Rotating disk reactor

Contactors in which the liquid flows as a thin film Packed columns Trickle bed reactors Thin film reactors Rotating disk reactors... 

Brief discussion of a total of over 25 reactors of all categories, such as fixed-, fluidized- and moving-bed reactors, bubble columns, sectionalized bubble columns, loop reactors, stirred-tank reactors, film reactors, rotating disk reactors, jet reactors, plunging jet reactors, spray columns, surface aerators... 

Stage including cage reactors, rotating disk reactors, wiped film reactors and extruder type reactors. 

Fig. 22. Schematics of chemical vapor deposition epitaxial reactors (a) horizontal reactor, (b) vertical pedestal reactor, (c) multisubstrate rotating disk reactor, (d) barrel reactor, (e) pancake reactor, and multiple wafer-in-tube reactor (38).

Fig. 3. Schematic of three commonly used types of MOCVD reactors where the arrows indicate gas flow (a) vertical rotating disk where (— represents an inlet to promote a laterally uniform gas flow, (b) planetary rotation, and (c) hori2ontal.

Bozzetto (Bergamo, Italy) offers a continuous chlorosulfonic acid sulfona-tion process which comprises two water-jacketed glass vessels for sulfonation and neutralization, and an HC1 absorption column. Organic feedstock and chlorosulfonic acid are mixed on a rotating disk. Under the centrifugal action of the disk, the reaction mixture is sprayed as a thin film onto the wall of the reaction vessel. The acid product falls to the base of the reactor and then onto a similar rotating disk system, where it is mixed with alkali and sprayed onto the wall of the neutralization vessel. The unit is operated under slightly reduced pressure to remove HC1 gas. 

The finishing reactors used for PET and other equilibrium-limited polymerizations pose a classic scaleup problem. Small amounts of the condensation product are removed using devolatilizers (rotating-disk reactors) that create surface area mechanically. They scale as... 

The rotating-disk CVD reactor (Fig. 1) can be used to deposit thin films in the fabrication of microelectronic components. The susceptor on which the deposition occurs is heated (typically around lOOOK) and rotated (speeds around 1000 rpm). A boundary layer is formed as the gas is drawn in a swirling motion across the spinning, heated susceptor. In spite of its three-dimensional nature, a peculiar property of this flow is that, in the absence of buoyant forces and geometrical constraints, the species and temperature gradients normal to the disk are the same everywhere on the disk. Consequently, the deposition is highly uniform - an especially desirable property when the deposition is on a microelectronic substrate. 

Figure 1. Schematic of the rotating>disk chemical vapor deposition reactor.

Figure 2. Radial-axial velocity field and temperature contours for a rotating-disk reactor at an operating condition where a buoyancy-driven recirculation vortex has developed. The disk temperature is HOOK, the Reynolds number is 1000, Gr/Re / = 6.2, fo/f = 1.28, and L/f = 2.16. The disk radius is 4.9 cm, the spin rate is 495 rpm. The maximum axial velocity is 55.3 cm/sec. The gas is helium.

Figure 6. Species profiles in a rotating disk CVD reactor. Inlet gas is 0.1 percent silane in a carrier of 99.9 percent helium. The disk temperature is 1000 K and the spin rate is 1000 rpm.

Decolorization of azo dye R016 by immobilized cultures of I. lacteus was compared in three different reactor systems [59]. Different size of PuF was used for immobilization in reactors. Biomass concentration was reported to be 11.6, 8.3, and 4.9 g dw/L in Small Trickle Bed Reactor (STBR), Large Trickle Bed Reactor, and Rotating Disk Bioreactor, respectively. Decolorization rate was found high in STBR, where 90% decolorization rates were achieved after 3 days. Dye decolorization was highly efficient, but no direct relationship between the extracellular enzyme activities (laccase and MnP) and dye decolorization capacity was found. 

Cheong, S. I. and Choi, K. Y., Melt polycondensation of poly(ethylene terephthalate) in a rotating disk reactor, J. Appl. Polym. Sci., 58, 1473-1483 (1995). 

Fig. 6.12 Experimental smoke traces in a rotating-disk reactor, illustrating stable flow and buoyancy-induced instabilities [45]. When the disk rotation is too low for a given disk temperature, buoyancy can significantly interrupt the ideal flow patterns. Photographs courtesy of Drs. William Breiland and Pauline Ho, Sandia National Laboratories, Albuquerque, NM.

There are some good chemical-vapor-deposition reactors that deliberately starve the rotating disk. However, the similarity is broken by the recirculation, and the one-dimensional analysis techniques described herein lose their validity. If the chemical reaction on the surface is sufficiently slow, compared to mass transfer through the boundary layer, then the deposition uniformity will not be much affected by the boundary-layer similarity. In these... 

Consider a rotating-disk reactor that is designed to destroy CO on a catalytic surface. The CO is dilute in an air stream. Assume that the catalyst completely destroys any CO at the surface—meaning that the gas-phase mass fraction of CO at the surface is zero—and assume that there is no gas-phase chemistry. The CO2 that desorbs from the catalyst is so dilute in the air that its presence can be neglected. Thus the mass-transfer problem can be treated as a binary mixture of CO and air. Assume that the reactor is held at a fixed pressure of 1 atmosphere. 

In the previous problem we examined temperature profiles and reactant (SiH4) concentration profiles in a channel-flow chemical vapor deposition (CVD) reactor. At sufficiently high temperatures (and pressures) SM4 undergoes unimolecular decomposition into the species SiH2 and H2. This is followed by numerous reactions of the intermediate species [180]. One such intermediate species formed in the gas phase is Si (i.e., a gas-phase silicon atom). In this problem we consider the gas-phase formation and destruction reactions governing the spatial profiles of Si atoms in a rotating-disk CVD reactor. 

W.G. Breiland and G. Evans. Design and Verification of Nearly Ideal Flow and Heat Transfer in a Rotating Disk Chemical Vapor Deposition Reactor. J. Electrochem. Soc., 138(6) 1807—1816,1991. 

M.E. Coltrin, RJ. Kee, G.H. Evans, E. Meeks, FM. Rupley, and J.F. Grcar. Spin A Fortran Program for Modeling One-Dimensional Rotating-Disk/Stagnation-Flow Chemical Vapor Deposition Reactors. Technical Report SAND91-8003, Sandia National Laboratories, 1991. 

S. Joh and G.H. Evans. Heat Transfer and Flow Stability in a Rotating Disk Stagnation Flow Chemical Vapor Deposition Reactor. Numer. Heat Transf. Part A— Applications, 31 (8) 867—879,1997. 

S. Patnaik, R.A. Brown, and C.A. Wang. Hydrodynamic Dispersion in Rotating-Disk OMVPE Reactors Numerical Simulation and Experimental Measurements. Numer. Heat Transf. Part A—Applications, 96 153-174,1989. 

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. 

FIGURE 4 Schematic diagram of a typical large-scale highspeed vertical rotating-disk MOCVD reactor chamber including a simplified view of gas flow in a vertical RDR. The inlet gas stream contains the precursor flows and the main carrier gas flow. Typically, the Column V and Column III sources are kept separate until a few inches above the heated susceptor. 

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