Why does a kettle make noise?
Discussion
I am suitable amused!!!!
Thanks for the pointless information, it won't help me sleep tongiht but at least I won't rush out and buy a new kettle. Mine is falling to bits. But I love it, it's kind of a friend to me, it keeps me warm at night and settles my tummy.
Did I just say that out loud? I'm off...
Thanks for the pointless information, it won't help me sleep tongiht but at least I won't rush out and buy a new kettle. Mine is falling to bits. But I love it, it's kind of a friend to me, it keeps me warm at night and settles my tummy.
Did I just say that out loud? I'm off...
Zad said:
Absolute rubbish, no electrolysis happens at all. The bubbles are steam (water vapour). Incidentally, the "steam" you see coming out of the spout is condensed vapour, steam itself is relatively invisible. I can see from your faces that this is news to you all!
The noise is caused because small bubbles of vapour are generated next to the hotplate/element. They then detach and attempt to rise. But, because the rest of the water is <100C the steam condenses and the bubble rapidly implodes, taking a tiny fraction of the gaseous volume. This sends a negative shock wave through the water, and it eventually hits the wall of the kettle causing a n audible 'pop'. Older lower power (and quieter) kettles generated more convection currents which moved the heating water out of the way before vapour could be generated.
As the water heats up, more and more vapour bubbles make it to the surface and escape. This is much more gradual and doesn't generate and sharp shock waves. Hence, a boiling kettle is quieter than a 'hissing' one that is just heating up.
ETA: Why do I know this crap....
Not quite. The bubbles are air dissolved in the water. As the temperature of the water increases, the air is less soluble in the water and comes out of solution. It reflects Henry's Law, which applies if the temperature is constant. It also explains why a warm beer is less fizzy than a cold beer. The noise is caused because small bubbles of vapour are generated next to the hotplate/element. They then detach and attempt to rise. But, because the rest of the water is <100C the steam condenses and the bubble rapidly implodes, taking a tiny fraction of the gaseous volume. This sends a negative shock wave through the water, and it eventually hits the wall of the kettle causing a n audible 'pop'. Older lower power (and quieter) kettles generated more convection currents which moved the heating water out of the way before vapour could be generated.
As the water heats up, more and more vapour bubbles make it to the surface and escape. This is much more gradual and doesn't generate and sharp shock waves. Hence, a boiling kettle is quieter than a 'hissing' one that is just heating up.
ETA: Why do I know this crap....
I have to know this kind of crap to be an anaesthetist. The effect causes problems with air bubbles in IV lines coming out of solution when we use a fluid warmer.
dgb00 said:
Zad said:
Absolute rubbish, no electrolysis happens at all. The bubbles are steam (water vapour). Incidentally, the "steam" you see coming out of the spout is condensed vapour, steam itself is relatively invisible. I can see from your faces that this is news to you all!
The noise is caused because small bubbles of vapour are generated next to the hotplate/element. They then detach and attempt to rise. But, because the rest of the water is <100C the steam condenses and the bubble rapidly implodes, taking a tiny fraction of the gaseous volume. This sends a negative shock wave through the water, and it eventually hits the wall of the kettle causing a n audible 'pop'. Older lower power (and quieter) kettles generated more convection currents which moved the heating water out of the way before vapour could be generated.
As the water heats up, more and more vapour bubbles make it to the surface and escape. This is much more gradual and doesn't generate and sharp shock waves. Hence, a boiling kettle is quieter than a 'hissing' one that is just heating up.
ETA: Why do I know this crap....
Not quite. The bubbles are air dissolved in the water. As the temperature of the water increases, the air is less soluble in the water and comes out of solution. It reflects Henry's Law, which applies if the temperature is constant. It also explains why a warm beer is less fizzy than a cold beer. The noise is caused because small bubbles of vapour are generated next to the hotplate/element. They then detach and attempt to rise. But, because the rest of the water is <100C the steam condenses and the bubble rapidly implodes, taking a tiny fraction of the gaseous volume. This sends a negative shock wave through the water, and it eventually hits the wall of the kettle causing a n audible 'pop'. Older lower power (and quieter) kettles generated more convection currents which moved the heating water out of the way before vapour could be generated.
As the water heats up, more and more vapour bubbles make it to the surface and escape. This is much more gradual and doesn't generate and sharp shock waves. Hence, a boiling kettle is quieter than a 'hissing' one that is just heating up.
ETA: Why do I know this crap....
I have to know this kind of crap to be an anaesthetist. The effect causes problems with air bubbles in IV lines coming out of solution when we use a fluid warmer.
dgb00 said:
The bubbles are air dissolved in the water. As the temperature of the water increases, the air is less soluble in the water and comes out of solution. It reflects Henry's Law, which applies if the temperature is constant. It also explains why a warm beer is less fizzy than a cold beer.
I have to know this kind of crap to be an anaesthetist. The effect causes problems with air bubbles in IV lines coming out of solution when we use a fluid warmer.
That's interesting. So in the case of a patient where caisson disease is suspected, would it be recommended to keep their core temperature at a low level until they can be treated?I have to know this kind of crap to be an anaesthetist. The effect causes problems with air bubbles in IV lines coming out of solution when we use a fluid warmer.
Zad said:
Absolute rubbish, no electrolysis happens at all. The bubbles are steam (water vapour). Incidentally, the "steam" you see coming out of the spout is condensed vapour, steam itself is relatively invisible. I can see from your faces that this is news to you all!
The noise is caused because small bubbles of vapour are generated next to the hotplate/element. They then detach and attempt to rise. But, because the rest of the water is <100C the steam condenses and the bubble rapidly implodes, taking a tiny fraction of the gaseous volume. This sends a negative shock wave through the water, and it eventually hits the wall of the kettle causing a n audible 'pop'. Older lower power (and quieter) kettles generated more convection currents which moved the heating water out of the way before vapour could be generated.
As the water heats up, more and more vapour bubbles make it to the surface and escape. This is much more gradual and doesn't generate and sharp shock waves. Hence, a boiling kettle is quieter than a 'hissing' one that is just heating up.
ETA: Why do I know this crap....
The noise is caused because small bubbles of vapour are generated next to the hotplate/element. They then detach and attempt to rise. But, because the rest of the water is <100C the steam condenses and the bubble rapidly implodes, taking a tiny fraction of the gaseous volume. This sends a negative shock wave through the water, and it eventually hits the wall of the kettle causing a n audible 'pop'. Older lower power (and quieter) kettles generated more convection currents which moved the heating water out of the way before vapour could be generated.
As the water heats up, more and more vapour bubbles make it to the surface and escape. This is much more gradual and doesn't generate and sharp shock waves. Hence, a boiling kettle is quieter than a 'hissing' one that is just heating up.
ETA: Why do I know this crap....
NeMiSiS said:
We have accoustic engineers in work, they basically look for knocks/rattles/road noises and elliminate them using sealer strips/orbseal/foam/lagging etc. They are very technical white coat wearers and will set up masses of equipment to monitor a squeek, that me and you would find/elliminate in 2 mins.
We have just had one of these boffins in the office attempting to use the Vending machine, which is clearly empty and broken, so I called him over to explain the Vending machine was broken, as it says on the front ' Out Of Order.' But while you are here can you tell me why a kettle makes so much noise when boiling water. He looked at me oddly and said, " It will take me far too long to explain to YOU." This coming from a guy who tried to use a broken and empty vending machine made me smirk. But as he turned away he said, " If you put a cupfull of plain fishtank gravel in your kettle enough to cover the elliment, it wont interfere with heating the water and it wont be noisey at all."
Now then these aloof types like to take the pi55, and he was slightly injured from the vending machine 'out of order' quip, but is he right ?
Seem to remember in school putting pieces of pot in beakers whilst doing experiments. I think this was to reduce the shock of the boiling liquid so the above seems plausable. Bet it makes a rancid cup of tea though!We have just had one of these boffins in the office attempting to use the Vending machine, which is clearly empty and broken, so I called him over to explain the Vending machine was broken, as it says on the front ' Out Of Order.' But while you are here can you tell me why a kettle makes so much noise when boiling water. He looked at me oddly and said, " It will take me far too long to explain to YOU." This coming from a guy who tried to use a broken and empty vending machine made me smirk. But as he turned away he said, " If you put a cupfull of plain fishtank gravel in your kettle enough to cover the elliment, it wont interfere with heating the water and it wont be noisey at all."
Now then these aloof types like to take the pi55, and he was slightly injured from the vending machine 'out of order' quip, but is he right ?
Here's another question....
Why is it when you turn the hot tap on, as the temperature of the running water gets hotter, the tone of sound emmitting from the tap changes? (ok it only changes slightly, but enough to notice and puzzle me!).
Why is it when you turn the hot tap on, as the temperature of the running water gets hotter, the tone of sound emmitting from the tap changes? (ok it only changes slightly, but enough to notice and puzzle me!).
Edited by cqueen on Thursday 30th September 19:35
cqueen said:
Here's another question....
Why is it when you turn the hot tap on, as the temperature of the running water gets hotter, the tone of sound emmitting from the tap changes? (ok it only changes slightly, but enough to notice and puzzle me!).
For the same reason as the kettle changes sound as the water inside heats up.Why is it when you turn the hot tap on, as the temperature of the running water gets hotter, the tone of sound emmitting from the tap changes? (ok it only changes slightly, but enough to notice and puzzle me!).
Edited by cqueen on Thursday 30th September 19:35
qube_TA said:
For the same reason as the kettle changes sound as the water inside heats up.
The kettle makes noise as it heats up due to water in the vicinity of the element boiling, the bubbles rising and condensing/popping through the cooler water (if I understand what I've read here). I don't get how that can apply to water coming out a tap?Gassing Station | The Lounge | Top of Page | What's New | My Stuff