摘要:

From the viewpoint of information theory, the necessity that the under size material distribution follows the exponential law is discussed and the effect of differences in the initial particle-size of the material on the energy necessary to grind is examined

ISSN:0098-6445    

DOI:10.1080/00986448608911392

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The thermal regeneration of activated carbons loaded withp-nitrophenol (PNP) and other aromatic compounds was studied using a thermal balance. After pyrolysis of the adsorbates in nitrogen at 700°C, the residues were gasified with oxygen at 415 to 500°C or with steam at 840 to 920°C. Residues from PNP were several times more reactive to oxygen than the base carbons and also showed greater chemisorption of oxygen. For steam gasification, only small differences between spent and fresh carbons were found.

ISSN:0098-6445    

DOI:10.1080/00986448608911393

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Using a stochastic approach, a fresh analysis has been provided to resolve the possible causes of the existing conflicts in the reactivity ratio estimation in copolymerization systems. The analysis provides some new clues regarding the inadequacy of a transient system (batch reactor) and suggests the use of a steady state operation (CSTR) as a more reliable method.

ISSN:0098-6445    

DOI:10.1080/00986448608911394

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

An analysis of the rate of formation of the desired product and of the selectivity has been carried out for composite catalysts wherein small particles of zeolite are distributed nonuniformly within a large particle of the more porous silica-alumina. Two nonuniform distributions have been analyzed, namely, (i) the composite-center distribution, where a uniform dilute region of zeolite in silica-alumina is surrounded by a silica-alumina matrix, and (ii) the composite-surface distribution, where a uniform dilute region is located around the pure silica-alumina matrix. Two reaction schemes, A→B→C and A→C→D, which fairly approximate the catalytic cracking process over the Zeolite/silica-alumina catalyst have been examined. The reaction scheme A→B→C is employed for the composite-center distribution, while the reaction scheme A→C→D is considered for the composite-surface distribution, because the overall rate of formation of the desired product can be thus optimized. There are conditions under which the selectivity can also be optimized

ISSN:0098-6445    

DOI:10.1080/00986448608911395

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A penetration theory analysis is presented for the problem of gas absorption, with chemical reaction involving a volatile liquid reactant. Model equations are derived and solution techniques are presented. It is shown that as long as the diffusivities of two reactants are equal, the enhancement factors predicted by film and penetration theories only mildly differ. Except for slow and instantaneous reaction regimes, the liquid reactant volatility can be markedly detrimental to enhancement of absorption rate by chemical reaction.

ISSN:0098-6445    

DOI:10.1080/00986448608911396

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

QDMC is an improved version of Shell's Dynamic Matrix Control (DMC) multivariable algorithm which provides a direct and efficient method for handling process constraints. The algorithm utilizes a quadratic program to compute moves on process manipulated variables which keep controlled variables close to their targets while preventing violations of process constraints. Several on-line applications have demonstrated its excellent constraint handling properties, transparent tuning and robustness, while requiring minimal on-line computational load.

ISSN:0098-6445    

DOI:10.1080/00986448608911397

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A semi-empirical model is developed to predict the extent of the reaction between calcined Greer limestone and hydrogen fluoride. Grain expansion due to the reaction, and the effect of changing porosity on the effective diffusivity of hydrogen fluoride through the calcined Greer limestone were considered in the model. Initial effective diffusivity of HF through the calcined Greer limestone and the experimentally obtained kinetic rate constants were utilized in the model. The model was validated against the data reported by Byer,et al. (1) and has shown to predict accurately the percent conversion of calcined Greer limestone below 790°C.

ISSN:0098-6445    

DOI:10.1080/00986448608911398

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

In this paper the deformation of a translating fluid drop is examined in the limit of low Reynolds and capillary numbers. The general case of an arbitrarily varying interfacial tension is considered here. With the capillary number as a perturbation parameter, an expansion is carried out for small deformation to satisfy the normal stress condition. This leads to a rapidly converging Legendre series expansion for the deformation. This general result is applied to the special case of a translating drop with a stagnant cap of surfactant. An interesting feature of this special case is that although the shear stress at the interface has a square root singularity, the total normal stress is non-singular.

ISSN:0098-6445    

DOI:10.1080/00986448608911399

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The establishment of a permanent lunar base will employ separation processes that may be conducive to column operation. Reclamation of precious bodily fluids and products from chemical manufacture will be a part of routine necessity. The lunar environment, with reduced gravity and pressure, will offer some intriguing possibilities for operation such as vacuum distillation. The area for plate and packed columns will need to be increased in order to compensate for the reduction of gravitational forces responsible for moving the fluids. Plate efficiencies, hence column height, can increase or decrease, depending on the choice of scaling criteria applied to the plate geometry. Packed column height remains almost independent of gravity.

ISSN:0098-6445    

DOI:10.1080/00986448608911400

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Impeller power numbers in closed square vessels with/or without baffles and in closed cylindrical vessels with baffles were studied for impeller Reynolds numbers in the range between 75000 and 300000. A flat vertical blade disk style, a vertical blade open style and a 45° pitched blade open style impellers were used. A substantial reduction of power number is observed for all three impellers inside the square vessels without baffles in comparison with baffled cylindrical and square ones reaching up to 61 %.

ISSN:0098-6445    

DOI:10.1080/00986448608911401

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor