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目前国内多晶硅生产中,还原炉多采用高电压击穿的方式启动,但国外多晶硅生产中多采用低电压击穿,一些进口还原炉采用了低电压启动的结构设计。现本文将以MSA还原炉为例,分析阐述满足低压启动还原炉改成高压启动条件,对炉体结构的改造方案。 相似文献
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Catalytic ozone decomposition reaction was used to study the performance of a 76 mm i.d. and 5.8 m high gas–solid circulating fluidized bed (CFB) downer reactor. Optical fiber probes and an ultraviolet (UV) ozone analyzer were used to obtain comprehensive information about local solids holdup and ozone concentration profiles at different axial and radial positions at superficial gas velocity of 2–5 m/s and solids circulation rates of 50 and 100 kg/m2 s. Axial ozone concentration profiles significantly deviated from the plug-flow behavior, with most conversion occurring in the entrance region or flow developing zone of the downer reactor. Strong correlation was observed between the spatial distributions of solids and extent of reaction; higher local solids holdups cause lower ozone concentrations due to higher reaction rates. Radial gradients of the reactant (ozone) concentrations increased in the middle section of the downer, and decreased with increasing superficial gas velocity and solids circulation rate. Contact efficiency, a measure of the interaction between gas and solids indicated high efficiency in the flow developing zone and decreased with height in the fully developed region. 相似文献
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Dr.‐Ing. Hannsjörg Freund Dipl.‐Ing. Andreas Peschel Prof. Dr.‐Ing. habil. Kai Sundmacher Prof. Dr.‐Ing. habil. Kai Sundmacher 《化学,工程师,技术》2011,83(4):420-426
A novel methodology for the model‐based design of chemical reactors is presented. The aim of the method is the identification of the optimal reaction route and its technical realization. As an important characteristic of this novel approach, at the beginning a fluid element is considered on an abstract level. The fluid element is tracked over the reaction time and its state is optimally adjusted at any time. The advantage of this approach is that at the early design stage no constraints owing to predefined apparatus specific limitations are narrowing the solution space. That way it is possible to quantify the maximum potential of the reaction system. 相似文献
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The protocol for the measurement of ozone demand of water and the change in the dissolved ozone residual with time, using the Gas Ozone Test (GOT) was applied in monitoring water quality of two water treatment facilities. The change in the ozone concentration of water as a function of time was measured for each sample. The resulting half-time was correlated with the ozone dosage, although this parameter does not appear to be directly linked to the characteristics of the water samples studied. The change in the ozone concentration of water as a function of time and ozone dose, measured by the GOT, has direct applications in the sizing of ozonation reactors. 相似文献
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针对丁苯橡胶装置100 m3凝聚釜在运行中存在的搅拌效果不理想、釜内液面容易积胶、搅拌轴摆动大、中间轴承易磨损、调节拉杆易断裂等不足之处,提出了搅拌器改造方案。搅拌器采用CBY桨叶,取消中间轴承和调节拉杆,增大搅拌轴直径。这次改造满足了生产需要,改善了搅拌器搅拌效果,解决了搅拌器故障,延长了凝聚釜使用周期。 相似文献
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This study deals with the modelling of non-ideal flow in a tubular photocatalytic reactor with thin layer of TiO2 photocatalyst. The objective was to analyse different level of mixing in the photoreactor applying basic principles of chemical reaction engineering. For this purpose photocatalytic oxidation of toluene was used as the model reaction. Photocatalytic reactor was operated in two different flow modes: classic type of an annular reactor with basically ideal (plug) flow with some extent of dispersion and annular flow reactor acted as stirred tank reactor with mixing of reaction mixture accomplished by recirculation. A series of experiments with step input disturbance at the entrance of the reactor with different air flow was performed in order to achieve better understanding of the reactor hydrodynamics. Several reactor models are applied, such as one dimensional model of tubular reactor at the steady state conditions, axial dispersion model at non-stationary conditions and the model of the continuous non-stationary stirred tank reactor. Numerical methods necessary for solving model equations and parameter estimation were described. 相似文献
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