Hi all my first post...I have a workshop that's 20x28 that I am going to build a rocket heater for. The bell I am using is 15" in dia. and 28' long ( its an old LP tank ). I am going to use square tubing of .125 or .187 thick ( which ever I can find ) I was thinking of using 4" for the wood feed, burn chamber and riser tube ( I might use thicker for the burn chamber ) I'm not planning on insulating the riser tube at first in order to get this thing going as quick as I can. It will be a down feed design, been checking lots of videos on you tube and seems the type I am thinking of building works quite well for a work shop heat source....any comments and thoughts......thanks
Thanks Max for the link to your workshop heater, Yes Im sure I am going to build some sort of rocket heater for my shop and Im sure I need some advise from others who have made ones that work...Im not dead set on making it entirely from steel, the reason I was thinking steel is I have a metal fab shop with all the goodies to work with...Looking at the pictures of your stove I am now convinced I need some sort of insulated burn chamber and riser tube....I have worked with refractory cement and ceramic blanket building a metal forge.....looking forward to some advise and direction....
Well, if i was in the position of redoing a workshop one.
I would do a metal box 75cm x 75cm x 180cm tall. Put that on four legs of about 30cm. cut a hole for the firebox. Make a metal box lined with insulating firebrick. In the shape of a batch rocket. And fit a refractory flue liner at it's end, to make the heat riser; with a metal tube around (gas bottles work well for me. And fill the space in between with vermiculite or perlite. Even if the flue liners crack, the packed dry lose insulation hold them. There's some pics of in progress green machine, in the adventures with a horizontal feed thread.
That's a nice stove Icarus has built, I was trying to build a stove with a smaller footprint, my shop has a limited amount of room....Look at this stove this guy has built, looks like a nice smaller design... www.youtube.com/watch?v=q2eJec82D3I
Hi Metalmole. Well, his thing is too small. There's not enough radiating surface for heat extraction. Ok, daft me, i thought you had a 5600sqf shop, when it's 560'². My conversion into square metres is lousy. So i was gone astray. I think, do a six incher batch. J tubes are fiddly.
I think a 20"x20" column could accomodate the heat riser and part of the batch box. The general consensus is 50sqf of internal surface area for a 6 incher. But that's with a massonry bell. I think with metal, you could go smaller. Tho, if you do 20"x20" by 2m tall (aproximately 78") you have already about 4m of radiating surface, or 40sqf. That's small footprint. Tho, enough for extracting heat.
For the batch box, you can do like the guy has done in the video you've showed, metal on the outside, insulating firebricks on the inside, metal box to hold them. With about twenty bricks you can do the firebox. For the heat riser, have access to refractory tubes in Italy. Which you might not find on your side of the pond. Ask Matthewwalker for one of his risers.
Thanks Max for the thread, im in the process of reading through it, I have decided to do the horizontal batch box like most of the stoves on the thread, and to make it from fire brick or the clay chimney liner like you used, like these www.oneontablock.com/claychimney.html I will also use a refractory type heat riser, I might make it from round clay chimney liners, I need to do some more research. What do you think....
Metalmole, Those chimney liners will crack, unless you divide those in two lengthwise. Use superwool or equivalent as a gasket and tie them together by means of some steel wire or thin stainless steel hose clamps. The lower part of the riser, right behind the gate is the part which will recieve the highest thermal stress. The chimney liners aren't up to 2200 degrees Fahrenheit, so you have to use another material with better specs there.
Last Edit: Nov 16, 2013 7:49:58 GMT -8 by peterberg
Thanks Peter for the info, would it work to make the lower part of the heat riser from fire brick to a certain height and then use the clay liner ?? What about using the clay liner for the batch box, I don't wont to cut any corners and have this thing fail on me....
Well, metalmole. Been thinking bout you. shopstove.skp (164.11 KB)
Peter, i know the CSA isn't respected all the way, and there's some funy points, like where the heat riser meets the end of the burn tunel.
Metalmole, i haven't drawn the Peter Channel Just cos i have spent enough time on this. And you can work things out yourself.
A little metal box, a big metal bell. Onto which i haven't drawn the top, nor the outlet, which should be near the bottom. Dry stacked insulative fire bricks. As few cuts as possible. I've drawn it with a dimension i have, but doesn't seem to exist commercialy anymore. So adjustements will have to be made. But i think it's the simplest way to build one. You could narrow the firebox a smidge. Tho, mine is about that size, it smokes back every now and then, but i have about 8 metres of horizontal pipe and a restriction. Plus some is underground. With a far from ideal chimney. Etc! If you exit directly up after this, you don't have to worry, you could even power a little bell or some mass. Fill the four corners between the firebricks and the metal box with some rockwool or something to stop leaks from there. It doesn't need much. On mine, i've used one to make my P channel.
I don't know about your flue liners. What i'd do, stick one or two, whichever lengh you need into another tube, about two to four inches larger than the liners outside diameter (depending on insulation). Fill with loose insulation in between. I've used vermiculite. And if it cracks, be it. Or even splitting like Peter sugjests. Tho, being me, i wouldn't even bother puting a gasket in between. The vermiculite outside would stop enough of the gasses from comming into the bell. And even then! That doesn't matter much.
Metalmole, You could use metal for the firebox like Max said, and line that with superwool insulation and split firebrick. The same could do for the lowest part of the riser. That isn't easy to make round, but octagon is a pretty good approximation. Even the higher part of the riser could be made like this.
You could use stacked barrels as a heat exchanger. I've done that in my workshop and it do provide quick heat. No problems to keep it going, when the roar stops it's time for a refill.
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
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Sept 14, 2020 7:26:15 GMT -8
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Sept 14, 2020 7:29:27 GMT -8
deadstarsstillburn: Hi there. I was directed this way by folks on the Permies.com website and am hoping I can get some information on how a total newbie can get started designing, siting, building, and not-dying-in-a-horrible-house-fire with a new RMH in a 160-year old home
Oct 21, 2020 6:52:10 GMT -8
deadstarsstillburn: The people over there recommended either a 6" batchbox or an 8" J-tube. I don't know what those are but am going to try to figure that out. What I need is a blueprint that I can scale to fit the need for my house. I have something likne 5000 square feet
Oct 21, 2020 6:53:00 GMT -8
deadstarsstillburn: but I do not need to heat all of it by any means. probably only need to heat half of that, maybe less.
Oct 21, 2020 6:53:15 GMT -8
deadstarsstillburn: moreover, the house has 3 storeys (large attic) so I assume if I get very efficient heating on the ground floor, that will go a long way toward heating the upstairs as well, no?
Oct 21, 2020 6:53:59 GMT -8