摘要:

AbstractValues of thermal conductivity and temperature coefficients for thirty‐five pure organic liquids, in addition to those previously reported, obtained with a previously described apparatus (Part I), are presented. Values of thermal conductivity or temperature coefficients for twenty‐eight of these liquids have not been reported before. The experimentally determined maximum error is ±1.0%.The two methods for predicting the thermal conductivity of liquids previously proposed (Parts I and II) are extended to cover the types of compounds studied in this investigation, in particular ring compounds.The temperature coefficient of thermal conductivity was observed to decrease rapidly, approaching zero as the freezing point is approached. The existence of a transition temperature or region within the liquid state is shown and identified with the onset of molecular rota

ISSN:0001-1541    

DOI:10.1002/aic.690030120

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

摘要:

AbstractMass and heat transfer rates in extraction are studied theoretically and experimentally for the practical range of the variables involved. For the particular but typical case of liquid drops moving through another liquid a simple correlation for the over‐all mass transfer coefficient is presented, which holds with a probable error of 20%.Included are systems in which the rate is limited by either coefficient, as well as systems in which both coefficients are significant. The correlation, valid for both directions of transfer with either phase dispersed, is useful for the extrapolation of performance from system to system in a given piece of equipment. Also, together with correlations for transfer area and effective driving force, it is part of the information needed for desig

ISSN:0001-1541    

DOI:10.1002/aic.690030121

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

摘要:

AbstractThe pressure‐drop characteristics associated with one liquid and one gaseous phase flowing concurrently in a pipe or tube have yet to be understood. The operation of evaporators, boilers, and condensers has long stimulated interest in the pressure drop of steamwater mixtures, and more recently this specialized case of one‐component, two‐phase flow has received even greater attention from the applications in cooling nuclear reactors. The two‐phase–flow problems have not been amenable to through theoretical analyses, and therefore empirical and semiempirical correlations have attained unusual prominence in practical applications. The present investigation employs a new research tool for the study of two‐phase–flow structure.A variety of geometric flow patterns is possible. Bergelin, Alves, and others have classified these patterns according to visual appearance; whereas the Martinelli classifications were based upon whether the flow in each phase was termedviscousorturbulent. The distinction between viscous and turbulent flow in either phase is rather arbitrary, and if the Reynolds number for one phase, calculated on the basis of the total tube diameter, is greater than 2,000, the flow in the phase is calledturbulent. This investigation is confined to the study of annular flow, in which most of the liquid is found in an annular ring surrounding the central vapor core and the flow in each phase is turbulent.Boiling or flashing occurs when superheated water rises in an insulated vertical tube at atmospheric pressure. For a separated two‐phase flow geometry, the mean linear steam velocity may exceed that of the water. The fraction of the tube occupied by the steam (void fraction) at a given cross section cannot be obtained directly from a determination of the thermodynamic quality. Void fractions, however, must be known for the estimation of the pressure drops due to head and momentum changes.Void fractions and pressure drops for steam‐water flows were measured in an 0.872‐in. I.D. vertical tube at atmospheric pressure over a quality range of 0 to 4%. The test section was the hot leg of a natural‐circulation loop, and the inlet liquid flow rate ranged from 1 to 3 ft./sec. A new technique for measuring void fractions was used, and the method utilizes the difference between the gamma‐ray absorption coeffici

ISSN:0001-1541    

DOI:10.1002/aic.690030122

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690030123

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690030125

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690030101

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY