The traps connected to sanitary fixtures perform the hyginical functions. However, the trap seal is induced a water loss by the selfsiphonage or the pressure variation in the drainage systems. The authors introduced the macroscopic mechanical energy balance in regard to the motions of the trap seal water and numerically analyzed the mechanism of a trap seal-loss. Results of this study are as follows; 1) Comparing to the measured values, a certain degree of approximation was obtained. 2) The motions of the seal water were understood well depending on this theory.

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The flow in a miter bend is very complicated. The authors have reported the experimental and theoretical results of the flow in miter bends with different bending angles and areal ratios in turbulent flow, and in laminar flow adjacent to the critical Reynolds number. In this report the results for the flow in miter bends at the Reynolds number much lower than the critical one are reported. First, for the consideration of general features of the flow, the Navier-Stokes equation describing the laminar flow field in the plane miter bend was solved numerically by means of a finite difference relaxation method. The values of stream function, vorticity and velocity distribution are obtained. The results show that the flow changes extremely near the convex and the concave corner. Next, the experiments for the several miter bends with rectangular crosssection were made. The results show that the flows are almost two-dimensional in spite of bending angles and areal ratios when the Reynolds number is very low, but that they become three-dimensional with the increase of the Reynolds number. Finally, the computed results were compared with the experimental results. They coincide fairly well when the Reynolds numbers are sufficiently low and the actual flows are two-dimensional.

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The purpose of this paper is to propose a economical design method for duct systems, which have a number of air ducts and fan, by means of Dynamic Programming. Firstly, the system criterion function which can be expressed as the sum of initial cost and operating cost is formularized. Applying the principle of optimality, the functional equation is derived, and performing the computational procedure, the optimal solution can be obtained. Secondly, the author mentions to expand the generalized systems which have branch ducts, and shows how to select fan. Finally, performing a numerical computation example, the author considers the practical application of this method on comparing with conventional method.

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Experiments are performed of plate-type evaporative coolers in which almost all of the spray water forms vertical falling films along parallel plates with tubes. Data on heat-transfer coefficient and mass-transfer coefficient are presented to be compared with those of multi-tubular evaporative coolers in which the spray water forms both films and droplets. Typical examples of characteristic curves for the operation of evaporative coolers are also presented, which can be obtained by means of the method described in Part 1.

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In this paper, we make clear the performance of a magnetic filter in which the ferromagnetic wires are arranged perpendicular to the air flow (perpendicular stream type of magnetic filter). The perpendicular stream type of magnetic filter has been investigated by Watson, Luborsky et al. and the capture radius (i.e. single wire collection efficiency) was calculated based on the particle trajectory model. In their work the calculated capture radius was rather larger than the experimental results. The authors, in analytical and experimental estimation of the collection efficiency of air-borne particles, take into account the three points as follows. Firstly, in the previous models, as the flow pattern around a circular wire, were used the potential flow for high Reynolds numbers and the viscous flow due to Lamb for low Reynolds numbers. The actual flow for high Reynolds numbers, however, deviates very much from potential flow because of the dead water with eddies conditioned by the breaking away of the boundary layer. On the other hand, the viscous flow solution due to Lamb for low Reynolds numbers, exactly satisfies the boundary conditions at the cylinder, however, it doesn't pass over to the undisturbed parallel flow at infinity. Then in our model, as the flow field around a cylinder, is used the numerical solution of steady two-dimensional flow of an incompressible Newtonian fluid past the circular cylinder governed by the Navier-Stokes equations. Secondly, the inertia forces acting on a particle which could be usually neglected in slurry treatment by previous investigators, cannot be ignored for the magnetic filtration of aerosol particles. In the present model, the authors solve the differential equation of the trajectory of particles without neglecting the inertia terms. Thirdly, in the previous analyses of the magnetic filtration, the magnetic particle was assumed a sphere. The actual magnetic particle usually isn't spherical. So, in the comparison of the experimental collection efficiency with calculated results, on the analogy of the Stokes' diameter which is adopted in investigating the motion of particles in gravity, we choose the measured diameter based on the velocity of magnetic particles precipitating in the low gradient magnetic field near the polar of the permanent magnet.The inertia effect of fine particles on capture radius, which can be usually neglected in high gradient magnetic filtration for slurry treatment, cannot be ignored for removal of air-borne particles. Numerical calculation shows that the inertia effect makes a great difference between for the system with magnetic field parallel to air flow across the cylindrical wire and for that with magnetic field perpendicular to air flow. The capture radius calculated for the flow field in the intermediate Reynolds numbers region around a circular wire is smaller than that for potential flow field. Experimental data on model filters, which are made of a uniform parallel arrangement of wires oriented ar right angles with the flow direction, have shown good agreement with the calculated results.

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In the preceding papers, the authors have shown that high gradient magnetic filter (HGMF) is an effective method of removing small, weakly magnetic particles from gas streams. Several widely used industrial processes, primarily in the iron and steel and ferroalloy industries, emit large quantities of waste gas containing magnetic particles. Particulate emissions from these processes are presently controlled by conventional technologies such as electrostatic precipitation, wet scrubbing, and fabric filtration. HGMF offers the opportunity of combining magnetic forces with conventional filtration phenomena (primarily inertial impaction) to enhance the collection efficiencies and thereby reduce the overall cost of particulate emission control. The collection efficiencies of HGMF depend on the following parameters. 1) With respect to the filter, the intensity of the applied magnetic field, the air velocity, the diameter of ferro-magnetic wires, the intensity of magnetization of wires, the packing density, the filter thickness and the relative position of the wires, the applied magnetic field and the air stream. 2) With respect to the air-borne particles, the size distribution, the magnetization and the density. 3) As regards the exhaust gases containing magnetic particles, the viscosity, the temperature and the density. Among the various parameters mentioned above, the size distribution and the magnetization of the air-borne particles are the key parameters that will determine the practicality of fine particle emission control applications. Firstly in the present paper, we measure the size of air-borne magnetic particles from the sedimentation speed in the low gradient magnetic field near the polar of the permanent magnet. The measured diameter is independent of the particles' shape and corresponds to the Stokes' diameter which is measured from the sedimentation speed in gravity. Secondly, we measure at various temperatures the magnetic properties of basic oxygen furnace (BOF) dust, electric arc furnace (EAF) dust and dust of gas cutting of vehicles. The measured results show that all of their dusts have the ferromagnetic properties and have the Curie point at about 600℃. The authors make clear that high gradient magnetic filter (HGMF) has the potential utilization as a method of controlling particulate emissions at high temperature in steel, ferroalloy and various other industries.

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Heat storaging is an urgent demand for the saving of heat energy. This paper dealt with the storage of energy in a solid sensible heat storage unit of packed pebble bed type. In this storage unit, heat transfer gas exchanges the heat with pebbles during passing through the narrow zigzag channels in the packed bed. Since the amount of storaged thermal energy is time dependent, it is necessary to know the transient response characteristics of the heat storage unit. Dynamical heat transfer problems in the pebble bed were analized and the results of calculation were compared with the experimental ones which were obtained with a small scale alumina spheres- air heat storaging system. The agreement was fairly good.

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The number of solar cooling, heating and hot water supply systems has been increasing steadily in Japan in these recent years. The performance of such systems, however, is dependent on a number of factors, and it is very difficult to foresee how each piece of equipment will perform as a part of the system even when the performance of individual equipment is known beforehand. At present, only few papers can be found which deal with the quantitative analysis of effects of various factors on energy saving and economy as described in this report. Although economic advantages of solar cooling, heating and hot water supply systems are not firmly established at this stage, attempts have been made in this paper to pinpoint what sorts of impacts are necessary to make such systems econmically feasible, with such parameters as future energy cost, equipment durability, system cost reduction, system performance improvement and available financial aid being taken into consideration. Assumed for this study was a solar cooling, heating and hot water supply system as applied to a 100m^2 dwelling house forming one unit of a semi-detached house. A total of nine factors which were thought to be importantly involved in the system design were selected for analysis. These nine factors were: locality; collector area (both of which have four levels); insulation properties of the building; thermal storage capacity; insulation properties of thermal storage; design temperature; locations of back-up heater; orientation of collectors; and inclination of collectors (all of which have two levels). Possible combinations of these factors amount to as many as 2048; however, by the use of DOE method, the number of factor combinations to be computed was reduced to only 64. The systems subjected to the analysis were simplified models each composed of one pane selective surface collector, a thermal storage, an auxiliary heater, pumps, and room units. For the systems serving also a cooling purpose, a hot water heated absorption chiller and a cooling tower were added. Hourly cooling and heating loads were obtained by the inconstant heat load calculations. Using such loads as input, system simulation was carried out to compute heat collected, auxiliary heat, power consumption by pumps, heat loss from the thermal storage and piping, and so forth. In this present report, the outline of the DOE and the algorithm of mathematical models will be described. The results of the experiment and the analysis thereof will be reported in the succeeding paper. It is to be noted that the study described in this paper was made as a part of the research studies for 1977 as conducted by SHASE (Japan)'s Committee for solar Heating-Cooling Systems which was commissioned by Ministry of International Trade and Industry (MITI) to perform such research studies under MITI's Sun Shine Project.

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In applying solar cooling, heating and hot water supply system to a house having total floor area of 100m^2, nine factors which were thought to be very meaningful for design were selected as parameters from among nemerous factors closely related to the solar system, and the design of experiment was worked out for the purpose of qualitative and quantitative analyses. In this report, 64 cases of computer simulations (128 cases in total, since experiment is divided into two types, one with cooling system and other without it) were performed according to the DOE described in Part 1, and analysis of variance was made for % solar, energy saved, saved energy cost and economy (1/FOM). F-tests for effect of each factor or interaction of factors were conducted, and their results are represented as estimated effect tables (Tables 4 thru 11). With the aid of these tables, energy saving effect and economy in various cases can be calculated manually. Results of analyses of factors and their interrelation are as shown below: 1) Locality: This is a factor of medium significance for a cooling, heating and hot water supply system. A heating and hot water supply system is greatly affected by locality. Energy saving effect was proved to be conspicuous in a region where there are found large loads and rich solar radiation and to be less conspicuous in a warm region or a place of less solar radiation. 2) Insulation properties of the building: Heating loads decrease remarkably by improvement of the insulation properties. The decrease of energy saved is proportional to that of heating loads. If capacity of components of equipment is lowered according to the decrease of heating load, the system can be economically justified. 3) Collector area: Although the larger collector area bears the higher % solar and energy saving effect, a system of smaller collector area has an economic advantage. 4) Thermal storage capacity, and 5) Insulation properties of thermal storage: A system having larger thermal storage capacity is effective especially in heating. However, if insulation of thermal storage is inferior, such effect is apt to be counteracted. 6) Design temperature: It is preferable that efficiency of heat collection be enhanced by lowering temperature of heat collected, unless efficiency of components on the secondary side is lessened by such lowering. 7) Location of back-up heater: Whether back-up heater is installed parallel to or in series with thermal storage has little influence on the performance of solar system. 8) Orientation of collector, and 9) Inclination of collector: Orientation of collector has a great influence in winter when declination of the sun is little. Naturally, a heating and hot water supply system is effected by large inclination of collector. A system which also performs a cooling function should preferably have little inclination based on summer conditions, in disregard of demerit to be anticipated in winter. In Part 3, conditions to justify the economy of solar system and moreover energy saving will be considered by means of the estimated effect tables. It is to be noted that the study described in this paper was made as a part of the research studies for 1977 as conducted by SHASE (Japan)'s Committee for Solar Heating-Cooling Systems which was commissioned by Ministry of International Trade and Industry (MITI) to perform such research studies under MITI's Sun Shine Project.

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In applying solar cooling, heating and hot water supply system to a house having total floor area of 100m^2, nine factors which were thought to be very meaningful for design were selected as parameters from among numerous factors closely related to the solar system, and the design of experiment was worked out for the purpose of qualitative and quantitative analyses. As described in Part 2, 64 cases of computer simulations (128 cases in total, since experiment is divided into two types, one with cooling system and other without it) were performed according to the DOE described in Part 1, and analysis of variance was made for % solar, energy saved, saved energy cost and economy (1/FOM). F-tests for effect of each factor or interaction of factors were conducted, and their results were represented as estimated effect tables. In this present report, the authors, using the result of factor analyses reported in Part 2, intend to describe consideration on the economy and energy saving effcct of the solar system. Economy: In view that the solar cooling, heating and hot water supply systems are not yet economically feasible, the conditions that must be met to make it more economical were studied by using two evaluation factors, 1/FOM and F(N). The conditions are: 1. Improving durability (from 15 years to 20 years); 2. Increase of energy cost (from 4.5% to 10%); 3. Cost reduction of system (70% of the present); 4. Development of system performance. Against gas, which has higher unit cost per calorie, solar will be more economical if at least one of these conditions is met. If two of them are satisfied, the economy of the solar system will be evident. However, against kerosene whose unit cost per calorie is lower, the solar system can be barely competitive if at least two conditions are met, and three conditions need to be satisfied in order for it to have definite economic advantage. Thus, until all conditions sufficient for excelling the conventional systems are obtained, public economic aid, such as reduced interest (5.5% at present) should be granted to the solar system as the fifth condition. Heat insulation of the building: As the building has better heat insulation, heating load decreases remarkably. Further, if capacity of component, such as collector area is not lowered according to the reduction of heating load, the solar system cannot be economically justified. However, if the reduced heating load is converted to energy cost saving, heat insulation is economically compatible with higher % solar regardless of cost increase of insulation materials, etc. Such effect is more pronounced in the colder region. The economy thus viewed can even at present be probably achieved by making slight improvements in the design of the system. Energy saving effect of cooling: Although the larger collector area bears the higher energy saving effect, the system having smaller collector area has an economical advantage because the energy saving effect does not increase proportionally to the collector area. However, if the solar energy system is compared with the system using a double effect absorption chiller or an electric chiller which have a higher efficiency than a single-effect absorption chiller, energy saving effected will be insignificant unless % solar is raised by substantially increasing collector area. It is to be noted that the study described in this paper was made as a part of the research studies for 1977 as conducted by SHASE (Japan)'s Committee for Solar Heating-Cooling Systems which was commissioned by Ministry of International Trade and Industry (MITI) to perform such research studies under MITI's Sun Shine Project.

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