Fergus County Democrat

Combustion Without Flame.

Electrical World: If a porous plate of refractory substance is fitted on one side with a close-fitting cup and supply pipe, and inflammable gas is driven through the plate outward from the cup, the gas issuing from the plate can be ignited and the flame will cover the plate. If the right amount of air is now mixed with the gas in the cup, so as to produce an explosive mixture, the flame can be cut down to a mere surface film, the combustion occurring flamelessly inside the pores of plate. The plate becomes thereby intensely heated, since all of the combustion of heat which previously was liberated at the surface of the enveloping gas flame is now liberated within the much smaller surface of the porous plate. The plate is thus able to radiate off a large proportion of the generated heat from the highly heated solid plate substance. It may be that the greatly increased luminous intensity of a gas burner, produced by covering it with a Welsbach gas mantle and admitting air on the inside, partly owes its effect to this phenomenon of flameless combustion.

If, instead of using a porous refractory plate, use be made of a metal pipe filled with coarse granules of fireclay, and the explosive mixture of gases be admitted through a fireclay plug at one end, there will similarly be an intense heating of the granules and a flameless combustion within their pores. The metal tube containing the flameless burner may then be placed in a boiler to produce steam, or in a tank to melt lead. The explosion of the entering mixed gases in the case of a porous plate is prevented by the chilling effect of the pores on the cool or admission side. In the case of coarse granules the speed of the entering gaseous jet can be made to exceed that at which flame can be propagated backward through an explosive mixture.