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Drip-fed heater, why not meths?


BlueStringPudding

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Just a curiosity moment: I've had a drip-fed heater for a few years now (a Taylor's). When I light it with meths, the flame burns lovely and blue as it should. But when I turn on the diesel drip, the flame burns yellow. When the heater is fuelled by paraffin instead of diesel, again the flame burns yellow.*  The destruction manual says the flame should be blue. Other people I've asked in the past who had a Taylor's heater, have also said theirs burned with a mostly or entirely yellow flame. ?

So my question is, if the most efficient burn is a blue flame, and meths provides a blue flame, why isn't methylated spirits used as the main fuel instead of just to light the thing? Cost? Safety? Emissions? Availability in large quantities? Something else?

 

(Before anyone asks, no less than 3 × CO detectors at different heights, and 2 × smoke detectors, within 2-9ft of the heater, don't pick up on anything dangerous being emitted from the it. So I'm not concerned about its safety, just curious about the fuel.)

 

Thanks ??

 

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Meths has some oxygen in its molecule.  Paraffin and diesel do not, so will need even more air (ie oxygen) for full combustion.

 

The hydrogen content of the fuel will always burn first, in preference to the carbon in cool or low oxygen conditions.

 

The yellow is caused by particle of carbon (soot ie not fully combusted fuel) in the flame. 

 

Is the stove making excessive soot ?

Edited by jake_crew
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Not sure how your heater works, some Taylors work like a primus, pressure vessel and a tiny jet. I have a home made version and the burner started making yellow flames, changed the jet, problem solved, nice blue flame. One way or another it sounds like too much fuel for the oxygen to burn it cleanly. Is there a 'jet' or nozzle in the supply somewhere that could be changed? Do you have to pressurise the system? There is a company, I don't have a link sorry, that is actually called something like Taylors stoves, they deal in used units and things, the chap is v. helpful  (if you want to sell it incredibly cheaply I have some £5 notes in a jar, have you seen the price of the things?)

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2 hours ago, jake_crew said:

Meths has some oxygen in its molecule.  Paraffin and diesel do not, so will need even more air (ie oxygen) for full combustion.

 

The hydrogen content of the fuel will always burn first, in preference to the carbon in cool or low oxygen conditions.

 

The yellow is caused by particle of carbon (soot ie not fully combusted fuel) in the flame. 

 

Is the stove making excessive soot ?

Thanks. In answer to your question, it produces almost no soot. 

Any idea if there's an additive for either paraffin or diesel that can improve the burn and blue up that flame? I'm not sure how to get more oxygen into the burner pot in the absence of it being molecularly attached to the fuel. ??

50 minutes ago, Bee said:

Not sure how your heater works, some Taylors work like a primus, pressure vessel and a tiny jet. I have a home made version and the burner started making yellow flames, changed the jet, problem solved, nice blue flame. One way or another it sounds like too much fuel for the oxygen to burn it cleanly. Is there a 'jet' or nozzle in the supply somewhere that could be changed? Do you have to pressurise the system? There is a company, I don't have a link sorry, that is actually called something like Taylors stoves, they deal in used units and things, the chap is v. helpful  (if you want to sell it incredibly cheaply I have some £5 notes in a jar, have you seen the price of the things?)

Not pressurised. Just drip fed by gravity.

Edited by BlueStringPudding
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1 hour ago, Tracy D'arth said:

If its a yellow flame the burner need attention. Either too much fuel or not enough air.  Is the draw on the flue sufficient? A longer chimney may be needed,

It has the full flue length it came supplied with, and is mounted on the bulkhead not far above floor level. I wondered about air intake myself so as an experiment opened the larger draught hole (used for lighting) on the burner pot for a few minutes last night to increase air-in. It didn't change the colour of the flame. (And the destructions say that hole should be shut while the burner is in use anyway.) ?

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I have messed about with pressure stoves and oil lamps for many years, and and would not touch any stove that is fueled by meths, it is a highly volatile fuel which has an inconsistent flame, given to sudden flaring. Another problem is that the flame is almost invisible in bright sunlight, which is why meths stoves were banned years ago by Schools, Outdoor Education Organizations and Youth Groups. Meths burns much hotter than paraffin, which is why it is used to start pressure stoves and lamps, that require the burner supply tubes to be pre-heated. It performs well in that respect when using a clamp on wick, but that is the limit of it's practical use, where stoves are concerned. My advice is to steer away from meths as a stove fuel, and stick to the fuel your stove is designed to use.

 

Having said all that, I always have a good supply of meths in the workshop, where is is invaluable in the production of French Polish, Knotting, and furniture cleaning preparations.

 

 

Edited by David Schweizer
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In the Arthur Ransome book ''The Big Six''  Joe, Bill and Pete of their Death and Glory boat put on a feast for the Coot club members on the boat. They decided to finish off with Christmas pudding. Bill who had boiled it and was preparing it for presentation turned his back on the others.  matches were struck and Bill turned to present the pudding all aflame, ''blue flames''. He had used methelated spirit for the Christmasy effect, although it was only September. After eating the pudding they all had to eat oranges to neutralize the after taste of the meths. They all agreed it was lovely.

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Meths actually has a much reduced energy compared to diesel / paraffin, so not only is it 'twice the price', but you need to use almost twice as much to get the same heat.

 

Part of a presentation I made to a camping / hiking group on the 'best' (most bang per gram) types of fuels to use for stoves

 

Hexamine = 8 Wh / gram
Chafing Gel = 7.44 Wh / gram
Propane LPG = 13.6Wh / gram
Mixed Camping Gas = 14.2 Wh / gram
Seasoned Dry Wood = 4.2 Wh / gram
Methylated Spirit = 7.22 Wh/Gram
Petrol / Diesel = 12.5Wh / gram
Anthracite = 8.6 Wh / gram
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The Dickinson heater site has this useful little guide to flame colour.

http://dickinsonmarine.com/dm/wp-content/uploads/2016/03/Fuel-to-Air-Ratio-for-a-Clean-Burn-with-Diesel-Appliances.pdf

Not sure if “lemon yellow” appears on Dulux charts; but it’s certainly the colour that I see in my Lockgate heater. I run on paraffin/28sec heating oil, the flame has yellow tips once stabilised, but will be entirely yellow for a while after turning up the fuel supply.

 

 

Edited by Eeyore
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10 minutes ago, Alan de Enfield said:

Meths actually has a much reduced energy compared to diesel / paraffin, so not only is it 'twice the price', but you need to use almost twice as much to get the same heat.

 

Part of a presentation I made to a camping / hiking group on the 'best' (most bang per gram) types of fuels to use for stoves

 

Hexamine = 8 Wh / gram
Chafing Gel = 7.44 Wh / gram
Propane LPG = 13.6Wh / gram
Mixed Camping Gas = 14.2 Wh / gram
Seasoned Dry Wood = 4.2 Wh / gram
Methylated Spirit = 7.22 Wh/Gram
Petrol / Diesel = 12.5Wh / gram
Anthracite = 8.6 Wh / gram

How about Acetylene? That'd be hot...

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Opening the lighting port will not introduce more air to the combustion. It will ,in fact, reduce it because the flue draught will by pass the flame. Make sure all the air intakes in the burner are clear and that the fuel flow is unrestricted. Check all seals in the flue and in the stove above the flame like rope on doors and flue connections Any leaks here will reduce the flue draw.

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35 minutes ago, Tony Brooks said:

Cor - a carbide cooker for camping and pray the rain does not get through your rucksack - you may do an involuntary jet suit flight.  :giggles:

In the 'old days' (45-50 years ago) when I used to go caving (Pot-holing) I had a carbide head-lamp, once you put the water in the tank & opened the valve it was like standing next to an Eberspacher exhaust but it did give off a fairly good light and could be used to warm your hands.

I probably only paid 'a couple of pounds' from 'Blacks' (Scout & Camping shop) for it but they now seem to be fetching around £100 on ebay.

 

Lumps of Carbide in the bottom, water in the top, open the valve and let the water dribble down onto the Carbide which then produced Acetylene, flick the spark-wheel and away you went.

 

Picture 1 of 5

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1 hour ago, WotEver said:

Are you sure?  This chart from Wikipedia shows them to be much the same, with kerosene being slightly hotter:

https://en.wikipedia.org/wiki/Adiabatic_flame_temperature

I have looked at that chart and would be interested to see where you get that from metyhylated spirit is not listed.

 

With regadrd to comparative heat, have you ever tried pre-heating a Primus Stove or Tilley lamp using paraffin? With a bit of imagination it can be done, but it takes for ever to heat the tubes and makes a lot of smoke.

 

 

 

Edited by David Schweizer
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1 hour ago, Alan de Enfield said:

Meths actually has a much reduced energy compared to diesel / paraffin, so not only is it 'twice the price', but you need to use almost twice as much to get the same heat.

 

Beat me to it by an hour. For the same reason, diesel oil has a greater energy density than petrol, although the difference isn't so pronounced.

...So I'm not sure about the last line of your table, lumping the two fuels together.

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47 minutes ago, Alan de Enfield said:

In the 'old days' (45-50 years ago) when I used to go caving (Pot-holing) I had a carbide head-lamp, once you put the water in the tank & opened the valve it was like standing next to an Eberspacher exhaust but it did give off a fairly good light and could be used to warm your hands.

I probably only paid 'a couple of pounds' from 'Blacks' (Scout & Camping shop) for it but they now seem to be fetching around £100 on ebay.

 

Lumps of Carbide in the bottom, water in the top, open the valve and let the water dribble down onto the Carbide which then produced Acetylene, flick the spark-wheel and away you went.

 

Picture 1 of 5

Affectionately known as "Stinkies" to cavers. I still have one as a mantelpiece ornament. We were using larger versions, with a big acetylene generator on a waist belt, with a hose feeding a helmet mounted burner and reflector up till the turn of the century, especially for trips and expeditions abroad. Since replaced by LED lamps. Not seen one in use for over a decade. Had an exciting experience where in a narrow squeeze the hose came off the helmet burner and the escaping gas ignited. Managed to escape with only minor singes!

 

30 minutes ago, Loddon said:

There are stories told of feeding seagulls carbide pellets.

I will leave the result to the readers imagination ; )

 

A common party trick with cavers was to drop a pellet in to a plastic (never glass) drinks bottle, with a little water. Screw the lid down and throw it in to a crowded room. I've also seen it used to launch dustbins over roofs.

We've taken the thread completely off topic now.

Jen

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40 minutes ago, David Schweizer said:

I have looked at that chart and would be interested to see where you get that from metyhylated spirit is not listed.

 

With regadrd to comparative heat, have you ever tried pre-heating a Primus Stove or Tilley lamp using paraffin? With a bit of imagination it can be done, but it takes for ever to heat the tubes and makes a lot of smoke.

 

 

 

I tend to think that meths is used to pre-heat as it burns cleaner than paraffin without a forced draught.  Some pressure lamps and stoves have gadget to alllow pre-heating using the paraffin, but they still end to smoke 

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1 hour ago, David Schweizer said:

I have looked at that chart and would be interested to see where you get that from metyhylated spirit is not listed.

Ethanol and Meths are fundamentally the same thing as I understand it.

1 hour ago, Tacet said:

Some pressure lamps and stoves have gadget to alllow pre-heating using the paraffin, but they still end to smoke 

My dad's old paraffin blowlamp was always fun to light.

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2 hours ago, Jen-in-Wellies said:

Affectionately known as "Stinkies" to cavers. I still have one as a mantelpiece ornament. We were using larger versions, with a big acetylene generator on a waist belt, with a hose feeding a helmet mounted burner and reflector up till the turn of the century, especially for trips and expeditions abroad. Since replaced by LED lamps. Not seen one in use for over a decade. Had an exciting experience where in a narrow squeeze the hose came off the helmet burner and the escaping gas ignited. Managed to escape with only minor singes!

 

A common party trick with cavers was to drop a pellet in to a plastic (never glass) drinks bottle, with a little water. Screw the lid down and throw it in to a crowded room. I've also seen it used to launch dustbins over roofs.

We've taken the thread completely off topic now.

Jen

We used to have wonderful devices called dry ice bombs. Evian bottle, half full of water add a handful of pellets cap it and run. I got it down to a fine art, holding onto the bottle for a few seconds before lobbing it in the air and running. You can make a lot of people wet with a mid air explosion ; )

 

 

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1 hour ago, WotEver said:

Ethanol and Meths are fundamentally the same thing as I understand it.

 

Similar, but not the same. Methylated Spirit is aprox 95% denatured Ethanol, whether there is any difference in burn temperature, I do not know.

 

 

Edited by David Schweizer
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1 hour ago, David Schweizer said:

Methylated Spirit is aprox 95% denatured Ethanol

That simply means they’ve made it taste horrid. It shouldn’t positively affect its burning temperature. 

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