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Post by josephcrawley on Aug 22, 2019 14:43:51 GMT -8
Forgot to mention: the (horizontal) duct between firebox and topbox is acting as a balancing pipe, it worked not as well without it. I need to check whether the port is actually taller and narrower, as you say it is. This isn't correct, it should be the same as standard batchbox dimensions. Mark however, height of port is measured from the top of the floor channel's feed instead of from the actual floor. I'll check the port dimensions in the drawing and correct when necessary. That's the height discrepancy. I hid the back wall to take the port measurement so it did not include the floor channel. I will remeasure and correct my post. Does the balancing pipe refer to the area directly behind the port that is standard riser dimension that leads to the top shoebox? Thanks |
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Post by peterberg on Aug 23, 2019 10:07:06 GMT -8
The port is indeed too narrow, by 2 mm to be precise. I checked the height and that is correct. Does the balancing pipe refer to the area directly behind the port that is standard riser dimension that leads to the top shoebox? What I meant is the horizontal duct in the door frame between firebox door and top box door. This is open to the vertical ducts left and right. In order to illustrate that point, I included a separate picture of the left vertical door frame part in the drawing. |
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Post by josephcrawley on Aug 23, 2019 11:16:33 GMT -8
I assume the top box door needs to open in order to clean out accumulated ash? Is there a risk of the steel in the top box door and frame degrading from the temps? or is the hollow tube enough to keep it cool.
The balancing pipe is clear to me now.
Thanks
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Post by peterberg on Aug 24, 2019 6:14:20 GMT -8
I assume the top box door needs to open in order to clean out accumulated ash? Good point. I didn't use the development model long enough to have ash in quantities to speak of. What I could see however, was a clean spot right under the exit port, a bit larger than that. It would be interesting to see what happens when one doesn't clean the ash out. What I've seen led me to believe there won't be clogging up, similar as in my J-tube variant with a backsweep/kicktail. All the ash in that one ended in the bell and accumulated there. Is there a risk of the steel in the top box door and frame degrading from the temps? No degrading to be expected, the frame gets hot but not overly so. |
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Post by smartliketruck on Aug 25, 2019 14:43:23 GMT -8
Has anyone tried a DSR2 open or closed built with hard fire brick splits or somewhat equivalent material insulation wise? Will it run free standing without the draw of a chimney?
I tried one a few months ago but perhaps made too many compromises with the dimensions and it wouldn't run freestanding. Now that Peter has posted a sketchup of one made of brick splits I'll give it another go but need to know if I need to have bell & chimney ready to go first.
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Post by peterberg on Aug 26, 2019 0:12:23 GMT -8
Has anyone tried a DSR2 open or closed built with hard fire brick splits or somewhat equivalent material insulation wise?Will it run free standing without the draw of a chimney? I tried one a few months ago but perhaps made too many compromises with the dimensions and it wouldn't run freestanding. Now that Peter has posted a sketchup of one made of brick splits I'll give it another go but need to know if I need to have bell & chimney ready to go first. I did build one out of splits and ceramic fibre board. A one meter piece of larger stove pipe was placed on top over the exit port and it ran without too much of a hiccup. You need to have some draw otherwise the thing won't work, it isn't self starting like a standard batch box core where the riser is providing initial draft. |
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Post by Orange on Aug 26, 2019 2:03:37 GMT -8
hm, so it might have a problem starting when outside temperature and pressure is high and chimney draws backwards.
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Post by peterberg on Aug 26, 2019 4:22:04 GMT -8
hm, so it might have a problem starting when outside temperature and pressure is high and chimney draws backwards. Any heater would have problems with reverse draw. |
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Post by independentenergy on Aug 27, 2019 8:19:39 GMT -8
in fact could a system without isolated riser be more subject to smoking behind than a riser system?
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mac84
New Member
Posts: 5
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Post by mac84 on Aug 27, 2019 9:19:42 GMT -8
Do we know how big of an air inlet is needed for the open system to operate properly?
For example, if you wanted to have a closed door, but you had a large air inlet in the door, how big would the air inlet need to be to operate as an open system? Would 50% of system size be enough?
The idea is a door with glass window and a closable air inlet.
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Post by josephcrawley on Sept 3, 2019 18:28:07 GMT -8
Would you recommend these door changes be applied to the old style floor channel core? I would imagine you haven't tested this but what's your gut feeling? Specifically I'm asking about the primary/secondary air routing.
Thanks
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Post by peterberg on Sept 4, 2019 0:39:30 GMT -8
Would you recommend these door changes be applied to the old style floor channel core? I would imagine you haven't tested this but what's your gut feeling? Specifically I'm asking about the primary/secondary air routing. The old style primary air/p-channel arrangement employs a very agressive primary air feed directly blown in low in the fuel stack. The floor channel arrangement is gentler in this respect. The threshold guides the primary air more or less up and the proportions of primary and secondary air changes during the burn in favor of secondary air. The shoebox' air arrangement is a little different, it distributes the primary air better in the whole of the fuel pile. At the same time the automatic proportion shift during every burn is even more pronounced. As a bonus, the glass of the door stays clean much longer. And you are right, I didn't test this air configuration on a standard batchrocket. Given that I would consider a rebuild of my own heater the new style air arrangement would be my choice, no doubt about that. It's a little bit more work but it's much more sophisticated. Now that I come to think about it, this would have been possible in the Mallorca build due to the way the door frame is mounted on that one. |
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Post by Lucian on Sept 4, 2019 2:47:52 GMT -8
Here's a DSR II open system Calculator: Thank you Orange for sharing this.
One question though: the formula for port depth in this calculator is "port width x 0.8".
Is this right?
The table on batchrocket.eu shows a fixed value of 50mm for all system dimensions. I wonder if the port depth will influence the burn much.
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Post by peterberg on Sept 5, 2019 0:37:28 GMT -8
Do we know how big of an air inlet is needed for the open system to operate properly? For example, if you wanted to have a closed door, but you had a large air inlet in the door, how big would the air inlet need to be to operate as an open system? Would 50% of system size be enough? The idea is a door with glass window and a closable air inlet. I tried this at some stage. Results were good with air two air inlets, one left and one right. Both were slightly larger than half of system size if I remember correctly. This is what led me to believe it could be run without a door at all and it did. |
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Post by peterberg on Sept 5, 2019 0:52:24 GMT -8
Thank you Orange for sharing this. One question though: the formula for port depth in this calculator is "port width x 0.8". Is this right? The table on batchrocket.eu shows a fixed value of 50mm for all system dimensions. I wonder if the port depth will influence the burn much. This has been on for debate some time ago. In a very early stage (of the batchrocket concept) I tried deeper ports and found adverse effects when the port was deeper than twice the width. Making it shallower than width meant nothing happened until it was below half of the width. So I concluded port depth should be close to width- say within a margin of 25%- in order to get the right proportions. As it happened, I used firebricks for those experimental builds of just over 50 mm (2"). The system size at the time was 150 mm or 6", and I arrived at the port's about 2" width by trying a number of different widths and heights. So in that configuration the port was as deep as it was wide. That said, in 2014 I built an 8" version where the port was slightly wider than deep and the thing performed admirably. So there is some tolerance in there. Does this answer your question? |
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