Showing papers on "Packed bed published in 1983"
TL;DR: In this paper, the Brinkman-equation is solved by an equivalent variational problem in order to obtain steady flow profiles which satisfy the conditions w = 0 and e = 1 at the container wall of a packed bed.
290 citations
TL;DR: In this article, the reduction of NO by carbonaceous solid has been studied in a packed bed reactor, and the reaction rate per unit total surface area is found to be first order in NO, to have an apparent activation energy of 44 kcal/mole for temperatures higher than 873K, enhanced by the presence of CO, and to vary by approximately an order of magnitude between graphite and coal chars.
231 citations
01 Nov 1983
TL;DR: In this paper, an analysis of the transient response of a packed bed thermal storage unit is presented, in two-spatial dimensions and considering the influence of both axial and radial thermal dispersion for an arbitrary time and radial variation in the inlet fluid temperature.
Abstract: An analysis, with experimental results, for the transient response of a packed bed thermal storage unit is presented. The analysis is in two-spatial dimensions and considers the influence of both axial and radial thermal dispersion for an arbitrary time and radial variation in the inlet fluid temperature. Both charging and recovery modes are included. Spatial variations in void fraction are found to have significant effect on the dynamic response of both fluid and solid temperatures. The influence of radial velocity variations, wall heat capacity and wall thermal losses are considered. The analysis is valid for fluids of various Prandtl numbers. Experimental measurements of temperature distributions in a randomly packed bed of uniform spheres, with air as the working fluid, compare favorably with the analytical results over a broad range of Reynolds numbers. Results are presented for full-sized rock beds which indicate pronounced effects of void distribution in such systems.
175 citations
74 citations
TL;DR: In this paper, reaction rate data are presented of potassium carbonate-catalysed C02 gasification of an activated carbon, measured in a Packed Bed Balance Reactor over a C02 pressure range of 0.05-2.03 MPa at 1050 K.
68 citations
TL;DR: In this article, the capacity of an adiabatic gas absorption column is limited through the formation of a temperature plateau, and the major heat effects are taken into account in the design of the column.
Abstract: In the design of adiabatic gas absorption, the temperature distribution within the column is an important consideration Temperature influences the degrees of heat and mass transfer through the thermodynamic phase equilibrium relationships and reaction rates The capacity of an absorber is limited through the formation of a temperature plateau Gas absorption in a chemically reactive solvent in an adiabatic packed column is modelled rationally for the first time taking into account the major heat effects An iterative computational method for computing packed bed height is presented The design procedure is illustrated by sample calculations for carbon dioxide (CO2) absorption in monoethanolamine (MEA)
64 citations
TL;DR: In this paper, the authors describe the transition from gas-continuous to pulsing flow, the liquid holdup and the pressure drop over the column, which is described by an effective Froude-number.
61 citations
TL;DR: In this article, high temperature gas heating through porous media (SiC and ZrO 2 particles) in both a fluidized bed receiver and a packed bed receiver was investigated.
60 citations
TL;DR: The use of a packed bed reactor containing Ca-alginate immobilized Clostridium beijerinckii cells for continuous IBE (isopropanol-butanol-ethanol)-fermentation has been studied as mentioned in this paper.
57 citations
TL;DR: In this paper, a packed-bed reaction with horse radish peroxidase was optimized for use in flow injection systems and the most active and stable immobilizations were produced by azo linkage to porous glass.
54 citations
TL;DR: In this article, the gas hold-up and friction factor of a constrained inverse gas-liquid-solid fluidized bed and a semi-fluidized bed were analyzed and empirically correlated.
TL;DR: A micro packed-column anion chromatograph with a UV detector has been constructed and the applicability of the system is demonstrated in this paper, where a flexible fusedsilica capillary (0.19 mm I.D.) was used as a chromatographic tube and a surface-agglomerated and bonded low ion exchange capacity anion-exchange resin, developed for ion chromatography, was packed into an ion exchange column.
Patent•
05 Oct 1983TL;DR: In this article, a process and apparatus for filling and packing a chromatographic column by the wet route is described, in which a compression chamber is attached to one end of the column having an internal bore equal to the internal diameter of a column and aligned therewith to form a combined chamber, a fluid suspension of packing particles is introduced into the combined chamber and then a piston member is axially displaced within the compression chamber toward the column to compact the packing particles in the column.
Abstract: A process and apparatus for filling and packing a chromatographic column by the wet route in which a compression chamber is attached to one end of the column having an internal bore equal to the internal diameter of the column and aligned therewith to form a combined chamber, a fluid suspension of packing particles is introduced into the combined chamber and then a piston member is axially displaced within the compression chamber toward the chromatographic column to compact the packing particles in the column. The suspension liquid flows out of the column through a conduit formed through the piston and/or through the cap at the other end of the column. After compression, the compression chamber and piston are separated from the column and the packed column may then be attached to a chromatograph for use. Vibrators may be provided on the column or compression chamber to promote transverse rearrangement of the particles during compression. The liquid suspension of packing particles may be introduced into the combined chamber via a channel through the piston, or through the compression chamber after removing the piston, or through the opposite end of the chromatographic column. A porous plate may be placed over the conduit to prevent packing particles from exiting the combined chamber with the suspension liquid.
TL;DR: In this paper, the adhesion of uniform rod-like β-FeOOH particles onto stainless steel was studied as a function of dispersion pH, ionic strength, and flow rate using the packed bed technique.
TL;DR: In this paper, a model including longitudinal thermal dispersion and intraparticle conduction is developed to describe the transient response of a packed column with a time-varying inlet temperature.
Patent•
07 Nov 1983
TL;DR: In this paper, the rapid pyrolysis of lignocellulosic products, especially forest waste, is conducted in a fluidized bed of hot refractory particles.
Abstract: The rapid pyrolysis of lignocellulosic products, especially forest waste, is conducted in a fluidized bed of hot refractory particles The pyrolysis products, comprising solid carbonaceous residue (ie, char), tars and gas, escape from the bed and cross an overheating zone comprising a packed bed contactor supplied by a rainfall of hot refractory particles The carbonaceous solid residue is then separated from the produced gases, a portion of which is recycled to fluidize the bed, and burned in a conveyed bed combustion reactor, thus heating the refractory particles that supply the packed bed contactor and the fluidized bed
TL;DR: In this paper, the holdup of fine particles in the packed bed of dense particles in a multisolid pneumatic transport bed was experimentally examined and an interaction coefficient between fine particles and dense particles was defined based on the momentum balance equation.
TL;DR: In this article, the axial and radial thermal dispersion coefficients are estimated under nonreacting and reacting conditions in an almost adiabatic packed bed using steady state temperature profiles and dynamic data simultaneously.
Journal Article•
TL;DR: Both the source of carbon and nitrogen form influenced strain specificity and the frequency of occurrence of denitrifying bacteria at the concentration of 1,000 mg N/l in anaerobic packed bed reactors.
Abstract: The effect of different organic compounds, nitrites and nitrates at the concentration of 1,000 mg N/l on the quantitative and strain-specific selection of denitrifying bacteria was determined in anaerobic packed bed reactors. Both the source of carbon and nitrogen form influenced strain specificity and the frequency of occurrence of denitrifying bacteria. The frequency of denitrifying bacteria within packed bed reactor ranged in different media from 11% (glucose and nitrates) to 100% (methanol and ethanol with nitrates). A single species selection was observed in the presence of nitrites within packed bed reactor: Pseudomonas aeruginosa in medium with acetate. Pseudomonas stutzeri in medium with ethanol, Pseudomonas mendocina in medium with methanol and Pseudomonas fluorescens in medium with glucose. When nitrates were present in packed bed reactor, the dominating bacteria were: P. stutzeri in medium with acetate, P. fluorescens in medium with ethanol, Paracoccus denitrificans in medium with methanol and Alcaligenes faecalis in medium with glucose.
TL;DR: In this article, a pore diffusivity model was developed for temperature swing separation in a packed bed of sorbent, and experimental results on the effects of total pressure, particle size, adsorption temperature, and flow rate on separation efficiency compared favorably to the model's predictions.
Abstract: A pore-diffusion model, developed for temperature swing separation in a packed bed of sorbent, can interpret experimental data for the separation of H/sub 2/ and CH/sub 4/ in a packed bed of activated carbon operated at pressures up to 800 psi. Experimental results on the effects of total pressure, particle size, adsorption temperature, and flow rate on separation efficiency compared favorably to the model's predictions. In addition, this study clearly demonstrates that pore diffusivity is a factor as important as contact time and equilibrium amounts adsorbed in determining the separation efficiency.
Abstract: Two-phase pressure drop and dynamic and total liquid saturation are experimentally determined for air-water system under cocurrent downflow through packed beds using packing differing widely in geometry The experimental data of the present study as well as that available in literature is satisfactorily correlated in terms of: (a) Lockhart-Martinelli parameters; and (b) the Reynolds numbers defined for the respective phases and the bed porosity, taking into account the flow behavior of the phases through the packed bed
Patent•
08 Jul 1983TL;DR: In this paper, the hydrotreatment of hydrocarbons in the liquid phase is effected in a column containing a catalyst bed supported by a grid, where through passes an ascending stream of the charge admixed with hydrogen which expands the catalyst bed, the perforations of the grid being small enough to prevent passage of the catalyst particles but large enough to permit passage of a hydrogen-charge mixture, the reaction effluent being withdrawn from the top of the column.
Abstract: The hydrotreatment of hydrocarbons in the liquid phase is effected in a column containing a catalyst bed supported by a grid, wherethrough passes an ascending stream of the charge admixed with hydrogen which expands the catalyst bed, the perforations of the grid being small enough to prevent passage of the catalyst particles but large enough to permit passage of the hydrogen-charge mixture, the reaction effluent being withdrawn from the top of the column.
TL;DR: In this article, a laboratory scale submerged filter filled with crushed marble was used for the nitrification process investigation and the results obtained showed that the alkaline reactor filling material react with the hydrogen ions released during the process course which enables reactor exploitation without any pH value or alkalinity control.
Patent•
02 Aug 1983TL;DR: In this paper, a method of filtering fine solids from a fluid (gas or liquid) flowing upwardly through a chamber containing a semifluidized bed of discrete filter particles is described.
Abstract: A method of filtering fine solids from a fluid (gas or liquid) flowing upwardly through a chamber containing a semifluidized bed of discrete filter particles. During a filtering operation, the upper or packed section of the bed is immobilized by a porous retainer at the top of the chamber and, as the operation proceeds, the packed bed section gradually expands downwardly, and the fluidized bed section below it progressively decreases in size, thereby extending the duration of the filtration run and yielding a more uniform distribution of solids throughout the filter medium.
Patent•
08 Dec 1983
TL;DR: In this article, the authors proposed to almost perfectly remove silane gas in exhaust gas, by allowing the silane gases in the exhaust gas of a semiconductor preparing apparatus to pass a packed bed based on solid metal oxide to treat the same.
Abstract: PURPOSE: To almost perfectly remove silane gas in exhaust gas, by allowing the silane gas in the exhaust gas of a semiconductor preparing apparatus to pass a packed bed based on solid metal oxide to treat the same. CONSTITUTION: A quartz tube 1 is packed with solid metal oxide particles to form a packed bed 2. The part of the packed bed 2 is heated within a range of a room temp. W800°C by an electric furnace 3. Silane gas is diluted with nitrogen gas while the diluted silane gas with predetermined concn. is stored in a gas reservoir 4 and subsequently passed through the packed bed 2 through a flow meter 5, a needle valve 6 and pump 7. The treated gas 8 from the outlet of the packing layer 2 is collected and the concn. of silane gas therein is analyzed. The concn. thereof is reduced at least to 0.5ppm or less, pref., 0.1ppm or less. In order to regenerate or exchange the packing material, a plurality parallel sytem is pref. employed. COPYRIGHT: (C)1985,JPO&Japio
TL;DR: In this paper, the role of gas/vapour mixture properties on the effective conductivity of thermal energy storage systems was investigated and it was shown that very large increases in effective conductivities are achievable.
TL;DR: In this article, the SO2 breakthrough curves were obtained by changing temperature and initial concentration in a tubular packed bed reactor, and the kinetic parameters were determined by fitting breakthrough curves to the theoretical kinetic model.
Abstract: Removal of SO2 gas from simulated flue gases was carried out, using copper oxide adsorbent. The copper oxide absorbent is made by impregnation of γ-alumina tablet in a solution of copper (II) nitrate, followed by oxidation. SO2 breakthrough curves were obtained by changing temperature and initial concentration in a tubular packed bed reactor. The kinetic parameters were determined by fitting breakthrough curves to the theoretical kinetic model, and the rate equation was obtained. The saturation capacities were calculated by the numerical integration of breakthrough curves, and the equation representing breakthrough curves was obtained. By means of this equation, the influence of space time on breakthrough curves was estimated.
TL;DR: In this article, the live principle is used to transfer components from a packed column to a capillary column without any loss, which can accommodate both the high flow-rates from the packed column and the low flow rates supplying the capillary columns.
Journal Article•
TL;DR: Etude experimentale menee sur ZnCl 2 : elimination du zinc soluble, sorption dans la biomasse et performance du reacteur en terme DCO as discussed by the authors.
Abstract: Etude experimentale menee sur ZnCl 2 : elimination du zinc soluble, sorption dans la biomasse et performance du reacteur en terme DCO