A circulating fluidized bed cfb reactor is extremely the same as a bubbling fluidized bed reactor. First reactor is an isothermal fixed bed with indirect heat exchanger. In this type of reactor, a fluid gas or liquid is passed through a solid granular material usually a catalyst possibly shaped as tiny spheres at high enough velocities to suspend the solid and cause it to behave as though it were a fluid. In this polymerization reactor, the bubbling fluidized bed operates by the mixed gas fluidization process. Chemical engineering department ahmadu bello university, zaria, nigeria.
They are also used in the oxidation of naphthalene to phtalic anhydride, roasting of sulfide ores, coking of petroleum residues, and the calcination of limestone. Phenol degradation in an anaerobic fluidized bed reactor packed with low density support materials 89 brazilian journal of chemical engineering vol. Consequently, a detailed design of a fluidized bed reactor that would allow flexible operation at high temperature and high pressure at several gas velocities will be conducted in order to serve for the future development of new hydrodynamic models. Cfd analysis of a fluidized bed reactor for industrial. Fluidized beds typically are more complex to design, build, and operate than other types of reactors, such as packed bed and stirredtank reactors. Correlations and models for the prediction of the minimum fluidization and bubbling conditions, the expansion and voidage of fluidized beds, the size. In particular, the mechanisms of devolatilization and. Its a bit a of a unique design different in design to typical fluid bed reactors. Adapted for the internet from the fluid bed reactor, produced by the national historic chemical landmarks program of the american chemical society in 1998.
This results in the medium then having many properties and. Fluidized beds are prone to erosion and particle attrition caused by the moving particles. Granulated polymer particle was used as the bed material because of its suitable mechanical stability. This is a reasonable approximation of a fluidized bed, but there are many more complicated models that can be seen in the above figure. Fbc fluidized bed combustion is a combustion technology used to burn solid fuels in steam boilers. Medcram medical lectures explained clearly recommended for you. Parr fluidized bed reactors are used extensively in the chemical process industries. Micro organisms are thus supplied with oxygen, and the entire content of the reactor is blended. In the present work a modelling approach is presented which is able to handle the most important aspects of industrial fluidized bed reactors. Many industrial plants prefer this method which has high efficiency.
The material that follows is based on what is seemingly the best model of the fluidized bed reactor developed thus farthe bubbling bed model of kunii and levenspiel. The bubbling fluidized bed is doubtless the foremost standard reactor for quick shift. Gas extraction ports are evenly distributed along the height of the reactor to extract product gases and accommodate thermocouples for temperature measurement. Computational fluid dynamics simulation of fluidized bed polymerization reactors by rong fan a dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of doctor of philosophy major. Bubbling fluidized bed reactor chemical engineering world.
International journal of engineering and computer science. The article gives an overview on fundamentals and applications of fluidized. The wastewater is ventilated intermittently in the fluidised bed reactor. An accordingly designed aeration system provides ventilation in fine bubbles. Two radiation furnaces 64 kw are used to heat the reactor. This is to certify that the thesis entitled fluidized bed reactor. Fluidized bed is one of the reactors using fluidization 24. In fluidized bed combustion boiler technology when air or gas is passed through an inert bed of solid particles such as sand supported on a fine mesh or grid, the air initially will seek a path of least resistance and pass upward through the sand. Design, construction, and testing of a fluidized bed reactor tanner iszler mechanical engineering, dr.
As highgrade feedstocks become depleted, companies want to diversify their production capabilities and minimize capital expenditures at. Jerry downey montana tech design and build phase sand was used for the fixed bed and air was used for fluidization. Threedimensional computational fluid dynamics cfd study of the gasparticle circulation pattern within a fluidized bed granulator. Experimental and computational fluid dynamics investigations of light alkane dehydrogenation in a fluidized bed reactor.
A fluidized bed is a physical phenomenon occurring when a quantity of a solid particulate substance usually present in a holding vessel is placed under appropriate conditions to cause a solidfluid mixture to behave as a fluid. It will be fluid moving through a relatively densely packed bed. Fluidization occurs when small solid particles are suspended in an upwardflowing stream of fluid, as shown in figure r12. Fluidized bed reactor with biofilm for optimal wastewater. The mechanical design of the parts of the plant and the layout was realized in a native 3d modelling environment i. Fluidized bed biofiltration technology for oligotrophic.
Various aspects such as solid circulation rate, gas mixing, solids mixing, and pressure. A particular focus is to describe the relationship between catalyst attrition, solids recovery in the reactor system and chemical performance of the fluidized bed reactor. Proceedings of the asme 2014 international mechanical engineering congress and exposition. This project presents a specified design of a smallscale fixed bed reactor for the purpose of investigating the gasification processes of biomass and municipal solid wastes. More information about mechanical design can be found in towler and sinnott. Vaccari, anna, pinelli, michele, pirani, luca, and gandolfi, nicola. A mechanical filter must be used in series before the fluidized bed biofilters, to remove the suspended solids and maximize performance of the fluidized bed. Air distributor designs for fluidized bed combustors. Depending on the distributors design in a fluidized bed. Fluidized bed systems have wide application as dryers, roasters, calciners, classifiers, and reactors within the metallurgical, chemical, oil and gas, and pharmaceutical industries. This reactor possesses an overall volume of 100 l with the expanded bed volume taking up 30 l. A fluidizedbed reactor was designed and constructed for. Especially for reactor design it is necessary to clarify to what extent experimental kinetic data gained at low heating rates can be applied to heating conditions like in a fluidized bed or in an. Design, construction, and testing of a fluidized bed reactor.
With this brief introduction to gassolid flows in fluidized bed reactors, major reactor engineering issues, conventional design practices and the role of. Chemical engineering and reactor design of a fluidised bed gasifier. The nozzle will not be doing any filtering, it will just have an inbuilt perforation to contain the. Packed bed situations include such diverse processes as filtration, wastewater treatment, and the flow of crude oil in a petroleum reservoir. Part b presents a synthesis of the literature available on selected subjects of primary importance to the design of fluidized bed reactors. Design, simulation analysis and performance evaluation of a fluidized bed reactor for the pyrolysis of biomass article pdf available august 2018 with 280 reads how we measure reads.
Pdf simulation of circulating fluidized bed reactors. Second reactor is an adiabatic fixed bed reactor to increase total ch 4 yield j two fluidized bed reactors. This is usually achieved by the introduction of pressurized fluid through the particulate medium. This paper describes the simulation procedure of a bubbling fluidized bed reactor, where three different meshing approaches were applied. Nearly all of the significant commercial applications of fluidized bed technology concern gassolid systems, so these are treated in this section. A ball valves v110 is placed for manual control of the natural gas flow and a. Temperature maintenance in each type of reactor and temperature profiles in each type reactor is discussed.
University of groningen particle transport in fluidized. They are often used when there is a need for large amounts of heat input or output, or when closely. Design aspects of industrial fluidized bed reactors. A fluidized bed reactor fbr is a type of reactor device that can be used to carry out a variety of multiphase chemical reactions. Consequently, a detailed design of a fluidized bed reactor that would allow flexible. If the gas rate of a bubbling fluidized bed will increase, at some location the force exerted on the particle are enough to move it upwards, carrying it outside of the bed. Chemical engineering laboratory 3, ce 427 packed and fluidized bed experiment introduction packed and fluidized beds play a major role in many chemical engineering processes. Cfd analysis of a fluidized bed reactor for industrial application. The heat of reaction of the exothermal hydration reaction is removed by water, evaporating in a cooling coil, immersed in the fluidized bed.
Nowadays, fluidized bed is widely used in different kinds of industry, such as power plant, petroleum industry and food processing industry. Using this novel fluidised bed, gravimetric measurements and high heating rate, the thermal conversion of biomass was investigated. Design of a circulating fluidized bed combustor for lignin. Computational fluid dynamics simulation of fluidized bed. Fluidized bed reactors are commonly used in catalytic cracking processes. In order to design such a fixed bed reactor, it is necessary to be able to predict the temperature and concentration at every point in the reactor, since present design methods are based on the numerical integration of basic differential equations which can be derived from material and energy balances over a differential element of the bed. Martin town, alan craig, and barry bartram from the mechanical workshop and martin vale. Development of a continuous fluidized bed reactor for. Both with two feed inlets and two intube heat exchanger bundles. Simulation of circulating fluidized bed reactors using aspen plus. Fluid bed furnaces thermal processing technologies from. Recent studies of heat transfer mechanisms in a fluidized bed. Natural sciences and engineering research council of canada nserc is.
Design and construction of a smallscale fixedbed reactor. During testing, the flow of air was manually adjusted until fluidization of the sand bed. Recently the petrochemical industry uses fluidized bed for catalytic processes such as residue fluidized catalytic cracking rfcc 1. Polypropylene production optimization in fluidized bed. Continuous fluid bed furnaces reactor systems for advanced material processing.
Usually operate to one or more mechanical limits common limit is capacity to burn carbon from the catalyst if air compressor capacity is limit, capacity may be increased at feasible capital cost. Mod01 lec18 fluidized bed reactor design i youtube. The model includes a sizing procedure consisting in. Dilute phase riser reactor design molecular sieve based catalysts 1960s. Chemical engineering and reactor design of a fluidised bed. The purpose of initial fluidized bed design was coal gasification 79.
45 471 887 715 1463 712 616 1543 1118 61 377 1254 554 177 489 1587 1198 418 1552 658 15 1030 346 1484 976 80 1312 1437 758 556