Oscillation of Flame Cones

Abstract

THE phenomenon described in the foregoing letter is in part dealt with in a paper by Dr. Ingle and myself in the Transactions of he Chemical Society for 1892 (vol. lxi., p. 204). The continued oscillation of the inner cone is, I think, explained by the fact that the mixture of gas and air in the tube is not uniform. We have, indeed, found it necessary to use elaborate mixing appliances to make it uniform. When a portion of the mixture rich in air reaches the top of the tube the inner cone is propagated through it and descends until it reaches a stratum richer in gas, when it re-ascends. The fluctuation in the composition of the gaseous mixture escaping from a Bunsen burner can be seen by the throbbing of the inner cone, when the air supply is considerable. I may add that in the construction of burners for the incandescent mantle great importance is attached to the perfect mixing of gas and air, since it becomes possible thereby to have a steady flame with a relatively large quantity of primary air.