A Piezo igniter causes a spark. Is it the spark that ignites the gas, or is it the heat generated by the spark? I remember being told a long time ago that if I were foolish enough to grab the wire when handed to me by my ex-work partner as he pushed the button, that what I would feel when he pushed the button would actually be skin cells exploding due to a rapid over abundance of heat. What annoyed me the most about him was that he was usually always right. That and the fact that he was always nonchalantly saying,here hold this while trying to hand me the wire. Was he right?

Whilst this is not to say that there is no heat generated, it is the ionisation brought about by the high electrical stress that lights the gas.

Heat alone results in faster moving molecules. It does not increase their chemical activity (burning) just increase the chances of tthe right two molecules colliding.

But once ionised , the chemical activity increases dramatically, promoting the spread of burning.

 

34 minutes ago, studiot said:

Whilst this is not to say that there is no heat generated, it is the ionisation brought about by the high electrical stress that lights the gas.

Heat alone results in faster moving molecules. It does not increase their chemical activity (burning) just increase the chances of tthe right two molecules colliding.

But once ionised , the chemical activity increases dramatically, promoting the spread of burning.

 

Thanks.

2 minutes ago, jajrussel said:

Thanks.

The spark is also activation energy, perhaps I will expand on that in the other thread later this evening - I have to go feed the cat - I see you asked for more detail there.

 

But take this with you.

The whole point about activation energy is that the process produces energy once it gets going, it just need that initial kick up the proverbial to get started.

Edited October 3, 20187 yr by studiot

20 minutes ago, studiot said:

The spark is also activation energy, perhaps I will expand on that in the other thread later this evening - I have to go feed the cat - I see you asked for more detail there.

 

But take this with you.

The whole point about activation energy is that the process produces energy once it gets going, it just need that initial kick up the proverbial to get started.

The only video I've had a chance to watch so far about activation energy is this one. He is using temperature, so I thought heat. Perhaps wrongly.