Humidification-dehumidification spray column direct contact condenser. Part II: Experimental co-current flow

2018 ◽  
Vol 132 ◽  
pp. 20-29
Author(s):  
Aly Karameldin ◽  
Loula A. Shouman ◽  
Dalia A. Fadel
Keyword(s):  
Direct Contact ◽  
Current Flow ◽  
Spray Column

Performance of a Three-Phase, Spray-Column, Direct-Contact Heat Exchanger

1989 ◽  
Vol 111 (1) ◽  
pp. 166-172 ◽  
Author(s):  
T. C¸oban ◽  
R. Boehm
Keyword(s):  
Heat Exchanger ◽  
Direct Contact ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Column Height ◽  
Contact Heat ◽  
Factors Affecting ◽  
Spray Column ◽  
Three Phase ◽  
New Formulation

A numerical model of a three-phase, direct-contact, spray-column heat exchanger has been developed. This model has been used to calculate performance information about this type of device and to compare, where possible, to experiments. General equations are defined for distance up the column using a physically based model for the local heat transfer. This model has been used to investigate a number of characteristics of these devices, such as temperature and holdup distributions through the column. A new formulation is given for a mixed, time-averaged temperature that may be representative of measurements taken with temperature transducers in direct-contact heat exchangers. Little has been given in the literature about quantitative variations of performance as a function of the key independent variables, and information on these aspects is presented here. Although the results presented are for a specific geometry (0.61 m diameter, 3 m active column height, evaporating pentane in 85°C water), the variations shown can give insights generally into the factors affecting performance in these devices. In virtually all cases examined here, extremely good comparisons are shown between predictions and measurements. Conclusions are drawn about the applicability of the model and the important effects demonstrated.

scholarly journals Analytical Modelling of a Spray Column Three-Phase Direct Contact Heat Exchanger

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Hameed B. Mahood ◽  
Adel O. Sharif ◽  
Seyed Ali Hosseini ◽  
Rex B. Thorpe
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Direct Contact ◽  
Relative Velocity ◽  
Contact Heat ◽  
Spray Column ◽  
Three Phase ◽  
Direct Contact Heat Exchanger

An analytical model for the temperature distribution of a spray column, three-phase direct contact heat exchanger is developed. So far there were only numerical models available for this process; however to understand the dynamic behaviour of these systems, characteristic models are required. In this work, using cell model configuration and irrotational potential flow approximation characteristic models has been developed for the relative velocity and the drag coefficient of the evaporation swarm of drops in an immiscible liquid, using a convective heat transfer coefficient of those drops included the drop interaction effect, which derived by authors already. Moreover, one-dimensional energy equation was formulated involving the direct contact heat transfer coefficient, the holdup ratio, the drop radius, the relative velocity, and the physical phases properties. In addition, time-dependent drops sizes were taken into account as a function of vaporization ratio inside the drops, while a constant holdup ratio along the column was assumed. Furthermore, the model correlated well against experimental data.

Heat Transfer With Vaporization of a Liquid by Direct Contact in Another Immiscible Liquid: Experimental and Numerical Study

1991 ◽  
Vol 113 (3) ◽  
pp. 705-713 ◽  
Author(s):  
L. Tadrist ◽  
J. Sun ◽  
R. Santini ◽  
J. Pantaloni
Keyword(s):  
Heat Transfer ◽  
Theoretical Model ◽  
Void Fraction ◽  
Direct Contact ◽  
Numerical Study ◽  
Water System ◽  
Immiscible Liquid ◽  
Transfer Model ◽  
Two Phase ◽  
Spray Column

An experimental setup was designed to study direct-contact evaporators using a liquid dispersed in another immiscible liquid. The study was carried out on an n-pentane–water system to determine the influence of different parameters on these systems, and consequently to construct a model for this type of evaporator. An optical probe was used to measure the local void fraction. At different column abscissas along a selected diameter, the local void fraction variations were determined. The shape of the curves can be attributed to the different processes occurring in the spray column. A one-dimensional heat transfer model in the spray column was established. Simplifying assumptions were used to establish and resolve the set of equations governing heat transfer and two-phase flow. The vaporization process induces a volumetric expansion of the two-phase mixture. A theoretical model was used, in which the coalescence between the spherical fluid particles is taken into account. Different coalescence laws dependent on particle density were introduced into the theoretical model and then tested. The numerical results are discussed and compared with the experimental data obtained for the n-pentane–water system.

The effect of packing on direct contact evaporation in spray column

2017 ◽  
Vol 95 (11) ◽  
pp. 2209-2220
Author(s):  
Runzhi Hu ◽  
Yanchao Jin ◽  
Qunwu Huang ◽  
Yiping Wang ◽  
Yong Cui
Keyword(s):  
Direct Contact ◽  
Spray Column
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