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Volume 17 (1967 - 196･･･
- Issue 2 Pages 1-
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Volume 17, Issue 2
Displaying 1-4 of 4 articles from this issue
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Paper
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T. MAEDA, T. TERAI, S. YAMAGUCHI1967 Volume 17 Issue 2 Pages 1-10
Published: 1967
Released on J-STAGE: July 19, 2013
JOURNAL FREE ACCESSAccording to the field experiment in the anteroom of the emergency staircase, equipped with smoke tower, it is found that smoke and air flow separately as two layers, in which upper layer is smoke and lower layer is air, and that their boundary height is determined by the volumetric ratio of air and smoke.
But, in the field experiment, the conditions of inlet and outlet openings and the volume of air and smoke are limited, so more systematic studies are needed, and this model experiment has been carried out.
In this model experiment it is assumed that, if ratios of air and smoke volume to anteroom volume are equal, flow patterns are same in the model and the field experiment.
Scale of the model is one tenth of that of the field experiment, therefore, the volume of model experiment in l/s corresponds to the volume of field experiments in m3/s.
Results of this model experiment are as follows.
(1) Flow patterns of smoke and air in the anteroom can be classified in O, A, B, C, D and E types, and criterion of these types depend only on supply air volume.
The types A, B, and C, have two layers flow pattern, in which lower layer is perfect or semiperfect transparent. The upper limit of air supply of this domain is 5.4 l/s.
The type B has perfect transparent lower layer, and the upper and lower limit of the domain of air supply of the type B are 1.5 and 3.5 l/s respectively.
(2) The curve of relation between boundary height and air to smoke ratio in the domain of types A, B and C, converges to two-thirds of the ceiling height with increasing air to smoke ratio.
Therefore, for emergency escape, upper limit of air supply and proper air to smoke ratio are 5.4 l/s and 2 respectively.
(3) Characteristics of vertical temperature distribution in the anteroom do not differ markedly for each type of A, B, C, D and E.View full abstractDownload PDF (760K) -
Takashi HANDA, Toshihiko HATA, Hiroko SHIMIZU, Hiromichi FUKUDA1968 Volume 17 Issue 2 Pages 11-24
Published: 1968
Released on J-STAGE: July 19, 2013
JOURNAL FREE ACCESSTheoretical approach to the problem on the visibility through aerosols has been pursued on following models.
Incident light is a parallel beam coming from backwards to the observer. The objective is a white infinitely long disk with a completely flat clean surface. Visibility is defined to be lost when the intensity of the sum of the total scattered light from aerosol particles to the human eye is balanced to the intensity of reflected light from the objective.
The particle size of aerosols are assumed to be relatively small to the wave-length of the incident light. Hence the Rayleigh and Rayleigh-Gans type scattering has been applied.
Then, visible distance (l) is estimated by the following equation :
∫{NI′J(π-θ)/R2+NI"J(θ)/R2}dυ=ƒI0exp(-2τl)
I′=I0exp(-τz), I"=I0exp(-τ（2ｌ-z))
dυ=2πz2tan θ sec2 θ dθ dz
The most important factor which affects the visible distance has been found to be the shape of the size-distribution of the aerosol particles. The visible distance through fog particles with Size-distribution is 1/10～1/100 times to the one in the case of uniform particle size.
The effect of wave length distribution of the incident light on the visible distance has been estimated shorten the distance ca. 1/10 times to the one in the case of monochromatized light.
Investigation are presently being on the Mie-type scattering case.View full abstractDownload PDF (863K) -
Takashi HANDA, Hiroaki SUZUKI, Minoru SAITO1968 Volume 17 Issue 2 Pages 25-33
Published: 1968
Released on J-STAGE: July 19, 2013
JOURNAL FREE ACCESSAnalysis on the data of fire test concerning various organic building materials has been pursued by the Madison-type tunnel furnace in the following items.
A) Flame-Spread Velocity
B) Heat Evolved
C) Smoke Evolved
We have reached to the following conclusion based on the above data ;
The smoke evolved from the materials deeply relates to the flame-spread velocity of the test material in the combustion-furnace and linear relation has been obtained between smoke density in terms of light-transmission and heat evolved per unit inch of flame-spread.
This can be derived from the ratio of the differentials taken at a given time on Q vs t diagram curve and flame spread Q vs t diagram curve.
The size-distribution of smoke-systems has been estimated with the aid of ROYCO particle Counter concerning plastics and woods.
The results agrees with the one from the data on Z-valves from Light-Scattering and on the photographic observation by Electron microscope.
The results illustrates the following fact that the flame-retardant works on the material to the increase of the Smoke density or mean particle size of the Smoke.View full abstractDownload PDF (980K) -
Shoichi HOSHINO1968 Volume 17 Issue 2 Pages 35-44
Published: 1968
Released on J-STAGE: July 19, 2013
JOURNAL FREE ACCESS: Report for smoke proof tower experience and Design Standard for highrise and underground buildings.View full abstractDownload PDF (766K)
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