A wastewater treatment plant (Aerated Filter), combined with the operational advantages of complex-media filter and the efficiency of activated sludge, was designed to give an effluent with good quality for reuse of recycled wastewater, providing consistent and relatively maintenance-free service. In this study, the experiments on the performance in the treatment of the plant were conducted, using pilot and full-scale treatment facilities. The results revealed that the quality of treated water was not dependent on activated sludge characteristics, the amount of the treated water was linear to the square root of water head of filtration, and the average reductions in COD and BOD across the facilities were 98 and 85%, respectively. In addition, it was found that COD and BOD were mostly reduced in the upper of the filtration bed, however, those were also reduced in the lower on the case of the load being placed in that, and the quality of treated water was dependent on soluble COD which was included in the aeration zone.

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The storage tank efficiency of stratified-type storage tank in a heat storage system is effected by factors related to system design as well as thermal property of the tank. The authors developed a mixing model of stratified-type water tank in order to simulate thermal responses of the tank in practical storage systems. Many computerized system simulations were carried out under various design factors using a simulation program combined with the mixing model. The effect of the design factors on the storage tank efficiency quantitatively was analyzed by the design of experiments method in which experiments are replaced by the simulations, and the simple estimation tables of the storage tank efficiency were prepared in the same manner as the multi-connected complete-blending tank in Part 3.

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Because of the recent increasing velocity in pipe, the elements in water pipe line systems are in danger of cavitation occurrence. The cavitation causes detrimental phenomena such as noise, vibration and sometimes damage of materials. Therefore, in the plan and design of such pipe line systems, it is very important to evaluate the energy losses as well as to predict the cavitation performances in it. This paper dealt experimentally with the cavitation performances of the confluent pipe with a single lateral pipe. First, for the T-shaped confluent pipe with equal square cross sectional areas of lateral and main pipes, the aspects of cavitation occurrence were observed in detail and its critical conditions were found. Then, the effects of the cross sectional area ratio of lateral to main pipe, the confluent angle, and the roundness at the junction part on the cavitation performance were experimentally investigated. The following conclusions are obtained. 1) Though the cavitation occurs slightly, there is no remarkable change in the loss coefficients for main and lateral flows due to confluence. 2) The desinent cavitation numbers are not so much affected by Reynolds number for the constant ratio of flow rate and expressed only by the ratio of flow rate. 3) For the T-shaped and y-shaped confluent pipes with equal cross sectional areas of lateral and main pipes, the cavitation appears in separating stream from downstream side edge of junction. 4) Increasing the area ratio of lateral to main pipe, decreasing the angle of confluence and rounding off the downstream corner of junction, the cavitation performances become higher. 5) For the T-shaped confluent pipe with a half area ratio of lateral to main pipe, there is not only the separating cavitation but also the vortex cavitation formed by secondary flow at confluent part.

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Thermal boundary layer in the corner of wall should be taken into account for the accurate calculation of heat transmission through the corner of the wall. However, most studies on thermal boundary layer have concerned flat wall, whether horizontal, vertical, or oblique. Thus, little research has been conducted concerning thermal boundary layer in the corner of wall. In our previous report, we analyzed the thermal boundary layer in the corner of two vertical right-angled wall in laminar free convection. In the present study, we have analyzed the thermal boundary layer in the corner of two vertical right-angled wall and horizontal bottom wall in laminar free convection. Here, thermometry method and formulation method of the shape of the thermal boundary layer in the corner of wall are discussed. Also, measuring the temperature by thermocouple, empirical formula is proposed concerning the thermal boundary layer in the corner of two vartical right-angled wall and horizontal bottom wall in laminar free convection. To ascertain that this empirical formula can be applied irrespective of the difference of temperature between wall surface and the air, verification experiment is conducted, simulated by numerical analysis (Finite Element Method). The results confirms that this empirical formula can be applied in cases where the difference of temperature between wall surface and the air is 15〜80℃.

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The Kita Ward Office Building and its air-conditioning system were designed with the intention of efficiently utilizing energy during the lifetime. The actual performances of energy conservation of the system were analyzed in the previous papers. As the grave role of the air-conditioning is to maintain the comfortable and hygienic conditions of indoor environment, it is necessary to verify the actual conditions of it through measurements and questionnaires. For that purpose, environmental variables such as temperature, humidity, carbon dioxide concentration, dust concentration and illuminance, and conditions which affect these variables, such as numbers of people, states of Venetian blinds and lighting, infiltration through entrance doors and clo value etc. were measured. And the questionnaires to occupants working in the building were carried out. Measurements and Questionaires were conducted in the summer of 1984 and the winter of 1985. The results are summarized as follows; 1) In the summer, the mean values of the actual room air temperature were about 1℃ higher than the designed condition on the first and the second floors, where the infiltration from the entrance doors had great influences on the heat loads of these rooms. In the winter, they were almost the same as the designed condition in all floors. The reason is that the system has had more sufficient capacity of heating in winter than one of cooling in summer. 2) The measurements showed that the concentrations of carbon dioxide and dust were kept within the allowable levels prescribed by the Building Management Code in Japan. The result of questionnaires, however, showed that about a half of the occupants complained about the contamination of the room air, which was caused by smoking. 3) Approximately 40% of the installed fluorescent lamps had been turned on even in the absence of the occupants. This fact indicates that the improvement of the switching circuits or zoning in the lighting system or the use of the task-lighting method could bring great effects for energy conservation.

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This paper presents an experimental study on the characteristics of natural convection and radiation heat transfer in a rectangular parallelepiped air space, which is enclosed by two opposite heated and cooled vertical walls and the other adiabatic walls and is separated by a partition plate. The heated and cooled walls are kept under uniform temperature, and the emissivities of them and the partition surfaces are changed from about 0.1 to 0.9. The Rayleigh number based on the temperature difference between the partition and air and the height of the partition ranges 3×10^7 to 10^8. The grade of temperature stratification of air, distributions of temperature, heat flux density and heat transfer coefficient along the height of the partition, and the effect of thermal radiation upon them are clarified. The data on the average heat transfer coefficient can be correlated by the equation for an isolated single plate with uniform temperature, if the air temperature at the upstream end and the wall temperature at the mid height are taken as respective representative ones. Also is shown a procedure to predict air temperature distribution and heat flow rate through the partition for given values of heated and cooled wall temperature by using experimental equations obtained in the present study.

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The solar shading characteristics of a window with a roll curtain are discussed. Two box style experimental equipments were made to examine the solar shading ability of windows and heat transportation of air flow through side slits between the window and the roll curtain. The quantitative estimation of the air flow heat transportation makes it possible to divide the solar shading effect of the roll curtain into the effect of transmission, radiation, convection, and ventilation. The results in this paper are as follows: 1) One experimental box was made for outdoor experiments to examine air distribution of the space between the window and the roll curtain. Air flow comes in from the lower part of side slits and goes out through the upper part. In the central area of the window, air turbulence caused by ventilation is small so that there is temperature stratification of air in case of low velocity indoor air flow near the roll curtain. In case of rather high velocity (0.7〜0.8m/s), the temperature stratification of air is broken, but the air turbulence is small when the width of slits is about 5mm. 2) The other box was made for the indoor experiments. It can measure the convective heat transportation through the slits by replacing the solar heat absorbed by a window glass pane heat generation within the glass. The value of the transported heat is shown in the chart which uses the width of the slits and the distance of the window and the roll curtain as parameters. 3) Solar heat gain coefficient (SHGC) of window to which a solar reflecting film was attached were compared with inside pasted film, a window with outside pasted film, a window with tightened air space. As a result, the SHGC of the window with the roll curtain is smaller than that of the window with inside pasted film, and the effect of roll curtains made of high solar reflective material is proved.

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The purpose of this study is to examine the sun control effects of various shading devices attached to the inside of the window. We have constructed an apparatus for the measurement of heat transfer components and presented its outline. The apparatus consists of i) a window model (The window glass and the shading devices are replaced by plane heater which can simulate the absorbed solar heart.), ii) a wind tunnel in which an vertical wall is provided with the window model (The inside space of the tunnel corresponds to the outdoors. Heat flow to the outdoors from the window is controlled by changing the wind velocity in the tunnel.), and iii) controlling and measuring instruments. Using this apparatus without providing the method with solar radiation, we can conduct an indoor experiment under hypothetical outdoor weather conditions. Examinations of the errors proved that the apparatus realizes the measurement within the error of 5%. Furthermore, we have reproduced an example of an outdoor experiment using the apparatus. Judging from the thermal images at the window surface, the reproduction is satisfactory.

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This report describes an experimental study carried out to investigate the effects of the installation of a horizontal baffle plate in a rectangular thermal storage water tank on the flow behaviour in the tank and the thermal characteristics of the tank, by flow visualization and the measurement of transient water temperature response for the case in which hot water was discharged through a rectangular duct into the upper part of the tank filled with cold water. Experimental parameters varied included hot-cold water temperature difference, flow rate, duct width and baffle plate length. From the experimental results, semi-empirical equations suitable for predicting the dimensionless equivalent tank height of the amount of mixed cold water into hot water region, Δh/b, and the thermal storage efficiency in the arbitrary region of the tank, η_<V'>, were both deduced as the functions of the Archimedes number based on inflow conditions, Ar_0, the Peclet number of liquid, Pe, and two dimensionless geometric parameters φ_1 and φ_2. The general conclusion reached was that, for relatively low Archimedes numbers, the installation of a baffle plate contributed to improve the thermal storage efficiency appreciably due to the prevention of the occurrence of short-cut flow.

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