Structured reactors

Biofilm Capillary Reactor Structure and Advective Transport... 

Schulson, E.M. (1994) A potential nuclear reactor structural material. In Intermetallic Compounds Principles and Practice, eds. Westbrook, J.H. and Fleischer, R.L. (J. Wiley Sons Ltd, Chichester, England), Vol. 2, p. 133. 

Various reactor types have been used as the foundation for microreactor designs, including coated wall reactors, packed-bed reactors, structured catalyst reactors, and membrane reactors. 

This study uses novel monolith structured catalysts in aiming to improve process productivity and selectivity. Apart from the advanced characteristics of low pressure drop, less backmixing, convenient change out of catalysts, the monolith reactor structure reduces the mass transfer limitation and potentially improves the selectivity. 

The oxygen and radiolysis products attack the outer layers of the stainless steel or nickel-based alloys used in the reactor structure, forming a thin oxide layer on these components. Corrosion products are released from this thin oxide layer by... 

S. P. Chitra and R. Govind. Synthesis of optimal serial reactor structures for homogeneous reactions. AIChEJ., 31 185, 1985. 

D. Hildebrandt and D. Glasser. The attainable region and optimal reactor structures. Chem. Eng.Sci., 45 2161, 1990. 

Previous workers have studied the influence of the ratio of the cross-section area of the downcomer to the riser [4,5], the reactor height [6,7], the gas-liquid separator configuration [8], and the distributor type and location [9]. All these affect the flow characteristics and mass transfer. Most previous works focus on global parameters, such as the liquid circulation velocity [10-13] and the average gas holdup in the riser [14-16]. Although much work has been carried out on EL-ALRs, the proper design and scale-up of an EL-ALR is still difficult because any variation in the physical properties of the gas or the liquid and the reactor structural feathers can have a considerable effect on the hydrodynamics... 

Structuring on the level of the catalyst and the reactor Structuring exclusively on the level of the reactor... 

The researchers interpreted the mass transfer coefficient with the mass transfer model for absorption, and the resulting empirical relationships represent the Sherwood number Sh as a function of Reynolds number Re. For details, the reader may refer to Ref. [25]. It is clear that the items included in the relationships they obtained are related closely to the reactor structure. 

The fusion reaction least difficult to initiate is the deuterium-tritium (DT) reaction which releases a 14.1 MeV neutron and a 3.5 MeV alpha particle. However, because neutrons activate the reactor structure, other fusion reactions have been considered. These reactions are either neutron free, or they produce fewer and less energetic neutrons. The required quality of confinement for these more desirable fusion reactions is much higher than for DT, and it is not yet clear if it will be achieved. Hence, fusion reactor designers have concentrated on the DT reaction for at least the first generation of fusion plants. 

It is clear from this classification scheme that by structured catalysts we mean regular structures free of randomness at a reactor s level, which is characteristic for a randomly packed bed of particles of various shapes. These structures are spatially arranged in a reactor. Structures at or below the level of particles (micropores in zeolites, macropores in MCM-41, or shaped pellets such as lobes, miniliths, and the like) are not dealt with in this book, since randomness of packing will always result in the lack of a uniform structure at the level of a reactor. 

Chitra, S. P.. and Govind. R. Synthesis of Optimal Serial Reactor Structures for Homogeneous Reactions. Part I Isothermal Reactors." AlChE J. 31, 177 (1985a). 

Hildehrandt. D.. and Glasser. D. "The Attainable Region and Optimal Reactor Structures." Proc. ISCRE Meet.. Toronto (1990). 

Both the scaling-up and numbering-up approaches are important for increasing the production volume in microflow processes. The number of reactors should be as low as possible, and the size of the reactor structure should be as large as possible, to the extent that the efficiency and selectivity of a reaction are acceptable. Flexibility is important in the designing of microflow processes and reactors based on flash chemistry in industrial production. The key points for the scaling-up and numbering-up approaches are ... 

When H20 is used as coolant, the same material serves also as moderator, so ihat the reactor structure can be simplified. Figure 1.8 is a schematic diagram of a pressurized-water reactor, in which the coolant and moderator consist of liquid water whose pressure of 150 bar (2200 Ib/in ) is so high that it remains liquid at the highest temperature, around 300°C (572°F), to which it is heated in the reactor. The main difference in principle from Fig. 1.7 is... 

In any neutron generation the neutrons experience a variety of fates (Fig. 19.6). Some neutrons escape the reactor and some are absorbed in the reactor structural materials and shielding (i.e. fuel cans, control rods, moderator, coolant, etc.). To take this loss into accoimt, two different multiplication factors are used k refers to a reactor of infinite dimensions (i.e. no leakage) while k f refers to a reactor of a finite size ... 

S.J. Zinkle, and N.M. Ghoniem, Operating Temperature Windows for Fusion Reactor Structural Materials, Fuusion Eng, Des., 51-52, 55-71 (2000). 

Veils, films, coats, fibrous materials, pipes, insulation, rustproof containers, facing of chemical reactors, structural and antifrictional machine parts, seals. 

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