回転管内における火炎伝ぱ限界(熱工学,内燃機関,動力など)

Flame Propagation Limits in a Rotating Tube

Sakai Yukio

Konno Tomohisa

Ishizuka Satoru

Ishihara Atsushi

日本機械学會論文集. B編

A polycarbonate cylindrical tube of 32mm inner diameter and 2000mm long is mounted horizontally on a lathe, and concentration limits of flame propagation are determined as a function of rotational speed up to 2000rpm. Mixtures of air and either of methane and propane, and their diluted mixtures with either of nitrogen and carbon dioxide are investigated. To prevent entrainment of ambient air, both ends are closed and the mixture is ignited at one end by an electric spark. Results show that with increasing the rotational speed, rich methane and lean propane limits remain almost constant, whereas lean methane and rich propane limits are varied away from the stoichiometry and the ranges of flame propagation are widened. It is interesting to note that the equivalence ratio at rich propane limit is increases from 2.05 at 0rpm to 2.70 at 1210rpm, which exceeds the standard flammability limit of 2.5 determined with an upward propagation flame in a tube of 5cm diameter. With increasing the rotational speed, the area of flame propagation in the φ (equivalence ratio) x (added inert gas concentration) plane is widened. The equivalence ratios at lean limit are decreased in methane and those at rich limits are increased in propane. The maximum allowable dilution ratio x is increased, and the equivalence ratio at which the maximum occur is shifted towards to lean side in methane, whereas rich side in propane. There aspects can be explained on the basis of diffusional stratification of species of different molecular weight in the field of centrifugal force of rotation.

Flame Propagation

Propagation Limits

Rotational Field

Rotating Tube

Flammability Limits

Dilution Limits

Technology. Engineering [ 500 ]

jpn

一般社団法人日本機械学会

社団法人日本機械学会

本文データは学協会の許諾に基づきCiNiiから複製したものである

[ISSN] 0387-5016

[NCID] AN00187441

[NAID] 110004999645 isVersionOf