ISSN:0001-1541    

DOI:10.1002/aic.690010401

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690010405

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractA useful method is reported for calculating temperatures and rates of flow in the unsteady‐state operation of natural‐circulation loops in single phase. A one‐dimensional mathematical model is used with the assumptions that (1) at any instant the volumetric rate of flow is constant around the loop and (2) steady‐state friction factors can be applied in transient operations. The loop, consisting of a heat source, heat sink, hot leg, cold leg, and connecting piping, is divided into a number of finite increments. The transient behavior is calculated by the iterative application of the finite‐difference momentum and energy balances. Numerical computations made for several cases of transient operations were carried out with the aid of the Standard Eastern Automatic Computer (SEAC).Comparisons of predicted with actual performances were checked by use of two experimental loops employing water and found sat

ISSN:0001-1541    

DOI:10.1002/aic.690010407

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractThis investigation is a study of the effect of flow rates and packing size and column diameter upon the holdup of a toluene dispersed phase, flowing countercurrent to a continuous water phase in packed liquid‐liquid extraction columns. Six different packings were used: ¼‐, ⅜‐, ½‐, ⅝‐, ¾‐, and 1‐in. nonporous, unglazed‐porcelain Rasching rings. Three extraction columns, 3, 4, and 6 in. I. D., were used in the experimental work.Three types of dispersed‐phase holdup, free, operational, and total, have been investigated. An empirical correlation is presented for the total holdup data below the loading point. A correlation of the effect of packing size on the exponential termrand the coefficientA1is developed for packing sizes 1/2 in. or larger when the column‐diameter‐to‐packing‐size ratio is at least 8 to 1. The termA1(VD)rin the equation accounts for at least 90% of the total holdup. The small magnitude of the residual termB1(VD) (VC8) did not permit a definite correlation of the coefficientB1or the exponents.Observation of the dispersed‐phase holdup during column operation revealed a transitional behavior of the 3/8‐in. rings as compared with that of the 1/4‐ and 1/2‐in. or larger packing. Two, and sometimes three, regimes of flow occur in packed extraction columns. the increase in holdup with increasing continuous‐phase flow rate differed for each zone. In the two zones below the loading zone the holdup was found to increase linearly with the dispersed‐phase flow rate for a constant continuous‐phase flow rate. A new method of randomly packing an extraction column h

ISSN:0001-1541    

DOI:10.1002/aic.690010408

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractAll available data on flow of non‐Newtonians in pipes have been correlated on the conventional friction factor — Reynolds number plot for Newtonian fluids. This correlation, theoretically rigorous in the laminar flow region, was tested with data on 16 different non‐Newtonian materials covering the 2.1 × 109range of Reynolds numbers from 6.3 × 10−5to 1.3 × 105. Pipe diameters varied from 1/8 to 12 in. As the correlation does not depend on the type of fluid encountered, it may be used with Newtonian and non‐Newtonian fluids alike.In spite of the great range of the available experimetnal data, further work is necessary in the transition and turbulent‐flow regions. No data at all were available on thixotropic, rheopectic, and dilatant fluids, and extension of the correlation to these materials should prove most illuminative from both theoretical and practi

ISSN:0001-1541    

DOI:10.1002/aic.690010409

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractA study was made of factors affecting the vapor‐handling capacity of perforated‐plate liquid‐vapor contacting columns. Vapor‐phase pressure drop across plates, liquid entrainment upward from plate to plate, and plate stability were investigated as functions of operational and geometric column parameters.Gas‐phase pressure drop across dry perforated plates was observed to follow functional relationships predicted from available information for single perforations. The presence of liquid on a plate increased the total pressure drop by the equivalent clear‐liquid head plus a small residue which is nearly constant for a given liquid.Entrainment was observed to be a function of column gas velocity, independent of gas velocity in the perforations. Weight rate of entrainment was also found to be proportional to the gas density, independent of liquid density, and inversely proportional to the liquid‐surface tension. For a given system, entrainment was observed to be proportional to approximately the third power of the group, gas velocity divided by the distance between the liquid surface and the plate above.The stability of perforated plates was observed to be adequate for many industrial and experimental applications, as also reported in recently published studies, but contrary to qualitative statements found in the earlier literature. Stability was found to increase with decreasing perforation diameter and decreasing total perforation area relative to column cross‐sectional area; to increase with greater gas density, liquid surface tension, and liquid wetting power; and to be virtually independent of liquid density and viscosity.Operating limits of vapor and liquid throughput are shown for a typical application of perforated plates in liquid‐vapor c

ISSN:0001-1541    

DOI:10.1002/aic.690010410

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690010411

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690010412

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractThe prediction of temperatures has been studied for a tubular flow reactor when heat is generated at a rate which is a linear function of the local temperature. Analytical solutions are presented both for the case where the wall is isothermal and for the case where the exterior surroundings are isothermal and the heat transfer coefficient between the tube wall and the surroundings is constant. This analysis should be helpful for estimating local temperatures and also for predicting the transient response to changes in one of the independent operating variables.

ISSN:0001-1541    

DOI:10.1002/aic.690010413

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY

摘要:

AbstractFor hypothetical two‐ and three‐component liquid‐phase reversible reactions, continuous processes are described in which the products are obtained in essentially pure form by carrying out the reaction in a single distillation column. Methods for plate‐to‐plate calculations in such reaction‐distillation systems and numerical solutions for two reactions ar

ISSN:0001-1541    

DOI:10.1002/aic.690010414

出版商:American Institute of Chemical Engineers    

年代:1955

数据来源: WILEY