• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.9
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• pp.895-903
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• 2001

Evaporation cooling phenomena of droplets containing fire suppression agents on a hot metal surface were experimentally investigated. Solution of water containing potassium acetate (30-50% by weight) and sodium bromide (10-30% by weight) were used in the experiments, and surface temperatures were ranged from 70-116$^{\circ}C$. The evaporation time of the droplet on the heated surface was determined by using frame-by-frame analysis of the video records. It is found that the apparent evaporation time is shorter in turns of pure water, sodium bromide solution and potassium acetate solution. However, the time averaged heat flux is higher in turns of pure water, sodium bromide solution and potassium acetate solution. In-depth temperature variation of the hot metal does not occur significantly by the kinds of additive.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.9
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• pp.1267-1276
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• 1998

Falling-film evaporation experiments with aqueous lithium bromide (LiBr) solution were performed to investigate the heat transfer characteristics of enhanced copper tubes. Enhanced tubes (a knurled tube, a spirally grooved tube, and a tube coated with $20{\mu}m$ aluminum particles) and a bare tube were selected as test specimens. Averaged evaporation fluxes of water were obtained from horizontal tubes with various film Reynolds numbers, system pressures, LiBr concentrations and degrees of wall superheat. The enhanced performance of steam generation was compared between tubes with varying parameters. The knurled tube geometry showed the most excellent performance among the tubes tested. The specified enhanced tubes were more useful for generating steam on a low grade heat source such as waste heat.

• Membrane and Water Treatment
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• v.4 no.4
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• pp.223-236
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• 2013

The paper presents an experimental set-up for osmotic membrane distillation, which can be operated continuously for several weeks. NaCl solutions were used as an osmotic solution. The influence of osmotic solution concentration on the obtained permeate flux is presented. The experimental set-up was equipped with a system for the regeneration of dilute brine. The regeneration was carried out using a method of natural evaporation to the air surrounding the installation. The evaporation area was created by the Białecki rings, assembled in the form of tower. The obtained evaporation rate was sufficient to maintain a constant NaCl concentration (over 300 g/L), for air with the relative humidity in the range of 30-80%. Accurel PP S6/2 hydrophobic polypropylene membranes were used in the study. The membranes exhibited 100% rejection for 600 h of the process duration.

• Korean Journal of Crystallography
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• v.14 no.1
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• pp.35-38
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• 2003

A simple multistep-concentration setting in capillaries was used to control the water-evaporation rate in vapor-diffusion protein crystallization. In the method used, a variety of evaporation rate curves were obtained by using the secondary precipitant solution referred to as “regulatory solution”, which is not directly exposed to the protein solution. The curves were applied to the crystallization of lysozyme as a model protein. The results clearly showed that crystal growth is dependent on the evaporation rate. Especially, the decoupling curves in which precipitant concentration in protein solutions increases to a certain point and then decreases to the equilibrium concentration gave the best crystals.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.2
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• pp.294-302
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• 1997

Falling-film evaporation experiments for aqueous solution of lithium bromide (LiBr) were performed on a horizontal smooth 19.05-mm-dia copper tube. Average heat transfer coefficients were obtained with varied film Reynolds numbers, system pressures, LiBr concentrations and degrees of wall superheat. Heat transfer coefficients increase with increasing system pressure and decreasing concentration. For degrees of wall superheat, the heat transfer coefficient did not't show the distinct trend. For this experimental ranges, heat transfer coefficients showed maximum values at an optimal film Reynolds number. The results of this work were compared with pool boiling data reported previously, and it was shown that the heat transfer performance is superior to the pool boiling.

• Macromolecular Research
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• v.13 no.2
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• pp.152-155
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• 2005

A dynamic density functional theory is presented for the observation of the phase revolutions of a solution-casting film of di- and tri-block copolymers under solvent evaporation conditions. With the evaporation of the solvent, the inverted phases, the minor part of the component becomes the continuous phase at the higher solvent evaporation rate, as observed in this experiment. Further simulation revealed that these inverted phases are converted into the normal phase and the major part of the component becomes the continuous phase, implying that the inverted phases observed in this experiment are unstable.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.11
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• pp.434-443
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• 2016

The evaporation of water from an aqueous solution is widely used in the food, desalination, pulp, and chemical industries. Usually, a large amount of energy is consumed in the evaporation process to boil off water due to atmospheric pressure. As a way of improving the energy efficiency of the evaporation process, the combination of multiple effect evaporation and thermal vapor recompression has been proposed and has become a successful technique. In this study, 4 multiple-effect falling film type evaporators for sugar solution are designed and the energy efficiency of the system is analyzed in response to the selection of the steam ejector position. Energy efficiency is increased and vapor is more compressed in the steam ejector as the Thermal Vapor Recompression (TVR) is arranged in the rear part of the evaporator system. A simplified 0-dimensional evaporator model is developed using non-linear equations derived from mass balances, energy balances, and heat transfer equations. Steam economy is calculated to compare the evaporation performance of the 4 proposed evaporators. The entrainment ratio, compression ratio, and expansion ratio are computed to check the ejector performance.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.441-443
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• 2008

A non-vacuum process for fabrication of $CuInSe_2$ (CIS) absorber layer from the corresponding Cu, In solution precursors was described. Cu, In solution precursors was prepared by a room temperature colloidal route by reacting the starting materials $Cu(NO_3)_2$, $InCl_3$ and methanol. The Cu, In solution precursors were mixed with ethylcellulose as organic binder material for the rheology of the mixture to be adjusted for the doctor blade method. After depositing the mixture of Cu, In solution with binder on Mo/glass substrate, the samples were preheated on the hot plate in air to evaporate remaining solvents and to burn the organic binder material. Subsequently, the resultant CI/Mo/glass sample was selenized in Se evaporation in order to get a solar cell applicable dense CIS absorber layer. The CIS absorber layer selenized at $530^{\circ}C$ substrate temperature for 30 min with various Se gas evaporation temperature was characterized by XRD, SEM, EDS.

• Journal of the Korean Ceramic Society
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• v.33 no.1
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• pp.17-24
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• 1996

Pb(Mg1/3Nb2/3)O3 powder with high purity chemical homogeniety and reactivity was prepared by solvent eva-poration of common solution. The common solution was fabricated using a Pb(NO3)2 Mg(NO)3 and NB solution which was prepared by dissolving NbC in H2O2 acquous solution. In precusor powder prepared by solvent evaporation method the synthetic temperature of Pb(Mg1/3 Nb2/3)O3 phase was lowered. And the formation of homogeneous Pb(Mg1/3Nb2/3)O3 phase was enhanced but the formation of pyrochlore phase was reduced. The dielectric constant of PMN ceramics from the synthesized powder was found to increase with both sintering temperature and excess MgO and subsequent analysis of the microstructures confirmed that this was due to an increase in grain size. The grain size dependence is explained as a consequence of low-permittivity grain boundaries.

• The Korean Journal of Ecology
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• v.2 no.1
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• pp.31-37
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• 1978

The salt accumulation on the soil surface can be mathematically described. Although the movement of salts in soil solution is expressed in terms of mathematical model, which has certain limitations in practical application, except the exchangeable and absorbable state salts in soil solution. This model is illustrated by analyticl experiments in which evaporation from the bare soils, transpiration of plants and rainfall are required. Agreement between the model and the measured data was satisfactory, which validating the salt accumulation theory on the soil surface.