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Volume 4 (1954 - 1955･･･
- Issue 2 Pages 33-
- Issue 1 Pages 1-
Volume 4, Issue 1
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Paper
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Shizuo YOKOI1954 Volume 4 Issue 1 Pages 1-3
Published: 1954
Released on J-STAGE: March 27, 2015
JOURNAL FREE ACCESSThe horizontal distributions of the mean upward velocity and temperature in the convection stream from a line and point heat sources were discussed.
In the case of line heat source, results derived from calculations based on the vorticity transfer theory had better fit to the experimental results than those based on the momentum transfer theory. In the case of point source, all results based on momentum transfer, modified vorticity and generalized vorticity transfer theory had pour fit to the experimental results.
The turbulent diffusion coefficient in the vertical direction has much larger value than in the horizontal direction in the stream and this is supposed to be one of the chief characteristics of it.View full abstractDownload PDF (250K) -
Seiichi FUJII1954 Volume 4 Issue 1 Pages 4-6
Published: 1954
Released on J-STAGE: March 27, 2015
JOURNAL FREE ACCESSThe temperature distributions of air along the ceiling in the early stage of a fire are measured, burning alcohol filled in the flat vessels in a concrete room.
As measuring apparatus of temperature I use 24 Cupper-Constantan thermocouples, recording their electromotive force by magnetic oscillograph.
In experiment A, the horizontal distribution of temperature in the plane 5cm under the ceiling is measured, and at the same time the effects of joists are investigated.
In experiment B, the vertical distributions of temperature in the hot layer directly under the ceiling at three points are measured.
From these experiments the following conclusions are obtained.
( 1 ) The effect of joists on the temperature distribution along the ceiling is almost negligible, but on the time lag of temperature rise amounted to several seconds is recognised.
( 2 ) The layer of hot air separated distinctly from cold air cannot be observed, but the temperature of air near the ceiling rises with time uniformly without changing its profile.View full abstractDownload PDF (266K) -
Kazuo AKITA1954 Volume 4 Issue 1 Pages 7-10
Published: 1954
Released on J-STAGE: March 27, 2015
JOURNAL FREE ACCESSIn this report, mathematical theory of ignition of wood is developed and as a special case, an equation determining the time lag in ignition, under the conditions that the wood board is heated one-dimensionally at constant temperature, is introduced by this theory.
Obtained equation is as follows :
τ=2/3ln{Hφ/2(1-ε)(ΣNi)}
+2/3ln{(1+θ0/Θ)(1-λ)F(Θ)/√1τκ(1-F)4}
-2/3ln{1-4(RΘ/E)(1-F(Θ))/F(Θ)}
+3/4ln{E/RΘ+2E/3RΘ (1-F(Θ))}
τ : time lag in ignition, φ : a limit volume of producted gases in space which has height H, and unit area, Θ : heating temperature (fluid temp.), κ : heat diffusibility of wood, E : activation energy of decomposition of wood, F (Θ) : a function of Θ, x0 : reduced thickness of heat transfer coefficient at wood surface, Ni : a coefficient of decomposition of wood on i component gas product, Σ : summation on all the component of produced gases, R,ε : constant.
Results of experiment in the last report [Bull. Fire Prev. Soc. japan, Vol. 3 No. 1, 2, (1953)] may be explained well by this equation.View full abstractDownload PDF (361K) -
Sanyo HORI1954 Volume 4 Issue 1 Pages 11-13
Published: 1954
Released on J-STAGE: March 27, 2015
JOURNAL FREE ACCESSIn this paper, the three dimensional figure of burning paper is discussed by the method of phenomenalism.
The late prof. T. Terada had been a formula to analyse a burning of a sheet of paper.
This formula is so called “Terada phenomenon,” and very useful to study the prevention of fire.
The “Terada phenomenon” is found to clear the three dimensional figure of burning paper in author’s experiment.View full abstractDownload PDF (521K) -
Kunio KAWAGOE1954 Volume 4 Issue 1 Pages 14-16
Published: 1954
Released on J-STAGE: March 27, 2015
JOURNAL FREE ACCESSA concrete block house (area 4.3+3.5m, height 5.8m, two storied) was used for experiment on which the combustion speed, the flame temperature CO2, CO% in dry exhaust gas and expansion of wall were measured.
Before the fire and after the fire the house was vibrated with the vibrator mounted by the flat roof.
Results were as follows :
1) The maximum temperature was about 800～900°C.
2) The rate of excess air as about 1.0.
3) The combustion speed was compared with the theoretical value explained in the same, bulletin Vol. 2, No. 1.
4) The expansion of the wall was very big, therefore large cracks were grew through the wall.
5) After the fire, the earthquake resistance of this house was unusually decreased.View full abstractDownload PDF (260K) -
Tomio IZUMI, Takakage SAKURAI1954 Volume 4 Issue 1 Pages 17-19
Published: 1954
Released on J-STAGE: March 27, 2015
JOURNAL FREE ACCESSA description is given of the performance of a fire-proofness test for use in laboratories with mechanical foams, and of the results obtained by the test.
The test is conducted that fire-proofness of foams was compared by the rate of destruction of foam layers by the gasoline flames.
Data was given on the following items :
(1) The reliability and precision of the test.
(2) Relation between expansion factor of foam and fire proofness.
(3) Relation between viscosity of foam and fire proofness.
(4) Relation between thickness of foam layer and fire proofness.
(5) Deterioration of fire proofness in time.
(6) Comparison of the fire-proofness of some air foam compounds in the market.View full abstractDownload PDF (309K) -
Katsura INOUE, Masao OKANOUE1954 Volume 4 Issue 1 Pages 20-22
Published: 1954
Released on J-STAGE: March 27, 2015
JOURNAL FREE ACCESSWhen a hill in Kozu Village, Jodo District, Okayama Prefecture was burned for afforestation, the wind distribution before and during the fire was observed in the hill and its neighborhood. Observations were carried on May 7, 8, 9 and 12, 1952.
The following results were obtained.
1) The wind direction in the valley during the observation period was parallel to its direction and the wind velocity in the valley was highest of all other places. This is attributed to the astringency of the wind.
2) The wind direction on this hill coincided to the prevailing wind and after passing the top of the hill the wind blew downward, but in the foot of the hill there was upward current along the slope.
3) Using the wind gauge of Piram type it was scarcely observed the increase of the wind velocity during this burning.View full abstractDownload PDF (629K) -
Kojiro KAMEI1954 Volume 4 Issue 1 Pages 23-25
Published: 1954
Released on J-STAGE: March 27, 2015
JOURNAL FREE ACCESSDuring the years from 1868 to 1945 ……… from the beginning of the Meiji Era to the 20 year of Showa ……… (about 77 years), we can count conflagration numbers in Japan about 958.
This report, in the first step, classified all those numbers into 7 Kinds of Fire Grading to find the character by the sizes of conflagration. In the second step, analysing above grading-data into cities, towns and villages in order to find the tendency by statistic treatment.
Result :
1) The peak of cities and towns conflagration frequency are found in Grading II, during Meiji-Taisho Era (about 1868-1926), but in Showa Era (1927-1945) such peak of frequency are found move to Grading I.
2) In Meiji-Taisho Era, Grading V-VII conflagration have been occurred in large cities only, but in Showa Era (1926-1945) such occurrences are frequently found in middle and small cities. (Population 50,000-150,000).View full abstractDownload PDF (655K)
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