摘要:

AbstractDevelopment of a new process for the solvent extraction of lubricating oils, known as EXOL N, is described. The selection ofN‐methyl‐2‐pyrrolidone (NMP) as solvent, the determination of its relevant properties, and its application through engineering and pilot‐plant studies are reviewed. This EXOL N process is now employed internationally in over a dozen full‐scale lube extracti

ISSN:0008-4034    

DOI:10.1002/cjce.5450630102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractMinimum fluidization data at elevated temperatures and pressures are relatively scarce in the literature. This study was undertaken to provide some new data under these conditions. Minimum fluidization velocities at temperatures up to 800°K and pressures up to 5 MPa were measured for uniformly‐sized glass beads with diameters between 0.2 mm and 4 mm in beds ranging in diameter from 30 mm to 50 mm. The experimental results are compared with a number of empirical correlations from the literature to determine the validity of the correlations under these elevated temperature and pressure conditio

ISSN:0008-4034    

DOI:10.1002/cjce.5450630103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe structure of Taylor vortices in the annulus of coaxial horizontal rotating cylinders with and without axial flow was studied by a flow visualization technique based on the colour change of analytical indicators. Flow interaction effects can be characterized by three parameters whose numerical values are obtained from photographs and super 8 mm film strips.

ISSN:0008-4034    

DOI:10.1002/cjce.5450630104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractPressure drop measurements and results of an extensive flow visualization study to examine the particle‐free air gap formation around horizontal, rigidly‐mounted circular cylinders in a two dimensional vibrated bed, are presented. Effects of particle size and surface stickiness as well as other key operating parameters viz. aeration rate and vibrational frequency were examined for single as well as multiple cylinder configurations in staggered and in‐line arrange

ISSN:0008-4034    

DOI:10.1002/cjce.5450630105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe mass transfer performance of 5 cm diameter reciprocating plate column has been measured with the systemn‐butyric acid/kerosene (dispersed)/water (continuous). In most of the tests, the reciprocating plate stack was made of stainless steel which was preferentially wet by the continuous phase. During the mass transfer process the holdup and in some cases the Sauter mean droplet diameter were measured.The mass transfer effectiveness, expressed as the height of a transfer unit (Hax) corrected for axial mixing, depended on the phase flow rates, the agitation rate and the direction of mass transfer. For continuous to dispersed phase mass transfer (c → d), the mass transfer was more effective, i.e.Haxwas lower than ford → cmass transfer under the same external conditions. Qualitative and quantitative observations indicated much larger drop sizes in thed → ccase due to enhanced coalescence. Although mass transfer was less effective underd → cconditions, the column capacity was increased. The same effects were also observed when the plate stack was modified by inserting some Teflon plates which were partly wet by the disper

ISSN:0008-4034    

DOI:10.1002/cjce.5450630106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractA general criterion is developed for testing the relative importance of intraparticle and external, concentration and temperature gradients on the observed rates, for reactions catalyzed by porous solids. The criterion is applicable to any multiple reaction system and to reactions conforming to any rate law. The applicability of such criteria is extended to reaction systems with highly nonlinear temperature and concentration dependence, by taking into‐account the higher order terms in the Taylor expansion of the rate expressions in the derivatio

ISSN:0008-4034    

DOI:10.1002/cjce.5450630107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractGrinding of coal in fuel oil for coal‐oil mixtures (COM) preparation is simpler and may give better slurry properties than dry grinding followed by dispersion in oil. A 42 weight percent slurry of 600–840 μm particles of Pittsburgh coal in #2, #4, and #6 fuel oils has been ground with the novel Szego mill. Particle size distributions at different residence times are reported down to a 10 μm median size, together with energy consumption data. Low mill hold‐ups and high rotational speeds enhanced the rate of g

ISSN:0008-4034    

DOI:10.1002/cjce.5450630108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractComputations are presented for multi‐dimensional flows in gas‐stirred liquids contained in vertical cylindrical vessels. Mass, momentum, energy and concentration equations were solved for the buoyancy driven transient flows under investigation. Turbulence was simultated by using zero order and differential models of turbulence. The use of convective and diffusive time scales was analyzed. Reasonable agreement with available experimental data was obser

ISSN:0008-4034    

DOI:10.1002/cjce.5450630109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe interpretation of results of a chemical reaction carried out in a trickle bed reactor is not immediate when the key reactants are volatile; in fact some authors state that the overall conversion rate increases at very low liquid flow rates, i.e. when the catalyst is unevenly wetted. In these conditions, the reactants may penetrate inside the catalyst pellets directly through the “dry” zones; therefore the mass transfer resistance is diminished and the conversion rate can be increased.To investigate this phenomenon tests on the catalytic oxidation of ethyl alcohol dissolved in water were performed at different operating conditions in a trickle bed reactor. An interpretation of the results was tried by using two different models based on partially wetted particles. This approach considers both the cases in which “dry” zones are active or not for mass transfer and mass transfer rates are affected or not by the chemical r

ISSN:0008-4034    

DOI:10.1002/cjce.5450630110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractAxial mixing characteristics and performance of a liquid fluidized bed reactor for the sucrose inversion reaction, which was catalyzed by immobilized invertase was studied. The invertase enzyme was immobilized in polyacrylamide gel by the bead polymerization technique. Well‐defined spherical gel particles of five different sizes (0.29–3.16 mm) were prepared. Efficiency of the immobilization technique, the optimum working conditions and the kinetic parameters were determined in a batch system. It is shown that as the particle size increases the rate of inversion first increases due to decrease of enzyme loss by leaching and then decreases because of diffusional limitations after a maixmum is reached. The performance of the fluidized bed reactor was investigated dynamically by introducing a step input of substrate at the inlet and analyzing the response curves. These experiments were performed at the optimum temperature (55°C) and using the optimum particle size (2.15 mm). The axial dispersion coefficient was found to increase from 0.45 to 1.26 cm2/s by changing the liquid velocity from 0.32 to 0.58

ISSN:0008-4034    

DOI:10.1002/cjce.5450630111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY