quote:

Originally posted by Murphy:
Who of us has a regular life? Define regular...
I can teach anyone with half a brain to weld inside of an hour.. Its not that difficult of a thing to do.. As for the fabrication, I am limited to my tools.. Oh how I so want a box brake.. Anyone willing to donate a lathe?

Well, I know of a quasi-intelligent baboon who would love to learn to weld, but I think you're a little far away for him to get there for such things.

I love the design, too; seems simple and robust to say the least. Could it possibly be modified to heat water/coolant for a radiant heat setup? Or to, say, be used as a furnace for both shop heat and processing heat? That, for me, would be striking gold... I fire up one burner when I go out to make fuel, and have both processing heat and shop heat with only one source to tend (In a separate room, of course, to keep down the potential for a fire from the vapors...).

quote:

Originally posted by TurbinePowered:
Well, I know of a quasi-intelligent baboon who would love to learn to weld, but I think you're a little far away for him to get there for such things.

I love the design, too; seems simple and robust to say the least. Could it possibly be modified to heat water/coolant for a radiant heat setup? Or to, say, be used as a furnace for both shop heat and processing heat? That, for me, would be striking gold... I fire up one burner when I go out to make fuel, and have both processing heat and shop heat with only one source to tend (In a separate room, of course, to keep down the potential for a fire from the vapors...).

Dual purpose heating was considered during the design phase. It is not practical to do with a conduction type setup because you would have to use both parts of it at all times. (IE: No shop heat unless your reactor is on and no reactor heat unless your shop heat is on.) this would be bad during the summer.. My next project (currently in design) is to heat water. Basically, I need to be able to provide 250,000 to 500,000 btu's of hot water. This will enable me to heat both the main building, my shop, my reactor, and provide hot water for washing. Since we already have hot water heat, we have most of the heat exchangers needed.
The basic principle is to adapt the techniques I used to more resemble a central boiler. (www.centralboiler.com) These are open atmosphere type units so no pressure controls are required.
I want to be able to burn wood, WVO, WMO, and incinerate glycerin all in the same system and have it heat a 250+ gallon tank of water that I could then feed off for various heating loads. 190+ degf water can do allot of work and would be perfect for running through a heat exchanger for reactor heating.

If you talk to anyone who owns one of those centralboiler.com units, they usually love them and say they provide all of their heating needs with energy to spare. I'm in the process of designing something like that.. The secrets to it seem to be the insulation.. It must be the spray-on polyurethane type.. That's the expensive part and the only thing I can't do myself. Other than that, I'm going to make a water jacket with a burner/blower unit mounted to the loading door. Burn wood or oil or both at the same time. Right now, my second biggest problem is materials. I have the stuff needed to make it but I'm not happy with the firebox size. For oil it would be fine but I'm not going to be able to get as much wood into it as I want. The lack of volume also means a lack of heat transfer area. At 1200 degF into water, your only talking about 4000 to 6000 btu's per square foot of transfer area. I think the solution is to create a dual or triple pass system and I am currently trying to figure out the best way to do it with the fewest welds. Its a much more complicated puzzle than that green thing I built..

The other thing they don't tell ya right up front is that there is a $10 per foot cost for the special tubing that you need to run from the heater to the unit being heated. Well, when I'm done, it will save $1500 a month in heating bills and have a $7500+ system. All built using other peoples junk !!!

Thanks for your interest.. I should be starting the building of the above project some time in the next 2 weeks or so. I have one modification to make to my green thing before I offer up plans for it. I'll have to build another green thing and take photos of the build process first. All this stuff takes lots of time.

Very intertesing.

murphy-
as far as the poly foam insulation, most cost in spraying the foam lies in setup and cleaning of equipment. the chemicals are pretty inexpensive.

so a suggestion is to contact a local foam applicator and see if your schedules line up well enough that you could maybe bring the unit to a job site while they are all set up to spray. that way you could save on $$$ of set-up for such a small(for them) project. I do realize that the unit you are talking about is not small, but maybe you could work it out with a trailer, etc.

I had done this w/ 55 gal drums, to float the boathouse on.

good luck, mo

You can get small foam sprayers from places that supply refrigeration engineers.

quote:

Originally posted by mobetta:
murphy-
as far as the poly foam insulation, most cost in spraying the foam lies in setup and cleaning of equipment. the chemicals are pretty inexpensive.

so a suggestion is to contact a local foam applicator and see if your schedules line up well enough that you could maybe bring the unit to a job site while they are all set up to spray. that way you could save on $$$ of set-up for such a small(for them) project. I do realize that the unit you are talking about is not small, but maybe you could work it out with a trailer, etc.

I had done this w/ 55 gal drums, to float the boathouse on.

good luck, mo

That's a good idea. Its going to be skid mounted anyhow.. The entire unit I am building should be 6 feet x 6 feet square and weigh in at less than 1200-1400 lbs(dry).. very portable..
Now to find one of those insulation guys.

What did you do to the 55 gallond drums? Fill them with foam? or spray it on the outside? What did it cost you?

Murphy, try doing a google search for "afterburner flame detector". You might find something useful.

Ken

I had one filled for free, to test out for putting under the boathouse. the added weight seemed to not make it worth while, and the drums are cheap. they usually last ten years or better, in the mississippi.

the boathouse is a cabin built on a floating foundation of barrels.

the houseboat i take out for the weekend.

I expect if you find a cool insulation guy, it would be under $100 to spray a boiler.

good luck,mo

Murphy -- I am finaly getting my syphon-style gun burner heater put together, it is firing upwards into a 100 pound propane tank similar to yours except that the flue pipe comes directly out of the top of the tank. I originally had intended to only place a fan behind the propane tank to move around the hot air but realized it would be easy to simply cut holes in the ends of a barrel and drop it down over the propane tank and use it as a heat collecion housing similar to what you did. I can place a blower (smaller than yours, probably) through the side of the barrel at the top end and cut a few holes around the bottom end as the hot air outlets.

You mentioned having a minimum of 85 degrees in temp rise out of your outlets, you also mentioned that your large blower had 3 speeds but that you are only using one speed, what speed are you using when you get the 85 deg temp rise, and do you have any type of fins or such on the outside of the burn chamber, or is this amount of heat being collected from only the smooth outside surface of the propane tank burn chamber ?

I am considering placing some sort of "filler" inside the upper end of my burn chamber tank to force the hot flue gasses out against the burn chamber tank's inside wall. This filler will be far enough above the end of the flame so as to not cause any extra soot and will run up to just a couple inches below the flue outlet end of the tank (still need to calculate the free-space volume as compared to the flue volume to deturmine how nerrow the free space can be between the inner wall of the burn chamber and the filler tank). I am thinking of using a 30 pound freon tank as the filler, may weld a thicker plate on the end that is closest to the actual flame.

My old oil-o-matic burner has been tested using diesel fuel, the burner stand is completed, It is made from a bowl-shaped 16 inch diameter farm cultivator disk blade placed horizontally (bulged side up) with 3 legs welded around the edge, the burner is bolted vertically up through the center of this disk.

I should get the 6 inch flue outlet welded to the top of the propane tank burn chamber tomorrow, the bottom of the tank has already been cut away. The tank simply sets over the burner and is located by a 1 1/2 inch high ring of 1/4 inch flat iron welded around the top of the burner stand disk, this allows the entire tank to be lifted off of the burner so everything can be cleaned. Hope to have it fired up burning diesel in a day or two, I will then work on adding the fuel heating assembly (almost built) to get it burning veg or used engine oil.

Foam spray guy -- My local foam guy mainly insulates farm buildings (expensive, something like $3.00 per square FOOT, says one set of 55 gallon barrels for the 2-part foam chemicals costs over $350.00 plus shipping) but he also has a sidline occasionally spraying foam into fiberglass burial vaults at his shop, he says if I bring something by when he is set up for the vaults he will only charge a nominal amount for the foam and the time.
He also says I can have his empty plastic barrels for free but I don't have a clue how to clean out the stickey foam resin so I have not taken him up on this yet.
check around, never know what wierd situation you may run in to.

Tim,

My combustion chamber has fins welded to it just like Gee_Dubya does except my fins are welded pointed up instead of down like his are... I don't understand why he pointed them down like that.. Doesn't make sense to me.. heat rises up and will climb steel.. His fins seem to just create dead pockets of protected air under each fin.. Also, my fins are angled so that when the air from the top blower moves down, it also twists around the combustion chamber.. This creates a swirl effect to scrub the chamber of as much heat as I can get from it.. So as the cold air enters the top of the unit, it not only moves downward, it also circles around. I also have way more fins than he has (twice as many?) but they are more rectangular shaped.. I think I cut them 1.5 inches wide by 2 inches long.. The 1.5 side is welded to the combustion chamber.. the fins are at a 45 degree angle pointed UP (not down) and they are also twisted 45 degrees (all the same direction).
A quick and dirty surface area calculation tells me that the fins increase the surface area about 80%. I think it makes a HUGE difference.

See Gee_Dubya's photo:
http://x5.freeshare.us/view/?122fs4004783.jpg

The blower is running on the middle speed setting.. (whatever that is).. That blower came from a 125,000 or 150,000 btu furnace.. That 85 degree rise in temperature was taken when the unit was running at mid-throttle setting.. I can lower it, or raise it by increasing or decreasing the fuel feed and air pressure adjustments. It runs most efficiently somewhere in the middle..(which is where I took all my data from).

The reason my exhaust comes out the side is for the exact reason you are talking about putting a deflector plate in yours.. My exhaust is about 8 inches below the top of the combustion chamber..

My combustion chamber is sealed.. This is why I installed an 8 inch square access door.. I used angle iron to create a protrusion with a flat surface.. (Like an angle iron picture frame with the sides cut to match the diameter of the combustion chamber) I have a plate cut to size with a high temperature seal and two thumb screws that hold it tight against the combustion chamber. It takes about 10 seconds to remove it and the door allows complete access to the inside for cleaning or whatever.. The door is NOT the quick and dirty cut you normally see.. it has its own heat seal and all that stuff.. The other thing I like about the door is that I can see the entire flame and take notes on changes if I adjust something. (I should note that opening the door does change the environment inside the chamber and I realize that)


Thanks for the info on the foam spray.. I'm just now re-designing my latest idea.. i scrapped the first design because the combustion chamber wasn't big enough to put wood into.. Now I'm working on a 200 gallon combustion chamber that will fit into a 600 gallon tank to heat water... (a design still in progress).

I hope this information helps you.

Murphy, check out http://www.dectra.net/garn/Movie.htm
bout what you're doing.

quote:

Originally posted by Blackie:
Murphy, check out http://www.dectra.net/garn/Movie.htm
bout what you're doing.

I've seen many units like that and have done extensive research on the design of these units.
The secrets seem to be a combination of combustion gas residence time withing the unit and an after-burner fed by preheated air.. (they took that idea from the wood stoves)..

Anyhow, I HATE YouTube.. Everytime I go to that site or view a video linked to it, my computer starts to freeze up.. Seems that YouTube is trying to load advertisements into my computer..

Thanks for the info.. Its nice to know the idea works so well.. Ever seen a HeatMor or CentralBoiler.com unit? Very nice stuff..

Murphy -- thanks for the info, I will do the initial testing without any fins, don't need a huge amount of heat for my application, don't expect to need more than about 50-70,000 BTU/HR of heat, may add them later as it would definitely improve the efficiency of the unit.

--Opening the door disturbes the flame -- A local fellow here was having the same problem while developing his vaporizing oil burner, he bought a cheap pyrex casserole dish, 8 X 8 by 2 inches deep, this has about a 1/2 inch flat lip around the top. He cut out the center of his door and used standard fiberglass door gasket material, that was first saturated with plain old home sealing type silicone caulking, available at all home improvement stores (100% silicone, tube costs about $4.00, "clear" (no pigment filler) seems to work best and will stand the heat), the dish is mounted to the outside of the door using a couple of metal tabs with the same fiberglass and silicone between the metal and the glass, the saturated fiberglass seal was placed between the flat glass rim of the dish and the steel door. The gasketing seals completely and still allows the pyrex to "move" a bit with heat so nothing gets strained enough to cause it to crack.

I intend to eventually do something similar through the side of my burner, probably use a 3-4 inch round pyrex dish, no door, just want to be able to see the flame.

-- Thoughts about a piston fuel pump -- I have not done much research on this yet but there are quite a few pressure washers that get tossed and end up at my local salvage yard, they all seem to use some form of a high-pressure pump for the water, usually they are multiple piston or plunger types that are a bit big and definitly overkill but they are built for rough duty and have close tolerances and good valve design. These are expensive if new but cheap by the pound if bought as scrap. They are speced at a couple gallon/minute at high speed but I bet if these were turned real slowly they would draw and pump thick oil just fine ? I could be wrong about them drawing oil well, in another thread about using an oil-fired steam cleaner as a flash evaporator it was stated that an additional centrifigul pump was needed to feed oil to the high-pressure pump as it did not draw thick oil well on it's own, but this was when making 300 PSI and moving 5 gallon of oil per minute.
We don't need the high pressure so the pump could be turned with pretty small motors, probably 1/10 Hp would be overkill. If DC motors are used the speed is pretty easy to control, could even use cheap surplus stepping motors and have very precise fuel delivery. I will watch for one of these pumps for testing.

Garn wood heater -- Reading between the lines it looks like these are designed to burn the wood as hot and as fast as possable, making a huge amount of heat in a short time, makes sence as the thermal transfer of heat is greater when the temp of the heat source and the heat storage area have the greatest differance.
There are no air dampers to limit the air and they even use a blower to insure a big draft of air is available for the firebox and secondary burn chamber (wish they explained this secondary chamber a bit more - ceramic chamber ??). the excess air causes a real hot burn and definitely reduces the amount of smoke and creasote, the same idea is used in what are generally called " Scandinavian or swedish or Russian stoves, these store the heat in tons of brick and cement rather than water but the idea is the same, make LOTS of heat fast with a hot clean burn, store it, and release it slow.

Tim,
Pyrex idea is a good one.. I like that..

I don't think a pressure washer pump would pump the oil very well. The reason is that the stroke length on the pistons is very short. These pumps require inlet pressure to work even with water.. Usually this means household or city water pressure through a hose. Thick oil is going to require a longer and slower stroke length to create a deeper vacuum for inlet draw.. Most high pressure plunger pumps have short fast strokes.

Wood boilers,
If you do a bit of looking at the wood stove manufacturers, you'll find they also use secondary combustion chambers. Some of them use a catalyst screen, others are true after-burners.. I'm not sure which is better but I think the catalyst screen is just another thing to go wrong. The true after-burners basically route the primary combustion gases through a second chamber that is in the path of the primary combustion path. Thus, when the original fire burns, it pre-heats the secondary combustion chamber.. It also pre-heats clean combustion air through a second inlet path.. When combined, the un-burnt gasses re-ignite and you get a cleaner burn.. If I remember correctly, the catalytic ones get a higher temperature on the secondary burn. But again, its at the cost of another thing to go wrong.
The other thing is that I have not seen any of these units that use WVO or WMO as an alternative fuel.. I don't see it being all that difficult to adapt... Just gotta make sure the waste oil burner points down 10 degrees or so..

I looked over some cut-away drawings of pressure washer pumps, I think you are correct, they have extremely short strokes, pretty much explains why they won't "suck" even water. I should research these ideas a bit more before I mention them. There has to be some type of existing long stroke piston pump around somewhere..

Secondary burn chamber -- I will do more reading on these. I was aware that some of the newer wood stoves had a ceramic catalitic converter just before the stack outlet, I think this is just something else that will eventually clog up and get removed as they are basically filtering the smoke through a porous ceramic brick that has to eventually clog with residue from either the cooler smoke at startup or some sort of residue from burning creasote or something. They make replacement ceramic bricks but they are very expensive from what I remember. rather not use that approach. passing the smoke through a hot chamber and introducing additional air might be worth it ?

what about the vacuum pump used to generate the assist for the brake servo on a car or truck?

That is a small piston pump I think, easily turned and designed to 'suck'.

A small motor should drive it easily.

very cheaply and widely available from scrappers or ebay. Pugeot vac pumps seem very reliable. Never had a problem with one.

Murphy,
regarding the spray on isulation you were writing about, I searched for the stuff before. I found that there are kits available for the do-it-yourselfers. If you search for foam insulation kits you will get several hits. Here is one link http://www.tigerfoam.com/products.php?cat_id=1
They sell a kit that will cover 200 square feet for $335. Maybe you can go this route.

its actually a bit cheaper from the rerigeration places.

They sell kits as well.

Small cylineers with hose and gun.

gun etc is reusable.

Just buy more cylinders.

Murph you asked about cascading boiler ignition transformers to get a higher voltage. Here is how it is done

http://www.kronjaeger.com/hv/hv/src/obit/index.html

The diagram at the bottom shows how to get three times the voltage of one transformer using five identicalish transformers of the grounded midpoint type. This is supposedly typical of oil boiler ignition transformers or OBITs as he calls them.

If you look around his site, he records many other ways to get high voltages. You would apparantly be hopeing for 20kv to 30Kv as OBITs are normally 10kv to 15Kv I believe.

quote:

Originally posted by Tim c cook:

Secondary burn chamber -- I will do more reading on these. I was aware that some of the newer wood stoves had a ceramic catalitic converter just before the stack outlet, I think this is just something else that will eventually clog up and get removed as they are basically filtering the smoke through a porous ceramic brick that has to eventually clog with residue from either the cooler smoke at startup or some sort of residue from burning creasote or something. They make replacement ceramic bricks but they are very expensive from what I remember. rather not use that approach. passing the smoke through a hot chamber and introducing additional air might be worth it ?

I don't think so Tim,
As I understand it, as the creosote and smoke particles come in contact with the screen, a catalytic process takes place.. the smoke re-heats and re-ignites and this action keeps the screen clean. They've been on the market for 10 years or so and I have yet to hear of one clogging up.. But my thoughts are on the same line as yours about that.. my mind is beginning to change because you can't argue with long hard data..
The important thing here is that I highly doubt the specific material used in that screen to ignite wood gases is going to be the same material required for oil(s). That's a big problem cause it could, and probably would, lead to a clogged catalytic converter..

Gennerally speaking, any time you add combustion air, you're going to get a much hotter and cleaner burn. Natural draft is very innefficient because its very uncontrolled in my own opinion.

I look at it like this:
If you burn wood, does it burn at 2000+ deg? It will if you set a house on fire.. but no camp fire would ever reach those temperatures.. Why? Draft efficiency vs. size.. Small fires can't suck in the air fast enough.. big fires suck it in like a vacuum..
I watched an interesting thing this summer. The wife an I were out oil-hunting and when we came back home, the house down the street was on fire. No water available so the fire-department just let it burn. When we got there, there was only 1 cop car.. then all the fire trucks started showing up.. Here's the cool part.. While the house produced lots of smoke and some really cool fire when it was burning, the big stuff didnt come until the roof caved in.. once that happened, a big puff of black somke, then a few seconds later the fire leaned-out.. the flames got really tall and the amount of smoke it was producing was drastically reduced. It was the in-rush of air.. This really hot burn only lasted for a few minutes but it was the brightest part..