Mass transfer from a moving bubble during a slow chemical reaction

A previously proposed method for solving inhomogeneous problems in the theory of heat and mass transfer is refined. As an illustration, the stationary mass transfer from a moving bubble during a slow chemical reaction of first or second order is examined.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 42, No. 4, pp. 595–599, April, 1982.     

Mass transfer in a moving drop when it periodically collides with a hard surface

The article describes an experimental study of mass transfer in a moving drop which periodically collides with a hard surface. An empirical formula for calculating the coefficients of mass exchange within the drop is obtained.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 26, No. 5, pp. 908–913, May, 1974.     

Mass transfer in a reactive spherical particle

A macrokinetic model is presented for the solid-phase transformation of a particle under arbitrary relationships between the sorption-desorption, dissolution, and diffusion rates of the initial and final products.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 48, No. 5, pp. 796–803, May, 1985.     

Mass transfer in the chemical interaction of a solid with a moving liquid,complicated by the evolution of a gas phase

The mass transfer taking place during the interaction of a spherical solid with a moving liquid is analysed for the case in which a gaseous reaction product is also evolved.     

Mass transfer between a spherical particle and a liquid for small Peclet numbers

Analytic expressions are obtained in calculating the concentration field during nonstationary mass exchange between a spherical particle and a liquid flow.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 43, No. 1, pp. 134–139, July, 1982.     

Mass transfer at a moving particle in a fluidized bed of coarse material

An experimental study has been made of mass transfer to a moving particle in the fluidized bed of coarse inert material. The experimental results are presented in terms of dimensionless relationships.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 47, No. 2, pp. 235–242, August, 1984.     

Effects of suction on heat and mass transfer along a moving vertical surface in the presence of chemical reaction

Heat and mass transfer effects on a continuously moving vertical surface with chemical reaction of first order is considered. The velocity and concentration profiles are studied for different parameters like Schmidt number, Prandtl number and Chemical reaction parameter. It is observed that the velocity and concentration increases during generative reaction and decreases in destructive reaction.     

Effect of a homogeneous chemical reaction on heat transfer

Heat and mass transfer processes are investigated in the presence of homogeneous physico-chemical conversions of a substance.Institutes of Mathematics and Mechanics, Academy of Sciences of Turkmenistan, Ashkhabad. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 64, No. 6, pp. 734–739, June, 1993.     

Refrigerant R134a vaporisation heat transfer and pressure drop inside a small brazed plate heat exchanger

This paper presents the experimental heat transfer coefficients and pressure drop measured during refrigerant R134a vaporisation inside a small brazed plate heat exchanger (BPHE): the effects of heat flux, refrigerant mass flux, saturation temperature and outlet conditions are investigated. The BPHE tested consists of 10 plates, 72 mm in width and 310 mm in length, which present a macro-scale herringbone corrugation with an inclination angle of 65° and corrugation amplitude of 2 mm.The experimental results are reported in terms of refrigerant side heat transfer coefficients and frictional pressure drop. The heat transfer coefficients show great sensitivity both to heat flux and outlet conditions and weak sensitivity to saturation temperature. The frictional pressure drop shows a linear dependence on the kinetic energy per unit volume of the refrigerant flow.The experimental heat transfer coefficients are also compared with two well-known correlations for nucleate pool boiling and a correlation for frictional pressure drop is proposed.     

Refrigerant R134a condensation heat transfer and pressure drop inside a small brazed plate heat exchanger

This paper presents the experimental tests on HFC-134a condensation inside a small brazed plate heat exchanger: the effects of refrigerant mass flux, saturation temperature and vapour super-heating are investigated.A transition point between gravity controlled and forced convection condensation has been found for a refrigerant mass flux around 20 kg/m² s. For refrigerant mass flux lower than 20 kg/m² s, the saturated vapour heat transfer coefficients are not dependent on mass flux and are well predicted by the Nusselt [Nusselt, W., 1916. Die oberflachenkondensation des wasserdampfes. Z. Ver. Dt. Ing. 60, 541–546, 569–575] analysis for vertical surface. For refrigerant mass flux higher than 20 kg/m² s, the saturated vapour heat transfer coefficients depend on mass flux and are well predicted by the Akers et al. [Akers, W.W., Deans, H.A., Crosser, O.K., 1959. Condensing heat transfer within horizontal tubes. Chem. Eng. Prog. Symp. Ser. 55, 171–176] equation. In the forced convection condensation region, the heat transfer coefficients show a 30% increase for a doubling of the refrigerant mass flux. The condensation heat transfer coefficients of super-heated vapour are 8–10% higher than those of saturated vapour and are well predicted by the Webb [Webb, R.L., 1998. Convective condensation of superheated vapour. ASME J. Heat Transfer 120, 418–421] model. The heat transfer coefficients show weak sensitivity to saturation temperature. The frictional pressure drop shows a linear dependence on the kinetic energy per unit volume of the refrigerant flow and therefore a quadratic dependence on the refrigerant mass flux.     

Mass transfer from the surface of a motionless spherical particle in the wake behind a cavitating cylinder

Mass transfer from the surface of a sphere made from benzoic acid in the wake behind a cavitating cylinder is investigated experimentally.     

Heat transfer by mixed convection in a moving rod bundle

A mathematical model of mixed convection in moving rod bundles is proposed, and cooling in an open space is analyzed. Estimates of the local Nusselt numbers are obtained for quasistabilized conditions.Translated from Inzhenerno-fizicheskii Zhurnal, Vol. 61, No. 2, pp. 230–238, August, 1991.     

Unsteady mass transfer with a heterogeneous chemical reaction during laminar flow past a sphere

Unsteady mass transfer toward a solid sphere is investigated in the region of Peclet numbers 1Pe1000. Diffusion flow in the presence of a first-order chemical reaction is calculated and the relaxation time of the steady regime as a function of the Peclet number is determined.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 30, No. 1, pp. 73–79, January, 1976.     

Stacking ionizable analytes in a sample matrix with high salt by a transient moving chemical reaction boundary method in capillary zone electrophoresis

The paper presents a novel on-line transient moving chemical reaction boundary method (tMCRBM) for simply but efficiently stacking ionizable analytes in high-salt matrix in capillary zone electrophoresis (CZE). The powerful function and stability of the tMCRBM are elucidated with the ionizable test analytes of L-phenylalanine (Phe) and L-tryptophan (Trp) in the matrix with 85.6-165.6 mM sodium ion and further compared with the normal CZE of Phe and Trp samples dissolved in running buffer. The results verify that (1) the on-line tMCRBM mode can evidently increase separation efficiency, peak height, and resolution, (2) with the mode, the analytes in a 28-cm high-salt matrix plug can be stacked successfully and further separated well, (3) the values of relative standard deviation of peak height, peak area, and migrating time range from 3.9% to 6.1%; the results indicate the high stability of the technique of tMCRBM-CZE. The techniques implies obvious potential significance for those ionizable analytes, e.g., protein, peptide, and weak alkaline or acidic compound, in such matrixes as serum, urine, seawater, and wastewater, with high salt, which has a deleterious effect on isotachophoresis (ITP) and especially on electrostacking and field-amplified sample injection (FASI). The mechanism of stacking of zwitterionic analytes in a high-salt matrix by the tMCRBM relies on non-steady-state isoelectric focusing (IEF) but not on transient ITP, electrostacking, and FASI.     

Experimental two-phase heat transfer coefficient and frictional pressure drop inside mini-channels during condensation with R1234yf and R134a

The present paper reports condensing two-phase flow pressure drop gradient and heat transfer coefficient (HTC) inside a mini-channel multiport tube with R1234yf and R134a. Several models available in the literature are used to compare predictions of these two fluids. Experimental data are analysed to get the influence of saturation temperature, mass flux, vapour quality and fluid properties. HTC values of R1234yf seem to be lower than R134a under similar conditions. Two-phase flow pressure drops are also lower in the case of the new refrigerant R1234yf.     

Numerical solution of the spectral radiation-gasdynamic problem of radiative cooling of a spherical plasma volume taking into account nonstationary radiation transfer

The method of averaging is generalized to the case of the nonstationary equation of radiation transfer taking into account scattering. Results are presented for calculations of radiative cooling of a spherical plasma volume.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 41, No. 2, pp. 318–327, August, 1981.     

Mass transfer study of an extractive electrochemical sulfide/sulfur reaction in a parallel plate reactor

Abstract

The mass‐transfer phenomenon between an aqueous‐organic phase and an electrode producing sulfur from sulfide ions in a parallel plate reactor is studied. A kinetic model of the electrochemical conversion and extraction process is developed and tested. Under steady‐state conditions, the electrochemical reaction rate at limiting operation, defined as K‘_m A (1 – θ) C_R/α, is equal to the extraction rate, defined as K‘_d A θ (C^sat _s/β ‐ C_s/β ) for this extractive electrochemical system. Experimental parameters include volume fraction (X_d ) and fluid velocity (Re‘). The mass transfer coefficients, K‘_m and K‘_d, were obtained as K‘_m = 7.044 × 100^–5 Re‘ ^? (1.073 + 0.575 X_d – X ² _d ) and K‘_d = 5.15 × 10^–4 Re‘ ^? X_d with a Reynolds number between 18～54 and volume fraction under 70% for this two‐phase solution.