Galley stove/ovens

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  • 22 Sep 2017 19:49
    Reply # 5275287 on 5275182
    Anonymous member (Administrator)
    David Tyler wrote:
    Darren Bos wrote:

    But, for those with less experience, maybe it is worth pointing out the danger of CO poisoning?

    It is. I wouldn't run an Origo in a small cabin without an active CO alarm.'

    I would not argue against those good arguments. In my defence:

    • In the 'Poor Man's Webasto' piece, the stove and the Fuji heater were only used for the first 20 minutes. Then the Taylor heater (with a flue), which had been runneing from the start, kept on alone.
    • As mentioned, I cook with the hatch more or less open.
    • If that hpv-Salsa were to be pressed into use as a heater, it would anyway run empty of fuel within two-three hours (and the hatch a bit open).
    • I never go to sleep with any heater on  -  Stavanger is Stavanger, not Tromsø or Spitsbergen 

    So, yes, a CO alarm may end up under my Christmas tree, this year.


    Arne

    Last modified: 22 Sep 2017 19:50 | Anonymous member (Administrator)
  • 22 Sep 2017 18:38
    Reply # 5275182 on 5275166
    Darren Bos wrote:

    But, for those with less experience, maybe it is worth pointing out the danger of CO poisoning?

    It is. I wouldn't run an Origo in a small cabin without an active CO alarm.'
    Last modified: 22 Sep 2017 18:44 | David
  • 22 Sep 2017 18:21
    Reply # 5275166 on 5274622
    Arne Kverneland wrote:


    Personally, I could think of having two different single-burner stoves side by side each other, in Ingeborg, one hpv-Salsa and one Origo 1500

    Arne

    This is essentially what we are doing on Leeway Arne.  We have a multi-stove approach.  We have a Dickinson Pacific that provides heat and can be cooked on when in use.  We have a Maxie-two burner that mounts on top of the Dickinson when it it too hot to use the diesel stove.  To complement both the Maxie and the Dickinson we have an in-counter Origo 2000 with a glass top that lets us normally use the counter top, but can be put into use if we need a third burner, or to cook things that are less convenient to cook on the diesel stove.

    Reading the link for your poor mans webasto, you clearly have a lot of experience using non-vented heat sources in the cabin.  But, for those with less experience, maybe it is worth pointing out the danger of CO poisoning?

    Last modified: 22 Sep 2017 18:27 | Anonymous member
  • 22 Sep 2017 14:45
    Reply # 5274779 on 1195343
    Anonymous member (Administrator)

    David,

    I see your point with the missing rail, the steel body and the low power. Still, I had a two-burner Optimus paraffin stove in Malena, with a steel body, and that held very well.

    Actually, I was thinking of giving the Salsa another job (in addition to cooking): To heat the cabin. If it turns out to burn without making smoke, smell or soot, that could produce cheaper kilo-Watt-hours than my present butane-cartridge heater. Combined with a 12V fan, it would turn into a Poor Man’s Webasto.

    The butane heater was supposed to be very safe in use and turn itself off if tipped over, or if the O2 dropped below 16%. However, one day I returned to the boat, there was a suspect smell of gas. It turned out that the almost full cartridge had leaked empty during the last twelve hours. I opened up all hatches and cabin sole and left the place for an hour.

    Therefore, I will rather deal with alcohol. I do any filling of canisters etc. in the self-draining cockpit. Any spilling can be washed away with water.

    Arne


    Last modified: 22 Sep 2017 15:16 | Anonymous member (Administrator)
  • 22 Sep 2017 11:10
    Reply # 5274642 on 1195343

    The HPV stoves are interesting. Yes, there is a long history of this principle of stove being made in Germany, and they do use the same principle as the Maxie. 

    Against:

    • A mild steel cooker body (though the fuel tank now seems to be all brass)
    • A brass burner - the Maxie burner is brass, and I think this is why it doesn't last long, when in full time use
    • Very low heat output
    • No fiddle rail or pan clamps
    Yes, I do use a raised tank to supply my Maxie burner, and I suspect that this may be shortening its life, causing it to burn too fiercely, and also it doesn't simmer as well as I would like.
  • 22 Sep 2017 10:41
    Reply # 5274622 on 1195343
    Anonymous member (Administrator)

    The hpv Salsa blue flame alcohol stove

    If a blue-flame alcohol stove still is on my mind in the future, I might order the single-burner Salsa, or twin burner Mambo, from the German manufacturer, HPV . It seems that Germany, including DDR, has had a long tradition of making these stoves, and the Salsa and Mambo appears to be of quite high quality. However, its output is only 1.0 kW (burning 0.20 l/h), so an efficient pot could be welcome. See the description of it by this user. To me, it looks like the Salsa works much like the Maxie stove, but possibly, the burner lasts longer. Maybe a raised tank (with its own stop valve) would boost its performance a little, and make it less vulnerable to the boat’s heel angle? Wasn’t that what you did to your Maxie stove, David?

    Personally, I could think of having two different single-burner stoves side by side each other, in Ingeborg, one hpv-Salsa and one Origo 1500

    Arne

    Last modified: 22 Sep 2017 10:54 | Anonymous member (Administrator)
  • 21 Sep 2017 00:56
    Reply # 5272338 on 5272065
    Arne Kverneland wrote:

    Until I find a stronger, but still cheap air pump, I’ll drop this project. What I have gained, apart from some experience, is a weird collection of funny-looking bent pipes and twisted copper and tin plates. Maybe I should frame them and hang them up one the wall. A temporary title could be

    “Twisted products of a twisted mind”

    Any better suggestions?

    Cheers,
    Arne

     


    Don't know why I did not think of it before but a cheap automotive tire inflating pump (also used to fill beach ball & fenders) would probably be what you want. They are not expensive and run off 12V plus they are designed to pump again a resistance....
  • 20 Sep 2017 21:19
    Reply # 5272065 on 1195343
    Anonymous member (Administrator)
     

    Darren, thanks for an interesting input.

    Today I had a final go with the Origo ‘upgrade’. I had some (3/16”?) copper pipe laying around, so I bent it to fit into the central fire tube of the burner. Two rows of 1mm holes were drilled, see photo below, left. The idea was much the same as yours, to inject air into that central flame.

    Boil tests showed about 4:30min to boil (dry kettle), about the same as without the booster, yesterday. Frankly, the aquarium pump was not strong enough to make much difference. On the photo below, right, one can see the flame with the booster off. As can be seen, the central flame is yellow while it turns blue when spreading out. Today was very calm, and this helps to get this nice flame  -  the Origo doesn’t like too much draft.

    The kettle, made to fit electric stoves, actually appears to make good use of the alcohol burner. The handle does not get very hot. As for smell, I always cook with the main hatch open. The galleys of all my boats have been in this position.

    I now have the option to keep on using the Origo, or to reinstall my (kerosene) Optimus stove from Johanna. For my simple use, I guess I will stick with the Origo. It is good enough and safer and simpler in use than any other stove I have had or used.

    Until I find a stronger, but still cheap air pump, I’ll drop this project. What I have gained, apart from some experience, is a weird collection of funny-looking bent pipes and twisted copper and tin plates. Maybe I should frame them and hang them up one the wall. A temporary title could be

    “Twisted products of a twisted mind”

    Any better suggestions?

    Cheers,
    Arne

     


  • 20 Sep 2017 19:57
    Reply # 5271916 on 1195343

    I ran some tests with my Origo and Maxie a while back.  I used one litre of water at 14C and the tests were done in my kitchen using denatured ethanol with 10% methanol as the denaturing agent (meths or denatured alcohol vary a fair bit from different suppliers and in different parts of the world).  The average boil time for one litre of water on the Origo was ten minutes and the average for the Maxie was nine minutes.

    I also tried a Fire Maple kettle with a built-in heat-exchanger.  This decreased the boil times for both stoves (Origo 8.5 minutes, Maxie 7.5 minutes), but had a strange effect on the Origo.  I got a strong alcohol smell when using the Origo with this kettle.  I suspected that the fins that conduct the heat into the kettle were quenching the flame on the Origo.  The other thing that happens with the Origo with any pot, is that the handles become very hot compared to the same pot on the Maxie.

    I think what is going on with the Origo is that you have a column of vaporized alcohol rising from the burner.  Combustion can only occur at the periphery of this column where oxygen can mix.  The rest of the alcohol vapor column continues up till it is diverted by the bottom of the pot and spreads.  At this point air can mix more completely and most of the alcohol is burnt.   Thus, the handles of pots get hotter on the Origo as combustion likely continues around the periphery of the pot.  

    My conclusions were, as it is the Origo is not as efficient as the Maxie.  10% isn't much in terms of fuel use or time, but it is something to be aware of in terms of an alcohol smell in the cabin and CO production (we have friends who've set off their CO alarm using the Origo).

    I think injecting air could still help.  I would be tempted to use a very fine tube like a hypodermic needle and inject the air low in the centre of the flame pointed vertically.  A stainless tube that does not conduct heat as well might be a better choice than copper.  A lower tech alternative might be to cannibalize an Origo cannister and add a tube that goes out through the bottom and sits open above the wick.  This might also allow air to mix into the centre of the vaporized column of alcohol.

    Although the Fire Maple heat-exchange kettle did not work well with the Origo, a better choice might be an MSR heat exchange unit.  This might work to both trap heat along the side of the kettle and maybe even give you a chance at more complete combustion.  You might be able to accordion a piece of aluminum foil and hold it tight to the pot with a bit of wire to give it a try.

    As Arne has pointed out, the stove works quite well, is exceptionally safe and the Swedes that designed the stove are a pretty clever group and we may not be able to improve upon it.  However, it is entertaining to try.

  • 20 Sep 2017 10:52
    Reply # 5270997 on 1195343
    Anonymous member (Administrator)


    .. yes, the kettle is also important..

    David,

    I agree with you with respect to soot and CO. As can be seen below, my kettle has been blackened quite much. However, it doesn’t seem to build up much soot on it. I wonder if it has to do with my use of it. After other cooking, I generally fill the kettle up for heating dish-washing water. This I do with the burner on the lowest setting with all-blue flame. Maybe this helps to burn the kettle clean.

    I can think of two more tests of the booster before I drop it: One is to use the shown ring of copper, and then raise the kettle about 10mm to improve airflow. The other is to use a thin copper pipe and bend it to a J-shape and fit it down the primary flame tube of the stove. With a number of 1mm holes in that pipe, hopefully that will add enough oxygen. That solution would not hinder normal airflow under the kettle.

    Quite another thing is the shape of the kettle. Heating any normal kettle or casserole over an open flame is very inefficient.

    The specific energy capacity of water is 4.183kJ/(kg K). In plain English that means that that it takes 4.183 seconds to heat a litre (= 1 kg) of water one degree (Celsius or Kelvin) if one Kilowatt heat power is added.

    To heat 0.5 litre of water from 15°C to 100°C, one should therefore need an energy of...

    0.5kg x 85°K x 4.183kWs/kgK =177.8kWs =177.8kilo-Joule.

    If we add 2000 Watt (2kW) heat power right into the water with no loss, it will take just..

    t= 177.8kJ/2kW=88.9seconds to bring it to boil.

    Now, the makers of Origo 3000 claim that each burner produces 2kW.

    Since I needed 4:30min. =270secons to heat that water,...

    then the efficiency can only have been 88.9s / 270s = 0.33, or 33%. In other words; two thirds of the energy is lost!

    Increasing the temperature on the flame will improve the efficiency, but my hunch is that that there is a lot more to gain from improving the kettle than from modifying the stove. Thinking of how the boilers of steam locomotives are built, should give a hint...

    Arne

    PS: Just to compare, now I tested my domestic 2kW electric water kettle. From cold, it took 118 seconds, and on the next test, with the now warm kettle, it took 93seconds to boil that 0.5 litre. That gives about 75 and 96 % efficiency...

     


    Last modified: 20 Sep 2017 10:59 | Anonymous member (Administrator)
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