Reactors, agitated tank

This research used mechanically agitated tank reactor system shown in Fig. 1. The reactor, 102 mm in diameter and 165 mm in height, was made of transparant pyrex glass and was equipped with four baffles, 120 mm in length and 8 mm in width, and six blades disc turbine impeller 45 mm in diameter and 12 mm in width. The impeller was rotated by electric motor with digital impeller rotation speed indicator. Waterbath thermostatic, equipped with temperature controller was used to stabilize reactor temperature. Gas-liquid mass transfer coefficient kia was determined using dynamic oxygenation method as has been used by Suprapto et al. [11]. 

Figure 24.2 Agitated tank reactors for gas-liquid reactions (a) single-stage (b) two-(or multi-) stage...

Repeat Example 24-2 for the xylene (B) oxidation reaction carried out in an agitated tank reactor (instead of a bubble-column reactor). Use the data given in Example 24-2 as required, but assume the diameter D is unknown. Additional data are the power input without any gas flow is 8.5 kW the impeller rotates at 2.5 Hz the height and diameter of the tank are the same (h = D) the impeller diameter is DI3, and the impeller contains 6 blades assume ubr = 1.25usg. In addition to the vessel dimensions for the conversion specified (/B = 0.16), determine the power input to the agitator (P,). 

Aniline is to be hydrogenated to cyclohexylamine in a suspended-particle agitated-tank reactor at 403 K (130°C) at which temperature the value of k is 90 s 1. The diameter dp of the supported nickel catalyst particles will be 0.1 mm and the effective diffusivity De for hydrogen when the pores of the particle are filled with aniline is 1.9 x 10 9 m2/s. 

Continuous stirred tank reactor (CSTR) an agitated tank reactor with a continuous flow of reactants into and products from the agitated reactor system ideally, composition and temperature of the reaction mass is at all times identical to the composition and temperature of the product stream. 

To transfer ozone to a water phase very often fine bubble columns or stirred or agitated tank reactors are applied. The bubbles in these reactors are small. The value of m for ozone is relatively high. Furthermore the diffusion coefficient of ozone in the gas phase is very high compared with the diffusion coefficient of ozone in the water phase. These three reasons lead to the conclusion that in bubble columns and stirred tank reactors the resistance to mass transfer in the gas phase can be neglected. Equation (20) can than be simplified to ... 

J. Alvarez, J. Alvarez, and R. Suarez. Nonlinear bounded control for a class of continuous agitated tank reactors. Chem. Eng. Set., 46(12) 3341-3354, 1991. 

Agitated tank reactors Batch agitated reactor This is a batch stirred tank reactor. For liquid-solid systems, the liquid is agitated by a mechanical apparatus (impeller) and the reactor is of tank shape. For gas-solid systems, the gas is agitated and rapidly circulated through a fixed-bed of solids. This reactor is basically an experimental one used for adsorption, ion exchange, and catalysis studies. 

In fluidized beds, mass transfer involves two different mechanisms. The first one is the ordinary mass transport between the fluid and the solid. The treatment of this type of transport is quite similar to fluid-solid mass transfer found in other types of operations such as fixed beds and agitated tank reactors. This mechanism of mass transfer is not always significant in fluidized beds and can be totally neglected in some cases. 

In connection with the engineering content of the book, a large number of reactors is analyzed two- and three-phase (slurry) agitated reactors (batch and continuous flow), two-and three-phase fixed beds (fixed beds, trickle beds, and packed bubble beds), three-phase (slurry) bubble columns, and two-phase fluidized beds. All these reactors are applicable to catalysis two-phase fixed and fluidized beds and agitated tank reactors concern adsorption and ion exchange as well. 

A.K.S. Murthy, Notes on the Design of Agitated Tank Reactors, The BOC Group, Murray Hill, NJ, USA. 

Agitated Tank Reactors Flow Patterns of Gas and Liquid... 

Note that three-phase bubble columns and agitated tank reactors are sometimes referred to as slurry reactors. 

In cases when the feed stream is a liquid, which requires rather long residence times, the suspension bubble column or an agitated tank reactor is used (Figures 1.2(b) and 1.2(c)). Here, in the reactor exit, quite elaborate filtering systems are required to remove the catalyst from the liquid stream. In these reactors a gas generally is supplied, because these suspension reactors are mostly used for hydrogenations and oxidations. 

To put it simple, the enzyme reactor is an agitated tank reactor in which the substrate is placed and stirred together with the enzyme for a certain period of time at a certain temperature in the liquid phase. The enzyme is added preferably in a concentration of 0.1 to 1% and is lost after completion of the reaction. 

The continuous stirred-tank reactor (CSTR) is a mathematical model that describes an important class of continuous reactors—continuous, steady, well-agitated tank reactors. The CSTR model is based on two assumptions ... 

Yn H-S, Tan Z-C. (2012) New correlations of volumetric liquid-phase mass transfer coefficients in gas-indncing agitated tank reactors. Int. J. Chem. Reaction Eng., 10(Article A-50) l-18. 

Another alternative for three-phase catalytic reactors with suspended catalyst particles is to use mechanically agitated tank reactors (Figure 6.7). In a tank reactor, the flow profile can approach complete backmixing. 

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