Origo Stove Wanted

  • 21 Dec 2019 15:42
    Reply # 8347199 on 8069377

    For you, Arne, a quick hot drink might be your priority.

    But for cruisers, of equal importance is a reliable simmering setting, just enough to keep the pressure cooker up to pressure, but without going out and without burning the meal by needing too high a setting to stay alight. It would be of interest to know how well the HPV does in this respect.

  • 21 Dec 2019 16:31
    Reply # 8347470 on 8069377
    Anonymous member (Administrator)

    You have a point, David.
    It could be that the Origo is too powerful on lowest setting. However, at least it is at its best, combustion-wise, with all blue flame at lower settings.
    I have wondered if it makes sense to have two single-burner stoves, that is, one powerful for faster cooking, and one optimised for fuel-efficient slow cooking.

    Arne


    Last modified: 21 Dec 2019 23:19 | Anonymous member (Administrator)
  • 22 Dec 2019 09:08
    Reply # 8353107 on 8069377

    Arne - I'll try the test you suggested. I'll wait for delivery of the new stove (hopefully a few days) and test on that.

    David - the tubing sounds very useful. I'll measure (again) on the new stove in case it is different. With alcohol the tube does need to be as heat resistant as possible in case spillages catch fire.

    It'll be interesting to see whether gimbals make the pressure vary too much. I think it'll work if the tube comes in somewhere vertically below the pivot point rather than at the rear.... 

    Matthew


  • 23 Dec 2019 17:42
    Reply # 8366269 on 8346984
    Arne wrote:

    Matthew,

    just for the science; could you measure up exactly 0.5l water and then check how long it takes to bring it to boil?

    My Origos spend from 4min 40s to 4min 50s on it. I found that adding water in the alcohol until it is 80% did not slow down cooking, but when the canister is low on alcohol, the power of the flame drops noticeably.

    Arne

    Today I took delivery of an ALOCS brand kettle with a corrugated heat exchanger on its base.

    Also, I’ve now re-housed my Maxie burner in a way that suits my boat, on a shelf that can be mounted on hinges with barrel bolts to hold it level or at an angle of heel (better than gimbals).

    So, I carried out this boiling test, in the interests of science: 5min 20.7 sec to a full boil. The Maxie burner seemed to be running rather slowly, but I don't know why. Anyway, that's fast enough.


    Last modified: 23 Dec 2019 17:44 | Anonymous member
  • 25 Dec 2019 12:53
    Reply # 8385014 on 8069377

    I've now done the test ... And I'm a bit slow. 9 mins 5 sec to a full boil from cold using denatured ethanol.

    But, it does burn very cleanly and, with this fuel, no smell at all. Possibly the speed doesn't matter?

    I've been trying, unsuccessfully due to the vagaries of Ebay/Paypal - or possibly a setting (on the vendor's apart, I think), to buy the 2 burner. In the light of this test, I may rethink. There are also various older ('vintage' according to their vendors) stoves for sale - perhaps they may be more powerful.

    A fun experiment for Christmas morning..... But I won't try cooking the roast on it.

    Matthew


  • 26 Dec 2019 09:07
    Reply # 8392579 on 8069377

    Matthew, with the original Maxie cooker (which has the same low tank as the Enders and HPV), I used to find that it would run slowly as the fuel got low, and that's how I knew to add more fuel. I used to think that it needed just the inch or two of head of pressure to function properly, but now that I'm running a Maxie burner with a remote tank at least a foot higher, I realise that's not the case. So now I'm wondering whether the Enders and HPV would run a bit hotter with the raised, remote tank that we've talked about?

  • 05 Jan 2020 20:59
    Reply # 8485775 on 8069377

    I've now repeated the .5 litre test with the Enders Cooky and an Alocs Kettle.

    Much better. 4min 46 seconds.

    So that's good. What's not so good is that the fuel tanks fitted are steel, and already showing some sign of corrosion. I imagine it will last quite a while - and I'm intending to fit a remote tank anyway.

    Matthew



  • 06 Jan 2020 09:05
    Reply # 8490627 on 8069377
    Anonymous member (Administrator)

    Excellent, Matthew!
    This strengthens my hunch that there is a lot to win on improving the kettles, since they are generally terribly inefficient:

    Just look at this:
    To heat 0.5l of water from 10 to 100°C, it only takes 188kWs (=188kJ – kilojoule)
    My Origo stove theoretically puts out 2kW and it takes about 4min 40s or 280s to heat up that water. That should be an energy of 560kWs. In other words, the efficiency of my stove-kettle combination is only 188/560= 34%.

    I ordered a 0.9l Alocs kettle yesterday and will repeat the test with that one, when it arrives.
    This could well end up with big savings in fuel when cooking. Even when cooking rice or beans, one should first heat the water in the Alocs kettle before pouring it over into the bean- or rice (or whatever) pot.
    The Alocs certainly could end up living a very busy life...

    Arne


  • 06 Jan 2020 17:00
    Reply # 8493931 on 8490627
    Anonymous wrote:

    My Origo stove theoretically puts out 2kW and it takes about 4min 40s or 280s to heat up that water. That should be an energy of 560kWs. In other words, the efficiency of my stove-kettle combination is only 188/560= 34%.

    While 34% is a bit low, it is not that bad compared to the average house bound natural gas (mostly methane) stove, at about 40% or even the standard electric rings at 50 -60%. This makes induction look great at 90%... but if that power is coming from a generator at 25 - 30% (or solar for that matter), it is no better. Using a kettle with it's own fire box to get things preheated indeed sounds like a win from all sides. I think this would be true even with propane as the losses have less to do with the fuel and more to do with the heat transfer to the pot instead of the stove frame and surrounding air.
  • 06 Jan 2020 19:35
    Reply # 8495291 on 8493931
    Anonymous member (Administrator)
    Len wrote:While 34% is a bit low, it is not that bad compared to the average house bound natural gas (mostly methane) stove, at about 40% or even the standard electric rings at 50 -60%. This makes induction look great at 90%... but if that power is coming from a generator at 25 - 30% (or solar for that matter), it is no better. Using a kettle with it's own fire box to get things preheated indeed sounds like a win from all sides. I think this would be true even with propane as the losses have less to do with the fuel and more to do with the heat transfer to the pot instead of the stove frame and surrounding air.


    That is exactly my view as well. Whatever the fuel is used, making better use of the the flame is the name of the game. Hopefully Alocs will also make a set of pots and pans with the same efficient bottom.

    My armchair guess is that natural gas stoves come out a bit better than my Origo since I believe that the flame temperature is higher on a gas flame.

    Arne

    Last modified: 06 Jan 2020 23:36 | Anonymous member (Administrator)
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

                                                              Site contents © the Junk Rig Association and/or individual authors

Powered by Wild Apricot Membership Software