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Distributed addition of gaseous reactants in fluidized beds.

机译：在流化床中分散添加气态反应物。

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In the current study, the effect of feed distribution on reactor performance and hydrodynamics is investigated by studying: horizontal jet penetration, pressure fluctuations, gas mixing and reaction. Most of the experiments were carried out in a column of 152 mm diameter at atmospheric temperature and pressure with fluid catalytic cracking catalyst particles, while reactor experiments were conducted in an industrial pilot plant of diameter 97 mm operating at a temperature of 265°C and a pressure of 202.6 kPa absolute with oxidative dehydrogenation catalyst particles. The results provide a better understanding of the effect of injecting secondary gas through one or several injection points along the bed height.; Significant changes in a fluidized bed hydrodynamics were encountered when part of the total gas flow was distributed along the fluidized bed height compared to the case when all the gas is fed through the main distributor. For constant total gas flow, introducing secondary gas decreases the primary gas velocity, leading to lower bed expansion and smaller bubbles. Based on the pressure fluctuations measurements, fluidization quality generally improved when secondary gas was distributed over several levels along the bed.; The secondary gas concentration profile at the injection level was almost uniform for higher secondary gas injection velocity and lower primary gas velocity. However, the concentration profile was not uniform for lower injection velocities or when the primary feed superficial gas velocity was high. In addition, secondary gas becomes readily mixed with bed material after a short distance above the injection level. Backmixing is primarily influenced by the primary feed superficial gas velocity rather than by the secondary gas injection velocity. Experiments show that regardless of the secondary gas injection velocity, the secondary gas was barely detected below the injection level at low UP. However, at higher UP it was detectable. Comparing axial dispersion coefficients and mass transfer coefficients for a bed with all the gases fed through the windbox with a bed where part of the total gas was distributed at one or more higher levels, axial dispersion and mass transfer decreased significantly.; The effect of distributing oxygen along a fluidized bed reactor for ethane oxidative dehydrogenation reaction was studied experimentally in a pilot-scale unit. The results confirmed that oxygen distribution along the reactor height allows the reactor to be operated safely with promising performance. (Abstract shortened by UMI.)
机译：在当前的研究中，通过研究：水平射流渗透，压力波动，气体混合和反应，研究了进料分布对反应器性能和流体动力学的影响。大多数实验是在直径为152 mm的色谱柱中于大气温度和压力下使用流化催化裂化催化剂颗粒进行的，而反应器实验则在直径为97 mm的工业中试装置中进行，并在265°C的温度和氧化脱氢催化剂颗粒的绝对压力为202.6 kPa。结果更好地理解了沿床层高度通过一个或几个注入点注入二次气体的效果。当全部气流的一部分沿流化床高度分布时，与所有气体均通过主分配器进料的情况相比，流化床流体力学发生了重大变化。对于恒定的总气体流量，引入二次气体会降低一次气体速度，从而导致较低的床膨胀和较小的气泡。根据压力波动的测量结果，当次生气体沿床层分布在几个水平上时，流化质量通常得到改善。对于较高的二次气体喷射速度和较低的一次气体速度，喷射水平的二次气体浓度曲线几乎是均匀的。但是，对于较低的注入速度或一次进料的表观气体速度较高时，浓度分布不均匀。另外，在高于注入水平的一小段距离之后，二次气体很容易与床料混合。回混主要受主要进料表观气体速度的影响，而不是受次要气体注入速度的影响。实验表明，无论二次气体注入速度如何，在低U P 下都几乎检测不到二次气体。但是，在较高的U P 下可以检测到。比较床的轴向弥散系数和传质系数与所有通过风箱送入的气体以及床中一部分总气体以一个或多个较高的水平分布的情况，轴向弥散系数和传质系数显着降低。在中试规模的装置上，通过实验研究了沿流化床反应器分配氧气对乙烷氧化脱氢反应的影响。结果证实，沿反应器高度的氧气分布使反应器能够安全运行，并具有良好的性能。 （摘要由UMI缩短。）

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