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Volume 22 (1991 - 199･･･
- Issue 3 Pages 145-
- Issue 2 Pages 69-
- Issue 1 Pages 5-
Volume 22, Issue 2
Displaying 1-7 of 7 articles from this issue
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Akihiro TANAKA, Yoshiyasu AIHARA, Makoto NARA, Minoru ITOU, Tomoyuki S ...1991 Volume 22 Issue 2 Pages 69-77
Published: November 29, 1991
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe 1/3 scaled model test was carried out to determine the characteristics of air distribution in a windowless piggery equipped with the positive pressure ventilation system. This system provided the air from the attic to the piggery room through the slots on ceiling by ventilation fans. The internal air is exhausted through the slits on both side walls. The ventilation rate for the scaled model was adjusted for both summer and winter conditions. The air velocity and the air temperature for the prototype were also estimated using the law of similarity based on Archimedes number.
The airflow patterns on the cross section were affected by the incoming jet air direction under the summer condition. Under the winter condition, the uniformity of air temperature was affected by the number of air changes, and the temperature difference between the air discharged from the attic and the representative point in the piggery room. Longitudinal variation of air velocity and air temperature were not uniformly. The air velocity and the air temperature were depended on the longitudinal position of structure. These were significantly induced by the longitudinal not uniformly variation of incoming jet velocity from the slots on ceiling. The incoming jet from the slots on ceiling was induced by the positive pressure difference between the attic and the piggery room. There are two points would be noticed when a structure with this ventilation system being designed. One is to increase the positive pressure in the attic, and the other is to adjust the positive pressure in the attic uniformity.View full abstractDownload PDF (3283K) -
Design of the Drying System with Heat-PumpRyuzo TAKEUCHI, Jiahu SUN, Masatugu DOI, Hiroaki YAMAMOTO, Hisashi HOR ...1991 Volume 22 Issue 2 Pages 79-85
Published: November 29, 1991
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSIn order to recover the exhaust-heat of a drier including latent-heat and utilize it for heating the inlet-air, a practical scale drying system with a heat pump was designed and the performance of the heat pump were tested.
Experimental apparastus is composed of heat pump system with compressor, evaporator, condenser and air circulated system with ducts (∅250mm), drying chamber (700×1200×1200mm) and blower.
As the results of heat-pump performance test, the evaporator had a capacity absorbing heat of 4000-5900kcal/h and the drying system can deliver a warm air of temperature 50-60°C, relative humidity 14-26% to the drying chamber. The coefficient of performance of the heat pump was about 4-5.View full abstractDownload PDF (769K) -
Susumu MORIMOTO, Kiyohiko TOYODA, Ryuzou TAKEUCHI, Hatsuo KOJIMA, Dan ...1991 Volume 22 Issue 2 Pages 87-94
Published: November 29, 1991
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe objectives of this study are to develop a simple mathematical model which can accurately predict the moisture content of wheat in the thin-layer drying process. Then a thin-layer drying experiment of wheat was carried out.
The drying operations of wheat in Japan are finished at moisture content of 14 to 15% w.b. generally. The data under 14% w.b. is not important.
To improve prediction accuracy above 14% w.b. by the drying model, thin-layer drying process of wheat which could be divided into three drying periods, was investigated. It was assumed that a drying process of wheat could be composed of the surface drying of wheat and intra-kernel drying, then a two-term exponential model could be fitted to those drying. As a result, it was found that the two-term exponential model could interpret drying characteristics of thin-layer of wheat accurately. The relations between parameters of the two-term exponential model and drying air temperatures and initial moisture contents of wheat were defined. Tempering effect was discussed as an example of application of the two-term exponential model.View full abstractDownload PDF (1049K) -
Jisheng LONG, Hidehiko TAKAHATA, Kazutaka UMETSU, Hideo HOSHIBA, Ichir ...1991 Volume 22 Issue 2 Pages 95-102
Published: November 29, 1991
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThis report deals with two points: the relationship between walk-through loads and walking conditions of cattle, and the factors influencing the measurement accuracy of the livestock walk-trough scale. The walk-through loads showed a pattern of two peaks in normally walking cattle, and a pattern of one peak in trotting cattle. Faster cattle produced more abrupt changes in their walk-through loads. The use of the walk-through approach had an effect on evening out cattle walk-through loads.
The experiment results showed that the number of steps cattle take walking through the scale platform, cattle gait speed, and the walk-through approach were the main factors influencing measurement accuracy. Fewer steps or faster cattle produced greater measurement errors. The walk-through approach improved the measurement accuracy greatly. The individual error, accuracy and precision of measurement were within ±1.01% of bodyweight, ±0.4kg and 2.04kg respectively, when the walk-through approach was used. These results clearly showed that a scale platform of 3.50m can provide reasonable measurement accuracy which meets the requirements of cattle management very well when the setting condition is satisfied.View full abstractDownload PDF (2403K) -
Rattanachai PAIRINTRA, Osamu KITANI, Hiroshi SHIMIZU, Toshinori KIMURA ...1991 Volume 22 Issue 2 Pages 103-110
Published: November 29, 1991
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSFor both up-flow and down flow gasifiers, pyrolysis process is the main process for volatile and charcoal generation. Therefore, investigations into understanding the pyrolysis process is particularly important in the design of up-flow and down flow gasifier. Basic experiments of biomass pyrolysis were conducted and fundamental data of pyrolysis process were accumulated. The productions of pyrolysis were ash, pitch, charcoal, liquid tar and gas. The total heating value of pyrolysis gas was 10, 720kJ/kg, while the heating value of liquid tar was 17, 700kJ/kg. In order to obtain valuable liquid fuels from liquid tar, atmosphric fractional distillations were conducted. Distilled liquid tar which was obtained at the lowest distillation temperature was yellowish and the heating value was 25, 500kJ/kg. This distilled liquid tar was mixed with diesel fuel and used for diesel engine. It was found that engine power decreased with the increase of mixing ratio.View full abstractDownload PDF (849K) -
Toshinori KIMURA1991 Volume 22 Issue 2 Pages 111-116
Published: November 29, 1991
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThis study reveals the relationship between processing condition and quality of parboiled rice, focusing on the hardening characteristics of rice grains after cooking.
The experimental results showed that not only cooking conditions but also drying conditions greatly affected the hardness of parboiled grains. Especially, the condition of moisture migration during drying process that came from the particular relation between the final moisture content and the drying period played very important role in the hardening characteristics of parboiled grains.View full abstractDownload PDF (670K) -
Water Management for Aquatic Animal and Nutrient Characteristics of the Waste WaterTakahiro SAITO, Fusakazu AI, Kengo WATANABE, Seishu TOJO, Tessho UCHID ...1991 Volume 22 Issue 2 Pages 117-124
Published: November 29, 1991
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSCombined Aquatic Animal and vegetable production system is developed and investigated. It is anticipated that the waste water from fish culture could be put into better use through recycling system to save water and nutrient. Basic data required to develop a combined fish and plant production system were determined from an experimental system consisting of a fish tank, hydroponic bed and water management section (nitrification) in a greenhouse. Fish tank and biofilter water temperatures could be maintained at a suitable range within the whole year, but the air temperature in the vegetable section at times was more than 35°C and necessary control was required. Nitrification (the oxidation of NH4+ to NO2- and NO3-) is required for fish and it took 45 days to breed microorganism which facilitates this process. After this period, the recycle was confirmed to be working satisfactorily since only NO3- could be detected. Hence, for the water management, linear regression equations could be given in terms of the elements in water and the number of days. Using the equations, the expected nutrient characteristics of waste water after 85 days were determined and it was found that the resulting nutrient balance was almost the same as that in hydroponic solution when KOH was added to maintain pH level, however the resulting concentration of nutrient was quite low for plant production.View full abstractDownload PDF (962K)
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