gas stove flame?

Question

ok i know black smoke is from an oxygen deffeicent environment, does white smoke come from an oxygen rich environmnet....and also if there is no smoke i would assume a perfect balance of natural gas and oxygen, but then i would wonder how the gas and stove companies figured out how to tweak the mixture to make it perfect....any ideas?

Answer 1

For naturaly gas, an oxygen rich mixture will not produce visible smoke (black or white or other).

Oxygen is, of course, invisible. As you observed, with insufficient oxygen, the fuel cannot be completely burned, so there is dark smoke. With too much oxygen, the fuel is still completely burned and there is just more oxygen. If fact, burners have to have more than the exact needed amount of oxygen for full burning because the fuel molecules will not be able to quickly encounter the oxygen molecules unless there is excess oxygen.

White smoke is either condensing steam, or imcompletely burned fuel that doesn't appear dark.

The only downside of too much excess excess oxygen is efficiency. Since you have to heat up all the air that is put through the burner, some burners will waste heat heating up extra combustion air.

Answer 2

The composition of domestic gas is kept within a specification. Properties such as density, calorific value and flame speed may affect performance. Gas burnt with too much air will reduce efficiency and may blow out (this has to be quite excessive) but will not produce white smoke. To do this I imagine one has to have something like white metal oxide powders (magnesium?). I have always wondered how the Vatican produces its white smoke when choosing a pope - might ask a question. To some extent gas burners are self regulating, more gas flow entraining more air.

Answer 3

Trial and error. The number and diameter of the holes the unburned gas comes through, and the size of the opening that admits air to mix with the gas before combustion, have all been determined by trial and error.