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Volume 1962 (1962)
- Issue 33 Pages 2-
- Issue 32 Pages 2-
- Issue 31 Pages 3-
Volume 1962, Issue 31
Displaying 1-6 of 6 articles from this issue
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Characteristics of Grinding of CarbonsYoshitami Fukuda, Kunitaro Kawasoe, Kenji Ikeda1962 Volume 1962 Issue 31 Pages 3-8
Published: April 30, 1962
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSBy the application of the air permeability method to the specific surface measurement of materials ground in a steel ball mill the energy required for grinding and the new surface produced has been established for base materials (pitch cokes), baked and electro-graphitized carbon rod. It has been shown that for these materials the relationship between the energy and new specific surface may be represented by a convex curve (dS/dE>0).
The results were as follows:
Judging from the increase of the specific surface of ground materials only,
(1) the cokes carbonized from binder tend to be ground more easily than the base materials (pitch cokes).
(2) Final value of specific surface (S∞) and comminution coef.(K) were measured. It was found that K was constant for carbons, which was probably fixed according to inner structure and surface characteristics of the carbon.
Final specific surface was discussed from the point of maximum impact stress produced in the pulverized materials.View full abstractDownload PDF (724K) -
II. Distribution of Inorganic Impurities in Domestic Graphite Electrodes.Tokiti Noda, Michio Inagaki, Chihiro Sugie1962 Volume 1962 Issue 31 Pages 9-12
Published: April 30, 1962
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe distribution of inorganic impurities in 14″ and 18″ domestic graphite electrodes was investigated by means of radiography.
The distribution of impurities in these electrodes was found to be different from that in 18″ Acheson electrode reported in the previous paper (Carbon (Tanso) No.30, 26 (1961)) In most electrodes, minute particles of impurities were found to be distributed fairly uniformly all over the electrode. In some electrodes, however, small clusters of impurity particles existed in the interstices of coke grains. The amounts of impurities in the electrodes were fairly smaller than those in Acheson electrodes.
The textures of graphite electrodes were also detectable by means of radiography. The texture of 14″electrode was found to be more compact than that of 18″, and the texture of the central part of an electrode was less compact than that of the peripheral part of the same electrode. It could also be observed that the sizes of coke grains in 18″ electrodes were larger than those in 14″ electrodes.View full abstractDownload PDF (6754K) -
Junpei Inagaki1962 Volume 1962 Issue 31 Pages 13-20
Published: April 30, 1962
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe sparking and arcing phenomena on d-c machines were investigated by means of the new commutation testing apparatus which consisted of three parts, i. e. a pulse height analyzer, a simulated commutation tester and a photomultiplier spark detector. The important results described in this paper are:
(1) The sparking voltage is distributed over the range from about 2 volts to 5 volts and its mean value is about 2-3 volts.
(2) The arc limiting values for brush current, commutating inductance and commutator speed were measured.
(3) When the average reactance voltage exceeds the limiting value, i. e., at above 0.4 volts, an arc appers between the brush and the commutator segments.
(4) The arc duration time is respectively proportional to the difference between the factors described above and its arc limiting values.
(5) The arc energy is proportional to the squave of the arc duration time, and to the cube of the brush current.View full abstractDownload PDF (1093K) -
No-destructiv Testing of GraphiteSennosuke Sato1962 Volume 1962 Issue 31 Pages 21-27
Published: April 30, 1962
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSNon-destructive testing is important with graphite material for discovering internal defects inherenty liable to be found in this material which cause it to be inhomogeneous and brittle.
The requirements for non-destructive testing methods suitable for reactor graphite are (a) To measure if possible without contact with the material in order to avoid contamination.(b) To provide for total inspection rather than spot checking.
The author considered on a test selecction chart varions method of inspecting cracks in given cross sections of a sample, with due consideration of the properties of graphite, and as a result recommends the eddy current mathod as the one best suited for testing reactor graphite.
Density is usually adopted as a measure for representing the mechanical strength of graphite, but the relation between the two properties is not simple and direct, and material of the same density may vary widely in strength. Strength is related more to the microscopic bonding of the internal structure than to dencity, and the modulus of elasticiy should be a better standard for representing this condition. If this modulus could be determined non-destructively, it would enhance the reliablity of the mechanical strength properties of this material. A comparative evaluation was made of diverse method now in use, upon which the author concluded that the method most adapted to reactor materials is the one which measnred the propagation speed of ultrasonic waves.View full abstractDownload PDF (8861K) -
[in Japanese]1962 Volume 1962 Issue 31 Pages 28-34
Published: April 30, 1962
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1130K) -
[in Japanese]1962 Volume 1962 Issue 31 Pages 35-42
Published: April 30, 1962
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (986K)
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