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Post by satamax on Jan 30, 2012 9:59:56 GMT -8
Hi everybody.
Well, i'm keen on making a better RMLH well, it will have mass, but not too much, as i have no room in the workshop. I have thoses big gaz bottles which i like working with, about twenty nineish cm inside. I can buy some thin firebrick, which i thought about assembling dry inside the gaz bottles after welding my J shape, to protect the steel. So i need a pretty consistent cut on both sides of all of them to taper them; so they fit inside the round without falling with the steel expansion. How could i cut them? Another question, will 3cm thick firebrick be enough insulation for the heat riser?
Thanks a lot.
Max.
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Post by matthewwalker on Jan 30, 2012 10:42:20 GMT -8
Diamond masonry blades come in all sizes, and will cut them easily. Either a little one for an angle grinder, or larger for a circular saw or chop saw. I purchased one for my circular saw for about $28.
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Post by satamax on Jan 30, 2012 12:25:53 GMT -8
Ok, thanks a lot. I think i'll get myself a wet tile cutter.
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Post by peterberg on Jan 31, 2012 4:58:21 GMT -8
Another question, will 3cm thick firebrick be enough insulation for the heat riser? Firebrick won't provide any insulation at all. It will protect the steel tube of the riser, yes. And cutting the sides of the bricks at an angle will make it possible to slide them in and hold them in place. If you want to build a real rocket stove, the insulation like perlite, vermiculite, expanded clay, expanded shale or superwool have to go around the steel tube, with a minimum of 2" or 5 cm. |
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Post by satamax on Jan 31, 2012 8:22:44 GMT -8
Thanks Peter. Well, could i use some of thoses www.svk.be/fr/autres/boisseaux_refractaires_introInto the gaz bottle, and fill in between the tube with vermiculite. That would make a nice heat riser  Burn tunel and feed tube. All in 8 inch. Tho, i don't know if this is internal or external diameter. It would make the next rocket way simple to build. Any idea about the life expectancy of such "bushels" You might remember my thread about the first cyclonic rocket i've built. Do you think i should pursue in this direction. I was thinking last night to feed the burn tunel tangentialy into a cone made out of firebricks. Before the heat riser. But is it worth the extra effort? Thanks a lot. Max. |
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Post by peterberg on Jan 31, 2012 9:04:33 GMT -8
@max,
Ehrmm... The gas bottle's internal diameter is 29 cm, so I would say you could use one of those 18 cm diameter refractory pipes. Don't know about the life expectancy, they don't provide the specifications at the site. Given the specs would be 1200 C, these are a good choice. Don't be frugal with the insulation, the more the better.
The cyclone system required a higher air velocity in order to work properly. When you have a choice, go for the simpler J-tube layout. It will really run better in most circumstances.
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Post by satamax on Jan 31, 2012 9:17:55 GMT -8
Ok, thanks a lot Peter. J tube i'tll be. I've asked for a quote from the belgian company, as they do'nt sell localy to me. If too expensive. I'll talk with a localish company. May be i'll ask them if they sell "coullis" which is a refractory mixture of brick powder and clay. Ready to mix with whatever. To make my own parts instead. www.prse.biz/ |
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bob
New Member
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Post by bob on Jan 31, 2012 20:33:55 GMT -8
peter
can we use sawdust and clay mix as insulation for the heat riser?
if air is the best insulator, why not leave space around the riser?
(trying to cut expenses)
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Post by peterberg on Feb 1, 2012 3:48:33 GMT -8
can we use sawdust and clay mix as insulation for the heat riser? if air is the best insulator, why not leave space around the riser? Clay slip and sawdust, yes. Because the sawdust will burn away eventually and leave air pockets behind. Air is the best insulator, indeed. But it need to be still air, trapped in small pockets. Just an open air space will distribute the heat nicely by moving currents. |
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Post by countryatheart on Feb 1, 2012 13:51:54 GMT -8
I wonder if paper pulp and clay slip would work as well as sawdust? I make a paper pulp, clay, sand and cement mixture that I pour into a mold or slip form to make walls, was wondering if the same would work to cover the flue pipe as cob is used, if the straw in cob does not burn when covering the flue pipe then the paper pulp should not burn either, but I can see that if the sawdust in a clay slip mixture burns away in the riser, then also paper pulp would burn here as well.
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Deleted
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Post by Deleted on Feb 2, 2012 0:39:18 GMT -8
Paper pulp should work even better, as by weight the fibers will leave more and smaller holes.
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Post by satamax on Feb 15, 2012 9:18:34 GMT -8
can we use sawdust and clay mix as insulation for the heat riser? if air is the best insulator, why not leave space around the riser? Clay slip and sawdust, yes. Because the sawdust will burn away eventually and leave air pockets behind. Air is the best insulator, indeed. But it need to be still air, trapped in small pockets. Just an open air space will distribute the heat nicely by moving currents. Peter, if i'd mix wood chips (about 8mm square, by 1 mm thick) with "ciment fondu" (the easiest i can get here) This would be insulating enough in 5cm thickness? Or should i mix with vermiculite or perlite? Plenty of things running through my head and i need to make a decision for the next two Thanks. Btw, i haven't heard back from the guys from SVK! Max. |
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Burn tunel and feed tube. All in 8 inch. Tho, i don't know if this is internal or external diameter. It would make the next rocket way simple to build. Any idea about the life expectancy of such "bushels" 
