Showing papers in "Chemical Engineering Communications in 1978"
TL;DR: A review of the parameters influencing the nucleation of scale from natural waters on a heat transfer surface and its prevention is presented in this article, where the importance of variations in pressure and temperature, which directly change the saturation limit of the scaling species, are emphasized.
Abstract: A review is presented of the parameters influencing the nucleation of scale from natural waters on a heat transfer surface and its prevention. Little is known about this phenomenon in comparison to subsequent scale growth. The importance of variations in pressure and temperature, which directly change the saturation limit of the scaling species, are emphasized. The influence of fluid motion, the type of heat transfer surface material and its condition, on scale nucleation, is also discussed. Both chemical and physical methods of water treatment used to prevent nucleation and growth of scale are reviewed. It is considered that more work is required before a full understanding of scale nucleation can be obtained and optimum preventative measures undertaken.
53 citations
TL;DR: In this article, the authors present a review of the general population balance mode of UNPREMIXED FEED-STREAM CHEMICAL REACTORS, which is used in this paper.
Abstract: (1978). GENERAL POPULATION BALANCE MODELLING OF UNPREMIXED FEEDSTREAM CHEMICAL REACTORS: A REVIEW. Chemical Engineering Communications: Vol. 2, No. 6, pp. 249-264.
14 citations
TL;DR: In this article, transition boiling heat transfer coefficients have been obtained for water at pressures of 25 to 75 psia (1.72 to 5.17 bars) and mass velocities from 14,000 to 140,000 Ibs/hr ft2 (19-190 kg/m2 · sec).
Abstract: Transition boiling heat transfer coefficients have been obtained for water at pressures of 25 to 75 psia (1.72 to 5.17 bars) and mass velocities from 14,000 to 140,000 Ibs/hr ft2 (19-190 kg/m2 · sec). The water flowed inside a 0.40 in (1.02 cm) ID tube and was heated by hot mercury flowing in an annulus around the tube. Thermocouple pairs placed on the outside of the central tube and outer pipe at several axial elevations allowed the rate of heat transfer to be determined. The data agreed reasonably with the correlation previously proposed.17 However, the observed heat transfer coefficients show less of a decrease with increasing temperature than was seen in previous tests12 in which the water flowed in an annulus.
8 citations
TL;DR: In this article, the effect of the gas and liquid flow rates on the mass transfer rate in laminar gas streams in wetted-wall columns with countercurrent gas-liquid flow was studied.
Abstract: The effect of the gas and liquid flow rates on the mass transfer rate in laminar gas streams in wetted-wall columns with countercurrent gas-liquid flow was studied. An approximate analytical solution was obtained for the average gas-phase Sherwood number as a function of the gas-phase Graetz number and the dimensionless interfacial gas velocity. Experiments were carried out on the absorption of ammonia into aqueous sulfuric acid solution and of methanol vapor into water, using two columns of different lengths. The agreement between the experimental and the predicted effects of both gas and liquid flow rates on the gas-phase mass transfer rate was found to be fairly good.
7 citations
TL;DR: In this article, Axial dispersion coefficients for steady-state systems computed from exact solutions for the concentration profiles are shown to be strong functions of axial position for the homogeneous first-order reaction case.
Abstract: Mass transfer to the wall and a homogeneous first-order chemical reaction are considered separately for laminar Axial dispersion coefficients for steady-state systems computed from exact solutions for the concentration profiles are shown to be strong functions of axial position. For the homogeneous first-order reaction case, the axial dispersion coefficient is a function of the reaction rate constant.
5 citations
5 citations
TL;DR: In this article, the authors discuss the role of zone ABSORPTION KINETICS in AQUEOUS PHENOL SOLUTIONS, and discuss the relationship between ozone depletion and ozone depletion.
Abstract: (1978). TEMPERATURE DEPENDENCE OF THE OZONE ABSORPTION KINETICS IN AQUEOUS PHENOL SOLUTIONS. Chemical Engineering Communications: Vol. 2, No. 4-5, pp. 219-221.
5 citations
3 citations
TL;DR: In this article, a complete theoretical study of convective diffusion from a non-uniformly distributed source in a nonNewtonian fluid flowing through a straight tube is presented, and the influence of the governing parameters on the dispersion process is examined in terms of the interaction of rheology, fluid mechanics and diffusion.
Abstract: This work presents a complete theoretical study of the process of convective diffusion from a non-uniformly distributed source in a non-Newtonian fluid flowing through a straight tube The influence of the governing parameters on the dispersion process is studied and the results are examined in terms of the interaction of rheology, fluid mechanics and diffusion Experimental studies have been conducted to obtain the diffusivity values of NaOH in aqueous polymer solutions and provide the first test of the potential of this technique for diffusivity measurement in difficult systems
1 citations
TL;DR: In this article, a one-dimensional spray regime model with finite spray "throw" was developed with inlet and outlet conditions and the effect of spray mixing on tray efficiency was evaluated.
Abstract: The usual models for predicting the effect of liquid mixing assume a diffusion model as is reasonable for the foam and froth regimes Here a one-dimensional spray regime model is developed with finite spray “throw,” allowing for inlet and outlet conditions and the effect of spray mixing on tray efficiency is evaluated The extension to less restricted models is indicated
TL;DR: In this paper, the authors describe a plane-converging DRAG FLOW of NEWTONIAN and INELASTIC non-Newtonian FLUIDS. But their focus is on the non-newtonian fluid.
Abstract: (1978). PLANE CONVERGING DRAG FLOW OF NEWTONIAN AND INELASTIC NON-NEWTONIAN FLUIDS. Chemical Engineering Communications: Vol. 2, No. 4-5, pp. 197-218.
TL;DR: In this paper, Fick's first law is compared with the Stefan-Maxwell equation indescribing the compositon of a constant evaporating mixture, and the maximum deviation between the two predictions varies with the system: 17% for toluene-ethanol solutions evaporating in air, 8.5% for benzene-methanol solution in air.
Abstract: Fick's first law is compared with the Stefan-Maxwell equation indescribing the compositon of a constant evaporating mixture. The maximum deviation between the two predictions varies with the system: 17% for toluene-ethanol solutions evaporating in air, 8.5% for benzene-methanol solutions in air.