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Post by independentenergy on May 19, 2014 7:57:28 GMT -8
I was wondering what was the best form and material for a riser system in a batch-box.
Given that I would use a round riser, I have two possibilities dependent on the material that I can find
Insulated pipe 316 stainless steel or cast riser.
I thought that even if the steel pipe to deteriorate over time it could easily replace by buying another one.
Point out that the affected part of the double vortex is refractory, height equal to the height of the batch-box
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Post by peterberg on May 19, 2014 11:31:34 GMT -8
The cast riser is the preferred solution. Yes, you could replace an insulated 316 ss riser. But the riser will fail when the stove is run to its limits. Typically in the depth of winter, the most inconvenient time to wait for the stove to cool down and to open it up. One of my earliest beta models happened to be equipped with a ss riser, it failed miserably after an estimated burn time of 40 hours.
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Post by independentenergy on May 20, 2014 8:46:59 GMT -8
Ooo really ?!?Thanks for the information I will try to build the molds to make the riser.Regarding the p-channel I can use 304 stainless ?It's the only one I can find with ease
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Post by independentenergy on May 20, 2014 8:49:36 GMT -8
It is better to build small circles from 20 cm to complete the riser , or do both halves ?
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Post by peterberg on May 20, 2014 10:20:40 GMT -8
Regarding the p-channel I can use 304 stainless ?It's the only one I can find with ease The p-channel is another story, it's air cooled and will hold out much longer. When made of stainless probably indefinitely. |
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Post by peterberg on May 20, 2014 10:24:19 GMT -8
It is better to build small circles from 20 cm to complete the riser , or do both halves ? I would prefer halves, especially when it's not round but octagonal. A mold like that is much easier to make. |
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Post by independentenergy on May 20, 2014 12:07:33 GMT -8
thanks Peter
about the riser octagonal, which I think has the same construction difficulties of the round, to comply with the measure 150mm how do I structure?
I measure them on the flat sides?
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Post by Robert on May 20, 2014 12:37:35 GMT -8
i was just investigating the riser made out of a ceramic blanket soaked in ridgidizer... when i made it it was kind of hard like glazed ceramics... after few fires it looks like the ridgidizer is melting while it is hot, and it softens... i dont know if it is going to survive long...
Peter how is your vacumed form ceramic fibre riser? I am still thinkink if it is going to hold...
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Post by peterberg on May 20, 2014 23:28:15 GMT -8
thanks Peter about the riser octagonal, which I think has the same construction difficulties of the round, to comply with the measure 150mm how do I structure? I measure them on the flat sides? The 150 mm circle should just fit in the octagon, or crossing the lines ever so slightly. In effect, the cross section area would be more or less the same. Can't give you the size of the octagon's sides, my main computer is already dismantled, because of moving house. The same goes for drawings of the octagon riser mold, on the main computer as well... |
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Post by peterberg on May 20, 2014 23:32:52 GMT -8
Peter how is your vacumed form ceramic fibre riser? I am still thinkink if it is going to hold... The riser's still holding quite well. In fact the inside was soft the last time I had a look, but 5 mm inside the wall thickness it's still quite firm. It looks like the binder is gone in that top layer, but underneath it is protected by that same insulating top layer. |
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Post by independentenergy on May 21, 2014 11:15:06 GMT -8
Thank you Peter.
another problem has arisen, all manufacturers of refractory or insulating concrete in my area only sell large quantities minimum order of 250 euro :-(
it is possible to make a mixture for this purpose?
What materials should I use?
fireclay?
other?
thanks
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Post by mintcake on May 22, 2014 10:59:40 GMT -8
it is possible to make a mixture for this purpose? What materials should I use? fireclay? other? Maybe on Saturday, I'm planning on using locally dug up fire clay + perlite (1:1) with some sodium silicate (waterglass). The waterglass seems to make it gel quickly (minutes) to a fairly stiff, sticky mixture, which doesn't flow at all as far as I've been able tell. So I'm not sure yet how to put it into my mould. My mould will have an inner surface from a plastic drain pipe, the outer surface will probably be metal plate, or maybe I'll just slap it on a smooth it down with something. If I do take that approach then I might try squashing it with a large plastic bag and a vacuum cleaner. Has anyone tried that? |
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Post by independentenergy on May 22, 2014 11:37:27 GMT -8
to vibrate you can not distribute it?
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Post by DCish on May 22, 2014 12:11:19 GMT -8
Mint, i think Karl posted something recently about water glass turning to gel if it is mixed with something that changes the pH too much... I believe it has to stay on the basic side of neutral or it turns to gel. I did some initial checking but couldn't figure out if that changes its properties as a binder or not. Might be worth searching out his post as a double-check.
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Post by Deleted on May 23, 2014 3:51:21 GMT -8
The waterglass seems to make it gel quickly (minutes) to a fairly stiff, sticky mixture, which doesn't flow at all as far as I've been able tell. So I'm not sure yet how to put it into my mould. As I have told you already that is due to polymerization of waterglass to colloidal silica at PH values below 11. You could add up to 40% lye (sodium hydroxide, drain cleaner) by weight of the waterglass. With 40% lye the mixture will act as an alkali activator for pozzolanic active aluminosilicates. For a geoplolymer binder the ratio would be 40% activator by weight of aluminosilicates. |
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