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Post by fasardi on Jan 17, 2020 7:09:05 GMT -8
Is there some room to tweak a little the dimensions of the firebox and the top box? I did my math and tried to have the same cross section area than in the charts in each box. It's only to avoid cutting a lot of firebrick. Also, i made the firebox 25% longer, but i'm planning to leave the top box to the original depth Firebox W: 208 H: 340 D: 540 Top Box: W: 196 H: 240 Do you think it will work? Otherwise I won't risk it and go with the original measures. Thanks!
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Post by peterberg on Jan 18, 2020 1:31:47 GMT -8
Do you think it will work? Otherwise I won't risk it and go with the original measures. Thanks! Honestly, I don't have the foggiest idea whether or not this will work. Simply put: I tried a multitude of dimensions and the ones that are recommended worked best. Which also means there are others that won't work at all or poorly at best. Don't be fooled by cross section area, this is definitely not a good measure to go by. I don't remember what size you want to build and what kind of bricks you intend to use. But in case it's a brick that's twice as long as it is wide, it would be best to take the width of the brick as the base number. You will see that by doing that, the firebox is three half bricks high, one full length wide. The top box will be two half bricks high and one full length wide again.
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Post by fasardi on Apr 2, 2020 8:00:20 GMT -8
I finally got the bricks to start making the core, and i have two questions before starting with it: Im planning to extend the firebox 25% more, do not extend the top box, and make the stumbling block and the exit port in the original position, half way in the top box and 3/4 of the top box. Is that ok? I have some doubts about how to size the exit port, i`m aiming to a 166 mm system, and the exit port should be 240x70mm, am i right? Thanks in advance.
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Post by peterberg on Apr 3, 2020 7:28:05 GMT -8
Im planning to extend the firebox 25% more, do not extend the top box, and make the stumbling block and the exit port in the original position, half way in the top box and 3/4 of the top box. Is that ok? I have some doubts about how to size the exit port, i`m aiming to a 166 mm system, and the exit port should be 240x70mm, am i right? In Januari, you were planning a firebox 25% deeper. Are you saying you want to extend it another 25%, so 50% deviation in total from the recommended values? I won't recommend that. In case only the firebox is extended 25%, not more, this could probably be done. The exit port is as wide as the top box' internals and its CSA is 5% more than the port. I recalculated the riser port and the end port, your numbers are correct. In case you want to build a cook stove with it, the top gap, between end port and cooking plate should be the riser's diameter or less. How much less I don't know, to my knowledge there isn't a succesful cooking range built around this core yet.
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Post by fasardi on Apr 3, 2020 10:12:04 GMT -8
In case only the firebox is extended 25%, not more, this could probably be done. Thanks Peterberg! No i meant a total deviation of 25%, so i think it´ll work. My real doubt was about the location of the exit port and the stumbling block in the top box, if i can leave it in the original size and don´t extend it with the firebox
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Post by peterberg on Apr 3, 2020 12:42:58 GMT -8
My real doubt was about the location of the exit port and the stumbling block in the top box, if i can leave it in the original size and don´t extend it with the firebox Yes, I think it will work.
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Post by fasardi on Apr 6, 2020 5:48:35 GMT -8
My real doubt was about the location of the exit port and the stumbling block in the top box, if i can leave it in the original size and don´t extend it with the firebox Yes, I think it will work. Well, thanks a lot Peterberg! this weekend i finished the core. I have a final doubt, before making the bell. Since i used refractory half bricks and ceramic hollow brick around them, the exit port, Will be too thick in my opinion. If i put the hollow bricks just in the opening side it will be 14cm deep. I thought about leaving the hollow bricks at 5cm of the opening, but then maybe it will be too Slim, because the half bricks width is only 23 mm. My best guess is to leave the hollow bricks at 5 cm each side of the exit port and put two half bricks togheter an get a 50 mm Depth. Do you think it will work? or it`s unnecesary?
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Post by peterberg on Apr 7, 2020 12:50:26 GMT -8
Since i used refractory half bricks and ceramic hollow brick around them, the exit port, Will be too thick in my opinion. If i put the hollow bricks just in the opening side it will be 14cm deep. I thought about leaving the hollow bricks at 5cm of the opening, but then maybe it will be too Slim, because the half bricks width is only 23 mm. My best guess is to leave the hollow bricks at 5 cm each side of the exit port and put two half bricks togheter an get a 50 mm Depth. Do you think it will work? or it`s unnecesary? I am in the dark what you mean by hollow bricks so close to the end port. You need room there, lots of it, not a channel. So the thickness of that half thickness firebrick is largely irrelevant. You could use two of those thin bricks on top of each other to mimic my development model though, nothing wrong with that and just to be sure.
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Post by fasardi on Apr 8, 2020 3:45:12 GMT -8
I am in the dark what you mean by hollow bricks so close to the end port. You need room there, lots of it, not a channel. So the thickness of that half thickness firebrick is largely irrelevant. You could use two of those thin bricks on top of each other to mimic my development model though, nothing wrong with that and just to be sure. Here's a photo, just to check everything is ok. I isolated the top box with the hollow bricks, maybe it wasn't necessary. The core will be inside a brick bell than I'm starting to build.
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Post by BenAlexanderT on Apr 8, 2020 14:32:18 GMT -8
I am in the dark what you mean by hollow bricks so close to the end port. You need room there, lots of it, not a channel. So the thickness of that half thickness firebrick is largely irrelevant. You could use two of those thin bricks on top of each other to mimic my development model though, nothing wrong with that and just to be sure. Here's a photo, just to check everything is ok. I isolated the top box with the hollow bricks, maybe it wasn't necessary. The core will be inside a brick bell than I'm starting to build. The hollow bricks can not withstand high temperatures. When i was building my own heater, Peter told me, to use them bellow the height of the heatriser's exit. The tempertures above the heatriser's height are at the brick's temperture threshhold or heigher. My 120mm batchbox easily reaches the max temp of the hollwo bricks. Try testing it outside My experience is limited though. I have only built two heaters with hollow bricks. P/S: I like the car btw
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Post by fasardi on Apr 8, 2020 16:22:48 GMT -8
The hollow bricks can not withstand high temperatures. When i was building my own heater, Peter told me, to use them bellow the height of the heatriser's exit. The tempertures above the heatriser's height are at the brick's temperture threshhold or heigher. My 120mm batchbox easily reaches the max temp of the hollwo bricks. Try testing it outside My experience is limited though. I have only built two heaters with hollow bricks. P/S: I like the car btw Ouch! I used hollow bricks as isolation, and half refractory bricks in the inside. I think than someone told me than it works, but maybe it doesn't...
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Post by peterberg on Apr 9, 2020 0:53:48 GMT -8
Posts moved from the "Double Shoebox Rocket mark II" thread.
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Post by fasardi on May 6, 2020 4:19:16 GMT -8
Posts moved from the "Double Shoebox Rocket mark II" thread. Well, i finished the bell, had to stay with the hollow bricks isolating the firebox, hoping they last, but leaving a way to replace them if they fail in time. My system is a DSR-II open, is still drying out, buy I´m starting slow with some wood and seems to work very well. Only problem so far is than sometimes a little smoke comes out, aparently it depends on how the wood is stacked. I`m thinking on some kind of door, but have some doubts about the air opening. I don`t remember seen this subject in the DSR-II post (but perhaps I missed it). I´m thinking of leaving maybe the lower 30% part of the door opened so the air can come in, and with something to close it when the fire is out. And another question, someone give me an old gas oven glass, but i don`t really know if it will crack, is there some test to try it?
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Post by Vortex on May 6, 2020 7:18:28 GMT -8
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Post by peterberg on May 6, 2020 8:02:03 GMT -8
My system is a DSR-II open, is still drying out, buy I´m starting slow with some wood and seems to work very well. Only problem so far is than sometimes a little smoke comes out, aparently it depends on how the wood is stacked. Your fuel need to be at a minimum of 5 cm inside the firebox, shorter is better. And there need to be a space above the fuel, 5 cm at least again. I`m thinking on some kind of door, but have some doubts about the air opening. I don`t remember seen this subject in the DSR-II post (but perhaps I missed it). I´m thinking of leaving maybe the lower 30% part of the door opened so the air can come in, and with something to close it when the fire is out. The best restricted air opening in an open DSR2 turned out to be two openings, left and right. Middle half of the door blocked and full height. And another question, someone give me an old gas oven glass, but i don`t really know if it will crack, is there some test to try it? Oven glass is 99 out of 100 times tempered glass, exploding in small crumps when overheated. The glass top of an induction cooking plate is excellent but dark brown at best.
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