Grinding is a unit of operation of a pure mechanical process. An attritor is a grinder able to be used for fine or selective grinding. However, few studies have reported on the optimum design for the attritor. The attritor’s grinding characteristics and grinding effect depend not only on the operating conditions, but also on the geometry of the

. Therefore, we investigated the effect of the shape on the grinding efficiency from the viewpoint of experiments, kinetic analysis, and discrete element method (DEM) simulations. We conducted grinding experiments with two different agitators. One was A, a traditional design with two pairs of 90° staggered mixing arms at the middle and bottom of the mixing shaft. The other was B, with a lower mixing arm inclined by 10° along the horizontal direction. We found that the grinding rate constant of B was approximately 40% greater than that of A. Although the size distribution of the particles was relatively dispersed after grinding with B, the distribution was concentrated mainly within two ranges (<0.5 mm and 2–4 mm) with A. These results and an elemental analysis of each size fraction suggested that the dominating grinding mode in A was surface grinding, whereas in B, it was bulk grinding. In terms of the influence of the shape, the DEM simulation results showed that the kinetic energy of the grinding media in B was 0.0046 J/s, i.e., larger than the 0.0035 J/s obtained for A. A collision energy analysis showed that the dominating collision was between the media and wall in the tangential direction for both models. The collision energy of the media in B was larger than that of that in A. The results from the DEM simulation can help us evaluate the experimental results and infer the reasons why the grinding rate constant in B is larger than that in A.

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近年，温暖化等の地球環境問題への対策が各国に求められており，日本はパリ協定の約束草案で2030年度のCO₂排出量を2013年度比より26％削減することを目標とした。北越コーポレーション新潟工場でもパリ協定の約束草案達成に貢献する為，省エネプロジェクトを立ちあげた。プロジェクトの中から「8号機1次スクリーン高効率化」及び「9号機2次水フィルター増設による節水」の2つの事例を報告する。

新潟工場8号機1次スクリーン高効率化では，相川鉄工製B–1500型スクリーン用アジテーターをMaxi

に更新し，さらにプーリー比を変更して回転数をダウンすることで消費電力の削減を図った。新潟工場8号機には1次スクリーンが5台あり，すべてにMaxi 及びプーリー比変更を採用したところ，合計125kWの消費電力削減となった。

新潟工場9号機2次水フィルター増設による節水は，日本ポール製スピンクリン装置を2ユニット増設することで，余剰のあるスーパークリア水（再用水）の精製量を増やして2次水として利用し，不足により補給している工業用水を削減する。予想効果としては，170m³/hの節水となる見込みである。現在，2次水フィルター増設の手配・準備を進めており，本年12月に稼働予定である。

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近年，温暖化等の地球環境問題への対策が各国に求められており，日本はパリ協定の約束草案で2030年度のCO₂排出量を2013年度比より26％削減することを目標とした。北越紀州製紙新潟工場でもパリ協定の約束草案達成に貢献する為，当工場では省エネプロジェクトを立ちあげた。プロジェクトで実施した中から「新潟工場スチームトラップ診断」及び「新潟工場8号機1次スクリーン高効率化」の2つの事例を報告する。

新潟工場スチームトラップ診断は，工場構内に多数のスチームトラップが設置されているが，管理が十分で無かった為に蒸気漏洩しているものがあった。そこで，工場構内のスチームトラップを診断した結果，工場構内にはスチームトラップが1,445台あり，その内277台が不良（不良率19.2％），蒸気漏洩量は1.58t/hであった。診断結果をもとに各職場にて不良トラップを取替することで0.3t/hの蒸気ロス削減に繋げた。また，診断したトラップの型式・動作状態を記載した台帳及び配置図を作成することで，今後のスチームトラップ管理がしやすくなった。

新潟工場8号機1次スクリーン高効率化では，相川鉄工製B-1500型スクリーン用アジテーターをMaxi

に更新し，さらにプーリー比を変更して回転数をダウンすることで消費電力の削減を図った。新潟工場8号機には1次スクリーンが5台あり，すべてにMaxi 及びプーリー比変更を採用したところ，合計115kWの消費電力削減となった。

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The

is used for the purpose of reaction and mixing, and the quality of the product is determined by the flow inside it. The flow is affected by the geometry of the vessel and impeller, Reynolds number and fluid property. The authors are interested in the flow of viscoelastic fluids with the addition of surfactants to water. In an flow consisting of a complex shear flow, various experimental methods have been used to evaluate flow characteristics under conditions where viscoelasticity emerges. First, we tried to figure out conditions that show unique flow characteristics by stirring torque measurement and flow visualization with fine flake tracer particles. In the next, we evaluated mixing time by PLIF (Planer Laser Induced Fluorescence) measurement. It was found that in relatively low surfactant concentration case, flow characteristics are similar to those of water flow. On the other hand, in high surfactant concentration case, larger eddies, high torque and slow mixing are observed in the flow.

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Efficient Joule heating and cooling are necessary for the repetition use of the shape recovery force of shape-memory alloy (SMA) fiber reinforced smart composite materials. Then, the main factor on Joule heating and the cooling speed in the SMA single fiber and the SMA fiber reinforced smart composite materials was experimentally evaluated in this research. The effect of an environmental temperature, the forced convection, and the free convection was evaluated as the main factor in the SMA single fiber, and the structural condition of the matrix was evaluated in the composite material. The significant point in the temperature characteristic of the SMA electrical resistance was used as a marker of heating and the cooling progress. As a result, the cooling speed confirmed the decrease though joule heating speed rose by the rise of the operation environment temperature. Moreover, Joule heating and the cooling characteristic change greatly in the SMA single fiber depending on the air cooling condition. In the composite material, the result of the large change depending on the heat transmission characteristic and the structural condition of the matrix material was obtained.

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Usually, the truck is used to transport fresh concrete which is mixed at a concrete plant. In case of placing of concrete at a construction site, discharging efficiency of the truck influences on construction efficiency and quality of concrete. In this report, we observed flow of fresh concrete in , while we can't observe untill now, with help of the visualization technique, and investigated about influence of blade rolling pitch angle and rotational speed on discharging efficiency. As a result, it was cleared that the can have most suitable angle for discharging efficiency, and that the higher sliding resistance between concrete and surface of blade, the lower discharging efficiency.

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The preparation of core particles suitable for subsequent film coating was examined using different scales of agitation fluidized beds. Specifically, the effects of rotational speed and blade shape in different scales of granulators on granule properties such as mass median diameter, apparent density, friability and shape factor were studied. As the rotational speed was increased or when the blade height and angle were large, the mass median diameter and friability of the granules decreased, while the apparent density and shape factor increased, in a manner independent of the vessel size because the granules were subjected to greater compression, shearing and rolling effects. The same core particles could not be prepared using granulators with different vessel sizes by simply adopting a conventional scale-up theory^1,2) based on kinetic energy similarity. Here, a novel scale-up theory that takes into account blade shape factors is proposed.³⁾ When the two scale-up theories were compared, our new theory was capable of predicting the granule properties more accurately than the conventional theory. By adopting this novel theory, the same core particles could be prepared under different operating conditions in any scale of granulator.

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Using soya sterol (chemical composition by weight : β-sitosterol 56% ; campesterol 28% ; stigmasterol 4% ; sterol hydrocarbons and cholesterol 6% ; triterpene alcohols, keto-steroids and other steroid-like constituents 6%) and Span 85 as emulsifiers, with liquid paraffin as the dispersed phase in water, the effect of soya sterol and Span 85 on emulsion stability was evaluated in terms of the following five physicochemical parameters : (1) particle size, (2) degree of dispersion, (3) separation rate of dispersed droplets, (4) rheology of emulsion products, (5) sedimentation rate of dispersed droplets. An and a homogenizer were used to produce the emulsions. The following results were obtained. (1) The particle size of emulsions prepared with soya sterol was larger than that with Span 85, and consequently, soya sterol is a less effective emulsifier than Span 85. (2) Nevertheless, soya sterol has stronger stabilizing action on emulsions than Span 85, and this effect become especially marked when emulsification was carried out with a homogenizer at a high shear rate.

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An influence of the operating parameters on the grinding performance of the wet bead mill has been researched experimentally and by using a simulation technique based on the discrete element method (DEM). The rotational speed of the , the beads filling ratio, their diameter and material, and the slurry concentration were the subjects of the investigations. The grinding rate constant of the gibbsite sample was determined experimentally and compared with the specific impact energy calculated from the velocity of the grinding beads simulated. An increase in the rotational speed of the and in the filling ratio and a decrease in the slurry concentration cause an increase in the grinding rate constant. A similar effect of the operating parameters on the specific impact energy has been observed.

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北海道札幌市,手稲山頂で観測された地吹雪による正電場の発生,又札幌市内で観測された風塵による負電場の発生などの原因を説明するために,新しい装置を用いてこれらの現象を再現し,定性的な実験解析を行った結果,実験の際に見られる粒子の帯電符号と,同時に発生する優勢なイオンの符号を支配する興味ある規則性を見出した。即ち,実験の際,装置内の空間に浮遊する微小粒子の荷電符号と同時に発生する優勢なイオン符号はその物質の電荷担体の符号と一致するということである。
この規則性は,雷雲,火山の噴火,砂塵嵐などに伴う強度電場の発生現象や,粉体を扱うあらゆる種類のプラントなどで発生する爆発現象などの要因と考えられている強電場の発生などに統一的に寄与する一つの効果的機構と考えられる。

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Scale-up characteristics of agitation fluidized bed granulation using a pharmaceutical standard formulation was described. The effects of scale, air flow velocity and rotational speed on granule properties such as granule mass median size, size distribution, apparent density and shape factor were investigated experimentally. Based on the results obtained, the effects of these parameters on granule growth and the mechanism of granule formation in different sized equipment were discussed.

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For the solvent extraction of reprocessing plant, mixer-settler, pulsed column are op-erated and centrifugal extractor is expected to be used. Mixer-settler has the defect of long contact time. It comes out to cause the solvent damage by radiation in FBR fuel re-processing. In order to escape from the damage, pulse column and centrifugal extractor should be used for FBR spent fuel. However, the characteristics in centrifugal extractor have not yet been fully analyzed, while those of mixer-settler are advanced much. There-fore, the agitation experiment was made to find out the difference of drop formation be-tween mixer-settler and centrifugal extractor. From the results, the average drop diameter is proportional to Weber number to the power of -0.58, when the contact time is long. However, the agitation velocity did not affect the average drop size, when the contact time is less than 11.3 s.

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Scale-up of wet granulation in a vertical high shear mixer was conducted. Pharmaceutical excipient powders composed of lactose, cornstarch and micro-crystallinecellulose, and hydroxypropylcellulose as a binder were mixed together and then granulated with purified water under various operating conditions and vessel scales. A novel internal stress measurement system was developed and stress of normal and tangential directions that granules received from the blade during the granulation was continuously measured. The results indicated that granules received stress mainly from the tangential direction, which also showed the largest value near at the vessel wall. The effects of the tip speed and the centrifugal acceleration on the measured stress was investigated. It was found that the tip speed of the blade could be the main factor for the granule growth. The physical properties such as strength, size distribution and compressibility of granules prepared by changing the operating conditions and the vessel scales were evaluated and the scale-up characteristics of high shear granulation were investigated experimentally. The results showed that these physical properties had linear correlations with the tip speed. It was finally concluded that the scale-up of high shear granulation could be well conducted by means of the tip speed of the blade.

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Scale-up of wet granulation in a vertical high shear mixer was conducted. Pharmaceutical excipient mixtures composed of lactose, cornstarch and micro-crystalline cellulose, and hydroxypropylecellulose as a binder were mixed together and then granulated with purified water under various operating conditions and vessel scales. Torque of shaft was continuously measured and then agitation power per unit vessel volume was calculated. The agitation power per unit vessel volume showed a good correlation with physical properties of obtained granules, such as mass median diameter, strength and compressibility. This implied that the scale-up characteristics could be well analyzed by means of the agitation power per unit vessel volume. In addition, the effects of tip speed and Froude number on the agitation power per unit vessel volume were investigated. The results showed that the agitation power per unit vessel volume was well characterized by the tip speed rather than the Froude number. This meant that the granule growth mainly progressed by the shear stress from the blade. Dynamic characteristics of high shear granulation were also discussed here.

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The heat transfer coefficient between the heating wall and the granular bed in the stationary heating-plane type of indirect-heat agitated dryer was measured. Taking account of the effect of the clearance between heating wall and agitating blade, an improved heat transfer model was proposed. This model can also describe the dependence of the heat transfer coefficient on the circumferential velocity of the , the thermal properties of the granular material, the particle size and so on. Furthermore, it was confirmed that this model was usable when the particles were non-spherical or when scale-up of the dryer was considered.

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In the use of helical type , the mixing process is usually restricted to the laminar flow regime. Common examples of laminar mixing are found where the fluid has a very high viscosity, i.e., pseudoplastic fluids. It can be indicated that a helical type is sufficiently suited to the creeping flow mixing. The pumping characteristic of a Helical Screw with a draught tube (HSA) is required to evaluate its capacity for the optimal configuration of the mixing chamber. It could be executed by changing some parameters such as the number of helix, the angular velocity and the rotating direction and so on. In this study, the numerical simulation was carried out with the Eulerian multiphase mixture model and the moving mesh approximation. Some of the optimum design parameters have been developed with the aid of numerical data from the Computational Fluid Dynamics (CFD) analysis. Using the commercial code, Fluent, the pumping characteristics in the HSA are investigated from the rheological properties, and the results are graphically depicted.

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This paper describes an experimental study on the drying of wet granules in an agitation fluidized bed. Wet granules composed of lactose and cornstarch were dried in an agitation fluidized bed under various air temperatures, air velocities and rotational speeds. The effects of the conditions on the properties of granules such as mass median diameter, yield, shape and density of the granules are investigated. The relationships between the operating conditions and the drying rates were also examined. It is found that mass median diameter decreases with decreasing air temperature and velocity, and with an increase in rotational speed, while the apparent density, shape factor and yield of fine granules increases. Granules are compressed by the tumbling and compaction effects due to the agitation rotation, which simultaneously diminishes the size of the granules by grinding them. It is also found that the drying rate over a constant drying period increases with air temperature and velocity, but decreases with rotational speed. These results show that too much centrifugal force from rotation forms condensed masses, leading to a decrease in the interfacial drying area.
As a result, the mechanism of agitation fluidized bed drying is elucidated and optimal operating conditions are discussed from the view point of granule properties and drying rate.

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A newly developed mini-scale high shear granulator was used for scale-up study of wet granulation process from 0.2 to 200 L scales. Under various operation conditions and granulation bowl sizes, powder mixture composed of anhydrous caffeine, D-mannitol, dibasic calcium phosphate, pregelatinized starch and corn starch was granulated by adding water. The granules were tabletted, and disintegration time and hardness of the tablets were evaluated to seek correlations of granulation conditions and tablet properties. As the granulation proceeded, disintegration time was prolonged and hardness decreased. When granulation processes were operated under the condition that tip speed was the same, similar relationship between granulation time and tablet properties, such as disintegration time and hardness, between 0.2 L and 11 L scales were observed. Likewise, between 11 L and 200 L scales similar relationship was observed when operated under the condition that the force to the granulation mass was the same. From the above results, the mini-scale high shear granulator should be useful tool to predict operation conditions of large-scale granulation from its mini-scale operation conditions, where similar tablet properties should be obtained.

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