摘要:

AbstractThe Quasi‐steady‐state‐approximation (QSSA) applied lo continuous stirred tank reactors (CSTR) is examined. The induction period is found to be somewhat longer and the error in the QSSA larger than for batch reactors. This error is usually insignificant except when CSTR conversions are low. An alternative approximation is proposed for this case. The errors in the QSSA are also illustrated for the well known cases of Enzyme and Free‐Radical polymerization k

ISSN:0008-4034    

DOI:10.1002/cjce.5450470601

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe kinetics of the reaction between water and MgO powders has been investigated at 9°, 18°, 28° and 38°C in a stirred batch reactor. Six commercial samples of MgO prepared from Mg(OH)2plus two of unknown origin, with specific surface areas of 12 to 80 mg/g, were studied. After correcting for particle size distribution, the rate of reaction was found to be directly proportional to the surface area contained in a shell at the surface of the particles. The activation energy is 14.1 ± 0.2 kcal/g‐mole indicating chemical reaction as the rate controlling process. A reaction mechanism has been pro

ISSN:0008-4034    

DOI:10.1002/cjce.5450470602

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

年代:1969

数据来源: WILEY

摘要:

AbstractNumerical values of the cumulative residence time distribution in a continuous flow stirred tank reactor are commonly required. It is shown in the paper that the above distribution is easily transformed into a Chi‐squared distribution. This provides a fast easy way of obtaining the desired values from readily available statistical table

ISSN:0008-4034    

DOI:10.1002/cjce.5450470603

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

年代:1969

数据来源: WILEY

摘要:

AbstractKinetic energy and momentum factors are derived, evaluated and presented for fully developed turbulent flow in both uniformly sand‐roughened and commercial pipes as a function of Reynolds number and relative roughness. For the uniform sand roughness, the universal velocity profile and friction factor equations of Nedderman and Shearer were used, while for the commercial roughness the corresponding equations of Colebrook and White were employe

ISSN:0008-4034    

DOI:10.1002/cjce.5450470604

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

年代:1969

数据来源: WILEY

ISSN:0008-4034    

DOI:10.1002/cjce.5450470605

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

年代:1969

数据来源: WILEY

摘要:

AbstractUsing water as a binding agent, some of the factors affecting the preparation of superphosphate granules have been investigated. The amount of water added to the material completely dominates the other physical variables in determining the characteristics of the granules formed. An optimum water content was found for which the proportion of granules within a specified size range (–4 + 14 Tyler mesh) was at a maximum.Granulation with simultaneous drying showed that an increase in the drying rate results in a decrease in the rate of granule growth. The speed at which the granulator is rotated to obtain the correct “tumbling action” is influenced by the internal surface of the drum and the presence and design of internal flights.The mechanical strength of superphosphate granules depends on the quantity of binding agent used in the granulation process and the degree of agitation. The dry strength of the granules formed is considerably greater than the wet str

ISSN:0008-4034    

DOI:10.1002/cjce.5450470606

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

年代:1969

数据来源: WILEY

摘要:

AbstractEquations are developed for the performance of settling basins where hydraulics are characterized by residence time distributions. An illustrative calculation for a typical basin design using literature settling data and a residence time distribution predicts a reduction in solids removed of only about 10% over that predicted for an ideal basin where plug flow is assumed. This calculation suggests that the effect of residence time distribution on basin performance for realistic conditions may be just modest.

ISSN:0008-4034    

DOI:10.1002/cjce.5450470607

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

年代:1969

数据来源: WILEY

摘要:

AbstractTurbulent flow drag reduction is governed by elastic effects within the boundary layer of the flow. The effect of elasticity is to reduce the radial momentum transfer rates of large eddies that exist near the tube wall, and in so doing a reduction in the turbulent flow drag occurs. A recent theoretical analysis is used to formulate a general discussion of the significant features of drag reducing systems and is used to predict quantitatively the percentage reductions in drag for systems of practical significance. It is shown that little or no drag reduction can be expected in large tubes using polymeric materials that are presently available though micellar systems show effects of substantial magnitude which appear to be exploitable.An analysis is presented which indicates that laminar annular films of dilute polymeric fluids, used to enable the core fluid or a capsule to “slide” through a pipeline at reduced pressure drop, are of especial interest in that the normal stress field may generate forces which increase the concentricity of the core in the presence of major density differences. This exploitation of non‐Newtonian fluid properties, suggested some years ago by Lummus, does not appear to have been subjected to analysis before, nor do verifying experimental data appear to be avai

ISSN:0008-4034    

DOI:10.1002/cjce.5450470608

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe effects of external vibrations on the disintegration of a liquid jet are described. Conditions for the formation of uniformly sized drops are discussed and results presented to illustrate the effect of amplitude and frequency of vibration on the drop size and break‐up length of the jet. Liquids of various viscosity have been studied, 60‐1400 c.p., and the results compared with existing theories.This method can be used with standard pressure nozzles and may be of use in research experiments when dispersions of uniform drops are required. It also has application in the formation of uniform pri

ISSN:0008-4034    

DOI:10.1002/cjce.5450470609

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

年代:1969

数据来源: WILEY

摘要:

AbstractTemperature distributions are determined in a helium plasma, the power used being 27 kW and the gas flow rate 7.2 g/minute. Pressure conditions for the plasma under study are respectively 760 and 300 mm Hg.The spectroscopic method used for obtaining temperatures is that of Larenz or the method of maximum emission, applied to the 3,889 Å neutral helium line. A maximum temperature, on the plasma axis, of approximately 24,000° K is obtaine

ISSN:0008-4034    

DOI:10.1002/cjce.5450470610

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

年代:1969

数据来源: WILEY