In the present paper the attention is focused on the effect of cavities inside of in-line tube banks on vortex shedding. The relation between vortex shedding characteristics inside of in-line tube banks and that of cavity without acoustic resonance was experimentally examined. We measured the sound pressure level, the phase delay of acoustic pressures, the spectrum of velocity fluctuation and the gap velocity. As a result, the vortex shedding of S_t=0.15 were generated inside of the tube banks and the cavity without acoustic resonance. The velocity fluctuation of S_t=0.15 inside of the cavity downstream of fifth row tubes was larger compared with the results of no cavities. The existence of cavities of tube pitch ratio of 3.44 inside of in-line tube banks caused the resonance of S_t=0.15 component.

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This study is an experimental investigation with a small-sized model on aerodynamically generated noise of high-speed trains running in a guide-way, which consists of two sidewalls and a bottom. According to the sound field data measured for real trains, a main contributor to the noise has been identified as aerodynamic sound from the truck with a cavity in it. Through the model tests in which an acoustically permeable plate is adopted as the bottom of the guide-way, we have found that a principal source of the sound locates at the bottom opening of the cavity of the truck. We have also confirmed the effect of some devices that are expected to reduce the noise.

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This paper deals with evaluation of sound quality for aerodynamic sounds generated by a column in uniform air-flow. This study is aimed for improvement of sound quality and performed a sensory evaluation and examined the effect of changing the quantity of physical parameter of aerodynamic sounds on evaluation of tone quality by clarifying a factor concerned with tone quality. As a result of factor analysis, two factors were extracted from the modified aerodynamic sound. In addition, clarified a difference of evaluation about a feeling of change of a sound.

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Resonance pipe thermoacoustic engines was constructed and its performance was experimentally studied. Two types of stacks, laminated stainless plates and a bundle of ceramic pipes, were used in the experiment. Maximum sound pressure was obtained for a suitable length of the resonance pipe. Sound pressure was found to increase two times when the open end of the resonance pipe was changed to a bell mouth shape from a straight shape. Flow patterns of acoustic streaming at the open end of the pipe are also presented.

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Check valves to control reverse water flows in drainage systems often suffer from large impacts and loud noises through their sudden closure caused by an accidental cutoff of drain pumps. In order to find the alternative valve to reduce such large impact forces and noise, we investigated behaviors of the check valve and flow phenomena in drainage pipe and the impact force due to their sudden closure, using a 100 mm diameter model drainage system. Some modified check valves were also proposed and their characteristics are investigated.

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The effects of a volute angle of scroll casing and a groove hollowed out on the suction surface of blades on characteristics of aerodynamics and noise of a sirocco fan was investigated. It was shown that in the characteristics of aerodynamic and noise, the optimal value has the volute angle in about 5〜6 degrees, and the grooved blade fan is superior in aerodynamic characteristics and noise to ordinary blade fan. If the groove is hollowed out on the blade suction surface, the width of a wake will become narrow. Consequently the pressure and efficiency of the fan will increase a little, and a sound pressure level and a specific noise level become fall. Therefore, it became clear that the grooved blade fan leads to a characteristic improvement of the fan.

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We experimentally investigated the influence on reducing noise of blade loading on both single and two-stage jet-fans. To obtain high blade loading, We applied NACA 65 series airfoil to rotor blades. For the single-stage fan, the blade loading for fan with eight rotor blades was higher than for fan with four blades. The blade loadings were the same for two-stage fans with either four or eight blades. We found that the broadband noise depended on the blade loading, but the noise at the blade passing frequency (BPF) was independent of the loading. The noise level of the BPF in the two-stage fan was higher than that in the single-stage fan, and this decreased as the number of blades was increased from four to eight. The specific noise level of the two-stage fan was lower than that of the conventional jet-fan. We concluded that applying NACA 65 airfoil to the blades was useful for reducing jet-fan noise.

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We present a one-way coupled simulation of fluid flow, structural vibration and acoustical radiation analyses that we applied to predict noise radiating from a 5-stage centrifugal pump. A large eddy simulation was performed to compute pressure fluctuations on the internal surface of the pump. The computed fluctuations were then used in a structural analysis that was based on the explicit dynamic finite element method that computed the elastic wave propagating in the solid. The resulting external surface vibration was then used in a acoustical analysis that was based on the boundary element method that used the normal derivative form of the Helmholtz integral equation. The computed internal pressure fluctuations, vibration velocities on the external surface and the radiated sound pressure level of the pump were compared with the measured equivalents, and reasonably good agreement between computed and measured results were obtained. The proposed method thus shows promise as a tool for the prediction and reduction of flow-induced noise generated from hydraulic turbomachinery.

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The clutch is slid for a short time at the engaging the gear of a manual gear car. The self-excited vibration might be generated at this time, and this is called clutch judder. The simulation model of clutch judder is studied here to clarify the relation between the clutch characteristic and clutch judder. First, the validity of the model is examined compared with a past analytical model. It is confirmed that the stability area and the frequency response of the simulation model are corresponding to an analytical model. The simulation result by this model is the following. (1) When clutch judder is generated, the clutch engaging time becomes long. (2) Sensitivity for generating clutch judder is different on a relative speed. A negative inclination of the μ-V characteristic of a high relative speed shows high sensitivity, and the possibility to generate clutch judder is increased.

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This report deals with an experimental method for estimating sound pressure level from the acoustical enclosures. By using the acoustic reciprocity technique, we measured the acoustic transfer function for sound radiation from the acoustic enclosures. Especially in case of the opening, we calculated the volume velocity by using the measured pressure level and theoretical radiation impedance. Eventually, sound pressure level from the opening are estimated by using the measured acoustic transfer functions and the calculated volume velocity. The application of this technique on the white noise sound source and the roots blower sound source is demonstrated. The comparisons were made between predicting results using the reciprocal technique and directly measuring results. Agreement is fairly good and it suggests that this method can be used to evaluate the sound pressure level from the opening of the acoustical enclosures.

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The turbulent noise from the sirocco fan was predicted with the simple method of the potential theory, which is provided with the transformation of the cascade to the linear cylinders. And the flow characteristics of the impeller were examined with the experiments. The prediction of the turbulent noise was compared with the experimental results. The predicted noise levels are roughly similar to the experimental ones. The flow characteristics at the outlet of the impeller were large partial to the hub side. The partial flow condition becomes large with the flow rate. Then the noise level is varied with the flow rate in experiments.

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This paper describes the sound transmission loss for a low frequency noise. We measured the sound insulation for GRC plate, concrete and window glass and calculated the sound transmission loss for the same materials using the Stiffness Law. Moreover we simulated the sound transmission loss for concrete using a finite element method and a boundary element method. Measurements and simulation results are close to the Stiffness Law.

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When a high-speed train enters or leaves a tunnel, impulsive pressure waves are radiated from the entrance/exit portal toward the outside of the tunnel. A similar phenomenon occurs when a train passes a short structure (such as an over-bridge) in an open section. We call it a "structure-passing wave." Although the structure-passing wave is weak at present, it could cause an environmental problem as the train speed increases. In addition, people have become more and more interested in low-frequency noise. This paper describes the characteristics of the structure-passing wave based on the results of model experiments and acoustic analyses.

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Some trouble of low frequency vibration had been occurred at the new refuse incineration plant. Low frequency noise and vibration were induced around the forced draft fan when the draft fan was operated in the condition of low flow rate by controlling the floe valve. It was practically estimated with depending on the result of some measurements and analysis on the site that the acoustic resonance in the air supply duct and the vibrant resonance on the delivery silencer were excited by the low frequency pulsation of the discharge flow from the centrifugal fan. This trouble has been resolved by the reinforcement of the silencer and by the additional set up of the returning by-pass duct from the outlet to the suction side of the fan. It would be the next stage problem for solutions that mechanisms of low frequency pressure fluctuations induced by the special fan with high pressure and wide range of flow rate are made clear.

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[in Japanese]

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Hearing thresholds and acceptable limits of low frequency noise were measured for 21 ordinary adults and 10 complainants in psychophysical experiments, and the reliability and the validity of an evaluation method using the percentiles of acceptable limits were examined. In the results, the reliability of the acceptable limits for a bedroom in ordinary adults was high, and those values also agreed with equal unpleasantness contours from previous data. And the 10 percentiles of the acceptable limits for a bedroom most successfully discriminated the 1/3 octave band levels observed in the complainants' houses. Moreover, they were consistent with some of guidelines in European countries. The obtained results were utilized as "Reference values for mental and physical discomfort complaints" in "Handbook to Deal with Low Frequency Noise (2004)" which was published by the Ministry of Environment.

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Experiments were conducted to evaluate the economic value of the sound quality of machinery noise emitted from vacuum cleaners and hair dryers. In the experiment concerning vacuum cleaners, stimulus cards of twenty-seven kinds of vacuum cleaners were presented to participants. Each card gave participants details of the characteristics of each vacuum cleaner in respect to six attributes; manufacturer, price, noise level (dBA) and sharpness (acum) of the machinery noise, etc. Each attribute had two to five levels. For the attributes of noise level and sharpness, three levels were set up (64, 59, 54 dBA and 2.46, 2.21, 1.96 acum, respectively). 50 students evaluated their preferences for each vacuum cleaner. Rating values were applied to conjoint analysis. As a result, students regarded "price" as most important. The partial utilities of each level for each attribute were also obtained. In the attributes of noise level and sharpness of the machinery noise, the partial utilities increased as noise level and sharpness decreased. Furthermore, the estimated value for a 5 dBA reduction was 3347 Japanese yen, and for a 0.25 acum reduction, approximately 3692 Japanese yen.

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This paper describes the result of study and survey about working environment in the manufacturing industry by means of the quantitative evaluation method to acoustic environment, human impression. Main contents are summarized as follows: (1) The stress of worker was evaluated by original method (ChAIM) that modifies NASA-TLX. (2) In all factors about working environments, it was confirmed the noise influences to the worker. (3) The stress and efficiency of the worker with the knowledge base has a relation with the noise in working environment. (4) The improvement of the working environment by the optimum acoustic design based on the quantitative evaluation methods is important to administrate the manufacturing industries.

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For the decline in birthrate, the labor shortage of young generation becomes social problem. In order to solve this problem, it is necessary to improve the social surrounding of working by the parent with the infant feeling easy. In this study, the system for shortening the distance of the parent and the infant who was left to the house of parent or the nursery is developed. This system gives comfort and peace of mind to the infant by transmitting the heartbeat of the parent which the child is hearing through Internet and reproducing it in the doll which the child has held. At the same time, this system also gives peace of mind to the parent by observing the condition of the infant by the network camera anytime. Then, it is confirmed that the steady artificial heartbeat could be accurately transmitted and confirmed that the unsteady heartbeat could be almost accurately transmitted using the crosscorrelation function and the power spectrum.

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Recently, many researches who work with time-frequency analysis using wavelet transform have focused on analyzing wavelets that are derived using a mathematical approach. In the present analysis, a measured signal is adopted as the wavelet, and we analyze the correlation between acoustic signals in the car cabin and suction noise signals by applying the proposed system. Because traditional calculation of correlation repeats the averaging procedure, the original signal must be stationary. Consequentially, a technique for separating and identifying noise from each part of the engine is used for noise source contribution analysis. To apply the method to time-varying signals, the concept of an instantaneous correlation factor (ICF) is introduced, and we prove that a dominant feature of the correlation can be estimated by the ICF. The time-varying correlation for the noise source contribution analysis of an accelerating car is analyzed. And the fundamental experiment about the audibility impression in that case was also conducted.

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Powerfulness, Unpleasantness and booming sensation of car interior noise were investigated using continuous 7 categorical judgment,]According to the results obtained, even under the exposure of the same car interior noise, their judgments varied with respect to the variation of the vibration level. The tradeoff effects expressed in sound pressure level in dB were in proportion to the variation of seat vibration level in case of the evaluation of powerfulness but those tended to show saturation with respect to the variation of seat vibration level in case of the evaluations of unpleasantness and booming sensation. The effect of seat vibration to the perception of sound quality of car interior noise is smallest in case of booming sensation.

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Predicting high frequency sound field in a cabin of a car is essential for efficient acoustic design of noise reduction, but difficult because it's a large scale problem. In this paper, as the first step of study on numerical analysis of high frequency sound field in a cabin, fast multipole boundary element method (FMBEM) which has been developed as technique to reduce the computational time for large scale problems is applied to simulation of sound field in a simplified cabin model, and its availability is examined through comparison with computed result by BEM.

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The sound absorption panel composed of cloth and air space is proposed. The method of acoustical design of this panel is also shown. Specific acoustic impedance of cloth is identified by using two microphones method. Sound absorbing coefficient of this panel is calculated using the transfer matrix method which is introduced the value of specific impedance of cloth. Optimum design of the panel is based of the calculated sound absorbing coefficient. The performance of this panel is proved to be equivalent to one with conventional material.

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For the conventional narrow-gauge railways in Japan, main noise source is wheel/rail noise. In order to reduce railway noise, it would be appropriate to make a better understanding of wheel/rail noise. In this paper, the purpose is to make clear vibration behaviors in rail-track systems. The rail-track system is idealized as an infinite beam periodically supported by spring/mass/spring system. The model is tuned through field tests and validated in terms of vertical rail accelerance and decay rate. Using the model, various physical phenomena of importance to rail vibration are shown. Finally, parametric study on railpad stiffness is performed, and the relationship between the railpad stiffness and rail vibration behavior is pointed out.

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Steel railway bridges characteristically tend to generate high-level structure-borne noise. Therefore it is urgently required for railway systems, to decrease the vibration and noise of steel bridges. To develop effective countermeasures against this problem, it is important to study the noise generating mechanism and establish a method to predict the noise of steel bridge. The authors developed a new method for this purpose by combining the analysis of flexural vibration of plate based on the Rayleigh-Ritz method and finite element analysis method (FEM). The former is effective in predicting vibration in a wide frequency range including very high frequency areas, but doesn't suit the vibration analysis of a structure as a whole, while the latter complements the former in performance. In this paper, it is examined whether the proposed analysis method is proper or not by comparing the calculated values with the measured ones.

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Sound barriers have been widely adopted and installed to reduce the noise level produced at locations adjacent to Shinkansen track. Although a number of different types of sound barriers with specific features in their configurations have been developed; a quantitative evaluation for their advantages has not been clarified as yet. Therefore, a number of experiments with scaled models were carried out. Experiments were made to various types of sound barriers to evaluate the noise level as reduced. Furthermore, we proposed sound barriers of effective configurations based on the experimental results. Then we confirmed this effect in Shinkansen filed test.

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This report describes the active control systems for reducing floor impact noise. The systems are comprised of actively controlled modular panels of light weight, which wholly cover the surface of concrete slab structure in the ceiling, and in each of which the mechanical vibration is controlled independently with moving coil actuators. In this report, first, vibration control system is presented. Second, acoustic evaluation of active insulation panel is presented. In the latter evaluation lower performance was acknowledged than expected from the former measurement, which was inferred to be caused by less computing precision of micro-computer controller than PC controller.

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This paper describes the prediction on attenuation of a silencer tower with many resonators by using FEM. The purpose of this study is to realize the reduction of infra-sound which generates in various plants. The attenuation is firstly predicted by a conventional method and secondary calculated by FEM. In modeling of FEM, optimal mesh number is determined so that the variation of the natural acoustic frequency becomes within 10% of the detail model by calculating of various mesh models. Because the fine mesh model consumes much time to calculate. Finally, the experiment is performed and the calculated result is compared with the experimental one. As a result, it was clarified that the attenuation of a complex silencer with many resonators could be predicted by FEM. And the conventional method could also be predicted by taking into account of 70% the value of the calculated result.

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In this paper, a silencing unit was developed for reducing noise radiated from the cooling systems of OA-equipments or measuring instruments. It was proved by model experiments that a silencing rectangular bend with rather thin sound absorbing material for high frequency and acoustically transparent walls for low frequency is compact and has high noise reducing performance. They can reduce the radiate noise by about 7dB in the studied example. The noise reducing mechanism of acoustically transparent walls is considered to be that the acoustic energy radiated into a silencing rectangular bend and reflected from the duct exit passes through the acoustically transparent walls into a box and dispersed and absorbed by some electrical plates in the box.

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In 3-dimensional sound field, it is difficult to control noise in whole area. Instead of whole area control, the controlled area can be followed to people in that field by new approach proposed in this paper. In the proposed algorithm, FTF algorithm that has fast converging property is introduced to a direct adaptive algorithm which does not need an error path characteristic. A numerical simulation is carried out with a sound field that the error path changes during control. From the results of the simulations, the effectiveness of the proposed algorithm is shown.

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In recent years, LNG (Liquefied Natural Gas) plants have enlarged with the development of the technology, since the demand for LNG is increasing remarkably as a representative of clean energy. On the other hands, requirements concerning the noise are severe from the rise of the concern to HSE (Health, Safety and Environment). In this connection, this paper introduces as follows: (1) The production capacity of the LNG plant (2) Noise control requirement (3) HSE requirement (4) Our approach of the noise control for large-scale LNG plant including the measurement data.

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PCBs (polychlorinated biphenyls) are a type of chlorinated aromatic hydrocarbons widely used in condensers and other applications prior to 1970, but now recognized as serious environmental pollutants. "Law Concerning Extraordinary Measures for Promotion of Proper Management of Polychlorinated Biphenyl Waste", which came into effect on July 15,2001, made PCBs disposal mandatory, and many companies are thus engaged in research and development work on PCBs disposal and processing. For protection from PCBs it is necessary to monitor their concentration quite rapidly. But the conventional methods require extensive analytical time (several days per sample) and are not suitable for the above requirement. The objective of the research reported here was to develop the Laser ionization time of flight mass spectrometry (LI-TOFMS) capable of monitoring PCBs within 1 minute. The achievable PCBs sensitivity for real-time (1 minute) measurement was found to be in the ppbV range (0.01 mg/Nm^3) by comparison with the conventional gas sampling / GS-MS (gas chromatograph-mass spectrometry) method. For PCBs, a satisfactory proportional relationship was confirmed between laser-based and conventional results. We examined the exhaust gas measurement using the PCB monitoring system installed in the PCB treatment plant (hydrothermal decomposition). Accordingly, this method implies a useful method for the on-line monitoring of PCBs. In the future we will pursue practical application in the form of a safety management-monitoring device for environmental monitoring.

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The construction of the waste management system corresponding to the recycling society is needed. The construction of Best Available System is hoped for in all respects of the municipal waste from the exhaust stage to recycle or final disposal stage with its evaluation. We understood the current state of the municipal waste processing, and developed the evaluation system that facilitated making the improvement idea for the processing plan to the municipality. Concretely, we did the questionnaire survey concerning the collection and the processing form to some cities for making the data base of the supporting tool and grasping the realities of their waste management system. Then, we arranged, analyzed, and proposed the Best Available System to the waste management system.

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In recent years, global environmental problems become aggravated, and the shift to the sustainable society is required. The quantitative environmental load assessment is necessary to achieve the sustainable society. Though various LCA (Life Cycle Assessment) method is developed for such a demand, it is pointed out that there are a lot of problems in existing LCA. To solve such problems, Eco-Efficiency Potential Assessment (E2-PA) is developed. E2-PA is based on the concept of "Eco-Efficiency" and the "Potential Assessment". In this research, we pay attention to "Utility", the numerator element of the E2-PA, of the products. Utility is the quantitative index means the essential factors of products in terms of consumers. We propose a method to quantify the Utility, which is the great merit of E2-PA. The targets in this paper are television, used car, and the notebook computer. Through the analysis of the television's Utility, it was shown to be able to evaluate the product with a different adjustment technology, like CRT, LC and Plasma. On used car, the change in Utility before and after the ELV (End-of-Life Vehicle) Recycling Law was shown. On notebook computer, we took in the consumer's intention by questionnaire in the assessment of the Utility. By this study the necessity of the product development according to the knowledge level of consumers was shown.

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In recent years, global environmental problems have been aggravated. Especially the revolution of our lifestyle is requested. So, we have suggested the LSA (Life Style Assessment) as the environmental load assessment method in one's everyday life, and have evaluated the effect of environmental load reduction by improving the behavior of life style. In this report, we paid attention to the environmental load caused by heating apparatus and clothes in our life. In heating apparatus we compared the environmental load, the cost, and the utility. On clothes we evaluated the environmental load of 24 products. Moreover, to do such an assessment in individual's life style, we developed the LSA software. By using this software we enabled to understand the environmental load in the entire life quantitatively and showed the effectiveness of it.

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In recent years, occurrence of the accidents in the general waste disposal facilities is reported from many fields. Then, we surveyed the bulky waste disposal facilities, and made the accidents and troubles data base to prevent the accidents. We developed the New Safety Analysis Method built in accidents and troubles data base to find the potential risk from the design phase of the facilities. We examined the accident scenarios that have max risk point on the bulky waste disposal facilities with New Safety Analysis Method as the case study. As a result we obtained that the operator caused the explosion by the combustible gas with usual drive on the ripper is the highest risk accident.

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Life Cycle Assessment (LCA) becomes a more critical tool for ECP (Environmentally Conscious Products) designing. At the same time, Life Cycle Costing (LCC) and Environmental Accounting (Eco-Accounting) are becoming a necessary tool to make decision of WTP (willingness to pay) for avoiding certain environmental impacts. This paper proposes a conversion scheme of the environmental load reduction expressed in physical units due to countermeasures into money units based on the CO_2 emission dealing right price, which is able to be evaluated by the CO_2 equivalent NETS values. Additionally, several criteria for the environmental costs performance are proposed with case studies.

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Life Cycle Assessment (LCA) has been greatly paid attention to its effectiveness in evaluating environmental loads through the life cycle of any industrial products. The LCA method has been used to analyze the environmental loads of the processes. This paper focuses on the LCA evaluation at the manufacturing phase, especially at painting-coating process and plastic-injection process molding process. The various kinds of the inventory data of the processes are collected by measuring respective parameters. The objective of this study is to evaluate the LCA environmental loads in these two manufacturing processes based on the data analysis. It is recommended to use the here Numerical Eco-load Standard values in order to design the Eco-products.

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A new chemical decomposition technique of polymer using mixed acid formed between nitric and hydrobromic acid was proposed. This unique technique has the features that the decomposition rate is faster than the hot nitric acid and fibers keep the original solid shape. Fundamental data of strength degradation for recycled fiber reinforced plastic (FRP) composite were investigated in order to develop a recycling method. The strength degradation by mixed acid of two kinds of monofilament, i.e. a carbon and a glass fiber, was investigated. Further, the mechanical properties of FRP with recycled fiber were compared with FRP made from virgin fiber. It is understood that this new method has the potential to recycle the discarded FRP composite.

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We have developed the new chemical recycle system for waste polyolefin plastics using H-garosilicates. The catalytic degradation of polyolefin using H-gallosilicates was examined in present study using a bench scale reactor (1.0kg/hr) with continuous feeding. We tried a continuous examination using HDPE(High Density Poly-Ethylene) for 40 days. In this continuous long time experiment, two catalyst cracking reactor was used, and examined by repetition of cracking and regeneration every 24 hours. In this experiment, long time stability of cracking catalyst activity, and the problem of this chemical recycle process were studied. For about 1 month (720hr), BTX recovery rate was over 50wt%, and continued stable state. But after 1 month, BTX recovery rate decreased gently. Except the HDPE, polyethelene of industrial waste (IWPE), and RPF (Cl;850ppm) were studied. IWPE was the same result which was tested by repetition of cracking and regeneration every 24 hours for the recovery rate and catalyst life time. But, RPF was deactivated after 16 hours. As the impurity except chlorine, the effect of nytrogen which include in polyamides was supposed for the RPF.

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Sapporo Plastics Recycling Co., Ltd. (SPR) and Rekiseikouyu Co., Ltd. had developed and put to practical use of the liquefaction plant for municipal waste plastics including PVC and PET, and maintaining a high rate of making to oil, and waste plastic oil making technology to have done considerable results though the processing of making to these oil plant had passed five years or more since it began to have driven. The feedstock recycling that returns the generation light oil of these plant of making to oil as a raw material of the oil refinery (Japan Energy Corporation) is started that becomes the first in the world in April, 2004, and this also continues the stability driving well. In addition, progress to the technology that does the feedstock recycling can expect the waste plastic cracked oil in the future.

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In order to consider the effect of production conditions of wood powder on the bending properties of wood powder molding material, wood was ground to powder under the conditions of different temperatures and moisture contents, then stick specimens were produced by injection molding method. The specimens were produced only from wood powder in the steam atmosphere using self-bonding ability of wood powder. To evaluate the bending properties of the specimens, modulus of elasticity and bending strength were examined. In case of wood particle produced under the condition of high temperature and high moisture content (100℃ and about 30%MC), tendencies for intercellular layer to be exposed on surface of a particle and for aspect ratio of particles to belarge were confirmed. And in that case, the specimen showed the highest value in modulus of elasticity and bending strength. It is highly probable that the improvement of the self-bonding ability of the wood powder and the increase of the aspect ratio take part in the improvement of the strength properties.

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To construct the Sustainable Society, the importance of consideration to 3R (Reduce, Reuse, Recycle) in the design phase increases in various industrial products. Concerning Reuse and Recycle, the improvement of the disassembly property is important. Then we develop the quantity disassembly property assessment method. In this paper, we pay attention to foreign products, especially refrigerators and home cleaners, which are more and more sold into our country. We compare their disassembly property and 3R consideration at the design with Japanese ones. And also, we develop Disassembly Supporting Software which support the disassembly process of used products by showing disassembly flow and 3D animation

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A gas hydrate technology has been applied to the purification of bio-gas produced from sludge digestion tanks in a sewage treatment center. In this system, methane in the bio-gas is concentrated to more than 95% and is stored in the form of methane hydrate. It is possible for facilities with the biogas hydrate system to utilize the purified methane as fuel and the heat of the hydrate dissociation as coolant. Demand side managements of energy are expected to be realized by introducing gas hydrate systems in many facilities with bio gas-plans.

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This paper describes a low excess air ratio operating report of stoker type MSW (Municipal Solid Waste) incinerator using exhaust gas recirculation (EGR) system. EGR system was applied to an existing 150ton/day MSW incineration plant to confirm the features of lower emission pollutant and higher recycling efficiency. Comparing the operating data with the conventional operation data without EGR, we checked that EGR system was effective to reduce the toxic products such as NOx and CO, and it could make the low air ratio operation stable and could reduce running costs.

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In recent years, the existing capacity of the final disposal site has been tight, and technology such as incineration or melting processes is going to be utilized as practical use, after excavating and selecting the digged waste from existing disposal site in order to aim at the prolongation of life of existing disposal site. By reducing volume of the waste in existing disposal site by applying the technology, or changing it a reusable thing, the prolongation of life of an existing disposal site is aimed at, and the load to environment is reduced as a result. We performed a trial processing using blend of digged waste and municipal waste, by the gasification and melting method with a high purity oxygen blowing shaft type incinerator. As a result, even if digged waste of 20% is blended with municipal waste, all environmental regulations are satisfied and could process it properly. A study was made to the prolongation of life of the existing disposal site with this processing.

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Amount of biomass resources are enormous but energy recycle from those resources are difficult. The reason of difficulties are first, contained water in those resources which prevent energy recovery, second, change of various composite of those resources prevent stable treatment of recycle process. In order to solve this problem, we suggest pyrolysis gasification process. The feature of this system is combination of gasification by pyrolysis of biomass resources and reforming of pyrolysis gas. This systemenables the conversion of biomass resources into fue. Fuel gas that consists of hydrogen and carbon monoxide as the main inflammable components can be used as fuel for gas engine generators and heat source of pyrolysis kiln. Furthermore, char is generated in a pyrolysis process and also carbon is generated in a gas reform process. Both char and carbon are recycled as solid fuel or a reducing agent material and high-value-added carbon such as carbon black or nano-carbon. As mentioned above, high rate of recycling from biomass resources is realizable in this system.

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This study is devoted to clarifying the biomass gasification characteristics in a fluidized bed coupled with another bed as the char combustor. The necessary residence time for decomposing biomass fuels was first investigated through gasifying 1.0g coffee grounds and bagasse in a laboratory fluidized gasifier using steam as the reagent. Succeeding this a process simulation was conducted with respect to the gasification process quoted above to inter-correlate the available cold gas efficiency with fuel C conversion. The results demonstrated that for achieving cold gas efficiencies higher than 75%, the fuel water content should be necessarily lower than 5 wt.%, whilst the fuel's C conversion has to be over 60%.

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