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Volume 1 (1975)
- Issue 6 Pages 553-
- Issue 5 Pages 445-
- Issue 4 Pages 337-
- Issue 3 Pages 229-
- Issue 2 Pages 121-
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Volume 1, Issue 4
Displaying 1-18 of 18 articles from this issue
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Akira Kanagawa, Takeshi Takahashi, Yoichi Murase1975 Volume 1 Issue 4 Pages 337-343
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSA device for sampling of aerosol particles has been designed and built after considering the characteristics of thermal force. The aerosol is passed through two metal plates. The upper plate is heated and lower one cooled such that a steep temperature gradient exists between plates. The device can be readily applied to many types of aerosol because the operation range of flow rate and temperature gradient is very wide.
Experimental results show that the particle velocity by thermal force does not depend on particle size or particle conductivity in the range of 0.51.0μ. The maximum travelling distance from inlet can be determined by system parameters.View full abstractDownload PDF (1064K) -
Saburo Yashima, Fumio Saito, Takatoshi Sagawa, Hisashi Suzuki, Shigeru ...1975 Volume 1 Issue 4 Pages 344-350
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSIn single particle crushing, sphere specimens (nominal diameter of 2.0 cm) made of glassy materials and three kinds of minerals were used to determine conversion percent of fracture energy into kinetic energy of fragments and sound energy of fracture. From the experiments, the following results were obtained. 1) Cumulative conversion percent of fracture energy into total kinetic energy was 38.6 % in borosilica glass, 28.0 % in soda glass, 10.7 % in quartz, 5.7 % in feldspar, 2.0 % in limestone. 2) Conversion percent of fracture energy into sound energy of fracture was 10-410-5 % in all kinds of samples. Their values in five kinds of samples decreased with decrease in total kinetic energy of fragments.View full abstractDownload PDF (3360K) -
Eiichi Onuma1975 Volume 1 Issue 4 Pages 351-356
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSBased on operating data of a closed-circuit tube-mill process for cement clinker grinding, the following analysis has been made. First, by applying matrix simulation method, the influence of operating or design variables on the steady-state flowrate (P) and particle-size distribution of fine products has been estimated, under the condition that the specific surface of fine products (Sp) is always kept constant by adjusting cut-size of classifier. Next, based on the estimation, some fundamental ideas to optimize operating and design variables have been found out. Main conclusions are as follows.
1) The flowrate of classifier feed (F) to maximize P is strongly dependent on the flowrate of circulating air in the classifier, but is independent of aimed value of Sp. On the other hand, circulating load to maximize P is strongly dependent on aimed Sp. 2) To reduce the specific energy consumption, it is important to select the appropriate capacity ratio of classifier to mill, and also to maintain F at the optimum point.View full abstractDownload PDF (860K) -
Kunio Kato, Yoshihiro Shirota, Utaro Ito1975 Volume 1 Issue 4 Pages 357-362
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSNonuniform size particles are fed to the middle part of a tower packed with open-end screen packing and are classified into two parts by air flowing upward in the tower. This apparatus is defined as a packed fluidized particle classifier. The characteristics of particle classification are expressed by the fractional recovery curve of the particles. By obtaining fractional recovery curves for particle groups of different size, we found that the characteristics of particle classification of this apparatus were much better than those of centrifugal or gravitational particle classifiers. The fractional recovery curve of particles in this apparatus can be estimated from its operating conditions by establishing experimentally the relation between the fractional recovery curve of particles and the distribution function of gas flow in the apparatus.View full abstractDownload PDF (1106K) -
Masabumi Nishikawa, Fujio Kida, Takashi Kayama, Shinji Nagata1975 Volume 1 Issue 4 Pages 363-369
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSEffect of pressure drop, spouting velocity, particle size, particle density and vessel diameter on suspension of solid particles in a solid-liquid spouted vessel are measured and the performance of the spouted vessel is compared with that of mixing vessel or fluidized bed.
The spouted vessel, in which solid particles are blown off by the liquid jet from a nozzle at the bottom (at the top when particles are lighter than liquid), is superior in power efficiency to suspend solid particles. Also, large and heavy particles can be easily suspended at low superficial velocity in a spouted vessel.
The spouted vessel can be divided into two sections, a jetted turbulent section and a calm uni-velocity section.
Though in the former turbulent section mixing is almost perfect, turbulence is small and plug flow-type-mixing prevails in the latter section.View full abstractDownload PDF (1243K) -
Nobutoshi Tanaka, Toshiteru Izumi, Kazuyuki Hotta, Koichi Iinoya1975 Volume 1 Issue 4 Pages 370-374
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSWhen a dust collector is installed for two or three dust sources, the collector should be most economically connected with each source through pipelines. In this paper the optimal location of collector and the optimal diameters of pipelines are decided so as to minimize the total cost, which consists of the fixed costs of pipelines and a fan, and the operating cost of the latter.
The optimal solutions are analytically obtained when there is only one, or two sources. Especially for the latter case, the following simple and useful conclusion is obtained; the diameters of the two pipelines are the same, and the optimal solution is shown in one figure. For cases of more than two sources, a sophisticated algorithm is proposed to search for the optimal solution.View full abstractDownload PDF (1023K) -
Hideharu Hirosue, Hirotoshi Akimaru, Hisashi Shinohara1975 Volume 1 Issue 4 Pages 375-380
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSA method of calculating the average number of falling particles per unit length in rotary dryers and coolers is analyzed and an equation proportional to the average number of falling particles per unit length is derived as a function of some operating variables.
The effective number of falling particles per unit length is then determined from data on the pressure drop measured under various conditions, and is plotted for the calculated values from the above equation on a logarithmic chart.
The result is a fairly good correlation between the two. The effective number of falling particles per unit length is in proportion to the three-fourths power of the average number of falling particles per unit length in rotary dryers and coolers. This conclusion may be useful in estimating the number of particles which effectively contact the air flow for the purpose of analyzing the mechanism of mass transfer as well as heat transfer.
The pressure drop through the falling particles alone in rotary dryers and coolers can be estimated.View full abstractDownload PDF (994K) -
Ryotaro Izumi, Tsuneo Ishimaru, Wataru Aoyagi1975 Volume 1 Issue 4 Pages 381-386
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSThe mechanism of heat transfer for refrigerant condensing in a horizontal tube is so complicated that no useful empirical equation has been reported. In this paper, experiments on condensing heat transfer and pressure drop for refrigerant R-12 (CF2Cl2) were made under various heat fluxes, mass flow rates of refrigerant and void fractions chosen as the main experimental parameters for three tube diameters.
The heat resistance governing heat transfer depends on the thickness of condensate wetting the tube surface and is determined mainly by the flow pattern and flow rate of refrigerant. The heat transfer coefficient varies with the condensing temperature when the flow pattern is laminar, and with the condensing pressure when the tube diameter is larger.
In conclusion, including the effect of the tube diameter, an empirical equation of condensing heat transfer accurate within a limit of ± 15% error was obtained, and a correlation by which condensing pressure drop can be estimated was worked out.View full abstractDownload PDF (929K) -
Masashi Kuramae, Tatsuo Tanaka1975 Volume 1 Issue 4 Pages 387-392
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSLiquid moisture movement due to capillary suction pressure is considered with a simulated electrical circuit model which consists of numerous pores and connecting necks, so as to investigate the dependence of moisture content on the flow rate of water in a partially saturated granular bed.
As a result, it is shown that flow resistance rapidly increases with decreasing moisture content of the bed.View full abstractDownload PDF (1087K) -
Osamu Miyatake, Tetsu Fujii, Toshiaki Tanaka, Tsutomu Nakaoka1975 Volume 1 Issue 4 Pages 393-398
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSTo clarify the physical mechanism of flash evaporation, an experimental investigation was carried out with a quantity of pool water exposed to a sudden pressure drop.
The range of experimental variables include : superheats between 2.5 and 5.5°C, liquid temperature between 40 and 80°C, and liquid levels of 100 and 200 mm.
Flash evaporation is found to undergo two exponential decaying processes.
Measured values of maximum penetration depth of evaporation, non-equilibrium temperature difference, and coefficient of evaporation rate are subject significantly to the influence of liquid level, and flash evaporation is not always enhanced by the lowering of liquid level for larger values of liquid temperature.
The experimental data are also compared with data obtained in multi-stage flash evaporators.View full abstractDownload PDF (4631K) -
Teiji Yokota, Yasuo Hidaka, Toshio Yasutomi1975 Volume 1 Issue 4 Pages 399-403
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSThe mass transfer rates from the surface of a spherical as well as a cylindrical body submerged in a gas-fluidized bed were measured for naphthalene, water and n-butanol. Under the same conditions, the frequency and the ratio of contact time to total time of bubbles rising along the body were measured to estimate the contact time. In addition, the amount of substance adsorbed at equilibrium on the particle surface was measured to determine adsorption capacity.
Analogously to the theory of heat transfer proposed by Yoshida et al., the process was analysed by use of mass adsorption capacity instead of heat capacity, and the rates are correlated by an empirical equation containing bubble frequency.View full abstractDownload PDF (844K) -
Minoru Kuno, Masataka Nakayama1975 Volume 1 Issue 4 Pages 404-407
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSIn the tridiagonal matrix method, normalization is used to obtain a converged solution. But we cannot always obtain a converged solution in all problems thereby. Normalization method treats all components at the same level, and so we think we cannot obtain a converged solution by the interaction between components in the case of a large difference in characteristic between components. We developed a new partial normalization method in which we give priority to some components in order to check the interaction between components. These equations are :
Xij=xij, i=1, m
Xij=xij (1-mΣk=1xkj) /cΣk=m+1xkj, i=m+1, c where xij : mole fraction of component i in the liquid leaving stage j
c : total number of components
m : component number, which defines components given priority.
By using this method in place of the usual normalization method, we can solve problems which cannot be solved by the usual normalization method.View full abstractDownload PDF (752K) -
Yoshishige Hayashi, Eiji Hirai, Nobuaki Shimizu1975 Volume 1 Issue 4 Pages 408-413
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSTheoretical analyses for crossflow gas absorption with irreversible second-order chemical reaction were studied and both an approximate and a numerical solution for the reaction factor describing the effect of chemical reaction on the rate of gas absorption were derived. These solutions were compared with results calculated by the film theory and the penetration theory.
As a result, it is found that the reaction factor for irreversible second-order chemical reaction is the same as that for the penetration theory in the case of pure gas and that the reaction factor for instantaneous chemical reaction and for irreversible second-order reaction can be approximated by the penetration theory and by the film theory in the case of gas mixture, respectively.View full abstractDownload PDF (976K) -
Hirozumi Izawa, Hakuai Inoue1975 Volume 1 Issue 4 Pages 414-419
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSFor the estimation of kinetic parameters of a complex reaction system from experimental data, a non-linear least square method has been applied so far to treat all of the data. However, the procedure sometimes brings about numerous troubles, and needs a long computation time with fruitless iteration.
In this paper, the authors present a new statistical treatment to elucidate the reaction scheme and to evaluate their kinetic parameters.
In this treatment the overall rates of conversion of a key reactant and of the production of an appropriate final product are first analyzed statistically and their lumped rate equations and kinetic parameters are determined.
Next, a more detailed reaction scheme is assumed ; the reaction paths between the reactant, the final products, and the remains (all the other products treated as one group), and the rate equations and kinetic parameters of the individual reaction paths are estimated. Then an intermediate product is separated from the remains and a more refined reaction scheme is established.
These procedures are repeated until all of the detailed reaction scheme of the system and the kinetic parameters are definitely fixed.
In this treatment, all the reaction rates are assumed to be of the Freundlich type for convenience in statistical procedure.
This statistical treatment is less time-consuming than the former method, and is more advantageous in discovering and removing the insignificant reaction paths and negligible dependences on components in rate equations.
The detailed steps and techniques are discussed and an application to the experimental data of p-xylene oxidation is described as an example.View full abstractDownload PDF (1168K) -
Kunio Miura, Hiromichi Kobayashi, Takatoshi Miura, Shigemori Ohtani1975 Volume 1 Issue 4 Pages 420-426
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSWhen a fluid is ejected through a nozzle into a duct filled with the same fluid, the flow direction of the jet is deflected towards the side wall by the recirculating eddy generated near the nozzle. This phenomenon is called the Coanda effect.
To find a method for preventing the Coanda effect, we observed the flow pattern of the jet and also measured the position of reattachment, velocity distribution, and pressure distribution on the side wall of the duct when an air stream was supplied from the side wall or from an offset wall parallel to the axis of the jet.
It was found that the position of reattachment was displaced downwards as the amount of surrounding flow increased and that the recirculation eddy and the deflected flow could be successfully prevented when a surrounding flow rate was supplied equal to the flow rate entrained by the jet.View full abstractDownload PDF (3554K) -
Yoshiharu Murata, Taijiro Honda1975 Volume 1 Issue 4 Pages 427-431
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSPhysical properties such as self-diffusion, viscosity and density of melt in the vicinity of its melting point were measured. For the measurement of self-diffusion, the spin-Echo method using NMR is employed.
The observed values of these physical properties suggest the possibility of the existence of cluster under conditions of supercooling. The observed values of self-diffusion coefficient agree very well with the calculated values by Dullein's equation for the temperature range above the melting point, but disagree for supercooling.
In this paper, on the assumption that the above disagreement is due to the existence of cluster in the melt, the fraction of cluster Φ is determined by the deviation from Eyring's relation in viscosity in the vicinity of the melting point, and the correction factor ψ for Dullein's equation is obtained as follows :
ψ=1/ {(1-φ) +gφ} (1+αφ+βφ2)
where g is number of associated molecules in cluster.View full abstractDownload PDF (736K) -
On the time dependence of the rate of erosionMasanobu Matsumura, Friedrich Erdmann-Jesnitzer, Hartmut Louis1975 Volume 1 Issue 4 Pages 432-438
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSFor the purpose of making clear the causes of the variation in erosion rate, an experimental study was carried out of the cavitation erosion of iron and steel in a water tunnel system. Both scanning electron microscopic and metallographic observations were made on the damaged surface of the specimens with special attention to the behavior of ferrite which is contained in all of the materials tested.
As a result, the following conclusions are obtained. (1) Each ferrite in iron and steel has its own cavitation damage process, not always according to mechanical properties of the material damaged. (2) The mechanism of cavitation damage on Armco-iron turns from ductile to brittle with the lapse of testing time. (3) Some convincing evidence has been obtained to indicate that a part of the variation in erosion rate is caused by the transition of the mechanism of cavitation damage. Additional study is, however, necessary before this may be accepted as fact.View full abstractDownload PDF (9532K) -
Manabu Takatsu1975 Volume 1 Issue 4 Pages 439-443
Published: July 10, 1975
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSDownload PDF (847K)
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