Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Nov 7, 2017 7:13:23 GMT -8
...., the temperature drops as the gasses expands into the bell. Wrong. The gasses do not expand into the bell. There is no pressure drop, so there is no expansion, so there is no temperature drop, only a distribution into the larger volume which slows down the movement and thus actually increases the pressure towards the walls. |
|
|
|
Post by pinhead on Nov 7, 2017 7:46:25 GMT -8
...., the temperature drops as the gasses expands into the bell. Wrong. The gasses do not expand into the bell. There is no pressure drop, so there is no expansion, so there is no temperature drop, only a distribution into the larger volume which slows down the movement. I should have said the the heat expands into the bell or the gasses "spread" into the larger volume, i.e. the heat units (BTUs) which were confined within the riser are moved into a larger volume and dissipated within that volume. If we want to get technical, the gas will contract as it cools as opposed to expanding (though the pressure within the system, being primarily driven by chimney draft, will remain relatively constant). For the purpose of understanding the difference between heat and temperature, however, I believe my original statement is sufficient in context. For the sake of discussion, we can imagine two perfectly insulated volumes - one larger than the other - both starting at the same temperature. If we put the same number of heat units into each (same "amount" of heat), the volumes will have different temperatures; the temperature within the larger volume will be lower than that of the smaller volume. I'm not directing this at you, karl; you likely understand the physics behind this more than I. I'm just posting clarification for the sake of the free sharing of knowledge.  |
|
|
|
Post by esbjornaneer on Nov 7, 2017 7:53:39 GMT -8
What a shame your oven does not get up in temp!
Is the build working well otherwise?
The thought I have is... How important is the working of the oven for your client? Is it worth (maybe next summer) to dismantle the top 5 courses of bricks to lift the oven higher? Test it again and potentially move the oven again if it got too hot or still too cold.
It is a hassle selling something to a client when it isn't an exact replica of something that has been done before, and shown to work, there is such great scope of something not working as planned!
I would love to know what rocket stove setups have actually produced good ovens? And that is for actual cooking/baking purposes. If your friend got the oven to 250C how was his setup?
|
|
|
|
Post by Jura on Nov 7, 2017 8:32:12 GMT -8
What a shame your oven does not get up in temp! Shame on me ;-) Is the build working well otherwise? It is first 8 days of firing so no extreme was tried but we will.. The thought I have is... How important is the working of the oven for your client? Is it worth (maybe next summer) to dismantle the top 5 courses of bricks to lift the oven higher? Test it again and potentially move the oven again if it got too hot or still too cold. Well.. I described the situation in my starting post. It is not a client, I'd rather call him a friend. They need to move in into the house before Christmas time and there was no chance to get the gas line installed by that time. So they ended up with a house with no working heating system. I wish I could reposition the white oven but I'm out of the place now and winter is coming at an alarming pace so it is hard to dismantle the stove as it is in daily use and needed to continue working inside. It is a hassle selling something to a client when it isn't an exact replica of something that has been done before, and shown to work, there is such great scope of something not working as planned! yeap.. I tried to gather information before but to no avail. I only saw the application of such placed white ovens donkey32.proboards.com/post/24854/thread By a colleague who is a masonry man and sells his stoves. I would love to know what rocket stove setups have actually produced good ovens? And that is for actual cooking/baking purposes. If your friend got the oven to 250C how was his setup? That was the one in the link in the above quotation. |
|
|
|
Post by esbjornaneer on Nov 7, 2017 8:43:16 GMT -8
yeap.. I tried to gather information before but to no avail. I only saw the application of such placed white ovens donkey32.proboards.com/post/24854/thread By a colleague who is a masonry man and sells his stoves. Hi Jura, This thread is Klemen's. In his last post he only got to 170C. Which makes it possible to bake bread if done over a long time (1.5-3hours) if the heat is kept there, but it is not what most recipes talk of. My suggestion for moving your oven upwards was to do it next summer when the stove is not needed for heating the house any more. |
|
|
|
Post by satamax on Nov 7, 2017 9:09:29 GMT -8
Jura. I can't see cakes smell smoky. Except if they reload, and overfuel during the cooking. Cut that bottom out, to see if you can cet better temps. If not, close it back with a metal piece on thé bottom.
|
|
|
|
Post by drooster on Nov 7, 2017 9:46:10 GMT -8
It is first 8 days of firing so no extreme was tried but we will.. Perhaps the oven will get hotter, I mean eight days isn't much for a new masonry build. I wouldn't change anything, but it isn't mine  |
|
|
|
Post by Jura on Nov 7, 2017 10:52:29 GMT -8
Jura. I can't see cakes smell smoky. Except if they reload, and overfuel during the cooking. Cut that bottom out, to see if you can cet better temps. If not, close it back with a metal piece on thé bottom. That's something that would require disassembling the ceiling anyway. There is 250 liters of perlite to be removed from the ceiling and those corunde plates were awfully heavy  Quite some job. I'll surely report here what we decided and what it returned to us. if I were to open the stove I'd rather reposition the oven. As high as possible. It costed ~170 € (there are ppl here who need to work half a month to earn such amount here ) so I take it as no surprise the owner wants it to be of some use. |
|
|
|
Post by Jura on Nov 7, 2017 11:00:07 GMT -8
Perhaps the oven will get hotter, I mean eight days isn't much for a new masonry build. I wouldn't change anything, but it isn't mine Well I do pray daily to the Holy Hephaestus ;-).. I have poured Him some 100 ml of vodka the during the first run. And maybe that's why he rewards us just with the mere 100 oC Shall the offering be of 300 ml ? And what to offer him to extend the temps duration ?. |
|
|
|
Post by satamax on Nov 7, 2017 12:43:10 GMT -8
Jura. I can't see cakes smell smoky. Except if they reload, and overfuel during the cooking. Cut that bottom out, to see if you can cet better temps. If not, close it back with a metal piece on thé bottom. That's something that would require disassembling the ceiling anyway. There is 250 liters of perlite to be removed from the ceiling and those corunde plates were awfully heavy Quite some job. I'll surely report here what we decided and what it returned to us. if I were to open the stove I'd rather reposition the oven. As high as possible. It costed ~170 € (there are ppl here who need to work half a month to earn such amount here ) so I take it as no surprise the owner wants it to be of some use. Why? Angle grinder. Straight grinder, ans you cut the bottom out, leaving one inch on each side. Si you can refit a bottom if need be. |
|
|
|
Post by esbjornaneer on Nov 8, 2017 6:29:05 GMT -8
|
|
|
|
Post by Orange on Nov 8, 2017 9:07:07 GMT -8
how bout baking in the firebox?
and if you don't have insulation between heater and wall then the heat goes that direction too.
|
|
|
|
Post by Jura on Nov 8, 2017 9:20:17 GMT -8
Mind the oven you are talking about is a black oven situated in a beast rocket almost at the heat riser height. That's just the setup (and yasintoda's answer to my question) has sawn first grain of uncertainty in my soul as to the temp range reachable in a lower situated white oven. In fact I was soooo surprised to see one may have a glass door at the height of the heat riser end. (as I understood he used special kind of glass with a guaranteed of 800 oC ) So far the owner dries the stove with not much seasoned pine wood. I estimate around 10 kg a batch. Never got over 100 oC :-( The rest of the stove works as supposed. It holds the temp for 24 h. |
|
|
|
Post by Jura on Nov 8, 2017 9:37:13 GMT -8
how bout baking in the firebox? and if you don't have insulation between heater and wall then the heat goes that direction too. I informed owners about such option, still I saw some disappointment in their eyes. As to insulation there are 3,5 cm thick wool plates with aluminium sheet on one of their sides between the stove and house wall so I'm not much considered by that loss. I just realise how much energy those bricks used are capable of accumulating. (they are pretty dense 1 brick weighs 3,7 kg) |
|
