Concentric cylinder reactor

Imamura et al. [28] describe a concentric cylinder reactor in which one cylinder is rotated. The axial flow rale and rotational speed are such to generate flows with Taylcn vortices which save to narrow the residence time and particle size distributions. The reactor is also claimed to be useful for continuous suspension polymerization. 

As was shown in Fig. 2.5, the primary current distribution is only uniform when all points on the electrode surface are strictly equivalent and the current density is low. This is possible only with two reactor designs, a parallel-plate reactor having electrodes of equal area and occupying opposite walls and the concentric-cylinder reactor. There will be a variation of potential and current density over the surface for all other electrode arrangements an example is shown in Fig. 2.16(a) where the broken lines join equipotential points and the current densities are inversely proportional to the lengths of the arrowed lines. The highest current density is between the points closest together on the two electrodes and almost no current flows on the reverse side of the anode. 

If a fluid is placed between two concentric cylinders, and the inner cylinder rotated, a complex fluid dynamical motion known as Taylor-Couette flow is established. Mass transport is then by exchange between eddy vortices which can, under some conditions, be imagmed as a substantially enlranced diflfiisivity (typically with effective diflfiision coefficients several orders of magnitude above molecular difhision coefficients) that can be altered by varying the rotation rate, and with all species having the same diffusivity. Studies of the BZ and CIMA/CDIMA systems in such a Couette reactor [45] have revealed bifiircation tlirough a complex sequence of front patterns, see figure A3.14.16. 

Electrochemical reactors (cells, tanks) are used for the practical realization of electrolysis or the electrochemical generation of electrical energy. In developing such reactors one must take into account the purpose of the reactor as well as the special features of the reactions employed in it. Most common is the classical reactor type with plane-parallel electrodes in which positive and negative electrodes alternate and all electrodes having the same polarity are connected in parallel. Reactors in which the electrodes are concentric cylinders and convection of the liquid electrolyte can be realized by rotation of one of the electrodes are less common. In batteries, occasionally the electrodes are in the form of two long ribbons with a separator in between which are wound up as a double spiral. 

Concentration standards, 75 750-751 Concentrators, sulfuric acid, 23 787 Concentric annular reactors, 23 544 Concentric cylinder viscometer, 27 733 Concentric hemispherical analyzer (CHA), 24 103-104, 105 energy resolution of, 24 106 Conching, milk chocolate, 6 363-364 Concomitant polymorphism, 8 69 CONCORD program, 6 10 76 752 Concrete(s)... 

After regeneration, the catalyst enters the first reactor at the top. It passes through the reactor by gravity and is then transferred from the bottom of each reactor to the top of the next by a gas-lift. To minimize the pressure drop across the bed, a cross-flow technology was adopted The catalyst flows downwards from the top of the reactor between two concentric cylinders made up of grids, this allowing the radial passage of the gas phase. 

As an alternative to a cascade of CSTR trains, a novel continuous reactor with a Couette-Taylor vortex flow (CTVF) has been proposed, which can realize any flow pattern between plug and perfectly mixed flows [361-366]. A continuous Couette-Taylor vortex flow reactor (CCTVFR) consists of two concentric cylinders with the inner cylinder rotating and with the outer cylinder at rest. Figure 29 shows a typical flow pattern caused by the rotation of the inner cylinder. 

The heart of this facility is a refractory-lined reactor cylinder with 20 cm in-diameier and a total height of about 6.5 m. The internal refractory forms two concentric cylinders (each one of thickness 6.5 cm) with different thermal conductivity and wearing properties. Additionally, the reactor tube, the cyclone and the recycling line are protected with outside insulation in order to minimise heat losses. The gasifier components (raiser, cyclone and standpipe) are equipped with ten thermocouples (K-type) and pressure transducers. The thermocouples probes are connected to a computer based data acquisition and control system. In addition, the feed rates of gasification... 

What is noteworthy with this equipment is that the inverter, transformer, and corona reactor are not independently operating components. The concentric cylinder corona reactor was so designed that its capacitance, reflected to the primary of the transformer, formed a part of the... 

To create a plasma, two things are necessary a high frequency and a high power. In our process, the plasma is produced with a high frequency 60 kW power generator working at 10 MHz. As shown in figure 2, the plasma reactor is composed of two concentric cylinders [2]. 

Figure 4.19 Dependence of the diameter d, of the suspension particles on CaCl2 concentration. Volume reactor (1), tubular turbulent reactor of cylinder (2) and diffuser-confusor (3) construction. CjtK = 5 wt%...

The Couette-Taylor flow reactor consists of two concentric cylinders in which the outer one is fixed and jacketed, while the inner one rotates. Under some particular conditions, a flow pattern characterized by counter-rotating toroidal vortices is formed. This Couette-Taylor flow makes the RTD in this reactor similar to that of a train of CSTRs [74]. However, because viscosity may change substantially as polymerization proceeds (along the reactor), it is difficult to maintain the required Taylor number in the whole reactor. The use of a conical outer cylinder may counteract the viscosity increase [75]. However, no example of the production of a commercial-like latex (i.e., high solids content) has been reported. 

For submarine factory numbers 901,285,254,260, and 538, the radial thermal shields consisted of four concentric cylinders positioned around each reactor core and the bottom thermal shields consisted of four cylindrical plates positioned below the lower core plate. The four concentric... 

For submarine factory number 421, the radial thermal shields consisted of four concentric cylinders positioned around each reactor core and the bottom thermal shields consisted of seven cylindrical plates positioned below the lower core plate. The four concentric cylinders were made of an unspecified SS of, from the core surface outward, 25-, 25-, 30-, and 30-mm thickness, respectively. The four concentric cylinders and the inner surface of the RPV wall were separated by primary-circuit water of, from the core surface outward, 4.5-, 10-, 10-, 10-, and 15-mm thickness, respectively. The lower core plate and seven cylindrical plates were made of type 8X18H10T SS of, from the core surface downward, 90-, 25-, 25-, 25-, 25-, 25-, 25-, and 25-mm thickness, respectively. The lower core plate, seven cylindrical plates, and the inner surface of the RPV bottom were separated by primary-circuit water of, from the bottom surface of the core downward, 60-, 70-, 12-, 12-, 12-, 12-, 12-, 12-, and 65-mm thickness, respectively. Above each core are the upper core plate and two additional cylindrical plates, the latter two comprising the balance of the upper core barrel. The upper core plate and two cylindrical plates were made of an unspecified SS of, from the core surface upward, 50-, 120-, and 210-mm thickness, respectively. The upper core plate, two cylindrical plates, and the inner surface of the lid were separated by primary-circuit water of, from the core surface upward, 15-, unknown-, 95-, and 60-mm thickness, respectively. 

The Taylor-Couette reactor (TCR), sometimes referred to as a vortex flow reactor, consists of two concentric cylinders, one of which rotates. Figure 5.23. 

Reactor coolant pumps - The IRIS RCPs [12] are of a spool type, which has been used in marine applications, and are being designed and will soon be supplied for chemical plant applications requiring high flow rates and low developed head. The motor and pump consist of two concentric cylinders, where the outer ring is the stationary stator and the... 

The overall reactor geometry may utilize parallel-plate feeders, a concentric cylinder or a packed column. 

A natural early goal of FP researchers was to develop a reactor in which the monomer-initiator solution was pumped in such that the product would continuously flow out, without the input of heat. Attempts were made with reactors of tylindrical and spherical geometries. Zhizhin and Segal performed a linear stability analysis of a reactor consisting of two concentric cylinders. A radial, axisymmetric front was supposed because the monomer/initiator would be pumped through the permeable inner cylinder. The viscous reacted polymer was supposed to flow out through the outer permeable cylinder. No buoyancy-driven convection was included. They found that if the resistance of the outer boundary was small, the front would become hydrodynamicaUy unstable. They also considered a reactor with concentric spheres and found similar results. 

De Kepper has described a fascinating pattern of waves that can be studied in a continuous couette reactor. This is an open spatial reactor that provides a good approximation of a one-dimensional diffusion system, and consists of two concentric cylinders with a narrow gap between them. The inner cylinder can rotate while the outer one is fixed. At each end of the cylinder is a chamber fitted with a stirrer into which reactants can flow in and products flow out. Variation of the rate of rotation causes changes in the... 

The entire QSL process takes place in a single reactor as shown in Figure 6 (15). The reactor consists of an almost horizontal, refractory-lined cylinder, which can be tilted by 90° when operation is intermpted. Concentrates, fluxes, recirculated flue dust, and normally a small amount of coal, depending on the type of concentrate, are pelletized. The pelletizer ensures that the raw materials are mixed to the required degree of uniformity. 

Example 4. Depolymerization under Pressure.62 PET resin was depolymerized at pressures which varied from 101 to 620 kPa and temperatures of 190—240° C in a stirred laboratory reactor having a bomb cylinder of2000 mL (Parr Instrument) for reaction times of 0.5, 1, 2, and 3 h and at various ratios of EG to PET. The rate of depolymerization was found to be directly proportional to the pressure, temperature, and EG—PET ratio. The depolymerization rate was proportional to the square of the EG concentration at constant temperature, which indicates that EG acts as both a catalyst and reactant in the chain scission process. 

---