Coefficients of Heat and Mass Transfer in a Packed Bed Suitable for Solar Regeneration of Aqueous Lithium Chloride Solutions

1984 ◽  
Vol 106 (4) ◽  
pp. 387-392 ◽  
Author(s):  
G. O. G. Lo¨f ◽  
T. G. Lenz ◽  
S. Rao
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Lithium Chloride ◽  
Packed Column ◽  
Packed Bed ◽  
Transfer Coefficients ◽  
Transfer Rates ◽  
Vapor Transfer ◽  
Lithium Chloride Solution ◽  
Water Vapor Transfer

Reconcentration of a lithium chloride solution in an open-cycle absorption chiller can be accomplished by passing solar heated air through a packed column to which the dilute solution is supplied. Following a theoretical study of heat transfer and water vapor transfer rates in the column, experimental measurement of those rates was made. Heat transfer and mass transfer coefficients are correlated with rates of air and liquid flow, and with temperatures of air and liquid supply. Performance data are presented and commercial design and operating requirements are suggested.

Heat and Mass Transfer From a Rotating Disk

1959 ◽  
Vol 81 (2) ◽  
pp. 95-103 ◽  
Author(s):  
F. Kreith ◽  
J. H. Taylor ◽  
J. P. Chong
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Rotating Disk ◽  
Heat Transfer Process ◽  
Transfer Coefficients ◽  
Transfer Rates ◽  
Turbulent Vortex ◽  
Heat Transfer Coefficients ◽  
Adiabatic Surface ◽  
Measured Mass

The analogy between heat, mass, and momentum transfer is applied to a rotating disk. Experimentally measured mass-transfer rates from a disk rotating in an infinite environment under laminar and turbulent conditions are related to the corresponding heat-transfer process by means of an analogy method. The experimental analog is shown to eliminate difficulties associated with accurate measurements of heat-transfer coefficients. Experimental data on the effect of an adiabatic surface placed at various distances parallel to the disk on the transfer rate from the disk are presented. Observations of some unusual flow patterns resulting from Goertler type vortexes in the transition regime and from some as yet unexplained turbulent vortex phenomena are also reported.

Experimental Analysis of Air Dehumidification System With Liquid Desiccant

2010 ◽  
Author(s):  
Li Zhang ◽  
Tanaka Chitose ◽  
Eiji Hihara
Keyword(s):  
Mass Transfer ◽  
Lithium Chloride ◽  
Experimental Analysis ◽  
Chloride Solution ◽  
Experimental Results ◽  
Liquid Desiccant ◽  
Transfer Coefficients ◽  
Air Velocity ◽  
Mass Transfer Coefficients ◽  
Lithium Chloride Solution

The performance of an air dehumidification system with lithium chloride solution used as a desiccant was studied experimentally. First, the mass-transfer coefficients were measured for a structured packed dehumidifier/regenerator. It was shown that the overall mass-transfer coefficients varied from 2.5 to 7.8 g/(m2·s) when the air velocity was increased from 0.5 to 1.5 m/s in the dehumidifier and varied from 1.2 to 2.7 g/(m2·s) in the regenerator. Second, experiments on the air dehumidification system were conducted. The experimental results showed that higher humidity in summer and lower humidity in winter resulted in decreased dehumidifying (humidifying) efficiency.

Comparison of Mass and Heat Transfer Coefficients of Liquid-Desiccant Mixtures in a Packed Column

1991 ◽  
Vol 113 (1) ◽  
pp. 1-6 ◽  
Author(s):  
A. Ertas ◽  
E. E. Anderson ◽  
S. Kavasogullari
Keyword(s):  
Heat Transfer ◽  
Calcium Chloride ◽  
Lithium Chloride ◽  
Theoretical Study ◽  
Packed Column ◽  
Cost Effective ◽  
Liquid Desiccant ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Mass And Heat Transfer

In order to analyze the performance of packed columns for dehumidification processes, calculation of the mass and heat transfer coefficients of the packing material used in the column is necessary. This paper is concerned with the interface transfer of heat and mass when air is brought into contact with the liquid desiccant mixtures. A theoretical study of heat and mass transfer analysis in an air-desiccant dehumidification contact system (packed column) employing liquid-desiccants, namely calcium chloride (CaCl2), lithium chloride (LiCl), and a new liquid-desiccant mixture (Cost-Effective Liquid Desiccant, CELD) consisting of 50 percent lithium chloride and 50 percent calcium chloride is studied. Mass and heat transfer coefficients for the gas and liquid phase, by use of 0.5-in., 1-in., 1.5-in., and 2-in. ceramic Rasching rings, are calculated. The findings for the three liquid desiccants are compared and discussed.

Mass and Heat Transfer From an Enclosed Rotating Disk With and Without Source Flow

1963 ◽  
Vol 85 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Frank Kreith ◽  
E. Doughman ◽  
H. Kozlowski
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Rotating Disk ◽  
Reynolds Numbers ◽  
Correlation Equation ◽  
Rotating Disks ◽  
Transfer Coefficients ◽  
Transfer Rates ◽  
Smoke Visualization ◽  
Source Flow

The heat-transfer characteristics of a partially enclosed rotating disk have been investigated experimentally by means of a mass-transfer analog. Mass-transfer rates to air from naphthalene coated disks of 4 and 8 in. diameter were measured at speeds between zero and 10,000 rpm and the influence of the spacing between the rotating disk and its housing was investigated with and without source flow. From the experimental results a dimensionless correlation equation suitable for predicting average heat and mass-transfer coefficients for rotating disks with source flow in turbulent flow at rotational Reynolds numbers up to 4 × 105 was deduced. The flow pattern was investigated by means of a hot wire, a smoke visualization technique, and the china clay method.

Henry's constants and mass transfer coefficients of halogenated organic pollutants in an air stripping packed column

1998 ◽  
Vol 38 (6) ◽  
pp. 287-294 ◽  
Author(s):  
Pen-C. Chiang ◽  
Chung-H. Hung ◽  
J. C. Mar ◽  
E. E. Chang
Keyword(s):  
Mass Transfer ◽  
Methylene Chloride ◽  
Packed Column ◽  
Transfer Coefficients ◽  
Chlorinated Organic Compounds ◽  
Air Stripping ◽  
Mass Transfer Coefficients ◽  
Equilibrium Partition ◽  
Henry's Constants ◽  
Chlorinated Organic

Both Henry's constants and volumetric mass transfer coefficients (KLa) of eight priority chlorinated organic compounds including 1,1-dichloroethene, methylene chloride, chloroform, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,4-dichlorobenzene in an air stripping packed column were investigated in this study. The liquid and gas phase EPICS (Equilibrium Partition in Closed System) and direct calculating methods were applied to determine the Henry's constants of VOCs. The interference of co-solute on Henry's constants was also investigated. Experimental results indicated that decrease in Henry's constants of VOCs was observed in the presence of humic acid but no apparent effect on Henry's constants was detected when there was NaCl and surfactant in solution. Four different configurations of packing media including Intalox Saddle, Super Intalox Saddle, Telleret, and Hedgehog made of polypropylene were respectively packed in the air stripping tower and investigated in the study. The dependence of hydraulic loading, air-water ratio, and configurations of packing media on mass transfer coefficients of VOCs was discussed.

A Method for Estimating Mass Transfer Coefficients in a Packed Column Using Reactive Absorption Data

2005 ◽  
Vol 70 (3) ◽  
pp. 383-402
Author(s):  
Valery A. Danilov ◽  
Il Moon
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Optimization Technique ◽  
Packed Column ◽  
Effective Area ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Model Calculations ◽  
Unit Model ◽  
Reactive Absorption

This paper is devoted to the development of a new method for estimating mass transfer coefficients and effective area in packed columns in the case of reactive absorption. The method is based on a plug-flow model of reactive absorption of carbon dioxide with sodium hydroxide solution. The parameter estimation problem is solved using an optimization technique. Some mass transfer parameters are found to be correlated. Global sensitivity analysis by Sobol's technique showed that the unit model with the defined objective function is sensitive to the estimated parameter. Case studies of reactive absorption with different packings illustrate application of the proposed method for estimating mass transfer coefficients and effective area from column operation data. The model calculations are compared with experimental data obtained by other authors. The concentration profiles calculated by the unit model with the estimated parameters are shown to match well with experimental profiles from literature. A good agreement between estimated values and experimental data from literature confirms the applicability of this method.

Flow Past a Spinning Sphere With Surface Blowing and Heat Transfer

2005 ◽  
Vol 127 (1) ◽  
pp. 163-171 ◽  
Author(s):  
H. Niazmand ◽  
M. Renksizbulut
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Flow Regimes ◽  
Solid Sphere ◽  
Temporal Variations ◽  
Transfer Coefficients ◽  
Transfer Rates ◽  
Particle Spin ◽  
Flow Past ◽  
Angular Velocities

Computations are performed to determine the transient three-dimensional heat transfer rates and fluid forces acting on a stream-wise spinning sphere for Reynolds numbers in the range 10⩽Re⩽300 and angular velocities Ωx⩽2. In this Re range, classical flow past a solid sphere develops four different flow regimes, and the effects of particle spin are studied in each regime. Furthermore, the combined effects of particle spin and surface blowing are examined. Sphere spin increases drag in all flow regimes, while lift shows a nonmonotonic behavior. Heat transfer rates are not influenced by spin up to a certain Ωx but increase monotonically thereafter. An interesting feature associated with sphere spin is the development of a special wake regime such that the wake simply spins without temporal variations in its shape. For this flow condition, the magnitudes of the lift, drag, and heat transfer coefficients remain constant in time. Correlations are provided for drag and heat transfer.

Heat Transfer on Nanofluid Flow With Homogeneous–Heterogeneous Reactions and Internal Heat Generation

2014 ◽  
Vol 136 (12) ◽  
Author(s):  
Raj Nandkeolyar ◽  
Peri K. Kameswaran ◽  
Sachin Shaw ◽  
Precious Sibanda
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Heat Generation ◽  
Internal Heat ◽  
Internal Heat Generation ◽  
Heterogeneous Reactions ◽  
Transfer Coefficients ◽  
Transfer Characteristics ◽  
Fluid Properties

We investigated heat and mass transfer on water based nanofluid due to the combined effects of homogeneous–heterogeneous reactions, an external magnetic field and internal heat generation. The flow is generated by the movement of a linearly stretched surface, and the nanofluid contains nanoparticles of copper and gold. Exact solutions of the transformed model equations were obtained in terms of hypergeometric functions. To gain more insights regarding subtle impact of fluid and material parameters on the heat and mass transfer characteristics, and the fluid properties, the equations were further solved numerically using the matlab bvp4c solver. The similarities and differences in the behavior, including the heat and mass transfer characteristics, of the copper–water and gold–water nanofluids with respect to changes in the flow parameters were investigated. Finally, we obtained the numerical values of the skin friction and heat transfer coefficients.

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