Reactor cylindrical

The Los Alamos water boiler served as a prototype for the first university training reactor, started in September 1953 at North Carolina State College. The cylindrical reactor core used uranyl sulfate [1314-64-3] UO2SO4, and cooling water tubes wound inside the stainless steel container. A thick graphite reflector surrounded the core. 

Poly condensations of trimethylsilyl 3,5-diacetoxybenzoate Trimethylsilyl 3,5-diacetoxybenzoate (15.52 g, 50 mmol) is weighed into a cylindrical reactor equipped with a glass stirrer and gas inlet and outlet tubes. The reaction vessel is placed into a metal bath preheated to 200°C. The temperature is raised in 20°C steps over a period of 1 h and finally maintained at 280°C for 3 h. Vacuum is then applied for an additional 0.5 h. Finally, the cold reaction product is powdered, dissolved in CH2Cl2-trifluoroacetic acid (volume ratio 4 1), and precipitated into cold methanol. 

In scale-up of equipment both shape and size are changed. For instance, a one-litre round-bottom laboratory flask reactor is scaled up to a 50-litres pilot reactor and further to a 4 m cylindrical reactor with an ellipsoidal or torispherical bottom (see Fig 5.3-2). 

A particular shape of reactor, its specific internals, arrangements made because of special properties and/or behaviour of the reaction mixture, etc. are used as criteria to qualify a reactor. In fine chemicals manufacture two main groups of cylindrical reactors are in common use, viz. stirred-tank reactors with a small aspect ratio, and column reactors with a relatively large aspect ratio. Both types can be equipped with specific internals depending on process requirements. Researchers and designers are well acquainted with these reactors. A tendency to duplicate known equipment usually wins when considering the choice of reactor for a particular process. As a consequence, more and more stirred-tank reactors and column reactors are in use. 

Entezari MH, Petrier C, Devidal P (2003) Sonochemical degradation of phenol in water a comparison of classical equipment with a new cylindrical reactor. Ultrason Sonochem 10 103-108... 

First, laboratory and experimental reactors will be described. The vessel containing reactants or their supports are made of convenient dielectric materials (cylindrical or egg-shaped reactor). Original microwave reactors will be described. The first one is a metallic cylindrical reactor which is also the microwave applicator. It allow to reaches high pressures. The other one is a egg-shaped microwave reactor leading to high focusing level of microwave power. 

The cylindrical reactor-applicator has steel wall with thickness dose to 30 mm. This thickness permits to reach internal pressures above 30 Mpa. These operating pressure conditions are above the critical point of water. The internal diameter of the reactor is 50 mm and its length is 500 mm. The system is powered simultaneously with two 6-kW generators placed at the both ends of the reactor. This simultaneous supply is necessary to overcome the penetration depth within water. 

METEX [Metal extraction] A process for extracting heavy metals from industrial waste waters by adsorption on activated sludge under anaerobic conditions. It is operated in an up-flow, cylindrical reactor with a conical separation zone at the top. Developed by Linde, originally for removing dissolved copper from winemaking wastes. First commercialized in 1987. 

Common situations in reactors are when the conditions can vary with time and position as independent variables. Partial derivatives of dependent variables such as concentration and temperature with respect to each of the independent variables then are involved. Such an equation, for unsteady state dispersion in a cylindrical reactor, was derived in problem 5.08.01, namely... 

Five biomass samples (hazelnut shell, cotton cocoon shell, tea factory waste, olive husk and sprace wood) were pyrolyzed in a laboratory-scale apparatus designed for the purpose of pyrolysis (Demirbas, 2001, 2002a). Figure 6.4 shows the simple experimental setup of pyrolysis. The main element of the experimental device is a vertical cylindrical reactor of stainless steel, 127.0 nun in height, 17.0 nun iimer diameter and 25.0 mm outer diameter inserted vertically into an electrically heated tubular furnace and provided with an electrical heating system power source, with a heating rate of about 5 K/s. The biomass samples ground... 

The crowded conditions inside a reactor due to the presence of various probes and a phial-breaker usually limit the number and size of propeller blades which can be accommodated. However, these fittings also break up the laminar flow (which is inimical to efficient mixing) so that turbulence can be achieved at stirring speeds well below that which would be required for a cylindrical reactor free of solid obstructions. If there is sufficient space, mixing can be improved considerably by having two propeller blades, ca. 1.5 cm apart, on the same shaft, with opposite chiralities, so that the layer of fluid between them is subjected to an exceptional shear-rate. 

Packed Bed. Here, the hepatocytes are cultured on the inside surfaces of small pieces of highly porous resin that are packed randomly in a vertical cylindrical reactor [21]. A high cell density can be attained, as the cells grow in the minute pores of the resin. The cells are in direct contact with the blood. 

The discontinuous explosion process is the oldest technical process. It was mainly used for the production of color blacks. Continuous processes were later developed with production rates up to 500 kg/h [4.20], Acetylene or acetylene-containing gases are fed into a preheated, cylindrical reactor with a ceramic inner liner. Once ignited, the reaction is maintained by the decomposition heat that is evolved. The carbon black is collected in settling chambers and cyclones. Approximately 95-99% of the theoretical yield is obtained. 

Extended light sources may be installed around a tubular reactor or in the axis of an annular irradiated reaction volume. In the first case, an annular (or coaxial) radiation field focalized on the axis of the tubular reactor is created (Figure 10), and, in reaction mixtures of very low absorbance, irradiance as a function of the radius of the cylindrical reactor shows highest values in the axis of the reactor (positive geometry of irradiation, Figure 11 [2,3]). 

E(r) = irradiance in the interior of a cylindrical reactor at a distance r from its axis... 

Figure 10. Cross section of a cylindrical reactor with a coaxial radiation field (a) cross section perpendicular to the axis of the reactor (ft) cross section along the axis of the reactor (rR = reactor radius) [2, 3].

Incidence Models. First attempts to describe the radiant power distribution in photochemical reactors can be summarized under the heading of the RI model (radial incident model, Figure 25a). This model is based on the hypothesis of a radial radiation field [2, 3], that is, that all the light striking the reactor wall will be directed radially inward. Corresponding profiles of radiant power or of irradiance are strongly dependent on the radius of the cylindrical reactor (Eq. 68). 

The DI model (diffuse incident model, Figure 25c) is thought to take into account the abovementioned inadequacies. The model in which profiles of radiant power or of irradiance are independent of the radius of the cylindrical reactor was originally proposed by Huff and Walker [114] and has been tested by Jacob and Dranoff [111] using sensor equipment. Their results show that radius-independent radiant power or irradiance distribution can only be found for radii of less than 0.5 in. in their particular equipment (Figure 27). 

The vapour phase alkylation of 2-Et-A with methanol was carried out in a fixed bed down-flow reactor at 643K and atmospheric pressure. The cylindrical reactor of 17-mm diameter contained 3.4g catalyst. Catalysts were pretreated in flowing air at 720K for 1h and cooled to the reaction temperature in N2> The methanol to 2-Et-A molar ratio and the WHSV (92-Et-Ax 9cat x 1) were 5 and 0.22, respec t i ve1y. 

In a Pyrex cylindrical reactor adapted to the Synthewave system, 10 mmol of FDM (1.28 g) were mixed with 25 mmol of alkyl halide, 2 mmol of Aliquat 336 (0.8080 g) and 25 mmol of powdered KOH (1.6 g, containing about 15% of water). The mixture was then homogenized and submitted to monomode micro-waves with mechanical stirring for the adequate time. At the end of the reaction, the mixture was cooled down to room temperature and diluted with 20 mL of methylene chloride or diethyl ether. The solution was filtered (KOH in excess, generated salts). The filtrate was then concentrated and poured dropwise into 300 mL of methanol under intense stirring. The diethers 2 precipitate, therefore free from excess of reactants, catalyst and monoethers which are all soluble in methanol. After filtration and drying under vacuum, the product was recrystallized from adequate solvent. 

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