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Ichiro Funada, Kazuhiko Asahara, Yasuo Hirose, Hirosi Tatibana
1987 Volume 13 Issue 5 Pages
533-541
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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To design a compact upper column for a liquid air distillation system reasonably, and to determine the optimum, location of side-cut stage for improving argon yield, it is necessary know clearly the point efficiency at high load.
In this work, a small-scale distillation test apparatus was manufactured which had a 0.1-m column diameter and four stages of perforated plates. Many design factors were tested such as outlet weir height and open free area as plate geometry, and N
2-O
2 and Ar-O
2 systems at high load, under upper column pressure and total reflux as operation conditions.
Vapor-phase oxygen concentration was measured at each stage, and Murphree vapor-phase plate efficiencies were calculated on the basis of the definition.
Based on the fact that the liquid flow path length is very short on the stage, and load is very high, it can be assumed that liquid flow is perfectly mixed with vapor flow on the tray, so that plate efficiency is equal to point efficiency.
Estimation accuracy was improved by correcting conventional works. The double film theory was assumed for point efficiency of the liquid air distillation system. Open free area was related to experimental constant in N
G and expression of liquid holdup on the tray. Results from study of pressure drop in liquid air system were applied as the liquid holdup, which was necessary for estimation of contact time of vapor liquid mixing on the tray. The estimation method of point efficiency by using these factors was proposed.
Its accuracy is estimated as within 1.8% of concentration difference for the N
2-O
2 system, and within 2.5% the for Ar-O
2 system.
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Toshiyuki Yokota, Yasuhiro Abe, Hiroyuki Koseki
1987 Volume 13 Issue 5 Pages
542-547
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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In the freeze dry processing of a multicomponent aqueous solution to produce a uniformly mixed powder, segregation of components may occur under certain conditions of freezing operation. In this study, experimental investigation showed how much segregation occurred in an aluminum-magnesium two-component powder produced at various freezing rates. As the result, a freezing bath with sufficiently cooled
n-hexane liquid produced powder with little segregation. But using a freezing bath with liquid nitrogen had no advantage in producing low-segregation powder because a droplet of aqueous solution in the bath was enveloped in a layer of gaseous nitrogen and this insulating layer might impede the freezing rate and allow segregation of the components.
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Masaomi Tomomura, Shunsuke Nogita, Kazuo Someya
1987 Volume 13 Issue 5 Pages
548-553
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Pressure swing adsorption was applied to carbon dioxide and water removal instead of thermal swing adsorption as a pretreatment of compressed air for a cryogenic air separation plant.
Due to use of a two-layer-column method, with zeolite and activated alumina packed in two separate layers, the concentration of carbon dioxide in purified air is decreased from 340 ppm to 1 ppm.
The electric power unit for a pressure swing adsorption process was about 85% of that for a thermal swing adsorption process because no refrigerating heater or refrigerator was required.
The carbon dioxide concentration of purified air is expressed as
C=
86SV
2 (
Pa/
Pd)
-1.3x-2where
C is the carbon dioxide concentration of purified air,
SV is the space velocity of purified air,
Pa is the adsorption pressure,
Pd is the desorption pressure and x is the purge ratio.
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Hiroyuki Kawasaki, Hisaya Tanaka
1987 Volume 13 Issue 5 Pages
554-560
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Mass transfer coefficients
ks between particles and fluid were obtained by measuring the dissolution rate of benzoic acid active particles in air-water upward cocurrent flow through packed beds. Experiments were carried out using packings of spheres of 0.82cm and 1.52cm diameter and cylinders of 1.0cm diameter and 1.0cm length. The experimental conditions covered the regions of forced and free-rising bubble flow in regard to the flow parameter
Fp=
ub0p/ {(
ug0+
ul0) / ε}. In this parameter,
ub0p and (
ug0+
ul0) /ε are the characteristic velocities in each flow region, where
ug0,
ul0 and ε are superficial gas velocity, superficial liquid velocity and void fraction, respectively. Mass transfer coefficients were correlated with dimensionless groups as follows.
In the forced rising region,
Shp=0.48
Rep3/5Sc1/3In the free-rising region,
Shp=0.59
Rebp3/5Sc1/3where
Shp=
ksl/
Dl,
Rep=ρ
m (
ug0+
ul0)
l/εμ
l,
Sc=μ
l/ρ
mDl,
Rebp=ρ
m {(ρ
l-ρ
m) /ρ
m}
1/2 ub0pl/μ
l and ρ
m= ρ
l (1-φ) + ρ
gφ.
In these dimensionless groups,
Dl,
l, μ
l, ρ
g, ρ
l and φ are diffusion coefficient, characteristic bubble length, liquid viscosity, gas density, liquid density and gas holdup, respectively.
Assuming additivity of Reynolds numbers in both regions, the following correlation was obtained :
Shp=0.48 (1+2
Kp)
1/3Rep3/5where
Kp= [{(ρ
l-ρ
m) /ρ
m}
1/2Fp]
2.
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Masanao Imai, Shintaro Furusaki
1987 Volume 13 Issue 5 Pages
561-566
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Mixing between the inner and outer water phases in W/O/W emulsion was measured by means of a radioactive tracer under conditions excluding the effect of electrolytes in the water phases. The leakage fraction was proportional to the square of the agitating speed and inversely proportional to the 0.7 power of the concentration of the surfactant Span80
®. The leakage fraction increased as the volume fraction of the inner water phase inside the dispersed W/O emulsion droplets increased. The volume fraction of the W/O emulsion droplet in the W/O/W emulsion system had no effect on the leakage fraction. When hydrochloric acid was added to the inner water phase at small surfactant concentration, the leakage fraction was larger than the value for the system without electrolytes. When surfactant concentration was large, the leakage fraction did not increase even if hydrochloric acid was added to the inner water phase. The dependence on the agitating speed was the same as that for the system without electrolytes.
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Jun Fukai, Kazuya Suzuki, Hisao Matsubayashi, Takatoshi Miura, Shigemo ...
1987 Volume 13 Issue 5 Pages
567-573
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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A new method, based on the incremental theory, is proposed to predict thermal stress in the coke layer during carbonization. In this method, the deformation of the coke layer and the effect of the pressure caused in the plastic layer are considered. As a result of estimations of thermal stress variations with time at a constant heating rate, the tensile stress has a maximum value at each of the heated surfaces and the resolidification surface at the early step of carbonization, clarifying the time when microfissures are formed. The effects of heating rate and load on lump coke size are measured and it is found that the lump coke size decreases with increases of the heating rate and the load. The cause is clarified analytically that microfissures are producted easily with increases of heating rate and load and that they grow into macrofissures due to the tensile stress within the coke layer.
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A case of linear inequality systems suffering independent parameter deviation
Yoshiaki Shimizu, Takeichiro Takamatsu
1987 Volume 13 Issue 5 Pages
574-580
Published: September 10, 1987
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This paper is concerned with flexibility analysis and a design method that possesses flexibility by the aid of control action for uncertain process systems. Taking linear inequality systems suffering independent parameter deviation in particular, we present a simple but practical approach in terms of the permanent feasibility of the system. Compared with the previous methods, we can carry out flexibility analysis easily and straightforwardly by an algorithm formulated as a linear program. Furthermore, we formulated a multiobjective linear program by which a flexible design and control policy will be obtained through tradeoff analysis among the original system performances and that associated with flexibility consideration. Finally, through an illustrative example, we show that the proposed method is promising, and can be applied to real-world problems.
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Osamu Kashihara, Takashi Hibi, Yoshio Harano
1987 Volume 13 Issue 5 Pages
581-588
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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The crystallization of thiourea from its quiescent aqueous solution in the absence or presence of ammonium thiocyanate as an impurity was measured by a differential scanning calorimeter (DSC) at constant cooling rate. The results indicate that the metastable zone width decreases in the presence of impurity, to a minimum at its concentration of 2× 10
-3mol/
l The observed phenomena were analyzed theoretically by the method proposed previously, and from the rate-parameters of nucleation and growth thus obtained it was deduced that ammonium thiocyanate behaved as heterogeneous centers in the formation of thiourea clusters.
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Masahiro Ohshima, Iori Hashimoto, Takeichiro Takamatsu, Hiromu Ohno
1987 Volume 13 Issue 5 Pages
589-595
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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An attempt is made to extend the function of predicting the future disturbance in model predictive control (MPC). The dynamics of the disturbance is identified from the acquired time series data in order to predict the future disturbace.
Disturbance prediction improves the performance of MPC, especially in the case where the disturbance is slowly varying. The usefulness of the extended MPC is confirmed by both simulations and experiments.
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Satoshi Okuda, Hiroshi Takano, Tadashi Yamamura
1987 Volume 13 Issue 5 Pages
596-604
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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The properties of multiple light scattering of highly concentrated mono-dispersed aerosol particles are numerically and experimentally investigated in terms of particle size and number concentration. The numerical results show that by increasing the order of multiple scattering, the angular distribution function of scattering intensity becomes simple and is finally independent of the scattering angle. In the case where the collection angle for detecting the scattered light is in a wide range of 0-π radian, the relationship between the scattering intensity and the particle number concentration for each particle size is consolidated into a simple expression by introducing the multiple scattering factor, defined as the ratio of the multiple/singular scattering intensities for a single particle. Results of experiments performed in a highly resonanced laser beam using mono-dispersed polystyrene latex, indicate that multiple light scattering occurs even at relatively low particle number concentration. It is also confirmed that the measuring data on the multiple scattering factor obtained from the scattering intensity are quantitatively in good agreement with the numerical results.
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Jin Chen, Hisayoshi Matsuyama
1987 Volume 13 Issue 5 Pages
605-612
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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It is shown that the most powerful equation (the most powerful cocycle) for detecting gross errors can be easily obtained if all the measured variables in the process are constrained by only mass balances. An algorithm is developed for the rational decomposition of the problem of detection and identification of gross errors in the large-scale process and the efficiency of this algorithm is demonstrated by applying it to numerical experiments with the use of a simplified refinery model with 22 flowmeters.
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Dong-Wha Park, Takuya Honda, Atsushi Kanazawa
1987 Volume 13 Issue 5 Pages
613-620
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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To investigate the heat transfer from a thermal plasma to a particle, the temperature of a β-SiC particle (2-mm dia.) heated in an argon plasma tube flow was calorimetrically measured and numerically calculated using the energy equations. The plasma temperature and velocity in the tube which are required to calculate the heat transfer rate from the plasma to the particle were also determined by the calculations. The calculated results of the particle temperature are in good agreement with the experimental results. Therefore, it is shown that the simple calculation method presented is enough to estimate the temperature of a high-density particle like β-SiC which is heated in thermal plasma tube flow.
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Shigeki Toyama, Hidetoshi Mori, Yoshiteru Mizutani
1987 Volume 13 Issue 5 Pages
621-626
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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The fundamental properties of horizontal gas-flow granular-bed filters with dust loading were investigated experimentally.
Dust was always collected at the inlet part in the initial stage, and moved inside as the filtration process proceeded. The collection efficiency initially increased due to some retained particles, and was affected by reentrainment from critical inlet dust loads.
The additional pressure loss was proportional to the 1.3th power of the retained dust loading, and a conceptual model for predicting pressure loss buildup was proposed on the postulate that dust accumulated uniformly on the surface of a collector. The correction factor λ, a proportion of the specific surface area of retained dust that contributes to head loss, was dependent on the filtration velocity and was determined experimentally.
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Ryohei Yamazaki, Mitsuyuki Nakajima, Genji Jimbo, Tsuyoshi Oshimi
1987 Volume 13 Issue 5 Pages
627-633
Published: September 10, 1987
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A new mathematical model describing the spatial distribution of bubbles in the gas-solid fluidized bed was developed. From a comparison of calculated results with experimental results, this model was found to be useful for predicting the spatial distribution of bubble characteristics, such as bubble size, bubble flow rate and bubble frequency. It was also shown from calculated results of the radial position at which the maximum bubble flow rate appeared in beds that the geometrical similarity rule was not established for the radial distribution of bubbles in a fluidized bed.
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Korekazu Ueyama, Shinobu Tanimura, Shintaro Furusaki
1987 Volume 13 Issue 5 Pages
634-640
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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By using reported data of bubble coalescence probability and bubble coalescence time, the mechanism of flow transition between a bubble flow regime and a recirculating flow regime in a bubble column was experimentally studied. Hysteresis of the value of mean gas holdup, ε
G, against the increase and the decrease of superficial gas velocity,
UG, did not appear in this work, where impurities in both liquid and gas phases were carefully controlled. NaCl or various alcohols were added to the system as impurities, and their effects on the behavior of ε
G vs.
UG curves were experimentally examined. The maximum value of ε
G was observed only when the bubble coalescence was retarded by the effect of an impurity. These effects of impurities were observed even for very small concentrations such as 20 mol/m
3 of NaCl or 10
-2 mol /m
3 of alcohol. When the values of bubble coalescence time were set to be the same value by adjusting the alcohol concentrations, the maximum values of ε
G for several kinds of normal alcohols became identical. It was also observed that flow transition easily occurred when the flow pattern was inhomogeneous.
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Hideto Yoshida, Hiroyuki Yamashita, Yoichi Nagase
1987 Volume 13 Issue 5 Pages
641-648
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Experimental studies of fluid flow near field of double tube swirler and under strong swirl condition were conducted by use of LDV and high-speed video recorder. The swirl jet out of the annular part is expanded drastically as soon as it is exhausted from the nozzle. With this motion, straight flow out of the inside tube is induced to change its direction into radial flow and then recirculating flow on the center line is induced. The spreading rate of swirl radius decreases where swirl flow and straight flow, which has been turned to radial flow, merge with each other. Then the expansion of swirl radius increases again and the flow characteristics of the outer region of the swirl jet shift to the self-preserving type, independent of the inner flow. The scale of the recirculating flow and the degree of jet spread are experimentally correlated with swirl number.
The flow profile near the nozzle exit fluctuates dynamically with time. The fluctuation of flow can be recognized as involving three types of coherent profiles : axisymmetric, axi-unsymmetric and one-way types.
The fluid flow fluctuation causes the first and second peaks of intensity distribution, which correspond to the places where straight flow changes its direction rapidly and where they are merge into the annular swirl jet, respectively.
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Kosaku Ishimi, Sadatoshi Koroyasu, Haruo Hikita
1987 Volume 13 Issue 5 Pages
649-656
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Formation and structure of waves on the surface of falling liquid films in inclined wetted-wall columns were theoretically investigated on the basis of the linear stability theory. Approximate analytical solutions were obtained for the dimensionless numbers of length, velocity and spacial growth rate of temporally stable waves as a function of the liquid Reynolds number, the dimensionless surface tension, the inclination of the wetted-wall plate and the dimensionless wave frequency. The solutions showed that the wave is very small at the liquid inlet but that its amplitude increases exponentially in the direction of flow.
Frequencies, lengths, velocities and amplitudes of waves of water were measured in an inclined wetted-wall column. It was found that, with increasing distance in the direction of flow, the wave characteristics remain constant but the wave amplitude increases, and that visible waves appear at a point, i.e. a wave inception. A comparison between the experimental results and theoretical predictions indicated that the characteristics and inception of the waves can be predicted on the basis of the linear stability theory.
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Katsuroku Takahashi, Makoto Nakano, Hiroshi Takeuchi
1987 Volume 13 Issue 5 Pages
657-663
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Recovery of Cr (VI) from a feed solution of sulfuric acid into an aqueous solution of ammonia was studied by using a supported liquid membrane (SLM) of 3-(4-pyridyl)-1, 5-diphenyl pentane (PDPP). High recovery fraction of Cr(VI),
R, was attained with a multilayer of flat sheets. For the recovery solution containing only ammonia, Cr(VI)-PDPP complex was accumulated within the liquid membrane and then
R decreased with time. The addition of Cr(VI) to the recovery solution improved the value of
R due to the buffer effect of Cr(VI); the experimental results were in good agreement with the results calculated on the basis of diffusion through the liquid membrane and the aqueous boundary film and the interfacial reaction at both sides of the SLM. Permiation of sulfuric acid and ammonia through the SLM and the effect of coexisting heavy metal ions were also studied in the present system.
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Yoshiyuki Bando, Michio Kuraishi, Makoto Nishimura, Makoto Hattori, Ta ...
1987 Volume 13 Issue 5 Pages
664-670
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Flow characteristics in a three-phase fluidized bed with a draft tube, 0.164 m in diameter and 2.2 m high, were experimentally examined. Air and water were used as gas and liquid. Two kinds of particles of about 3 mm φ were used : Nylon (heavier than liquid) and polypropylene (lighter than liquid). Gas was sparged either into the inner section or into the annular section.
Above a certain gas feed rate, circulation flow was stable and longitudinal distribution of solid became uniform. Gas holdup increased with increasing gas feed rate. Gas holdup for sparging into the annular section was higher than that for sparging into the inner section, excepting the case where the draft tube diameter was large and polypropylene was used as solid. In most cases solid holdup was not affected by gas feed rate.
Liquid circulation rate increased with increasing gas feed rate. The liquid circulation rate at the same gas feed rate showed the maximum in the case using the draft tube whose diameter was about 60 per-cent of column diameter. Solid and gas circulation rates depended greatly upon liquid circulation rate.
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Ichiro Naruse, Hitoki Matsuda, Masanobu Hasatani
1987 Volume 13 Issue 5 Pages
671-677
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Fundamental flow behavior of a solid particle in a CFM-bed, such as minimum fast fluidization velocity, particle holdup, particle velocity distribution, and residence time, were observed in a two-dimensional visualized cold model by use of three kinds of solid particle : alumina balls, activated alumina balls, and coal particles.
The minimum fast fluidization velocity, defined as the critical gas velocity to form a stable state of a fast fluidized bed or an entrained bed in the inner pipe, almost corresponded to the terminal velocity of a single particle. When a solid particle with a high apparent density was employed, however, a slight increase of the minimum fast fluidization velocity was recognized with an increase in the height of the inner pipe. Particle holdup and particle residence time showed similar trends to those of the glass beads in the previous study, exponentially decreasing with an increase in superficial gas velocity in the inner pipe. The velocity distribution of the solid particle was slightly affected in the inner pipe by the apparent density of the particle, but was nearly in the free falling flow region in the annular part.
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Osamu Miyatake, Itsuo Tanaka
1987 Volume 13 Issue 5 Pages
678-684
Published: September 10, 1987
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The governing equations for the growth of a vapor bubble of solvent in a uniformly superheated solution containing a non-volatile solute has been formulated by taking into account the combined effects of heat and mass diffusions in the region of solution.
Numerical solutions of the governing equations obtained by means of a finite difference procedure are illustrated for specific examples of bubble growth rates in the superheated aqueous solutions of NaCl, covering the ranges of bulk temperatures of solution from 40 to 80°C, superheats from 5 to 20°C and mass fractions of solute from 0 to 0.20.
It is found that the superheat defined by the temperature difference between the bulk temperature of solution and the equilibrium temperature of solution corresponding to the ambient pressure dominates the rate of bubble growth at a given bulk temperature of solution.
Quantitative comparisons are also made to determine the effects of both the concentration of solute at the bubble wall due to the evaporation of solvent and the superheat of generated vapor due to the boiling point elevation by non-volatile solute on the numerical solutions.
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Osamu Miyatake, Itsuo Tanaka, Yuji Tsutsui
1987 Volume 13 Issue 5 Pages
685-690
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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To verify the authors' previous numerical analysis of bubble growth in a uniformly superheated solution containing a non-volatile solute, new experimental data on bubble growth rates in aqueous solutions of NaCl under completely constant and uniform superheat conditions have been obtained by using a unique experimental technique.
The ranges of experimental variables include : bulk temperatures of solution of 40 and 80°C, mass fractions of solute of 0.05 and 0.20 and superheats up to 16.5°C.
In the present experiments, the superheated condition was obtained by slowly decompressing a heated pool of solution, and a bubble nucleus was generated on the top of the cathode wire by electrolyzing the superheated solution.
Experimental observations of the growth of a vapor bubble of solvent initiated from the artificially generated bubble nucleus were made by using a high-speed motion picture camera.
The experimental data on bubble growth rates have been shown to compare favorably with the previous numerical analysis with the combined effects of heat and mass diffusions included, confirming the theory.
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Toshio Yahata, Fujio Komatsu, Makoto Akiyoshi, Koji Ando
1987 Volume 13 Issue 5 Pages
691-693
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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To evaluate the effect of an adjacent impeller on the axial mixing region of a turbine impeller in a stirred vessel with multiple-stage impellers, the mixing process of liquid was observed by the color reaction method at various distances between two-stage turbine impellers. The mixing region was measured by the mixing time method.
No meaningful effect of an adjacent impeller on the scale of the mixing region was observed. Therefore, measurements of the scale of the mixing region in a stirred vessel with an impeller hold in one with multiple-stage impellers.
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Masato Tanaka, Shigeyuki Hasegawa, Eiji O'shima
1987 Volume 13 Issue 5 Pages
693-697
Published: September 10, 1987
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Suspension polymerization of styrene was performed under such operating conditions that gas was vigorously entrained from the free liquid surface. After the completion of polymerization, the volume of gas included into the polymer particles was measured. The relationship between the included gas volume and the operating conditions was investigated. With increasing impeller speed, the volume of gas included decreased, became minimal at an impeller speed of 22 s
-1, and then increased. Moreover, it was found that the larger the polymer beads were, the more gas they included.
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Toshiyuki Yokota, Hiroyulki Koseki
1987 Volume 13 Issue 5 Pages
698-700
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Freeze dry processing of certain salt solutions is difficult because of their tendency to melt during drying operation. In this paper, the use of aqueous ammonia was investigated for making freeze-dried particles from such a solution of iron (III) sulfate, which forms frozen droplets difficult to sublimate. Aqueous ammonia promoted the phase separation by making cluster ions and prevented the formation of glassy state in the frozen droplets. By an optimum addition of aqueous ammonia, perfect dried particles were obtained.
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Takeshi Kataoka, Tadaaki Nishiki
1987 Volume 13 Issue 5 Pages
700-703
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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The effect of temperature on the demulsification of W/O emulsion by application of pulsed DC high potential was studied, using Span 80 and kerosene as a surfactant and a solvent, respectively. In systems concentrating mercury by C-24 and zinc by D2EHPA, demulsification was accelerated and the water content in the oil phase after breaking the emulsion decreased with a rise in temperature. Thus the separation efficiency was enhanced by heating of the emulsion. However, such an accelerative effect in operation at elevated temperatures was not detected in the copper-LIX64N system.
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Ikuru Toyoda, Satoru Kato, Junjiro Kawasaki
1987 Volume 13 Issue 5 Pages
703-706
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Bi-component adsorption equilibria were measured at 25°C for the synthetic zeolite 4A-CO
2-C
2H
6 and the synthetic zeolite 5A-CO
2-C
2H
6 or C
3H
8 systems. Obtained data were well correlated by the modified extended Langmuir-Freundlich equations derived previously by the authors in the correlation of the equilibrium data for the synthetic zeolite 4A-CO
2-C
2H
4 system, and it was found therefore that these equations describe well the bi-component adsorption equilibria for the systems of the synthetic zeolite-CO
2-C
2C
3 hydrocarbon.
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Yoneshiro Tazaki, Shigeo Chiba, Midori Yumiyama, Shohei Takeda, Senji ...
1987 Volume 13 Issue 5 Pages
706-709
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Hybrid particles of coal ash from gasifier and higher viscous residue and solid pitch from coal liquefaction were successfully produced by two new methods. They were then gasified by steam and oxygen in a fluidized bed under atmospheric pressure. Gasification characteristics of these particles, such as the distribution and yield of gas produced and the carbon conversion, were evaluated as a function of operating variables.
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Seiji Iwasawa, Naoshi Ototake
1987 Volume 13 Issue 5 Pages
710-713
Published: September 10, 1987
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Estimation methods for liquid thermal conductivity over the normal boiling point (N.B.P.) to the critical point have not been satisfactory. In this work, using the N.B.P., liquid density at the N.B.P. and liquid thermal conductivity at the N.B.P. correlated by the function of both molecular weight and reduced boiling temperature, a new estimation method for both alkanes and frons is developed. Root mean square deviation of the proposed method is 7.42% for 861 data points. If experimental liquid thermal conductivity at the N.B.P. is used, it is 5.40 %.
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Kinetics of the Hydrogenation of Acetone
Yukitaka Kato, Nobuyoshi Nakagawa, Hideo Kameyama
1987 Volume 13 Issue 5 Pages
714-717
Published: September 10, 1987
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The kinetics of the catalytic hydrogenation of acetone on nickel fine particles supported on active carbon particle was studied by a differential type of flow reactor.
Initial rates of reaction without 2-propanol were measured at atmospheric pressure over the following range of conditions : Temperature, 125210 [°C]; Partial pressure,
Pa=720 [kPa],
Ph=750 [kPa]. AS a result, the most feasible rate-controlling step was found to be in the surface reaction between one adsorbed acetone molecule and one adsorbed hydrogen molecule on the same type of active sites. The final equation recommended for the vapor-phase hydrogenation of acetone on a nickel catalyst is r=
kKaKhPaPh/ (1+
Ka+Pa-KhPh)
2
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Yoshikazu Kuga, Jiro Koga, Ichiro Inoue
1987 Volume 13 Issue 5 Pages
717-720
Published: September 10, 1987
Released on J-STAGE: November 12, 2009
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Soma sand with size of 500 to 1000 μm was crushed by a screen mill in the range of impact velocity from 32.3 to 91.0 m/s. The increase in specific surface of the product was found to be proportional to about 0.61-th power of the measured electric energy consumption in crushing of unit weight of material. A new representative quantity of energy consumption in crushing is proposed as the product of the apparent frequency of impact crushing during the mean residence time and the kinetic energy of unit weight of particles. It was shown that our new quantity had a good correlation with the electric energy consumption in crushing, since the quantity also exhibited similar power dependency.
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1987 Volume 13 Issue 5 Pages
e1a
Published: 1987
Released on J-STAGE: February 19, 2010
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1987 Volume 13 Issue 5 Pages
e1b
Published: 1987
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1987 Volume 13 Issue 5 Pages
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Published: 1987
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1987 Volume 13 Issue 5 Pages
e1d
Published: 1987
Released on J-STAGE: November 22, 2010
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1987 Volume 13 Issue 5 Pages
e1e
Published: 1987
Released on J-STAGE: November 22, 2010
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1987 Volume 13 Issue 5 Pages
e1f
Published: 1987
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1987 Volume 13 Issue 5 Pages
e1g
Published: 1987
Released on J-STAGE: November 22, 2010
JOURNAL
FREE ACCESS
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1987 Volume 13 Issue 5 Pages
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Published: 1987
Released on J-STAGE: November 22, 2010
JOURNAL
FREE ACCESS
