Vortex tube reactor

The vortex flow reactor was a glass Couette cell driven by a Bruker RheoNMR system. The cell consisted of a stationary outer glass tube with an id of 9 mm and a rotating inner glass tube with an od of 5 mm, giving a gap of 2 mm. The Couette was filled with cylindrical bacterial cells, F. nucleatum ( 2 x 20 pm), suspended in water at a concentration of =10" cells mL-1. 

A vortex tube has certain advantages as a chemical reactor, especially if the reactions are endothermic, the reaction pathways are temperature dependent, and the products are temperature sensitive. With low temperature differences, the vortex reactor can transmit enormous heat fluxes to a process stream containing entrained solids. This reactor is ideally suited for the production of pyrolysis oils from biomass at low pressures and residence times to produce about 10 wt % char, 13% water, 7% gas, and 70% oxygenated primary oil vapors based on mass balances. This product distribution was verified by carbon, hydrogen, and oxygen elemental balances. The oil production appears to form by fragmenting all of the major constituents of the biomass. 

Fig.2 and Fig.3 show the typical liquid velocity and gas hold up distribution in the ALR. From the figures, one notices that the cyclohexane circulates in the ALR under the density difference between the riser and the downcomer. An apparent large vortex appears near the air sparger when the circulating liquid flows fi om the downcomer to the riser at the bottom. In the riser, liquid velocity near the draft-tube is much larger than that near the reactor wall, the latter moved somewhat downward. The gas holdup is nonuniform in the reactor, most gas exists in the riser while only a little appears in the dowmcomer. 

Fig.8 illustrates the liquid velocity distribution at the bottom section of the reactor when the draft-tube diameter is 0.45m, 1.05m and 1.45m respectively. Results show that the liquid velocity at the outlet of the draft-tube lowers when the draft-tube diameter is raised, to subsequently influence the shape and size of the vortex at the bottom of the gas sparger. 

Figure 10-2. Reverse vortex flow system for gliding arc discharge stabilization (a) eonflgu-ration with a movable ring electrode (b) configuration with a spiral electrode. In the figures, (1) quartz tube (2) cylindrical reactor volume (3) swirl generator with tangential inlet holes (4) additional axial gas flow inlet (5) gas flow exit ...

In an ideal PFR, fluid elements do not mix in the axial direction (i.e. flow direction). However, in an actual tubular reactor, some amount of axial mixing of fluid elements may occur due to a number of reasons (such as vortex formation at tube inlet). A mathematical model called axial dispersion model was proposed by P. V. Danckwarts to account for axial mixing of fluid elemenfs in the tubular (plug flow) reactor. 

The AP1000 reactor internals consist of two major assemblies the upper internals and the lower core support assembly. The upper internals consist of the upper support, the upper core plate, the support columns and the guide tube assemblies. Figure 3.9-6 of the Reference 6.1 shows the upper core support assembly. The major containment and support member of the reactor internals is the lower core support assembly, which is shown in Figure 3.9-5 of the Reference 6.1. This assembly consists of the core barrel, the lower core support plate, the secondary core support, the vortex suppression plate, the core shroud, neutron panels, radial supports and related attachment hardware. 

Quench tubes bring quench gas into the reactor. Some are very simple -just a tube with a series of holes in it. Others, such as the ExxonMobil spider vortex design, are more complex, distributing gas horizontally through several spokes to different parts of the quench deck. 

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