Jet impact reactor

There are seven main sulphonation reactor systems used world-wide for SOs/air sulphonation for which there is proven practical and documented experience The Ballestra Sulphurex continuous stirred tank reactor (CSTR) cascade, the Ballestra Sulphurex F (a multitube falling-film reactor (MT-FFR)) the Chemithon falling-film reactor (FFR), the Chemithon Jet Impact Reactor, the MM falling-film reactor (FFR), the Mazzoni Sulpho film reactor (a multitube falling-film reactor) and the Japanese T-0 FFR reactor system. 

Co-current flow of the organic feedstock and the SOj/air is realised in all falling-film reactor types and the Chemithon Jet Impact Reactor. 

The pure falling-film reactors will have the shortest residence time, order of magnitude 30 seconds. The Chemithon FFR and Jet Impact Reactor, both with quench loop, could have an organic liquid residence time of about 2 to 5 minutes, depending on the liquid level in the de-gassing tank. Finally the Ballestra CSTR system shows a total residence time for the organic liquid of the order of 60 minutes. 

A high cooling surface area/reactor hold-up ratio is established in all sulphonation reactor systems. However, a peak temperature in the organic phase in the top region of all film reactors (and the Jet Impact Reactor) can not be avoided. 

The Ballestra Sulphurex CSTR system is relatively simple in its mechanical construction. The same can be said about the Chemithon Jet Impact Reactor. Film reactors are mechanically more sophisticated constructions, notably the organic liquid distribution systems. The delicate FFRs can not always be recommended for countries where the level of technology and maintenance is low. 

The Ballestra Sulphurex CSTR and the Chemithon Jet Impact Reactor are usually only used for simple feedstocks like alkylbenzene. 

Table 23 Final product specification for Chemithon Jet Impact Reactor...

The potential for internal hazards such as fire, flooding, missile generation, pipe whip, jet impact or the release of fluid from failed systems or from other installations on the site shall be taken into account in the design of the research reactor facility. Appropriate preventive and mitigatory measures shall be taken to ensure that nuclear safety is not compromised. Some external events could initiate internal fires or floods or lead to the generation of missiles. Such interrelation of external and internal events shall also be considered in the design, where appropriate. 

Of the various mechanical properties of a formed catalyst containing zeolite, attrition resistance is probably the most critical. This is particularly the case for FCC catalysts because of the impact on the addihon rate of fresh catalyst, particulate emissions of fines and overall catalyst flow in the reactor and regenerator. Most attrition methods are a relative determination by means of air jet attrition with samples in the 10 to 180 xm size range. For example the ASTM D5757 method attrites a humidified sample of powder with three high velocity jets of humidified air. The fines are continuously removed from the attrition zone by elucidation into a fines collection assembly. The relative attrition index is calculated from the elutriated fines removed at a specific time interval. 

Fortunately, for a couple of reasons, the likelihood of a terrorist attack on a nuclear reactor is quite low. Nuclear reactors operate under tight security and incorporate safety systems. In addition, the extensive shielding around reactors would require large amounts of explosives to create a breach. Even if terrorists could transport large amounts of explosives, they would have to breach a security cordon to reach the reactor. Alternatively, they could commandeer a jumbo jet plane to crash into a reactor or a nuclear pond of used cores, but they would have to breach security measures to do so. Computer modeling indicates that the constraction of most reactors would sustain a 300 mph impact from a commercial aircraft, but not aU scientists agree with these findings (1). 

Chemithon impact jet reactor Atomises organic feed in S03/air... 

For application in fluidization and fluid-particle systems, the attrition index is probably the most important particle characteristic. The particle attrition can affect the entrainment and elutriation from a fluidized bed and thus subsequently dictate the design of downstream equipment. The attrition in a pneumatic transport line can change the particle size distribution of the feed material into a fluidized bed reactor and thus alter the reaction kinetics. Davuluri and Knowlton (1998) have developed standardized procedures to evaluate the Attrition Index employing two techniques, solids impaction on a plate and the Davison jet cup. The two test units used are shown in Figs. 6 and 7. They found that these two test techniques are versatile enough to be applicable for a wide range of materials, such as plastic, alumina, and lime-... 

Chapter 1 provides a general overview and introduction of the principles and techniques of physical and mathematical modeling discussed in the book. It provides the rationale for modeling two-phase flow in gas-agitated reactors of materials processes. Chapter 2 presents the turbulence structure of two-phase jets and the impact on the mixing and chemical reaction rates in materials reactors agitated by... 

FIGURE 13.42 The Pd-Ag membrane reactor developed for the JET housekeeping waste detritiation (before assembhng). (Reprinted from S. Tosti, Membranes and Membrane Reactors for tritium Separation, in Tritium in Fusion Production, Uses and Environmental Impact, S. Tosti and N. GhireUi, eds., 203-240, Copyright 2013, with permission from Nova Science Publishers, Inc.)... 

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