的热解油中酯类、呋喃类和芳香族类等能够提高热解油品质的化合物质量分数均较高，而糖类、含氮类等化合物质量分数较低，能够提高热解油的稳定性．...
2020-09-03 16:42:35浏览：77
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MDEA与MEA脱碳反应动力学
通过双模理论及反应釜吸收实验的方法，建立了胺液脱碳拟一级传质反应模型，并对其进行了实验验证。通过模型中的增强因子、二级反应速率常数及传质速率分析了伯胺 MEA（乙醇胺）及叔胺 MDEA（甲基二乙醇胺）的动力学特性，以此为基础进一步分析了MDEA+MEA混合胺液的交互作用、动力学特性，并得到了较优的胺液配比。研究结果表明：伯胺MEA的增强因子及传质速率数值大于叔胺MDEA，随着气液传质过程进行，传质速率逐渐减小；对于混合胺液，表观反应速率常数以及增强因子随着 MEA 浓度的增加以及温度的升高而逐渐增大；当总胺浓度为3mol·L-1时，MDEA+MEA(2 mol·L?1+1 mol·L?1)的混合胺液增强因子数值为0.5，传质速率较大，为最优混合胺液配比。...
2020-08-30 18:25:27浏览：55
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加焦方式对气化炉内气流分布的影响
布料模式决定了料床的空隙度，而料床的空隙度分布决定了煤气流的二次分布。本文建立了研究三维气化炉炉料结构和煤气流分布的物理模型和数学模型，物理模型采用热电偶测温的方法，从炉内气体温度分布信息考察了气体的流动情况，由于物理实验无法获得内部空隙度分布信息，故基于离散单元法模型，以Fluent软件为载体，利用多孔介质模型并加入用户自定义函数，通过数学模型进一步研究了不同加焦方式下气化炉内煤气流分布的影响机理，获得了气化炉内煤气的速度场和流线。物理模拟与数值模拟结果相吻合。通过模拟计算获得的非均匀床层内气体流动规律的认识对COREX气化炉加焦工艺有借鉴意义。...
2020-07-13 09:55:48浏览：40
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浅析影响GE气化炉气体成分波动的原因
根据笔者自己对GE气化炉的操作经验进行了总结,并对GE气化炉在运行过程中的出现的一些问题从以下可能影响GE气化炉运行的几个方面进行了初步的分析,根据GE气化炉在运行过程出现的问题和现象可能对影响GE气化炉气体成分波动的原因进行了分析,并提出了解决问题的建议。...
2020-07-12 21:36:56浏览：44
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浅谈煤气化炉中分析系统的设计及选型
随着煤化工技术的日趋成熟,在线分析系统较多地应用到设备质量的测量诊断当中.概述了煤气化装置在线分析系统的设计及选型要点,针对不同的工艺检测要求选择合适的分析仪表.介绍了分析系统中的采样探头,预处理系统,在线气相色谱仪的结构、原理及应用,就如何采取有效的预警维护,有效地预防分析系统的隐形故障进行了阐述,保证了分析系统的稳定运行....
2020-07-12 21:36:56浏览：41
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PLC系统在污水处理装置上的应用
针对水处理过程开关量多,模拟量少的特点,以逻辑顺序控制为主,闭环回路控制为辅,因此PLC在污水处理行业得到了广泛应用。以某循环排污水回用处理项目为例,介绍了污水处理工艺流程,概括了PLC控制系统的配置和控制方式,以及由PLC控制站和上位机组成的控制系统的主要功能。该系统全面提高了设备的自动化控制水平,解决了污水处理过程中处理效率低下,出水水质不稳的问题。...
2020-07-09 15:51:42浏览：57
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Purification Influence of Synthesis Gas Derived from Methanol Cracking on the Performance of Cobalt
Synthesis gas derived from methanol cracking (SGMC) was applied as simulating feedstock of Fischer-Tropsch synthesis (FTS) in laboratory. With MS and GC detector, a trifle of sulfur compounds,a small amount of oxygenates including H2O, CH3OH, DME and CO2 as well as a few of low carbon alkanes were found in the SGMC. After purification, the sulfur compounds, H2O, CH3OH and DME could be eliminated efficiently from the SGMC while CO2 and the low carbon alkanes were partly removed.When the unpurified SGMC, the desufurized SGMC and the totally purified SGMC were sequentially applied in cobalt-based FTS, the catalytic performance of Co/ZrO2/SiO2 catalyst was gradually improved corresponding to the degree of purification. The untreated SGMC led to the serious deactivation of the cobalt catalyst, the partially treated SGMC slowed down the deactivation rate and the totally purified SGMC resulted in little deactivation of the catalyst, which was similar to what the pure synthesis gas(the mixture of pure H2 and CO) did. The results indicated that the SGMC should be purified and the purification course used in this paper was effective for the SGMC. Furthermore, the totally purified SGMC could substitute for the pure synthesis gas in cobalt FTS....
2020-07-08 21:52:19浏览：76
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Structural and micro structural studies of PbO-doped SnO2 sensor for detection of methanol,propanol
In the present work the structural information of PbO-doped SnO2 thick film sensor has been investigated with X-ray diffractometer(XRD)and scanning electron microscope(SEM).Initially,SnO2 powder was derived using sol-gel process and was subsequently doped with PbO and ground up to nanosized particles.A suitable gas sensor structure was fabricated on 1"× 1"alumina substrate using thick film technology.The necessary paste for screen printing was also developed.SEM results showed sol-gel derived powder gets more agglomerated in the thick film form.The sensitivity of the sensor has been investigated at different temperatures(150℃-350℃)upon exposure to methanol,propanol and acetone,yielding a maximum at 250℃ for acetone with 1 wt% PbO-doping while at 350℃ for propanol with 3 wt% PbO-doping of the sensor.The reduction of particle size to nanometers(validated through XRD)leads to a dramatic improvement in sensitivity of sensors for the chosen organic vapors.The results also correlate well with the microstructural properties of the material and the dopant....
2020-07-08 21:52:19浏览：60
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Process conditions of preparing methanol from cornstalk gas
The low-heat-value cornstalk gas produced in the down-flow fixed bed gasifier was tentatively used for methanol synthesis. The cornstalk gas was purified and the technical procedures such as deoxygenation, desulfurization, catalytic cracking of tar, purification and hydrogenation were studied. The catalytic experiments of methanol synthesis with cornstalk syngas were carried out in a tubular-flow integral and isothermal reactor. The effect of reaction temperature, pressure, catalysttypes, catalyst particle size, syngas flow at entering end and composition of syngas was investigated. The optimum process conditions and yield of methanol from cornstalk syngas were obtained. The experimental results indicated that the proper catalyst of the synthetic reaction was C301 and the optimum catalyst size (φ) was 0.833 mm×0.351 mm. The optimum operating temperature and pressure were found to be 235℃ and 5 Mpa, respectively. The suitable syngas flow 0.9-1.10 mol/h at entering end was selected and the best composition of syngas were CO 10.49%, CO2 8.8%, N2 37.32%, CnHm 0.95% and H2 40.49%. The best methanol yield is 0.418 g/g cornstalk. The study provided the technical support for the industrial test of methanol production from biomass (cornstalk)gas....
2020-07-08 21:52:19浏览：65
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A Study on the Effects of Carrier Gases on the Structure and Morphology of Carbon Nanotubes Prepared
Carbon nanotubes (CNTs) were prepared using different carrier gases,with ferrocene as the catalyst precusor and acetylene as the carbon source. The effects of ammonia and nitrogen as carrier gases on the structure and morphology of CNTs were investigated. Transmission electron microscope (TEM),high-resolution electron microscope (HRTEM),scanning electron microscope (SEM) and X-ray diffraction (XRD) were employed to characterize the products and the catalyst. Experiment results show that the CNTs grown in N2 gas exhibited cylindrical and tubular structure,while a bamboo-like structure was observed for the CNTs grown in NH3 gas. Moreover,vertically aligned CNTs were obtained on an Al2O3 disk when NH3 was used as the carrier gas. The carrier gas also exerted influence on the shape of the catalyst. Based on the theory of active centers of catalysis and combined with the particle shape of the catalyst,a growth model for the vertically aligned CNTs on the substrate is given....
2020-07-08 21:52:19浏览：53
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