Cfd simulation and optimization of mixing behaviors in a. When the gas flow rate is large enough, the spout reaches the bed surface and forms a fountain of particles in the free. Edit pdf free pdf editor working directly in your browser. Spouted bed circulating fluidized bed direct reduction system. A porous draft tube dt with suitable converging and diverging angles having varying porosity is newly introduced in a spouted bed sb for manipulating the fluid exchange rate from the spout to the annular region and thus to enhance the fluid residence time in the annular region. The free jet flow area comprises a few regions whose size depends on the distance between the nozzle and rebound air jet area.
Processes free fulltext fabrication of highly filled. Comparing and combining data from internationally renowned research groups, this is the only uptodate book on spouted bed research and practice. Some of the basic concerns in the analysis of spouted. Spouted and spoutfluid beds edited by norman epstein. Figure 3 from a conical spouted bed reactor for the. The conical spouted bed reactor csbr has been successfully used for the pyrolysis of other solid residues, such as biomass 15 and plastics 16. This online tool is compatible with windows, linux and mac devices. The pressure of the reaction chamber was controlled at 10 torr and the reaction temperature was kept at 300c for 1 hour. At stable spouting process, a spout appears at the. Pdf this research compared tfm and cfddem models for simulation of a slotrectangular spouted bed. Wo2004007805a2 spouted bed electrode cell for metal.
This variable has proven to have an important effect on product distribution. Spouted beds is a comprehensive chapter book that covers the spouting phenomenon and the special features and applications of spouted beds. Nanosized composite powders fabricated in the spouted bed for 30 and 60 min were denoted s30 and s60, respectively. We offer spouted bed systems for all powder processing industries.
Although there are cases of assuming other computational domains, they usually apply to more complex systems where the drying chamber is only one of the modeled elements cf. The gibbs free energy minimization method was used to predict the composition of the producer gas. Stationary or bubbling fluidised bed is the classical approach where the gas at low velocities is used and fluidisation of the solids is relatively stationary, with some fine particles being entrained. The effect of pyrolysis temperature on product distribution and properties has been studied in the temperature range from 425 to 600 oc. Microwaveassisted pulsespouted bed freezedrying of stem. Therefore, composites from iron oxide fe 2 o 3 and sbcpolymer styrenebutadiene block copolymer were fabricated by using a miniaturized spouted bed with an innovative fluidization gap design. Developments in spouted bed technology mathur 1974 the. Our spouted bed systems offer the same process flexibility our fluidized bed systems are known for worldwide.
A pilot plant provided with a conical spouted bed reactor has been used for the valorisation of waste tires by thermal pyrolysis in continuous mode. Pdf the applicability of the spouted bed technique 15 to drying of granular products that are too. Spoutfluid beds are a type of spouted bed in which, in addition to the central orifice. Different system parameters investigated are particle size, initial static bed height, material density, spout velocity and spout diameter. Cambridge core chemical engineering spouted and spoutfluid beds edited by norman epstein. The conventional spouted bed is a central jet spouted bed, while the modi. The behavior of particles in thin spouted beds, mostly equipped with draft tubes, has been investigated. The flow characteristics in a novel cylindrical spouted bed with spherical longitudinal vortex generators is numerically investigated by twofluid model tfm with kinetic theory for granular flow, the longitudinal vortex technol. The performed simulation studies have demonstrated that assuming computa.
Shreddedcoconut drying by spoutedbed technique for cold. The operation started with the introduction of a given load of inert material into the equipment. Development of laboratory scale conical spouted bed reactors. A spouted fluidized bed gasifier has a bed of coarse. The safety of your data is 100% guaranteed thanks to an advanced level of security. Fluidization behavior of spouted bed for a gassolid system has been studied by carrying out a number of experiments in a cylindrical perspex column of 5cm diameter and 100cm height. The applicability of the spouted bed technique 15 to drying of granular products that are too coarse to be readily fluidized e. Complete patent searching database and patent data analytics services.
Glatt fluidized bed and spouted bed technologies for sophisticated product design contact with the company. Seed drying in fluidized and spouted bed dryers article pdf available in drying technology 2810. Study of solids and gas distribution in spouted bed operated in. Shreddedcoconut drying by spouted bed technique for cold.
It is herein described an electrowinning cell with a spouted bed electrode 16 of growing metallic beads 15, separated by a semipermeable diaphragm and suitable for being assembled in a stack in a modular arrangement. After briefly discussing the history and features of spouted bed compared to fluidized bed, the book deals with the fluid and solid dynamics of spouted beds. Similar variations have been reported for variation of the minimum spoutfluidizing velocity with bed height, particle diameter for spout fluidized beds zhong et al. As it is browserbased, you can edit pdf online with mobile devices. Once the desired temperature was reached, feeding of the concentrated extract at a. Energies free fulltext modelling of spouted and spoutfluid. Pdf five little monkeys jumping on the bed big book a. Pdf seed drying in fluidized and spouted bed dryers. Document, government publication, national government publication. The initial setting up and preliminary tests on a square.
The aim of this article is to present an overview of spouted bed technology. Spouting occurred when air was injected at the base of the bed. A nonisothermal model of a spouted bed gasifier, fuel deepdyve. The fluidization characteristics of fine particles have been studied in both the fluidized bed and spouted bed. This thesis is brought to you for free and open access by the graduate school at lsu digital commons. A vessel for contacting a plurality of objects with a fluid and including at least one bottom wall inclined downwardly from at least one sidewall to an inlet for providing an upwardly directed stream of fluid, and a distribution shield arranged in spaced relation to the bottom wall. Furthermore, a comparison between combined microwavehot air spouted bed drying and hot air spouted bed drying methodson energyconsumptionis also investigated in detail.
Despite these advantages, circulating fluidized beds are still less commonly used because their height significantly increases their cost. The desirable characteristics of granules are dustfree with optimum size. The conical spouted bed reactor has interesting features for waste tire pyrolysis, such as small pressure drop, simple design or the capacity for handling coarse particles. These are rotating drum reactors, countercurrent moving bed reactors, floatingtype and fast circulating fluidized bed reactors, and finally spouted bed sb reactors. The bananas were sliced and crushed to obtain a paste and fed to the spouted bed dryer 12 cm height and t 80 c in order to obtain flour. Response surface methodology is used to optimize the draft tube height, the draft tube width and the gap between the bottom of the draft tube and the inlet nozzle. Spouted bed is gassolid contactor in which the gas is introduced through a single orifice from the centre of a flat base, instead of a multiorifice system, resulting in a systematic cyclic pattern of solid movement inside the bed as shown in figure 1. A computer program was developed in order to determine the flow pattern, pressure distribution in the fluid. Independently of the hydrodynamic configuration of the dryer, the principle behind this technology is based on the drying of a thin layer of the slurry that coats the surface of inert particles. The selection of the type of the reactor depends on the constraints of the process, and especially on the. From lab and pilot systems to complex systems for production.
Optimization of draft tube position in a spouted bed reactor. Spouted bed and jet impingement fluidization in food industry. Preliminary tests for the thermochemical conversion of. Guiding the reader through new developments, insights and models, this is a valuable resource for chemical and mechanical engineers in research and industry. Fluidised beds have a uniform bed area throughout their vertical height and spouted beds have a tapered base typically at 30o to 50o.
The circulation pattern of solids in spouted beds is illustrated in figure 1a and a picture of the batch spouted bed dryer used in this work is shown in figure 1b. Us6193858b1 spouted bed apparatus for contacting objects. This fractured film is removed with the exit air to be collected as the product and the filmfree bodies are recycled by the spouted bed to be recoated. Studies on fluidization behavior of spouted bed and. Our unique, patented spouted bed technology makes this possible. Circulating fluidized beds cfb, where gases are at a higher velocity sufficient to suspend the particle bed, due to a larger kinetic energy of. The flours obtained were subjected to analysis of moisture, protein. In this paper, the spouted bed reactor combined with plasma generator by the low frequency 20 khz ac electric source was used for the experiment and the effect of plasma condition on the fluidized behavior was evaluated. Dec 12, 2012 drying uniformity, microstructure, apparent density, rehydration, and texture properties were measured to evaluate the quality of stem lettuce slices dried in a pulsespouted bed microwave freeze dryer. Study of solids and gas distribution in spouted bed. Five little monkeys jumping on the bed big book a five little monkeys story by eileen christelow. As before, the present model assumes firstorder reaction kinetics for the gasification reactions and the spout is treated as a plug flow reactor of fixed diameter with cross flow of gas into the annulus.
Spouted bed reactor an overview sciencedirect topics. The annulus region is considered to be a single plug. Spouted bed drying of bauhinia forficata link extract. A comparative study of the exchange of the spouting gas argon into the bed of zirconia and glass beads in a. These are closely related with other design concerns such as spoutability, minimum spouting velocity and maximum spoutable bed depth. However, few studies of the fine particles fluidized behaviour in the cold plasmaenhanced spouted bed have been reported.
The filmfree particles are then recoated and the process is repeated. Spouted bed circulating fluidized bed direct reduction. The use of spouted bed reactors for several chemical processes coal carbonization, shale pyrolysis, ore roasting, cement clinker production, and thermal. Optimization of draft tube position in a spouted bed reactor used for treatment of wastewater containing low concentration of heavy metals is investigated in this paper. Drying of phytochemical preparations in a spouted bed. When the spout was established the inlet air was heated to the desired temperature. A schematic diagram of the spouted bed reactor is shown in fig. The tire material used is a rubber free of steel and other tire carcass elements and has been provided by jenecan s. A tworegion model of a spouted bed gasifier devised by the present authors has been further developed to include an enthalpy balance.
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