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Volume 7 (1981)
- Issue 6 Pages 545-
- Issue 5 Pages 435-
- Issue 4 Pages 327-
- Issue 3 Pages 215-
- Issue 2 Pages 109-
- Issue 1 Pages 1-
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Volume 7, Issue 5
Displaying 1-18 of 18 articles from this issue
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Tadashi Shinkawa1981 Volume 7 Issue 5 Pages 435-441
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSTo measure the mean thickness of annular liquid film in the evaporating pipe by the direct method is very difficult. Therefore, experimental equations for mean linear velocity of annular liquid film two-phase flow in the absence of heating and evaporation were obtained by using glass pipes as follows :
Upward flow :
Fr=32.9×10-12 (d/l) -2.0 (LρL/GρG) -0.88 (ReL) 1.60 (μL/μG) 1.41
Downward flow :
Fr=3.1×10-8 (d/l) -1.3 (LρL/GρG) -0.60 (ReL) 1.32 (μL/μG) 0.92
where Fr is Froude number. The pipes used in the study are 1.2 m in length and have different diameters.
The above equations were obtained by experiments examining the influence of physical characteristics and conditions : e.g. viscosity, surface tension, gas-liquid ratio, Reynolds number of liquid, etc. In the range of pipe diameter d=10.6 23.4 mm, when the flow configuration is in annular flow region, calculated values by the equations are similar to experimental measured values within ±15% approximately.
The mean thickness of liquid film B can be calculated using the mean linear velocity UL, of annular liquid film flow.
B=1/2× {d-√d2- (4L/πUL)}View full abstractDownload PDF (1073K) -
Yasuharu Akagi, Masafumi Nishikaze, Shigeru Yamamoto, Teruo Takahashi1981 Volume 7 Issue 5 Pages 442-448
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe weeping of sieve trays has been studied using 0.15 × 0.15 m trays with hole diameter of 0.003-0.020 m and ratio of total hole area to active area of 0.05-0.30. The effects on weeping rates of gas and liquid velocities, tray geometry and physical properties of liquid phase are investigated experimentally.
By using the gas velocity ((ugc) 0) at which liquid on the tray begins to flow over the weir and the critical velocity of weeping ((ugc) w), the ratio of weeping rate to total flow rate of liquid (weeping ratio) is presented as a linear function of superficial gas velocity.
It is found that (ugc) 0 can be expressed by the previous correlation for the gas and liquid velocities at incipient liquid stagnation on a tray, and (ugc) w is correlated as a function of the pressure drop, liquid holdup on a tray, liquid velocity, hole diameter, tray thickness, liquid density and surface tension.View full abstractDownload PDF (5558K) -
Toshimi Mukushi, Sankichi Takahashi1981 Volume 7 Issue 5 Pages 449-453
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSA supercooling-freezing process was developed for the treatment of highly concentrated organic waste waters. Since the process is based on the unstable behavior of the supercooled liquids, it is very important to understand the operating conditions which maintain the liquid in a supercooled state when it flows in a tube.
In the present paper, the influence of tube dimensions and flow rates on the supercooled states was studied experimentally using tap water, and the operating conditions which could maintain the supercooling during the operation were determined.
Furthermore, experiments using glucose solutions made clear the influence of the presence of the organic solute on the operating conditions. The industrial feasibility of the process was thus confirmed and the data necessary for industrial design were obtained.View full abstractDownload PDF (3045K) -
Yosuke Kawashima, Masayoshi Nakagawa, Satoru Iuchi1981 Volume 7 Issue 5 Pages 454-458
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe heat transfer characteristics for confluent flow in a downstream region of a two-dimensional right-angled T-shaped flow section were obtained experimentally and the effects of downstream flow on heat transfer were investigated. The experiments were carried out for several sectional area ratios m and Reynolds numbers Re at test section and the ratio Q1/Q3 was varied from 1.0 to 0.0 (Q1 : upstream flow rate of main stream, Q3 : downstream flow rate of main stream). The results were as follows :
The axial distributions of local Nusselt numbers normalized by the reference point value were affected very much by m and Q1/Q3, but were insensitive to Re.
The average Nusselt numbers in axial direction normalized by the value for the case of Q1/Q3=1.0 were expressed by a function of the contraction coefficient Cc in the flow separation region.View full abstractDownload PDF (1001K) -
Yoshihiro Iida, Toshikatsu Tsuyuki, Kazushi Kawabata1981 Volume 7 Issue 5 Pages 459-464
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSAn experimental study was made of saturated nucleate pool boiling at reduced pressure. Distilled water was boiled on a horizontal, flat nickel surface. Heat flux, surface temperature and liquid temperature profiles were measured and their fluctuating behavior was also measured. The pressure Pω was varied from 0.026 to 1.03 kg/cm2 and the heat flux from 5×103 to 2×105 kcal/m2hr.
Four types of boiling patterns were found to exist. For Pω≥ 0.2 kg/cmt, the pattern was basically the same as that observed at atmospheric pressure. For Pω≤0.2 kg/cm2 and low heat flux condition, boiling occurred intermittently. The intermittency was measured versus heat flux. The intermittent boiling patterns were classified into two groups : boiling with bubble generation in the superheated bulk liquid, and boiling with bubble generation from the surface only. For Pω≤0.2 and a high heat flux condition, continuous boiling with flash-like evaporation near the liquid surface was observed. However, the main liquid layer was maintained at subcooled condition.View full abstractDownload PDF (5195K) -
Harumi Matsuzaki, Osamu Kuroda, Sankichi Takahashi1981 Volume 7 Issue 5 Pages 465-468
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe effect of spacers on electric resistance in an electrodialyzer was studied for two different cases, using disk-type spacers with open space in the center and net spacers respectively.
The effect of dead space caused by the change of cross section area on electric resistance is clarified in the relation between the experimental values, τ, and the theoretical values, β (α-1).In this paper, βis geometrical shape factor in placing spacers and α is effective area ratio of electrode to spacer.
For pattern A whenβ (α-1) is less than 0.12 and also for pattern B whenβ (α-1) is less than 0.6, the relations betweenτandβ (α-1) are identical, i.e.τ-β (α-1). For other cases, τis greater thanβ (α-1) and is a function ofβ (α-1).View full abstractDownload PDF (813K) -
Tatsuo Nishimura, Yuji Kawamura1981 Volume 7 Issue 5 Pages 469-474
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSMass transfer in tube banks was studied in the fully developed region. Local and overall mass transfer coefficients were measured by the electrochemical method.
It was found that the mechanism of mass transfer depended strongly on local flow pattern in the tube banks. The overall mass transfer coefficient was correlated well with Reynolds number, regardless of pitch ratio, based on mean velocity through minimum spacing path between adjacent cylinders. The proposed correlations were in good agreement with the other results of heat and mass transfer. It was indicated that Colburn's correlations, often used for the in-line type, is questionable.View full abstractDownload PDF (1276K) -
Nobuyuki Imaishi, Masatsugu Sasaki, Mitsunori Hozawa, Katsuhiko Fujina ...1981 Volume 7 Issue 5 Pages 475-480
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSA laser Doppler velocimeter was used to measure velocity distribution under gas-liquid interface of aqueous solutions of sodium dodecylbenzene sulfonate in a two-dimensional flow cell. The liquid, fed to form fresh surface from a submerged nozzle located at the center of the cell, was allowed to flow horizontally along the surface and then to flow down the outer sides of weirs.
The measured velocity distributions provide information on the forces acting on the surface of flowing surfactant solutions. The results indicate the existence of the following two forces :
(1) A force, prevailing on freshly formed surface, that retards surface velocity.
(2) A force, prevailing near the weirs, that accelerates surface velocity.
(1) is attributed to the dynamic surface tension effect, and (2) to the surface elasticity of adsorbed surfactant.
These surface forces exert a marked influence on the surface hydrodynamics of surfactant solutions.View full abstractDownload PDF (1210K) -
Ikuho Yamada, Hideki Mori, Yasuhiro Oyama, Setsuro Hiraoka, Eiichi Miz ...1981 Volume 7 Issue 5 Pages 481-488
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSA method is proposed to solve the design problem of multi-effect distillation for both forward feed and feed partition, based on the consideration of number of degrees of freedom and constraints in the process. In this method a direct iteration with respect to operation variables is used, but a stable solution can be obtained with a simplified algorithm.
From numerical examples of two binary separation systems of hydrocarbons, it is concluded that the feed partition type is more useful than the feed forward type from the point of view of energy saving in the process.View full abstractDownload PDF (1184K) -
Ikuho Yamada, Setsuro Hiraoka, Masao Uchiyama, Takaitsu Iwata1981 Volume 7 Issue 5 Pages 489-493
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSA method has been developed to solve the minimum reflux problem of the operation type for the ideal multicomponent distillation process, based on consideration of a region of minimum reflux ratio which satisfies the assignment of heavy and light key components.
Equations used by Underwood in solving the minimum reflux problem for the design type are employed here. However, the proposed method is characterized by a very simple algorithm for assigning the heavy and light key components which were not assigned previously in the problem of the operation type. Moreover, the consistency of the proposed method is demonstrated by numerical examples of separation processes of hexagonal and decagonal systems.View full abstractDownload PDF (789K) -
Masahiro Takahashi, Hiroshi Takeuchi, Makoto Imanaka1981 Volume 7 Issue 5 Pages 494-499
Published: September 10, 1981
Released on J-STAGE: February 19, 2010
JOURNAL FREE ACCESSThe rates of transport of cations (Li, Na, K and Rb) across a liquid membrane containing the cyclic polyether dibenzo-18-crown-6 as the mobile carrier were measured for single-and/or multi-cation systems at 298 K by using a modified diaphragm cell. The liquid membrane consisted of the polyether-tetrachloroethane held in a piece of “Millipore filter”, being sandwiched between two sheets of Cellophane.
The initial flux of cation across the liquid membrane was estimated from the over all flux across the sandwiched membrane and the cell constant for Cellophane, and the selectivity was also calculated as the ratio of the respective ion flux. The results were consistent with the equation for multi-cation system, which extended the Reusch-Cussler model.View full abstractDownload PDF (1070K) -
For the case of growth rate proportional to n-th power of supersaturationSyouji Hirota, Keisuke Fukui, Masamoto Nakajima1981 Volume 7 Issue 5 Pages 500-504
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSWhen the crystal growth rate is n-th order (2≥n≥1) with respect to supersaturation, the design calculation of a classifying column crystallizer is very complicated because the many factors in crystallization affect one another.
In this paper, design equations for a classifying column crystallizer are proposed and void fraction through a crystallizer is discussed by these equations.
A simplified design method is also proposed to apply the calculation procedure in the case of n=1 to the n-th order.View full abstractDownload PDF (883K) -
Shigekatsu Mori, Souichi Nomura, Setsuro Hiraoka, Ikuho Yamada, Shohei ...1981 Volume 7 Issue 5 Pages 505-511
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSA simulation model without clinker trouble resulting from the segreation of inert silica sand and char between the two stages, and ii) total solid hold-up in the beds can be increased without slugging condition.of the two-stage pressurized fluidized bed coal-char gasifier was of the two-stage fluidized bed gasifier are : i) the temperature of the first stage is maintained Development Laboratory, Hokkaido.
Further, the calculated results presented here clarify that the most important advantages of the two-stage fluidized bed gasifier are : i) the temperature of the first stage is maintained without clinker trouble resulting from the segregation of inert silica sand and char between the two stages, and ii) total solid hold-up in the beds can be increased without slugging condition.View full abstractDownload PDF (1078K) -
Masunori Sugimoto, Taijiro Matsui, Kenichi Yamamoto1981 Volume 7 Issue 5 Pages 512-516
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSTo investigate the optimal separating conditions and separation efficiency of a horizontal rotating conical separator, which was designed on the basis of axial segregation characteristics of solid mixture in a conical vessel, continuous classification tests were carried out under various operating conditions by using several kinds of silica sands and of alumina particles having continuous size distributions as materials.
It was found that the Newton separation efficiency of the present separator reached more than 80 % under optimal conditions determined by rotating speed of the separator, axial position of feed in the separator and cut-off size (equilibrium size), and that the optimal separating conditions for a given cut-off size could be calculated from an experimental equation.View full abstractDownload PDF (873K) -
Takeshi Takahashi, Akira Kanagawa1981 Volume 7 Issue 5 Pages 517-523
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSCollection of aerosol particles by Nuclepore filters were studied theoretically and experimentally on the basis of the three particle-collection mechanisms of inertia, interception and diffusion. Theoretical collection efficiencies based on the capillary model given by Pich were determined from numerical solutions of the equations of particle motion for inertia-interception and of the convective diffusional equation for Brownian diffusion, using flow fields obtained by numerical solutions of the Navier-Stokes equation. The calculated results were compared with the experimental collection efficiencies of Nuclepore filters measured with polystyrene latex, dioctylphthalate and gold aerosols.
It was concluded that the calculated results agreed fairly well with experiments in both inertia- and diffusion-predominant regions, although they underestimated the efficiency data in the interception region.View full abstractDownload PDF (1125K) -
Shigeki Toyama, Takaaki Ameno, Morio Sogame1981 Volume 7 Issue 5 Pages 524-531
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSThe turbulent dissipation energy was measured in a non-baffled agitated vessel with a hot-film anemometer.
The energy calculation was subjected to the differentiated signal of turbulent fluctuation rather than to conventional energy spectrum method, because the former provided better results than the latter according to our investigation. The results also indicated that vertical insertion of hot film probe was better than horizontal.
The turbulent dissipation energy depends largely on location, and its values were expanded over the range of several multiples of ten. The value at each location was proportional to power input, and there was little change in shape of the contour map. The integrated amount of this energy over the bulk liquid was only below 20 % of the actual power input.
This result was verified by energy balance derived from the momentum equation considering the main flow vector fluctuation in the discharge flow region.
The amount of viscous dissipation energy in the boundary layer on the vessel wall was also calculated from the above equation and this was almost the same as that of turbulent dissipation energy in the bulk liquid.View full abstractDownload PDF (3539K) -
Yoichi Nagase, Hiroo Yasui, Tetsuhiro Sumimoto, Motomi Takagi1981 Volume 7 Issue 5 Pages 532-537
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSA compact unit was devised from a pair of circular beams crossing each other perpendicularly and of photosensors for each beam. This unit was immersed in liquid. Only the bubble which passes through the intersection zone of the beams gives similar response curve of light detected on the sensors. The curve was compared with theoretical ones.
In theory, bubbles were assumed to be rotating ellipsoids which moved toward their axes of rotations. Variation of light detected on the sensor through refraction within bubble and reflection on bubble surface was calculated geometrically for the bubble passing through the intersection zone. Results of calculations showed that it is convenient to use a set of parameters to estimate bubble volume and major-to-minor radius ratio for curve recognition. These were average gradients of the initial response and maximum light recovery due to refraction of light within the bubble.
Bubbles moving in an inclined direction to the beam in the detecting zone gave an unsymmetric response curve. An Approximate method of estimating equivalent diameter and alb is also presented for the case.
Bubble speed was calculated from the time covered by the bubble and equivalent bubble size. The direction of bubble motion can also be recognized if the photo sensor is divided into many small elements, at least four.View full abstractDownload PDF (1016K) -
Kunio Watanabe, Hiroshi Takeuchi, Yoichi Nagase, Tetsuhiro Sumimoto, M ...1981 Volume 7 Issue 5 Pages 538-543
Published: September 10, 1981
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSDownload PDF (932K)
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