ISSN:0001-1541    

DOI:10.1002/aic.690220102

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractThis paper presents a commentary on the status of application of modern control theories to industrial chemical processes. The difficulties encountered in the implementation of advanced control to chemical reactors are critically examined in order to determine the reasons for its limited success to date. Chemical processes, very often poorly understood because of the physicochemical complexities, are nonlinear, highly interacting, spacially dependent, and continuously disturbed by many uncharacterized noises. It is time‐consuming and expensive to develop advanced control methods for these systems because few of the available theories can be applied directly. Thus, we often find it difficult to economically justify advanced control project

ISSN:0001-1541    

DOI:10.1002/aic.690220103

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractThe countercurrent backmixing model of a fluidized bed reactor predicts axial concentration profiles quite different from those suggested by simple two‐phase models. The models can also be distinguished in terms of the dependence of conversion on operating variables.An experimental study of ozone decomposition in a reactor of 22.9 cm diameter has provided extensive data for comparison with backmixing and two‐phase models which incorporate bubble size variation. The measured profiles show a minimum concentration within the bed at gas velocities above a critical value, as predicted only by the backmixing model. The effect of operating variables on the shape of the profiles is also well accounted for by this model. The backmixing model is further supported by good agreement between predicted and measured reactant conversion. In particular, the variation of conversion with rate constant and gas velocity is fitted more accurately by the backmixing model than by two‐phase m

ISSN:0001-1541    

DOI:10.1002/aic.690220104

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractModels are presented for determining flow regime transitions in two‐phase gas‐liquid flow. The mechanisms for transition are based on physical concepts and are fully predictive in that no flow regime transitions are used in their development. A generalized flow regime map based on this theory is presen

ISSN:0001-1541    

DOI:10.1002/aic.690220105

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractPresent algorithms for the selection of design variables produce a single combination of design variables which results in a solution sequence of minimum difficulty. A new theory entitledsolution mappingresults in information about all optimal combinations of design variables. This theory gives detailed information about the structure of all underspecified systems of algebraic equations which do not contain persistent iteration.

ISSN:0001-1541    

DOI:10.1002/aic.690220106

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractThe effect of catalyst composition on the polymerization of butadiene initiated by CoCl2· 4Py‐Et2AlCl‐H2O in a batch reactor has been studied. It was found that the polymerization is first order with respect to monomer and cobalt concentrations, and both the deactivation of catalyst and the chain transfer reaction have great influence in conversion as well as molecular weight. A general conversion model was proposed, and it fits the experimental data

ISSN:0001-1541    

DOI:10.1002/aic.690220107

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractGas‐liquid chromatography was used to measure the solubilities of ethylene,n‐butane, vinyl acetate,n‐hexane, benzene, toluene, andn‐octane in three different samples of liquid, low‐density polyethylene. Solubilities in the different samples are similar. A correlation is presented for estimation of solubilities of nonpolar solutes in liquid pol

ISSN:0001-1541    

DOI:10.1002/aic.690220108

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractFriction coefficients determined from an experimental study of the flow of bubbly two‐phase mixtures in horizontal pipes are used, together with a homogeneous theory, to establish a method for the prediction of the static pressure drop in this class of flow

ISSN:0001-1541    

DOI:10.1002/aic.690220109

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractDropwise condensation heat transfer coefficients were measured for stream on gold surfaces electroplated on copper and nickel substrates. The effect on the heat transfer of the activation of very small nucleation sites present on the gold plated copper surface was observed. In addition, the heat transfer coefficient of the gold plated nickel surface was lower than that of the gold plated copper surface.

ISSN:0001-1541    

DOI:10.1002/aic.690220110

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractWe consider a mass transfer induced buoyancy force, superimposed on a thermally induced one, in a flow generated adjacent to a vertical surface. Flow and stability were investigated for a Prandtl number of 0.7; for Schmidt numbers of 2.0, 0.94, and 0.2; and for different magnitudes of the buoyancy effects.

ISSN:0001-1541    

DOI:10.1002/aic.690220111

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY