The definition of the residue curve is extended to heterogeneous systems by use of the mean liquid composition to analyze characteristics of heterogeneous azeotropes. The analysis of patterns of residue curves around heterogeneous azeotropes shows that the number of possible types for n-component heterogeneous azeotropes is given by (n-m+1), where m is the number of coexisting liquid phases, and that when n=m, in particular, the only possible type is a minimum azeotrope.
The velocity and behavior of crowded particles in the flow of gas-particle mixture as related to the shape of a convergent-divergent nozzle were investigated. Calculated values of the velocity of particles accelerated with various types of nozzle were compared with the experimental results measured by the double-flash photographic method. It was found that the calculations and experiments were in good agreement within the error of experimental measurement. On the other hand, by using the dimensional analysis method, the velocity of particles or the specific kinetic energy of particles was expressed as the function of the following parameters: particle size, particle density, nozzle geometry, and operating conditions for gas flow. It was also made clear that the velocity and behavior of particles through the nozzle strongly depend upon the mixing ratio and the nozzle geometry, particularly the geometry of inlet and throat.
Experimental studies by the electrochemical method were made to investigate the heat transfer problems of combined free and forced laminar convection for high Pr fluid in the thermal entrance region of rectangular ducts with the aspect ratio Υ=0.5, where the boundary condition of uniform wall temperature has been used. Experimental data for the local and mean Nu were compared with analytical solutions obtained by developing Leveque''s method and the numerical one, and the following conclusions were reached: i) for the region of forced convection in which the effect of free convection approaches zero, the experimental results are well-correlated with the analytical results obtained by developing Leveque''s method; ii) for the region where the effect of free convection exists, the experimental results are in satisfactory agreement with the numerical ones; and iii) for the onset of free convection effects, both experimental and numerical results are also in good agreement with the original correlative equation suggested by Ou et al.
The instantaneous heat transfer coefficients in a scraped-film heat exchanger have been determined using the electrochemical technique for a two-bladed, 78.7mm I.D. exchanger. The time-averaged local heat transfer coefficients were found to agree fairly well with previous work of Azoory and Bott, though some variation in liquid flow rate was detected. The timeaveraged local Nusselt number was found to be represented by Nu=Q.15(Rer•Pr)1/2Reaw with a=(l-3.74×10-2N)/9. The variation of heat transfer coefficient with time was observed to be very different from that predicted by the accepted model for the phenomena based upon unsteady state conduction.
Absorption rates of NO in aqueous solutions of Fe(II)-EDTA chelate as well as in mixed solutions of Fe(II)-EDTA and Na2SO3 were measured using a stirred vessel with a free flat gasliquid interface and a bubble column. The rate constants of the complexing reaction of NO with Fe(II)-EDTA were determined on the basis of the theory of gas absorption accompanied by a reversible reaction. The chemical equilibrium constants were also determined at various pH values. It was found that the rate constant was of the order of 108 l/g-mol-sec and that the equilibrium constant was about 106 l/g-mol at 25°C. These values are much higher than the corresponding values of the reaction between NO and Fe(II) in the absence of EDTA. The mechanism of the absorption of NO in mixed solutions of Fe(II)-EDTA and Na2SO3 was deduced from the observation that the absorption efficiency decreased in the early stage of absorption and then increased to some steady value. The absorption rates were satisfactorily explained on the assumption that NO coordinates to Fe(II) (EDTA) (SO2-3) irreversibly. It was also found that the absorption rate of NO in the aqueous solution of Fe(II)-EDTA was much higher than those of other liquid absorbents so far investigated.
Concentration history was studied when aqueous solutions of binary and ternary component systems were fed to the fixed-bed of activated carbon granules. The systems studied were phenol-benzoic acid, benzoic acid-para-nitrophenol and phenol-benzoic acid-para-nitrophenol of several concentration ranges. Because of different adsorptivity for each component, breakthrough curves observed for less-adsorbable component showed a typical profile consisting of four parts, namely, first adsorption zone, first equilibrium-attained zone, second adsorption zone and second equilibrium-attained zone. More-adsorbable component appeared in the last two zones described above. These zones, especially the first equilibrium-attained zone and the second adsorption zone, were studied with respect to their lengths and amount adsorbed, based on simple assumptions and the constant-pattern concept. Furthermore, breakthrough curves were obtained for the ternary system to show that the above discussion is valid for the system.
Bubble-to-liquid mass transfer rate coefficient of hydrogen in n-heptane was determined by three methods: (1) measurement of reaction rate, hydrogenation of α-methylstyrene, under the limitation of mass transfer, (2) moment analysis from break-through curve and (3) moment analysis from pulse response. The values obtained by the three methods agreed within allowable experimental error, indicating that the latter two methods, which are easy in experimental practice, can be used for the evaluation with good accuracy. Of the latter two, the estimation from breakthrough curve showed better agreement and smaller scattering of experimental points.
Application of the phenomena of particle growth by condensation to industrial dust collection was studied. The analysis to evaluate the extent of size enlargement was first introduced to the two essential and industrially useful methods, one of which is the mixing of hot saturated air with cold air, the other being injection of steam into air. Four typical processes are proposed for effective application to industrial exhaust gas and the procedure of using these processes is illustrated according to the various conditions of exhaust gas. The technique for size enlargement of aerosol particles by condensation was found to be essentially applicable to any industrial exhaust gas which contains submicron dust particles in low number concentration when the appropriate process shown herein is selected.
Electroosmotic dewatering is very effective for sludge which is difficult to dewater by mechanical methods. Its use under condition of constant voltage was investigated. The mechanism of electroosmotic dewatering for compressible sludge under condition of constant voltage was studied by using the model of electroosmotic flow through a compressible-particle packed bed. The rate of electroosmotic dewatering and the electric power consumption were theoretically analysed. Experiments were performed by using compressible sludges such as white clay and bentonite. The equations obtained theoretically were confirmed experimentally. The theoretical equations of electroosmotic dewatering proposed in this paper are useful for the design of practical electroosmotic dewatering equipment. A few characteristics of electroosmotic dewatering under condition of constant voltage are also shown.
The mass exchange type "micromixing" model in a flow system is extended to batch mixing rate process accompanying a second-order reaction between miscible reactive fluids A and B. The performance of batch mixing rate process accompanied by reaction and the dimensionless parameter q=krCb0/km are obtained from theoretical analysis of the model. When the value of q becomes less than about 0.1, the mixing effect is negligible on the course of reaction. Through analysis of the mixing characteristics of the model, the mass exchange coefficient km can be correlated with mixing time as follows. km=ln(l/δ)/t(δ)M:δ=1-F=√IS¥=ΔC/ΔC0 Theoretical studies mentioned above are confirmed through experimental studies of the alkaline hydrolysis of ethyl chloroacetate, for which the reaction rate is comparable to the rate of mixing and the infinitely rapid reaction of ammonium hydroxide and acetic acid. The experimental values of km determined in each experiment show that macromixing due to circulation of the fluid element has a dominant effect on the course of reaction in the experimental condition of 300 < Re < 5000.
A numerical algorithm of two-dimensional laminar flow in an agitated vessel is established and the numerical results of the power input, the stream line and the velocity profiles for paddle and anchor impellers of various sizes are compared with the experimental ones. Both results are in good agreement with each other and it is concluded that the flow pattern in an agitated vessel with large-width impeller is almost two-dimensional. It is also shown that the characteristic velocity and length defined for the analogy expression of the transport phenomena at the agitated vessel wall by the authors are very useful for the local similarity of momentum transfer at and near the vessel wall for small-size impeller of d/D<0.6 in high ReG range.