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Volume 6 (1956 - 1957･･･
- Issue 2 Pages 33-
- Issue 1 Pages 1-
Volume 6, Issue 2
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Kazuo AKITA1957 Volume 6 Issue 2 Pages 33-36
Published: 1957
Released on J-STAGE: November 11, 2014
JOURNAL FREE ACCESSIn this experiment, the wood boards were heated on the electric furnace. The distribution of the air temperature near the surface of board was measured by thermocouples with electromagnetic oscillograph and the processes of smoke and flame-formation at the ignition were observed by the methods of light absorption, ion probe and eye sight.
The important results are the followings :
(1) The air temperature near the surface of board is slightly raised before ignition by slow oxidation of combustible decomposition products.
(2) The flame starts at the surface of wood board and propagates away from the surface. But the flame at the surface can hardly be seen with naked eyes.
(3) The smoke formed by the thermal decomposition of wood, contains only liquid particles made from various hydrocarbons but no solid ones.
(4) The components of combustible gases which play the important role at the ignition of wood are, contrary to expectation, inflammable liquid vapours of higher hydrocarbon, rather than combustible gases such as CO and H2.View full abstractDownload PDF (442K) -
Katsura INOUE1957 Volume 6 Issue 2 Pages 37-39
Published: 1957
Released on J-STAGE: November 11, 2014
JOURNAL FREE ACCESSIn this report we observed the time lag in ignition and flame up when the leaves of grass and tree were exposed under several conditions of the temperature and moisture. These leaves were gathered from the Nopporo experimental forest in May 1955.
The leaves of twenty species were tested.
(1) The leaves of the grass are more susceptible to ignition than those of tree. Specially Pteridophyta is most susceptible. Sasa is easy to flame up in lower temperature.
(2) The dead leaf is easy to ignite than live one. The younger the leaf, the more inflammable. Probably this is due to the thickness of the leaf in addition to its types and chemical composition.View full abstractDownload PDF (208K) -
Tomio IZUMI, Takakage SAKURAI, Toshio IZUMI1957 Volume 6 Issue 2 Pages 40-44
Published: 1957
Released on J-STAGE: November 11, 2014
JOURNAL FREE ACCESSSurface of foam layer was easy to contaminate by petrol when foam stream was violently applied on the petrol surface. If the foam layer was contaminated by petrol, it was found that the heat resistance of foam was considerably deteriorated. A number of petrol products and crude oils were used to contaminate the foam layer, and experiments carried out for a number of different fire-fighting foams.
Consideration on the possibility of extinguishment of petrol fires by foams contaminated by petrols was given.View full abstractDownload PDF (420K) -
Keizaburo OKAJIMA, Yorio YAJI1957 Volume 6 Issue 2 Pages 45-48
Published: 1957
Released on J-STAGE: November 11, 2014
JOURNAL FREE ACCESSWe observed the shapes of flames of alcohol burning in small circular dishes in the wind (2～12m/s).
The effect of the wind on the burning depended on the length to the direction of the wind i. e. the diameter of the circular dishes in this case.
As the speed of wind was increased, the following tendencies could be seen :
1. The flame length decreases, the flame temperature becomes higher just above the flame base, and the burning speed becomes greater, while the temperature of the flame-end becomes lower.
2. When the wind velocity increases as much as showing its cooling effect to combustion, the above-mentioned quantities tend to their limiting values and combustion becomes unstable.View full abstractDownload PDF (670K) -
Sizuo YOKOI, Kunio KAWAGOE, Takasi SEKINE1957 Volume 6 Issue 2 Pages 49-53
Published: 1957
Released on J-STAGE: November 11, 2014
JOURNAL FREE ACCESSTokyo Metropolitan Fire Board made an experiment on the effect of the water spray method for the extinction of fire. We, research members of Building Research Institute, made use of this experiment, and measured the velocity and temperature of the fire flame when it was passing through the window of the burning house and its temperature after it passed the window. The important results obtained are as follows :
(1) In the window plane, the pressure difference between the inner and outer air increases linearly with the vertical distance from the neutral layer above which the inner pressure is larger than the outer, and so the stream velocity through the window increases quadratically with the height in the range above the neutral layer.
(2) The velocity distribution of that stream in the window plane is nearly similar to its temperature distribution.
(3) Above-mentioned similarity holds also between the velocity and temperature variation at any point in the window.
(4) The temperature decrease of the issued flame towards the down stream is just like that of the upward stream from the heat sources arranged on a circle or a circular heat source, already reported by S. Yokoi. The decrease is slight in a range near the window but it becomes remarkable from a certain distance and in this region the temperature is nearly inversely proportional to 5/3 power of the distance from the window.View full abstractDownload PDF (493K) -
Sanyo HORI1957 Volume 6 Issue 2 Pages 54-58
Published: 1957
Released on J-STAGE: November 11, 2014
JOURNAL FREE ACCESSIn this paper, there are reported the experimental studies on burning of the pile of paper tubes, the axis of which are parallel to the convection air stream.
The following results are obtained.
(1) There are three types in the form of propagation of burning along the pile of paper tubes.
(2) It can be easily known to which one of the three types the form of propagation belongs, when the tubes’ diameter, the slope of the plane, etc. are given.
(3) When the lower end of paper tube is closed, and the greater the velocity of wind the greater is the velocity of burning. But when the lower end of paper tube is opened, the relation between the velocities of wind and of burning does not follow to a simple law.
(4) The greater the diameter of tube, the greater is the velocity of burning in the direction of depth, having no relation to the lower end of paper tube being closed or not. But as the wind becomes stronger, the burning velocity of the closed-end-tubes becomes greater, while the burning velocity of the open-end-tubes becomes smaller.
(5) The three dimentional “Terada phenomenon” is observed.
(6) The direction of spread of burning of the closed-end-tubes is not the same as that of the open-end-tubes.View full abstractDownload PDF (564K) -
Kunio KAWAGOE, Hirosi IMAZU, Takaji TAKANO1957 Volume 6 Issue 2 Pages 59-64
Published: 1957
Released on J-STAGE: November 11, 2014
JOURNAL FREE ACCESSFire resistive constructions usually specified by the authorities should have quality more than 2nd class of JISA 1302. But in the case of moderate height (less than 45 ft. high) or lower fire resistive occupancy, 3rd class of JISA 1302 becomes the lowest limitations, restricted to the house.
The conclusions drawn from 3rd class fire tests on hollow columns and walls shown in Fig.
1, Fig. 8, are given briefly below.
1. Columns
(1) More than 40 mm thickness around the steel frame will be sufficient when cement mortar is used.
(2) More than 32 mm thickness around the steel frame will attain its purpose when ash aggregate mortar is used.
2.Walls
(1) More than 22 mm thickness in each side of steel frame will be sufficient when Cement mortar is used.
(2) More than 18 mm thickness in each side of steel frame will be sufficient when ash aggregate mortar is used.
(3) Wood fibre cement board will be unsuitable for the base of plaster or cement mortal because of its carbonization.View full abstractDownload PDF (522K)
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