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Ionisation electrode
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Dave Plowman (News)
Feb 22, 2013, 6:39:21 PM2/22/13
to
My Viessmann boiler threw a wobbly and tripped out. Press the re-set, and
it went through all the normal startup procedure (fans whirring, solenoids
clicking), but then tripped again, so I was hoping it was nothing major.
The fault code Eb, means 'heat draw off repeatedly too low during
calibration' The cure is to 'initiate heat draw off and trigger manual
calibration (see page 89)' which didn't help much as there's nothing on
page 89 about it. And when I did find it, it didn't seem to be applicable
to my version of the boiler as the calibration required you to use a code
number which didn't exist.
However, similar sort of faults mentioned the ionisation electrode so in
desperation I followed the service instructions for removing and cleaning
it - and to my delight it sorted things.
What does it do?
--
*That's it! I僧 calling grandma!
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
it went through all the normal startup procedure (fans whirring, solenoids
clicking), but then tripped again, so I was hoping it was nothing major.
The fault code Eb, means 'heat draw off repeatedly too low during
calibration' The cure is to 'initiate heat draw off and trigger manual
calibration (see page 89)' which didn't help much as there's nothing on
page 89 about it. And when I did find it, it didn't seem to be applicable
to my version of the boiler as the calibration required you to use a code
number which didn't exist.
However, similar sort of faults mentioned the ionisation electrode so in
desperation I followed the service instructions for removing and cleaning
it - and to my delight it sorted things.
What does it do?
--
*That's it! I僧 calling grandma!
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Mark
Feb 22, 2013, 6:45:46 PM2/22/13
to
Dave Plowman (News) wrote:
> My Viessmann boiler threw a wobbly and tripped out. Press the re-set, and
> My Viessmann boiler threw a wobbly and tripped out. Press the re-set, and
> I followed the service instructions for removing and cleaning
> it - and to my delight it sorted things.
> What does it do?
>
keeps heating “engineers” in nice easy beer money.?
> it - and to my delight it sorted things.
> What does it do?
>
or it’s a flame detector
-
harry
Feb 23, 2013, 2:30:56 AM2/23/13
to
On Feb 22, 11:39 pm, "Dave Plowman (News)" <d...@davenoise.co.uk>
wrote:
>
> Dave Plowman d...@davenoise.co.uk London SW
Air/fuel mix is a good insulator, a flame conducts.
You can try this by putting the probes of your ohm meter/multimeter in
a flame.
If you have a stable flame, you can test different parts of the flame.
In the hottest parts the resistance is less.
With industrial boilers, the ionisation detector is often a standard
automobile spark plug with a long electrode.
What mucks them up is when the insulator gets sooted up.
Before ignition they are tested by the control system. if they show
conductivity (ie sooted up) the boiler locks out.
So obviously the answer is to clean the soot off.
wrote:
> My Viessmann boiler threw a wobbly and tripped out. Press the re-set, and
> it went through all the normal startup procedure (fans whirring, solenoids
> clicking), but then tripped again, so I was hoping it was nothing major.
> The fault code Eb, means 'heat draw off repeatedly too low during
> calibration' The cure is to 'initiate heat draw off and trigger manual
> calibration (see page 89)' which didn't help much as there's nothing on
> page 89 about it. And when I did find it, it didn't seem to be applicable
> to my version of the boiler as the calibration required you to use a code
> number which didn't exist.
> However, similar sort of faults mentioned the ionisation electrode so in
> desperation I followed the service instructions for removing and cleaning
> it - and to my delight it sorted things.
> What does it do?
>
> --
> *That's it! I‘m calling grandma!
> it went through all the normal startup procedure (fans whirring, solenoids
> clicking), but then tripped again, so I was hoping it was nothing major.
> The fault code Eb, means 'heat draw off repeatedly too low during
> calibration' The cure is to 'initiate heat draw off and trigger manual
> calibration (see page 89)' which didn't help much as there's nothing on
> page 89 about it. And when I did find it, it didn't seem to be applicable
> to my version of the boiler as the calibration required you to use a code
> number which didn't exist.
> However, similar sort of faults mentioned the ionisation electrode so in
> desperation I followed the service instructions for removing and cleaning
> it - and to my delight it sorted things.
> What does it do?
>
> --
>
> Dave Plowman d...@davenoise.co.uk London SW
> To e-mail, change noise into sound.
Basically it enables the conductivity of the flame to be measured.
Air/fuel mix is a good insulator, a flame conducts.
You can try this by putting the probes of your ohm meter/multimeter in
a flame.
If you have a stable flame, you can test different parts of the flame.
In the hottest parts the resistance is less.
With industrial boilers, the ionisation detector is often a standard
automobile spark plug with a long electrode.
What mucks them up is when the insulator gets sooted up.
Before ignition they are tested by the control system. if they show
conductivity (ie sooted up) the boiler locks out.
So obviously the answer is to clean the soot off.
Brian Gaff
Feb 23, 2013, 3:15:58 AM2/23/13
to
Is it not supposed to detect the conductivity of the flame for some reason?
Maybe its to do with burning lean or otherwise, if this affects the
conductivity of the air in the flame.
Brian
--
From the Sofa of Brian Gaff Reply address is active
"Mark" <ma...@127.0.0.1> wrote in message news:kg8vtd$ffa$1...@dont-email.me...
Maybe its to do with burning lean or otherwise, if this affects the
conductivity of the air in the flame.
Brian
--
From the Sofa of Brian Gaff Reply address is active
"Mark" <ma...@127.0.0.1> wrote in message news:kg8vtd$ffa$1...@dont-email.me...
Andrew Gabriel
Feb 23, 2013, 6:02:33 AM2/23/13
to
In article <132c8550-712d-4917...@fn10g2000vbb.googlegroups.com>,
In others, they are separate.
As ionisation detectors, in some boilers they are dependant on
live and neutral being the right way around in the supply, and
the boiler being correctly earthed. If something has gone wrong
there, that can stop it working. Don;t know if that applies to
yours.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
harry <harry...@btinternet.com> writes:
> Basically it enables the conductivity of the flame to be measured.
> Air/fuel mix is a good insulator, a flame conducts.
> You can try this by putting the probes of your ohm meter/multimeter in
> a flame.
>
> If you have a stable flame, you can test different parts of the flame.
> In the hottest parts the resistance is less.
>
> With industrial boilers, the ionisation detector is often a standard
> automobile spark plug with a long electrode.
>
> What mucks them up is when the insulator gets sooted up.
>
> Before ignition they are tested by the control system. if they show
> conductivity (ie sooted up) the boiler locks out.
>
> So obviously the answer is to clean the soot off.
In many boilers, it also doubles up as the ignition electrode.
> Basically it enables the conductivity of the flame to be measured.
> Air/fuel mix is a good insulator, a flame conducts.
> You can try this by putting the probes of your ohm meter/multimeter in
> a flame.
>
> If you have a stable flame, you can test different parts of the flame.
> In the hottest parts the resistance is less.
>
> With industrial boilers, the ionisation detector is often a standard
> automobile spark plug with a long electrode.
>
> What mucks them up is when the insulator gets sooted up.
>
> Before ignition they are tested by the control system. if they show
> conductivity (ie sooted up) the boiler locks out.
>
> So obviously the answer is to clean the soot off.
In others, they are separate.
As ionisation detectors, in some boilers they are dependant on
live and neutral being the right way around in the supply, and
the boiler being correctly earthed. If something has gone wrong
there, that can stop it working. Don;t know if that applies to
yours.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
MJA
Feb 23, 2013, 8:54:41 AM2/23/13
to
On 2013-02-23, Andrew Gabriel <and...@cucumber.demon.co.uk> wrote:
> In article <132c8550-712d-4917...@fn10g2000vbb.googlegroups.com>,
> harry <harry...@btinternet.com> writes:
discussing flame ionization probes:
> In article <132c8550-712d-4917...@fn10g2000vbb.googlegroups.com>,
> harry <harry...@btinternet.com> writes:
>> Before ignition they are tested by the control system. if they show
>> conductivity (ie sooted up) the boiler locks out.
>>
>> So obviously the answer is to clean the soot off.
>
> In many boilers, it also doubles up as the ignition electrode.
> In others, they are separate.
>
> As ionisation detectors, in some boilers they are dependant on
> live and neutral being the right way around in the supply, and
> the boiler being correctly earthed. If something has gone wrong
> there, that can stop it working. Don;t know if that applies to
> yours.
Some boilers use the ionisation current to calibrate the air/gas
>> conductivity (ie sooted up) the boiler locks out.
>>
>> So obviously the answer is to clean the soot off.
>
> In many boilers, it also doubles up as the ignition electrode.
> In others, they are separate.
>
> As ionisation detectors, in some boilers they are dependant on
> live and neutral being the right way around in the supply, and
> the boiler being correctly earthed. If something has gone wrong
> there, that can stop it working. Don;t know if that applies to
> yours.
ratio, and it sounds as if the failure was during calibration.
The European Commission report "Preparatory Study on Eco-design of CH
Boilers", Task 4 Report (FINAL), René Kemna, Martijn van Elburg,
William Li and Rob van Holsteijn, Delft, 30 September 2007
<www.ebpg.bam.de/de/ebpg_medien/001_studyf_07-11_part4.pdf> is an
interesting read, and on page 88 there is a description of how this
works:
"6.3.1 Measurement of flame ionization
"This technology is based on the measurement of the ionization voltage
over flame and gas mixture. This ionization is already used for
flame-control reasons (in case no ionization signal is measured,
there is no flame and the gas valve is closed). With additional
electronic circuitry the intensity of the ionization signal can be
measured. And because the flame temperature (ionization voltage) is
directly related to the air factor, the ionization signal is a
indication for the quality of combustion.
...
"Viessmann uses this technology in the VITODENS boilers, and they gave
it the name “Lambda Pro Control”."
Quite an interesting read on modern boiler design including heat
exchangers, burners, control, etc.
Regards,
MJA
harry
Feb 23, 2013, 11:23:11 AM2/23/13
to
On Feb 23, 1:54 pm, MJA <m...@nospam.co.uk> wrote:
> On 2013-02-23, Andrew Gabriel <and...@cucumber.demon.co.uk> wrote:> In article <132c8550-712d-4917-943e-8b662882e...@fn10g2000vbb.googlegroups.com>,
I never heard saw that one before.
The resistance also varies with temperature so I don't see how it
works.
Big boilers have an oxygen sensor in the flue gases.
I seem to remember you're looking for 2% oxygen in the flues gas to be
efficient.
> On 2013-02-23, Andrew Gabriel <and...@cucumber.demon.co.uk> wrote:> In article <132c8550-712d-4917-943e-8b662882e...@fn10g2000vbb.googlegroups.com>,
The resistance also varies with temperature so I don't see how it
works.
Big boilers have an oxygen sensor in the flue gases.
I seem to remember you're looking for 2% oxygen in the flues gas to be
efficient.
Bernard Peek
Feb 23, 2013, 12:27:31 PM2/23/13
to
On 23/02/13 16:23, harry wrote:
> I never heard saw that one before.
> The resistance also varies with temperature so I don't see how it
> works.
It probably works in the same way as a Flame Ionisation Detector in gas
> I never heard saw that one before.
> The resistance also varies with temperature so I don't see how it
> works.
chromatography although that starts out with a hydrogen flame. When
complex organic molecules decompose in the flame they form ions which
can conduct electricity. In a lean flame these compounds are quickly
oxidised to carbon dioxide which does not ionise. In a rich flame the
carbon compounds spend longer in the ionised state before being fully
burnt. That means that the rich flame will conduct better than a lean
one. If the flame is very rich some of the fuel will be oxidised as far
as elemental carbon but no further. That makes the flame yellow and sooty.
--
Bernard Peek
b...@shrdlu.com
Dave Plowman (News)
Feb 23, 2013, 2:05:38 PM2/23/13
to
In article <slrnkihih...@eisvogel.myzen.co.uk>,
MJA <m...@nospam.co.uk> wrote:
[snip]
user, installations and service manuals that came with it - but they seem
to be written in a language I don't understand. ;-)
--
*When cheese gets it's picture taken, what does it say?
Dave Plowman da...@davenoise.co.uk London SW
MJA <m...@nospam.co.uk> wrote:
[snip]
> "Viessmann uses this technology in the VITODENS boilers, and they gave
> it the name �Lambda Pro Control�."
It is indeed a Vitodens, so thanks very much for the info. I have all the
> it the name �Lambda Pro Control�."
user, installations and service manuals that came with it - but they seem
to be written in a language I don't understand. ;-)
--
*When cheese gets it's picture taken, what does it say?
Dave Plowman da...@davenoise.co.uk London SW
geoff
Feb 26, 2013, 7:20:23 PM2/26/13
to
In message
Harry, it is obvious that you know fuck all about flame detection in
domestic boilers
As I have explained on numerous occasions and you have failed to take on
board, you are not looking for conduction (which would be quite a
dangerous way to sense a flame), but the rectifying effect of a flame,
which is not possible to get wrong
give it a rest, eh?
--
geoff
domestic boilers
As I have explained on numerous occasions and you have failed to take on
board, you are not looking for conduction (which would be quite a
dangerous way to sense a flame), but the rectifying effect of a flame,
which is not possible to get wrong
give it a rest, eh?
--
geoff
geoff
Feb 26, 2013, 7:08:25 PM2/26/13
to
In message <53223a1...@davenoise.co.uk>, "Dave Plowman (News)"
<da...@davenoise.co.uk> writes
--
geoff
<da...@davenoise.co.uk> writes
>My Viessmann boiler threw a wobbly and tripped out. Press the re-set, and
>it went through all the normal startup procedure (fans whirring, solenoids
>clicking), but then tripped again, so I was hoping it was nothing major.
>The fault code Eb, means 'heat draw off repeatedly too low during
>calibration' The cure is to 'initiate heat draw off and trigger manual
>calibration (see page 89)' which didn't help much as there's nothing on
>page 89 about it. And when I did find it, it didn't seem to be applicable
>to my version of the boiler as the calibration required you to use a code
>number which didn't exist.
> However, similar sort of faults mentioned the ionisation electrode so in
>desperation I followed the service instructions for removing and cleaning
>it - and to my delight it sorted things.
> What does it do?
>
Senses the flame
>it went through all the normal startup procedure (fans whirring, solenoids
>clicking), but then tripped again, so I was hoping it was nothing major.
>The fault code Eb, means 'heat draw off repeatedly too low during
>calibration' The cure is to 'initiate heat draw off and trigger manual
>calibration (see page 89)' which didn't help much as there's nothing on
>page 89 about it. And when I did find it, it didn't seem to be applicable
>to my version of the boiler as the calibration required you to use a code
>number which didn't exist.
> However, similar sort of faults mentioned the ionisation electrode so in
>desperation I followed the service instructions for removing and cleaning
>it - and to my delight it sorted things.
> What does it do?
>
--
geoff
geoff
Feb 26, 2013, 7:13:07 PM2/26/13
to
In message <kg9tpu$19j$1...@dont-email.me>, Brian Gaff
<Bri...@blueyonder.co.uk> writes
presents
It is also virtually impossible to get wrong (without using electronic
components)
>
--
geoff
<Bri...@blueyonder.co.uk> writes
>Is it not supposed to detect the conductivity of the flame for some reason?
>Maybe its to do with burning lean or otherwise, if this affects the
>conductivity of the air in the flame.
>
It is detecting the rectification effect which is what such a flame
>Maybe its to do with burning lean or otherwise, if this affects the
>conductivity of the air in the flame.
>
presents
It is also virtually impossible to get wrong (without using electronic
components)
>
--
geoff
Andy Burns
Feb 26, 2013, 7:47:20 PM2/26/13
to
geoff wrote:
> you are not looking for conduction (which would be quite a
> dangerous way to sense a flame), but the rectifying effect of a flame,
> which is not possible to get wrong
So, is the sensitivity of this effect to earthing the reason for
> you are not looking for conduction (which would be quite a
> dangerous way to sense a flame), but the rectifying effect of a flame,
> which is not possible to get wrong
problems when attempting to run boilers from temporary generators?
dennis@home
Feb 27, 2013, 2:51:02 AM2/27/13
to
Andy Burns
Feb 27, 2013, 3:04:06 AM2/27/13
to
dennis@home wrote:
> Do you want to explain the physics of how such a flame rectifies?
Pages 11-12 of this seem to do a reasonable job
> Do you want to explain the physics of how such a flame rectifies?
http://www.fireye.net/pdf/WV-96.pdf
harryagain
Feb 27, 2013, 3:19:06 AM2/27/13
to
"geoff" <tr...@uk-diy.org> wrote in message
news:Qx6EpqbH...@virginmedia.com...
So explain how a flame is a rectifier.
And how a recitfier does not conduct electricity?
And why determining that a flame is conductive would be dangerous.
Dave Plowman (News)
Feb 27, 2013, 6:22:26 AM2/27/13
to
In article <DQFQRVZ5...@virginmedia.com>,
Which would makes sense since it seems to be firing, then stops almost
immediately. Does this 4 times before giving up and showing the fault
light. The insulator did have a very thin coating of a dark material
(smoke?) - but would you expect it to be perfect? I cleaned the whole
thing and the actual electrode with emery paper as it says in the service
manual.
It hasn't tripped out once since.
--
*I started out with nothing, and I still have most of it*
immediately. Does this 4 times before giving up and showing the fault
light. The insulator did have a very thin coating of a dark material
(smoke?) - but would you expect it to be perfect? I cleaned the whole
thing and the actual electrode with emery paper as it says in the service
manual.
It hasn't tripped out once since.
--
*I started out with nothing, and I still have most of it*
Tim Lamb
Feb 27, 2013, 5:53:44 AM2/27/13
to
In message <qtydnbJiNbZoILDM...@brightview.co.uk>, Andy
Burns <usenet....@adslpipe.co.uk> writes
Umm... that appears to rectify due to size choices of the electrodes and
not a physical feature of conduction within a flame.
I failed engineering physics so don't shout, please:-)
--
Tim Lamb
Burns <usenet....@adslpipe.co.uk> writes
not a physical feature of conduction within a flame.
I failed engineering physics so don't shout, please:-)
--
Tim Lamb
Man at B&Q
Feb 27, 2013, 7:36:32 AM2/27/13
to
On Feb 27, 8:19 am, "harryagain" <haroldhr...@aol.com> wrote:
>
> > As I have explained on numerous occasions and you have failed to take on
> > board, you are not looking for conduction (which would be quite a
> > dangerous way to sense a flame), but the rectifying effect of a flame,
> > which is not possible to get wrong
>
> > give it a rest, eh?
>
> > --
> > geoff
>
> Right?
> So explain how a flame is a rectifier.
It isn't. Just as you need differently doped silicon in a "system" to
>
> > As I have explained on numerous occasions and you have failed to take on
> > board, you are not looking for conduction (which would be quite a
> > dangerous way to sense a flame), but the rectifying effect of a flame,
> > which is not possible to get wrong
>
> > give it a rest, eh?
>
> > --
> > geoff
>
> Right?
> So explain how a flame is a rectifier.
make a silicon rectifier, so you need a "system" of flame and
electrodes.
> And how a recitfier does not conduct electricity?
effects such as reverse recovery. But then I suspect you know that
bit.
> And why determining that a flame is conductive would be dangerous.
MBQ
dennis@home
Feb 27, 2013, 8:39:01 AM2/27/13
to
Man at B&Q
Feb 27, 2013, 10:38:58 AM2/27/13
to
On Feb 27, 1:39 pm, "dennis@home" <den...@killspam.kicks-ass.net>
wrote:
I'd like to see you make it work without the flame.
MBQ
wrote:
MBQ
Andy Burns
Feb 27, 2013, 11:43:41 AM2/27/13
to
Tim Lamb wrote:
> Andy Burns <usenet....@adslpipe.co.uk> writes
it, but it encouraged a bit of googling ...
It seems it stems from the burning of gas ionising it, so you've got
some free electrons available, if you try to pass A/C between the base
of the flame and the tip, it'll happen more readily in one direction
than the other, you detect the conduction varying with the phase (rather
than just conduction itself, or lack of it).
On the other hand, what's wrong with a thermocouple?
> Andy Burns <usenet....@adslpipe.co.uk> writes
>
>> http://www.fireye.net/pdf/WV-96.pdf
>
> Umm... that appears to rectify due to size choices of the electrodes and
> not a physical feature of conduction within a flame.
>
> I failed engineering physics so don't shout, please:-)
It's not something I claim to have known about before geoff mentioned
>> http://www.fireye.net/pdf/WV-96.pdf
>
> Umm... that appears to rectify due to size choices of the electrodes and
> not a physical feature of conduction within a flame.
>
> I failed engineering physics so don't shout, please:-)
it, but it encouraged a bit of googling ...
It seems it stems from the burning of gas ionising it, so you've got
some free electrons available, if you try to pass A/C between the base
of the flame and the tip, it'll happen more readily in one direction
than the other, you detect the conduction varying with the phase (rather
than just conduction itself, or lack of it).
On the other hand, what's wrong with a thermocouple?
Tim+
Feb 27, 2013, 12:19:59 PM2/27/13
to
Tim
Dave Plowman (News)
Feb 27, 2013, 12:33:58 PM2/27/13
to
In article <H7mdncKdCaUhqrPM...@brightview.co.uk>,
Thermocouple failure is one of the most common things to stop a boiler
working, IMHO. At least in my case just cleaning the electrode (or more
likely the insulator) got it working, which is a bit cheaper. And it's
rather easier to remove/replace.
--
*When I'm not in my right mind, my left mind gets pretty crowded *
working, IMHO. At least in my case just cleaning the electrode (or more
likely the insulator) got it working, which is a bit cheaper. And it's
rather easier to remove/replace.
--
*When I'm not in my right mind, my left mind gets pretty crowded *
harry
Feb 27, 2013, 2:00:01 PM2/27/13
to
> > Andy Burns <usenet.jan2...@adslpipe.co.uk> writes
When boilers became efficient they needed fans to push the combustion
gas out because there was no convection.
They also had no pilot light and had to be lit every time they fired.
The danger was that the gas valve might pass gas and on ignition, the
boiler would be full of gas and explode.
This couldn't happen when there was a permanent pilot light as any gas
leak would be quietly burned off.
So the boiler has to be purged (with air)on start up to clear any
gas.
The ionisation detector detects the flame. If there isn't one when
there should be, the boiler goes to lockout. (And gas is cut off)
The detector is tested before start up on every occasion and can only
fail "safe".
gas out because there was no convection.
They also had no pilot light and had to be lit every time they fired.
The danger was that the gas valve might pass gas and on ignition, the
boiler would be full of gas and explode.
This couldn't happen when there was a permanent pilot light as any gas
leak would be quietly burned off.
So the boiler has to be purged (with air)on start up to clear any
gas.
The ionisation detector detects the flame. If there isn't one when
there should be, the boiler goes to lockout. (And gas is cut off)
The detector is tested before start up on every occasion and can only
fail "safe".
dennis@home
Feb 27, 2013, 2:57:41 PM2/27/13
to
Andy Burns
Feb 27, 2013, 3:17:43 PM2/27/13
to
Tim+ wrote:
> Andy Burns <usenet....@adslpipe.co.uk> wrote:
>
>> On the other hand, what's wrong with a thermocouple?
>
> Ask anyone whose boiler won't light on Christmas Eve. ;-).
I've got a spare ... might take me until Boxing Day to find it though...
> Andy Burns <usenet....@adslpipe.co.uk> wrote:
>
>> On the other hand, what's wrong with a thermocouple?
>
> Ask anyone whose boiler won't light on Christmas Eve. ;-).
polygonum
Feb 27, 2013, 3:24:51 PM2/27/13
to
(Who else has a spare boiler?)
--
Rod
Andy Champ
Feb 27, 2013, 6:03:15 PM2/27/13
to
means a thermocouple, not a whole boiler!
Andy
polygonum
Feb 27, 2013, 6:26:33 PM2/27/13
to
--
Rod
geoff
Feb 28, 2013, 5:52:27 PM2/28/13
to
In message <512dbae6$0$58303$c3e8da3$88b2...@news.astraweb.com>,
"dennis@home" <den...@killspam.kicks-ass.net> writes
Sorry - was out till after midnight SCUBA diving last night
looks like andy posted an article that gives adequate explanation
--
geoff
"dennis@home" <den...@killspam.kicks-ass.net> writes
looks like andy posted an article that gives adequate explanation
--
geoff
Man at B&Q
Mar 1, 2013, 4:53:12 AM3/1/13
to
On Feb 27, 4:43 pm, Andy Burns <usenet.jan2...@adslpipe.co.uk> wrote:
> Tim Lamb wrote:
> > Andy Burns <usenet.jan2...@adslpipe.co.uk> writes
>
> >>http://www.fireye.net/pdf/WV-96.pdf
>
> > Umm... that appears to rectify due to size choices of the electrodes and
> > not a physical feature of conduction within a flame.
>
> > I failed engineering physics so don't shout, please:-)
>
> It's not something I claim to have known about before geoff mentioned
> it, but it encouraged a bit of googling ...
>
> It seems it stems from the burning of gas ionising it, so you've got
> some free electrons available, if you try to pass A/C between the base
> of the flame and the tip, it'll happen more readily in one direction
> than the other, you detect the conduction varying with the phase (rather
> than just conduction itself, or lack of it).
The way I see it, it also depends on the electrodes. A flame wil not
> >>http://www.fireye.net/pdf/WV-96.pdf
>
> > Umm... that appears to rectify due to size choices of the electrodes and
> > not a physical feature of conduction within a flame.
>
> > I failed engineering physics so don't shout, please:-)
>
> It's not something I claim to have known about before geoff mentioned
> it, but it encouraged a bit of googling ...
>
> It seems it stems from the burning of gas ionising it, so you've got
> some free electrons available, if you try to pass A/C between the base
> of the flame and the tip, it'll happen more readily in one direction
> than the other, you detect the conduction varying with the phase (rather
> than just conduction itself, or lack of it).
rectify just by being a flame.
MBQ
Man at B&Q
Mar 1, 2013, 4:55:22 AM3/1/13
to
On Feb 27, 7:57 pm, "dennis@home" <den...@killspam.kicks-ass.net>
MBQ
wrote:
> On 27/02/2013 15:38, Man at B&Q wrote:
>
>
>
>
>
>
>
>
>
> > On Feb 27, 1:39 pm, "dennis@home" <den...@killspam.kicks-ass.net>
> > wrote:
> >> On 27/02/2013 08:04, Andy Burns wrote:
>
> >>> dennis@home wrote:
>
> >>>> Do you want to explain the physics of how such a flame rectifies?
>
> >>> Pages 11-12 of this seem to do a reasonable job
> >>>http://www.fireye.net/pdf/WV-96.pdf
>
> >> So nothing to do with the flame then.
>
> > I'd like to see you make it work without the flame.
>
> > MBQ
>
> There are many ways to ionise the air/gas.
Which one would you recomend for a domestic boiler?
> On 27/02/2013 15:38, Man at B&Q wrote:
>
>
>
>
>
>
>
>
>
> > On Feb 27, 1:39 pm, "dennis@home" <den...@killspam.kicks-ass.net>
> > wrote:
> >> On 27/02/2013 08:04, Andy Burns wrote:
>
> >>> dennis@home wrote:
>
> >>>> Do you want to explain the physics of how such a flame rectifies?
>
> >>> Pages 11-12 of this seem to do a reasonable job
> >>>http://www.fireye.net/pdf/WV-96.pdf
>
> >> So nothing to do with the flame then.
>
> > I'd like to see you make it work without the flame.
>
> > MBQ
>
> There are many ways to ionise the air/gas.
MBQ
Tim Lamb
Mar 1, 2013, 4:33:13 AM3/1/13
to
In message <eZRHT8Yr...@virginmedia.com>, geoff <tr...@uk-diy.org>
writes
Ye-es!
I read it as implying that the detectable imbalance in current flow was
due to size choices for the electrodes rather than ions only flowing in
one direction.
I could easily be mistaken:-)
>
>
--
Tim Lamb
writes
I read it as implying that the detectable imbalance in current flow was
due to size choices for the electrodes rather than ions only flowing in
one direction.
I could easily be mistaken:-)
>
>
--
Tim Lamb
Andy Burns
Mar 1, 2013, 7:32:34 AM3/1/13
to
Man at B&Q wrote:
> "dennis@home" <den...@killspam.kicks-ass.net> wrote:
>
>> There are many ways to ionise the air/gas.
>
> Which one would you recomend for a domestic boiler?
Well I suppose just letting it squirt out of the jets would rip a few
electrons from the gas, though not much compared to burning it.
> "dennis@home" <den...@killspam.kicks-ass.net> wrote:
>
>> There are many ways to ionise the air/gas.
>
> Which one would you recomend for a domestic boiler?
electrons from the gas, though not much compared to burning it.
dennis@home
Mar 1, 2013, 8:56:46 AM3/1/13
to
On 01/03/2013 09:55, Man at B&Q wrote:
> Which one would you recomend for a domestic boiler?
>
50 MW plasma arc, or a very fast angle grinder.
> Which one would you recomend for a domestic boiler?
>
Man at B&Q
Mar 1, 2013, 9:51:51 AM3/1/13
to
On Mar 1, 1:56 pm, "dennis@home" <den...@killspam.kicks-ass.net>
wrote:
MBQ
wrote:
> On 01/03/2013 09:55, Man at B&Q wrote:
>
> > Which one would you recomend for a domestic boiler?
>
> 50 MW plasma arc, or a very fast angle grinder.
You will need some car body filler to hold those in place.
>
> > Which one would you recomend for a domestic boiler?
>
> 50 MW plasma arc, or a very fast angle grinder.
MBQ
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