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Volume 7 (1990)
- Issue 3 Pages 201-
- Issue 2 Pages 105-
- Issue 1 Pages 1-
Volume 7, Issue 1
Displaying 1-7 of 7 articles from this issue
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Shoichiro FUKUSAKO1990 Volume 7 Issue 1 Pages 1-32
Published: 1990
Released on J-STAGE: October 11, 2011
JOURNAL FREE ACCESSA comprehensive review of recent developments in research on a variety of water-freezing and ice-melting problems has been performed covering such subjects as analytical and numerical methods on freezing and melting problems, freezing of water without main flow, freezing of water with main flow, freezing of lake and river, freezing of seawater, atmospheric icing and sea icing, and various melting of ice. An attempt was furthermore made to review the thermophysical properties of pure ice and sea ice.View full abstractDownload PDF (2125K)
Paper
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Fumio KATOH1990 Volume 7 Issue 1 Pages 33-42
Published: 1990
Released on J-STAGE: October 11, 2011
JOURNAL FREE ACCESSThe spray dryer, which will satisfy the future demands, is developed through the engineering approach in accordance to 3A- Sanitary Standards in the food industry. The main points are as follows.
1) A High Discharge-Single Swirl Atomizer is adapted for practical use; which can mix effectively with single hot air jet.
2) An optimum jet distributer eliminates swirling components in the jet.
3) Secondary air from the periphery of the jet controls the diffusion and Coanda effect of the jet.
4) The drying chamber's wall is controlled at a temperature below the "Sticky Point" of products.
5) An optimum cooler is included in the bottom of the drying chamber.
The above devices prevent undried particles from adhering to the drying chamber's wall, improve the fluidity of products as powder particles, and bring about high efficiency, stable and high quality long lasting productivity.View full abstractDownload PDF (603K) -
1st Report: Cycle Characteristics with Pure RefrigerantsNoboru KAGAWA, Masahiko UEMATSU, Koichi WATANABE1990 Volume 7 Issue 1 Pages 43-56
Published: 1990
Released on J-STAGE: October 11, 2011
JOURNAL FREE ACCESSIn recent years there has been an increasing interest of the use of nonazeotropic binary mixtures to improve performance in heat pump systems, and to restrict the consumption of chlorofluorocarbon (CFC) refrigerants as internationally agreed-upon in the Montreal Protocol. However, the available knowledge on the thermophysical properties of mixtures is very much limited particularly with respect to quantitative information. In order to examine cycle performance for Refrigerant 12 (CCl2F2) + Refrigerant 22 (CHClF2) and Refrigerant 22 + Refrigerant 114 (CClF2-CClF2) systems which are technically important halogenated refrigerant mixtures, the heat pump cycle analysis in case of using pure Refrigerants 12, 22 and 114 was theoretically carried out in the present paper. For the purpose of systematizing the heat pump cycle characteristics with pure refrigerants, the cycle analysis for Refrigerants 502, 13B1, 152a, 717 (NH3) and 290 (C3H8) was also examined. It became clear that the maximum coefficients of performance with various refrigerants were obtained at the reduced condensing temperature being 0.9 when the same temperature difference between condensing and evaporating temperature was chosen.View full abstractDownload PDF (674K) -
Shoichiro FUKUSAKO, Kunihiko KITAYAMA, Makoto TAGO1990 Volume 7 Issue 1 Pages 57-64
Published: 1990
Released on J-STAGE: October 11, 2011
JOURNAL FREE ACCESSAn experimental study has been performed to determine free convection heat-transfer characteristics along a horizontal ice cylinder immersed in quiescent seawater. The measurements were carried out in 3.5% seawater for ambient temperature T∞=1.8 to 20.3°C. The local heat-transfer coefficient and average Nusselt number characteristics at the ice-seawater interface on steady state were extensively studied using such parameters as ambient temperature and Rayleigh number. The temperature field in the ice cylinder was determined from the observed ice profile by a point-matching method using a series solution of the Laplace equation in the ice. A monotonic downward-direction flow takes place along the horizontal ice-cylinder surface unlike those for pure water. Visualization photographs of the flow pattern and ice profiles are presented for T∞ = 2.9, 7.1, 11.9, and 16.0°C. It was found that the average heat transfer along the horizontal ice cylinder might be correlated using the parameter Ra0.25.View full abstractDownload PDF (506K) -
Akio MIYARA, Shigeru KOYAMA, Tetsu FUJII1990 Volume 7 Issue 1 Pages 65-73
Published: 1990
Released on J-STAGE: October 11, 2011
JOURNAL FREE ACCESSCOP of a heat pump using nonazeotropic refrigerant blends(NARBs) of R22 and R114 is calculated under the conditions that the heat pump thermal output and the inlet and outlet temperatures of the heat sink and source water are given. Heat transfer characteristics of the condenser and evaporator are either given as FK-parameters, which are the products of the heat transfer area F and the overall heat transfer coefficient K, or they are calculated with the empirical equations of the heat transfer coefficient and pressure drop. COP of NARBs is higher than that of pure refrigerants in case of large inlet and outlet temperature difference of both heat sink and source water and high heat transfer performance of heat exchangers. In case of same FK-value, heat transfer lengths of condenser and evaporator using NARBs are longer than those using pure refrigerant. The degree of improvement in COP estimated under the same heat transfer lengths condition is smaller than that estimated under the same FK-values condition.View full abstractDownload PDF (375K) -
Yoshinori TAKAISHI, Kosei OGUCHI1990 Volume 7 Issue 1 Pages 75-84
Published: 1990
Released on J-STAGE: October 11, 2011
JOURNAL FREE ACCESSThe paper describes measurements of vapor pressures for R 12/0il and R 22/0il mixtures. Refrigeration oil employed in the present study is an alkyl benzene base synthetic oil. The measurements have been carried out in the range of temperatures between 283.15 K and 333.15 K for both R 12/0il and R 22/0il mixtures using the same refrigeration oil. Correlations that interpolate the experimental vapor pressures with average pressure deviations of 0.21% for R 12/0il system and 0.42% for R 22/0il system have been reported. Furthermore, a calculation method based on a theory of vapor-liquid phase equilibrium has been tested for the systems using the present experimental data.View full abstractDownload PDF (462K)
Technical Note
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Fuyuo OHTA, Tetsuo YAMADA1990 Volume 7 Issue 1 Pages 85-90
Published: 1990
Released on J-STAGE: October 11, 2011
JOURNAL FREE ACCESSThe correlations were examined between the concentrations of K, P, Na and Cl of the unfrozen portions in the fish muscle juices kept at -6°C, and the denaturation rate of protein in the fish muscles frozen-stored at -6°C.
1) The denaturation of protein occurred most greatly in mackerel, next greatly in black porgy, while the denaturation was scarcely observed in the case of both rock bream and tuna. 2) The level of ion concentration of the unfrozen portions of muscle juices was higher in K and P than in Na and Cl. The concentration of each component was different among different species of fish. 3) To the difference of denaturation rate among four species of fish, the concentration of K was inversely proportional, those of Na and Cl proportional, and the concentration ratios of P/Cl and K/Na were both inversely proportional. 4) The content ratios between theminerals (P/Na and K/Na) in fish on the market. which were calculated from the literature values, were proportional to the already-reported cryo-tolerance of protein among species of fish. Thus, it was suggested that phosphates and chlorides may be related compositely to the denaturation of protein in frozen-stored fish.View full abstractDownload PDF (242K)
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