Publication Type. More Filters. Experimental and numerical investigation of bubble column reactors. View 1 excerpt, cites background. Bubble column reactors for high pressures and high temperatures operation. Bubble column reactors are multiphase contactors based on the dispersion of a gas phase in the form of bubbles inside a cylindrical vessel where a liquid or a suspension circulates.
Those reactors … Expand. Hydrodynamics and mass transfer in slurry bubble columns : scale and pressure effects. Slurry bubble columns SBC are widely used in the chemical industry as a multiphase reactor. Applications include oxidation and hydrogenation reactions, fermentation, Fischer-Tropsch synthesis, and … Expand.
Bubble column reactor as a gas—liquid contactor is extensively used in the chemical and biochemical industries. Mass transfer coefficients governing the transport processes in bubble contactors are a … Expand. Bubble columns are widely used as gas—liquid contactors and as reactors in chemical, petrochemical and biochemical industries. Effective mixing as well as high interfacial area between the phases, … Expand. Highly Influenced. View 3 excerpts, cites background. Bubble column reactors are well-known devices in many industrial applications for gas-liquid reactions.
Recently, they are being used as humidifiers and dehumidifiers in desalination and water … Expand. Abstract Multiphase contactors are intensively used in chemical, biochemical, pharmaceutical, petrochemical, and others industries.
The complexity and diversity of industrial processes implies that … Expand. Bubble column reactors have many important role in chemical, petrochemical and biochemical industries due to their relatively simple construction, favorable heat and mass transfer properties and low … Expand.
View 4 excerpts, cites background. Bubble column reactors are used in a wide variety of applications such as multiphase bioreactors, catalytic slurry reactors, and absorption processes. The superficial gas velocity-gas holdup … Expand.
Bubble columns operated under industrially relevant conditions — Current understanding of design parameters. Abstract Despite the fact that bubble columns are widely established within the process industry as multiphase reactors and gas—liquid contactors, common research has been focused on the description … Expand.
Liquid flow and phase holdup—measurement and CFD modeling for two-and three-phase bubble columns. Bubble columns are an important class of contacting devices in chemical industry and biotechnology. Their simple setup makes them ideal reactors for two- and three-phase operations such as … Expand. Hydrodynamic stability of multiphase reactors.
Gas-liquid bubble columns, solid-liquid fluidized beds, gas-solid fluidized beds, gas-liquid-solid fluidized beds, and transport reactors are very widely used multiphase reactors. These reactors … Expand. View 1 excerpt, references background. The past two decades have seen a steadily increasing number of papers on bubble columns and related reactors. In spite of the many publications, the design and scale-up of bubble column reactors is … Expand. View 3 excerpts, references methods and background.
On the mechanism of heat transfer in bubble column reactors. Abstract Bubble column reactors are often used to carry out highly exothermic reactions in liquid phase. Highly Influential. Log in with Facebook Log in with Google. Remember me on this computer.
Enter the email address you signed up with and we'll email you a reset link. Need an account? Click here to sign up. Download Free PDF. Bubble Column. Behnoosh Moshtari. A short summary of this paper.
Download Download PDF. Translate PDF. Noronha, M. Schmal, E. MAIN TEXT Introduction A bubble column is a device in which a gas phase is injected through a column of liquid to promote a chemical or biochemical reaction in the presence or absence of a catalyst suspended in the liquid phase [1].
The design and scale up of these reactors require comprehensive knowledge about hydrodynamic behavior under these operating conditions [2].
Most studies have shown that, there are two basic flow regimes in bubble columns; homogeneous and heterogeneous [3,4]. In a system with homogeneous regime the bubble size distribution is narrow and a uniform bubble size, generally in the range mm is found [5]. With increasing the superficial gas velocity the bubble size distributions will be changed. In heterogeneous regime small bubbles combine in cluster to form large bubbles in size ranging from 20 to 70 mm.
Different parameters such as: superficial gas velocity, gas distributor, liquid high, solid concentration, … can effect on type of flow regime. Shah et al. It can be defined as the percentage by volume of the gas in the two or three phase mixture in column. Moshtari et al. For the bubbly flow regime n varies from 0. In fact the gas hold up seems to increase linearly with superficial gas velocity in homogeneous flow regime and the gas hold up reach a maximum where the transition from homogeneous to heterogeneous flow regime occur then more none linear increase with superficial gas velocity[8].
Effect of gas hold up The solid suspension into a bubble column causes to formation of large bubbles. An increase of bubble size increases the bubble rise velocity, and reduces the residence time of bubble in reactors [9].
The solid particles in bubble column reactors are in micron size and suspended in liquid. When the concentration of solid particle in liquid increases, the gas hold up is reduce [5]. Effect of gas distributor There are different types of gas distributor, with different design in size and number of orifices.
Most common distributors are prose plate and perforated plat. The initial bubble size and distribution at the entire orifice could be controlled by sparger characteristics. The balance between coalescence and break up of gas bubble show that the initial bubble size created at the gas sparger would not completely describe the behavior of gas bubble size distribution in entire column [10].
A large number of correlation for gas hold up have been proposed in the literature, but the large scatter in the reported data dose not allow a single correlation.
In the present work, the effects of solid concentrations, sparger type and superficial gas velocity, on gas hold up into a bubble column reactor have studied, and the best correlation for predicting the hydrodynamic behavior on slurry bubble column reactors is suggested.
The column is equipped with sparger in bottom, a perforated plate and a porous plate both with 0. Designing of perforated plate is based on Weber number, this sparger consist of 21 holes with 1 mm diameter.
In all experiments the pressure at top of the column was atmospheric. Gas injected from the bottom of column. After injecting gas, the liquid bed expended and the hydrostatic pressure was changed.
For measuring the differential pressure through the column a manometer is used. The liquid phase is water, gas phase is air and solid particles are silica powder. In figure 1 the set up is showed. Figure 1- Experimental set up 3. All the experiments show the positive effect of superficial gas velocity on gas hold up figure 2.
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