In this paper, the experimental results are represented on the effective thermal conductivity of cellulose insulation powder which is made from recycled newspapers. This insulating material is useful for energy and resources saving. The steady state cylindrical absolute method is employed by considering the accuracy of measurement. The experimental results are compared with the ones measured previously by other methods.
The main results obtained are as follows;
(1) The effective thermal conductivity of this insulating material increases with increasing temperature and effective specific density, respectively. But, these increasing rate is not so large.
(2) The effective thermal conductivity is about 0.04-0.06[W/mK] at the range of the effective specific density less than 100 [kg/m³]. This value is comparable with other industrial insulating materials.

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この解説は混合物の中で大きな部分を占める分散系混合物の有効熱伝導率について解説するもので、 始めに、 モデルを提示して影響因子を明らかにし、 それと関連させながら実験に当たっての注意すべき事項および有効熱伝導率の推定式を上げ、 既存の実験結果と比較することによってそれらの評価を行った。 さらに、 分散系混合物の熱物性値の今後の問題を上げる。

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In the present study, effective thermal conductivities of wet clothing material were numerically analyzed based on a proposed heat transfer model. The following simplifications are made. The clothing material is woven with a single yarn, there is no air movement among yarns, and also mass transfer is neglected. Numerical calculations were made based on the finite difference equations of steady three-dimensional heat conduction equations for several composite materials representing wet clothing materials. The following results are obtained. The effective thermal conductivity increases with increasing thermal conductivity of yarn and of water content. It is found that the present numerical results are in good agreement with the previously measured ones. The effective thermal conductivity of wet layered materials depends on the distribution of water, and attains a maximum in the wet layer.

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We have been studying on a suspension as a new thermal storage material. The suspension is made from silicone oil-water mixture with some additive or water with that by cooling with stirring. When designing the ice storage system using this suspension, the thermal conductivity of the suspension is essential. The purpose of this study is to measure a thermal conductivity of the ice-oil or ice-water suspension with good fluidity. The thermal conductivity was measured by at ransient hot wire method. In this study, the relationship between thermal conductivity and IPF was clarified, and thermal conductivity was expressed as a function of IPF. Moreover, the uncertainty of measurement of the thermal conductivity was estimated.

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私共の周囲には, 固体・液体・気体の三相から構成されている物体が極めて多い. 著者らは, 最近, 種々の湿った多孔質岩石の有効熱伝導率を測定し, その結果を固相, 液相及び気相の体積割合で整理する式を提案した. その折に, 他の分野での三相系物体に対しては, 既にどのような整理式あるいは理論模型が提案されているのかを知りたいため, 各分野の三相系物体の熱物性に関する研究例を調べた. 本稿では, 三相系物体の有効熱伝導率の基礎的模型, 各分野における三相系物体の有効熱伝導率研究の現状及び著者らの研究の概要について述べる.

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The effective thermal conductivity of the clothing materials in which heat flows accompany with mass transfer has been studied.The condition of this measurement may be more similar to practical use of the cloths.The experimental apparatus based upon the steady state comparison method is slightly modified in this study.The water tank is put on the heater and heat is flowed through the sample cloths upward from the heater that is placed at the bottom of the apparatus.The ordinary clothing materials used widely are selected as the sample.
If the heater and the room temperature are kept constant, vapourizing rate η is scarcely independent of the number and the kind of cloths.The η, however, depends on the temperature difference between the heater and room temperature and relative humidity of the room.On the other hand, the temperature difference between upper and bottom surface of sample is nealy proportional to the number of cloths.Therefore, the effective thermal conductivity coexisting with heat conduction and mass diffusion may be evaluated by obtaining the sum of the thermal conductivity in the case that heat or mass transfers alone through the cloths.

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Measurements have been made by the steady state comparison method for the effective thermal conductivity of the clothing materials which consist of fiber (discontinuous phase) and air (continuous phase or matrix). The influence of the factors affecting the effective thermal conductivity of clothing materials is discussed. The experimental apparatus and the test specimen are inserted into a box which is able to control the humidity or the pressure inside it.
The thermal conductivity increases slightly with temperature for any specific density of clothing materials in the present experimental range in a similar way to that of the air, and it is also increases with the volume fraction of fibre except small fraction range. The effective thermal conductivity is, however, almost independent to relative humidity for cotton cloth and polyester one.
Experimental result are compared to predicting equations for the fibrous materials, and the one which has wider range applicability has not been found from among the existing equations.

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The authors have reported the works for the phase change process of heterogeneous composite materials involving coiled conductive solids in a medium. In these works,the effective thermal conductivity has been pointed out as an important one of the thermal properties of the composite materials. In the present study,the effective thermal conductivity of composite materials in which coiled conductive solids are packed in some medium,namely,ice,water,ethylene glycol or air,is measured by a steady state method. Otherwise,a heat conduction model is proposed by the authors and is compared with the experimental values. As a result,it was found that the effective thermal conductivity is considerably affected by factors such as the volume ratio of the conductive solids,the thermal conductivity ratio,the shape of the coils and the direction of the coils and the numerical calculations of the model agree qualitatively with the experimental values.

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The heat exchanger, especially shell & tube type, is basical appratus for heat transfer equipments in various industrial and district fields. The metal tubes, such as cupper, steel and so on, are usually employed in shell and tube heat exchanger. On the other hand, PFA tube using in this exchanger have many advantages that are stable against chemical solution, prevent to get rust, etc.. However, heat exchange efficiency is low value, since PFA has lower thermal conductivity than metals' one. If the conductivity of PFA tube is improved by mixing high conductivity powder in it for example, the effective thermal conductivity of tube may be more larger value and its means bring about large benefit on energy resources.
From this standpoint, we developed the apparatus to measure the thermal conductivity of the thin tube. The data on pure PFA tubes having different 3 sizes diameter are obtained and compared with the data taking from the same dia. tube mixed carbon powder. It is clear that the conductivity of mixed tube have grater value about 1.6 times than pure PFA tubes. Therefore, these mixed tube may be take many improvement to heat exchange coefficient.

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The effective thermal conductivity of corrugated insulating materials which are made by polypropylene or polycarbonate have been measured by employing steady state comparison method for several specimen having various thickness and specific weight. The thermal conductivity of them evaluated are also by using the thermal resistance models, and are compared with above measured values and raw materials' conductivity.
The main results obtained in this paper are as follows:
(1) In regard to the specimen in this paper, the effective thermal conductivity increases with increasing temperature, but the increasing rate of them is small.
(2) There are considerable differences between the measured values and the predicted ones that are estimated by using the thermal resistance model in which heat flow by conduction only. This differences increase with increasing specimens' thickness. This difference become extinct by considering the coexistence heat flow of conduction and radiation in the air phase of specimen.
(3) The thermal resistance of specimen increases linearly with increasing specimens' thickness.

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食品の加熱加工において，ジュール加熱法は，温度制御精度が良い，焦げ付きがない，加工環境がクリーンであるなどの特徴を有するため，様々な応用が期待されている．著者らは，これまで容器内に1 種類の物質を配置し，食品内部の温度分布を非破壊的かつ連続的に観察し，その現象を数値解析により再現することにより，正味のジュール発熱による温度変化を捉えることができた．しかし，一般的な食品加工では容器内には複数の物質が存在するため，本論文では，電位差分布による発熱の相違を考慮した熱伝導問題を解くことにより，発熱および熱移動現象を解明する方法を提案した．

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熱伝導率の異なる物質から構成される,巨視的にみても不均質な物質工学上にも多く用いられている.しかし,その熱伝導率の研究は少ない.本報は,このような複合物質を簡単なモデルにおきかえ,差分近似を用いた数値解析によって影響因子の分析を行い,熱伝導率の推定式を提案した.この式による推定値は,複合物質中の不連続相の大きさが広い範囲にわたって,数値解析結果と±3%以内で一致することが示された.

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