Forgot to tell about another simplification. The floor channel used to be in a trench so the floor of the riser was at the same level as the feed part of the channel. In this model, as you may know now, the riser is square, no chamfered corners, no back sweep plus the floor of the riser is the same level as where the floor channel is placed on.
To compensate for the feed's height of 30 mm the firebox is a corresponding distance higher, as is the port. Resulting in: all proportions are the same as in the straight batch box, but the riser's floor is lower. Of course there are refractory blocks left and right of the feed so there's a floor again.
In the development model the floor of the riser didn't accumulate lots of ashes, just filling in the bottom corners. I'm very curious what the effect of the lower riser floor will be. Will it stay largely empty, or will it accumulate ashes up to the feed's level? And if accumulating is what it does, would this stop at the level of the feed or not?
I'll keep you guys posted.
Last Edit: May 19, 2019 11:49:13 GMT -8 by peterberg
I would like to find a practical method to try on a final installation, because in this period I don't have the possibility to experiment
In that case, you have to wait until somebody else is doing the necessary work.
I could provide an educated guess, though. By 300 mm, I think you mean vertical distance between exhaust port of the core and a cooking plate? Provided there's lots of space in horizontal direction, in vertical direction system size figure would be plenty. And base figure (72.34% of system size) would be a good minimum. Mark, no channels, stream space need to be as wide as the whole of the range's internals.
So to answer your question directly: for a 150 mm (6") system around 105 mm (4") feels like a good distance between core and hot plate to me.
For dimensions: stick to the spreadsheet or table. So the port is 2.2 times base, width 0.5 times base. Base number is 72.34% of riser diameter. In case of a square riser, take the side of the square.
Dimensions that are specific to the double shoebox mark2 are end port size and placement. Current size is 5% larger csa as compared to riser port, full width of top box. Placement is at 1/4 of depth of top box, measured from the front. Stumbling block is questionable at the moment to be honest, the thing fell off the top box' ceiling during the second running-in burn yesterday.
As can be understood, the reference model is operational since yesterday night. Curiously, the lower level of the riser's floor seems to confine most of the afterburner flames inside the riser stub. No fireball out of the riser, just flames now and then. Today I tested part of a long burn using oak and the results are remarkable to say the least. It was started with a hot core and it behaved itself admirably, much to my surprise, albeit a bit slow. At the moment I'm not sure about the size of the floor channel, oxygen level seems to be too high now. To conclude, I am working on air inlet configuration, it might be that the smaller floor channel is the better option. More in a couple of days.
The pieces on the floor are the remnants of the stumbling block. It was glued to the ceiling but probably due to expansion differences it became loose.
Last Edit: Mar 6, 2020 10:00:19 GMT -8 by peterberg
Open DSR2 system in general: combustion efficiency is comparable, overall efficiency is a bit lower (between 5% and 10%) due to the higher gas velocity through the system. Completely open isn't advisable, sparks can fly and coals could fall out. So you need a door of some sort without glass but spark screen instead. This could be a very simple thing, just a simple screen panel placed in front of the fire box, as long one is making sure it can't fall over. And a chimney damper is necessary, otherwise a lot of heat is lost through the chimney.
Specifically: efficiency disadvantage could be alleviated by enlarging the heat extraction ISA so one could end up with the same overall efficiency. Provided there's a way to close the heater, my preference would be a proper airtight door of some sort. A chimney damper is an alternative but you need to be very sure the fire is out before closing up, even under the ashes. Carbon monoxide can't be seen, smelled or heard and at the same time being very dangerous.
A top down sliding door system with two doors, one screen and one closed steel quillotine would be sufficient.
In short: disadvantages are there but could be overcome. The whole of the construction would be simpler, no air inlets, no door. Something Paul Wheaton would appreciate!
Last Edit: May 22, 2019 0:54:56 GMT -8 by peterberg
Haha well it sounds good to me too! I had been thinking about the two piece sliding door also to have two panels that can go in a slot, or just have a permanent spark screen then a solid panel to place in after the fire is out. This is really good stuff, so fun to see it happen
martinm: any one here with info \ experience with heat (from a mass heater) distribution with ducts throughout two storey house ?
Sept 8, 2018 22:58:52 GMT -8
padica: Good morning, this is a wonderful subject, please someone can help me with the theme of double and triple combustion, how it is achieved, theory and design, thank you
Sept 15, 2018 7:13:40 GMT -8
wiscojames: I'm afraid you won't get a response to such a vague question - I suggest reading through some of the threads related to your questions before asking for an explanation. People will be very generous with their knowledge if your question is more specific.
Sept 18, 2018 4:48:00 GMT -8
daniel: in my experience as I am working now on something of that nature, I have thought of making a heat exchanger and distributing the heat through vents using a slower fan. Now after a few years I realize that mass heaters give out primarily radiant heat, for
Nov 30, 2018 12:48:38 GMT -8
coastalrocketeer: Anyone posting in this shout box... if you have something you want people to see and respond to, create a thread in the appropriate forum section... this is not the place...
Dec 16, 2018 18:10:49 GMT -8
vesuvius: High Temperature Glass options,
Jan 4, 2019 16:28:17 GMT -8
vesuvius: Do any of you have experience with using the glass from home oven doors on a rocket stove? I'd like to have a viewing port on my stove but don't want to fork out for new ceramic glass. Any thought as to whether it would take the heat of a rocket stove?
Jan 4, 2019 16:30:40 GMT -8
yaya: you dont need the blowair for that temp..
Jan 13, 2019 16:43:57 GMT -8
flybywire: Glass window from an old washing machine is designed to take high temps. Cheap solution to your need.
Jan 27, 2019 0:10:58 GMT -8
coastalrocketeer: Anyone posting in this shout box... if you have something you want people to see and respond to, create a thread in the appropriate forum section... this is not the place to have a discussion... it is for short announcements
Feb 7, 2019 0:11:23 GMT -8
coastalrocketeer: you won’t likely get replies to questions here, and it is not a spot that makes holding an ongoing discussion possible...
Feb 7, 2019 0:12:22 GMT -8
TexasGonzo: Sooooo glad I found this site! Its always rewarding to find such a super group of folks! To any and all, feel free to PM me anytime. Thanks for having me!
Mar 11, 2019 18:56:41 GMT -8
jlmtech: GADGET: CONSIDER USING A JET PUMP INSTEAD OF A BLOWER FAN TO INDUCE DRAFT; NO CLOGGING.
Mar 26, 2019 8:19:28 GMT -8
michaelegan: i am unable to open the sketchup files on my mac. I used sketchup a few years back but apparently the company now requires a subscription. does anyone have any advice/instructions on how to use the program or how to view pictures without spending money?
Aug 20, 2019 18:41:48 GMT -8
mannytheseacow: michaelegan: download AutoCAD student version for free... import .SKP
Aug 23, 2019 13:33:44 GMT -8
topbaza: hi everyone, been searching all over net and this is were i need to be i think!!
Sept 28, 2019 6:16:25 GMT -8
anounaki: Hi, why I cant upload photos when I make new tread to this forum?
Feb 28, 2020 2:09:40 GMT -8
ahansen: photos under 1 mb not possible?
Jun 4, 2020 0:09:21 GMT -8