Vertical flow reactor

Fig. 5 SEM images of ordered GaN nanopillars grown at a substrate temperature of 950 °C. a Reactor pressure of 8 bar with N2 as carrier gas (100 seem) using SMP 1 in a horizontal flow reactor and b at a reactor pressure of 4 bar with N2 as carrier gas (100 seem) in a vertical flow reactor. Inset-, side view of nanopillars...

A direct liquefaction technique, the SRC process involves mixing dried and finely pulverized coal with a hydrogen donor solvent, such as tetralin, to form a coal-solvent slurry. The slurry is pumped together with hydrogen into a pressurized, vertical flow reactor. The reactor temperature is about 825°F (440°C) and pressures range from 1,450 to 2,000 psi. A residence time in the reactor of about 30 minutes is required for the carbonaceous material to dissolve into solution. From the reactor, the product passes through a vapor/liquid separation system. The slurry solids remaining in the reactor are then removed and filtered. Various filtration techniques have been developed to remove solids from recoverable oil. 

Fig. 33. Vertical flow reactor and mass spectrometer sampling line [57]...

Vapour phase aniline alkylation is carried out over ca. 0.5 g catalyst at 673 K and feed rate 12 cm h" g in a vertical flow reactor. N2 is used as carrier gas. Products are collected every hour for 4h and are analysed by a gas chromatograph using a column of Apiezon-L treated with 2% KOH on chromosorb 80/100 A.W. Alkylated anilines obtained are analysed to be mainly N-ethylaniline (NEA), NN diethylaniline (NNDEA) and traces of toluidine. 

Figure 13-4. Deposition rate variations versus precursor concentration in the atomized solution, for aerosolr-gel deposited Si02 films (a), and MTPS-based hybrid orgmic/inorgmic Si02 films (b). The deposition rate is defined as the ratio of the film thickness, measured after soT-gel transformation, to the aerosol sweeping tune (deposition time). Films were deposited using a horizontalflow (a) and a vertical flow reactor (b).

FIG. 7-4 Typ es of flow reactors (a) stirred tank battery, (h) vertically staged, (c) compartmented, (d) single-jacketed tube, (e) shell and tube, (f) semiflow stirred tank. 

The riser is a vertical pipe. It usually has s 4- to 5-inch (10 to 1" cm) thick refractory lining for insulation and abrasion resistance. Typical risers are 2 to 6 feet (60 to 180 cm) in diameter and 75 to 120 feet (25 to 30 meters) long. The ideal riser simulates a plug flow reactor, w here the catalyst and the vapor travel the length of the riser with minimum back mixing. 

Figure 9. Streamlines (top) and relative gas phase composition of A1 species (bottom) In a vertical axlsymmetrlc reactor at five different times during growth of an AlAs/GaAs superlattice. Red corresponds to all A1 species, violet to no A1 species. The corner Insert portrays the variation In solid fraction of A1 across the Interface. Buoyancy dominated flow.

Fig. 5.1.2 Non-ideal capillary flow reactor (a) propagators [13] and (b) corresponding RTDs calculated from the propagator data, (a) The propagators indicate the distribution of average velocities over each observation time (A) ranging from 50 ms to 1 s. As the observation time increases the spins exhibit a narrowing distribution of average velocities due to the motional narrowing effect of molecular diffusion across the streamlines. The dashed vertical line represents the maximum velocity that would be present in the absence of molecular...

On the reactor side, the gas mixture enters from the top and is separated into 16 individual streams, going to each one of the reactors. Figure 11.3 shows the side view of the high-throughput reactor setup. The reactors are vertical flow-through reactors with a... 

The R D requirement exists solely in the production of synthesis gas from wood, since the catalytic production of methanol is well developed. The vertical shaft counter flow reactor developed by Union Carbide for municipal waste... 

D.I. Fotiadis, A.M. Kremer, DP. McKenna, and K.F. Jensen. Complex Flow Phenomena in Vertical MOCVD Reactors Effects on Deposition Uniformity and Interface Abruptness. J. Cryst. Growth, 85 154—164,1987. 

Figure 11. Mass-transfer Nusselt number (Nu) for various susceptor temperatures and inlet flow rates for a vertical CVD reactor with a 900 K susceptor and 300 K reactor walls and operating at 10.1 kPa (Reproduced with permission from reference 24. Copyright 1987 Elsevier).

Vertical reactor or stagnation point flow reactor at atmospheric and reduced pressure conditions... 

Vertical CVD Reactors. Models of vertical reactors fall into two broad groups. In the first group, the flow field is assumed to be described by the one-dimensional similarity solution to one of the classical axisymmetric flows rotating-disk flow, impinging-jet flow, or stagnation point flow (222). A detailed chemical mechanism is included in the model. In the second category, the finite dimension of the susceptor and the presence of the reactor walls are included in a detailed treatment of axisymmetric flow phenomena, including inertia- and buoyancy-driven recirculations, whereas the chemical mechanism is simplified to a few surface and gas-phase reactions. 

LPCVD reactor modeling involves many of the same issues of multi-component diffusion reactions that have been studied in the past decade in connection with heterogeneous catalysis. Complex fluid-flow phenomena strongly affect the performance of atmospheric-pressure CVD reactors. Two-dimensional and some three-dimensional flow structures in the classical horizontal and vertical CVD reactors have been explored through flow visual-... 

The flowsheet of a 1/2-ton (slurry) per day SYNTHOIL bench scale plant, currently in operation at the Energy Research and Development Administration laboratory in Bruceton, Pennsylvania, is shown in figure 1. The vertically placed reactor is made of two interconnected stainless steel tubings of 1.1-inch ID x 14.5-ft long each. The upper end of the first section is connected to the lower end of the second section with a 5/16-inch ID empty tubing. Thus, the plant may be operated with one or both sections of the reactor packed with catalyst while the fluids flow upwards through each. 

The research at MIT has been done in the cold-wall vertical tube reactor shown in Figure 14. The wafer is aligned almost parallel to the flow on a vertical silicon carbide-coated susceptor. The wafer is heated by optical radiation from high-intensity lamps to a temperature of 775°C. Silane was introduced... 

---