Recommended Posts

Warren, what is a 'roots' blower?

( I've been following this thread and thinking I might try a waste oil burner with a little veggie oil). Might be interesting.........)

Share this post


Link to post
Share on other sites

jayco,
It is the same type of blower used on Detroit diesels. Basically it is two intermeshing lobed elements within a close fitting oval housing. The two shafts are geared together at a one to one ratio. The air is drawn in at the top and discharged at the bottom. It works on the general principle of a gear pump bur instead of gear teeth it had two to three intermeshing lobes.
Warren

Share this post


Link to post
Share on other sites

A .75 should be plenty, if you go to the link that I posted to BYMC you can see the pics I posted of the burner running in a pipe, that flame is the burner at about 1/2 "throttle", but you can go with a 1 gph if your worried about it.
I don't think that the blower will substitute an air comp, at least not with the style nozzle that I have, it requires the air to create the siphon and atomize the oil. I run around 30-40psi to the nozzle and pressurize my oil tank at 10-20 psi depending on ambient temp and viscosity of the oil I'm burning.
The guy at BYMC that introduced me to this set up uses a small blower in addition to the air comp. but it isn't nessasary and I haven't tried it yet to say if it has much of a bennefit or not but he seems to really like it, but it is only a very small blower.

welder19

Share this post


Link to post
Share on other sites

Thank you welder 19,
One can learn a lot here, especially me who has a lot to learn. The reason that I thought one could use a roots blower is that the manufactures specs. on a couple of sites show up to 5 PSIG pressure but you can't argue with success.
Warren

Share this post


Link to post
Share on other sites

Well hi there, welder19. Fancy seein' you here. I'm matt22191 on BYMC.

You know, I never really paid a lot of attention to that burner thread. You're basically pumping air through the SS tube and siphoning oil with the copper tube, right? So it's basically a Daggoth burner, except that the pre-fabbed fitting makes it a bit less complicated to make, right? How big is your compressor? Mine can only produce about 5 SCFM. Would it be able to keep up?

Share this post


Link to post
Share on other sites

Hey Matt, it is the same principle as the Daggoth burner, I made a Daggoth burner a year or two ago and it is as simple as they get and works pretty good however doesn’t compare to this nozzle as far as performance and range of operation, you can’t fine tune it like this one, but it is still very effective and if your only looking for more or less one setting, then it’s fine, but for the $40 some dollars you can get the Cadillac of siphon nozzles, in my opinion.
My air comp. is a 7 hp 80 gallon 2 stage Devilbiss, so it has no problem running the siphon nozzle but I know a couple of the guys are running it off of small portable type compressors, they just run a lot, so I would think you would be able to run it, but that is why some are using the small blower as well as the air comp, that way you can run at a lower psi.
If your thinking about getting a siphon nozzle I suggest you read through that thread and even put your name on the list so you can try it out before you buy one.

welder19

Share this post


Link to post
Share on other sites

Yes, I also made a turbine wheel that the nozzle slides into, it causes the air to swirl which also improves the burn, causes better mixing of the air and oil. I don't think any of the pix show the turbine though, it is nothing more than a fan blade cut out of sheetmetal sized to fit the tuyere and has a 3/4" hole in the center that the nozzle slides into. It really makes a noticeable difference in the burn and the sound.

welder19

Share this post


Link to post
Share on other sites

Not to sound like a nuggget but I'm curious about the 'turbine' that slips onto the end of the burner. It it meant to spin or is it fixed?
I don't see anything about it from the various photo's that makes me sure it actually moves. I'm guessing it is fixed and the air running over and through it is what imparts spin to the air?
Are those nozzles available in the UK?

Share this post


Link to post
Share on other sites

That's right, the "turbolator" is stationary and causes the incoming air to swirl.

Can't tell you whether those are available in the UK, but I would bet they are.

Share this post


Link to post
Share on other sites

The turbin wheel is fixed but you have me thinking now about how it would be if it was able to spin, I'm gonna have to think about that and maybe expirament with it.
I don't know either about them being available over there but I would think you could probably google it and find out but if not and you really want one I don't think it would be too much to get the fitting and nozzle shipped over to you, they are small and weigh next to nothing, probably wouldn't cost too much more than a letter.

welder19

Share this post


Link to post
Share on other sites

I asked this question on 1-6. I now have read in a book that you need one cubic foot of furnace area to burn forty to sixty BTUs per hour. Motor oil has 145,000 BTUs per gallon. These figures should get one into the ballpark.
If you burn one gallon per hour one needs about three cubic feet of combustion space.
Warren

Share this post


Link to post
Share on other sites

I think you mean one cubic foot to burn forty to sixty thousand BTUs, Warren?

That sounds a little fishy to me. What's the book? Does it explain the basis of that conclusion?

Share this post


Link to post
Share on other sites

hello, im new to this forum but i have been a major hobbiest with blacksmithing, when i get time fromn work, well i usually use coal or charcoal, then i tried propane, propane was awsome but expensive. so i was looking around a saw this link Waste-Oil Forge and Foundry so i decide to give it a try, i had a reil burner that i made and turfed it. then made this one, gave it a test fire and man was i surprized. it actually worked, and it worked good, it is so stupidly simple and it cost me like $20 canadian to make it. i used black iron of course. rigged up a blower from a old vacuum like this guy did, a voola. this idea is awsome, it works as a forge burner, and it works good. or course i have a more fitting forge casing, a old air peg tank, with a 2inch thick layer of ceramic durablanket, i bought two rolls off ebay that were 1/4 inch thick, each roll was 12'' by 24'' by 25 feet. so 50 feet of this stuff for a grand total off 120 dollar booyah, well instead of plistix or stuff like that i went cheap, i used the fire cement clay, it works real good, look cruddy but it work awsome, and it alot cheap to repair. well in general, i love the waste oild burner and i plan on using it for a long time, i spend 6mins to get it up to running temp and a forge for hours. and it helps i have over 80gallons of used motor oil that i filter before burning it. i have no problem with smoke or fumes, butt i run a ventalation fan anyways, well thought id just tell you about this link. You GOT to check it out.

Share this post


Link to post
Share on other sites

the burner is the same one as in the link and instead of the castable refractory i use the ceramic lining or kaowool, and a coating of fire cement clay you buy in stores. it a very simple setup, i will try to get pics up when i find a camera to use.

Share this post


Link to post
Share on other sites

Hi

Have just built my oil forge but I am having some issues.I can't seem to get up to forging temp.
I am using compressed air with oil dripping to vaporize and although I get good flame it is yellow and not very hot, no amount of tweaking helps. I am running the air through a regulator at about 3-5 psi and have it rigged with a blower for more air. With gas the forge gets up to welding heat in no time.

Help!!!

Share this post


Link to post
Share on other sites

Oil flames are yellow. It has something to do with particulates in the flame, which incandesce. Don't expect to get a blue flame like propane from an oil burner. It's almost impossible -- and it's not important.

WIthout seeing yoursetup, my guess is that you're not delivering enough oil. How large is your forge, and how much oil are you burning per hour? Is your forge smoking? (If it's producing smoke, you aren't providing enough air.)

Share this post


Link to post
Share on other sites

It's bigger than your average knife forge. The system works but I am not used to oil so can't determine what a good flame is. I have noticed that to much oil cools it down and too little doesn't do much. Does nozzle size make a difference? I was using a 1.5 inch and it got to red heat, but reduced down to a 1 inch and now it doesn't get so hot. Is bigger flame better? I have noticed that a big flame smokes but a smaller one doesn't. When I add air it burns better, but too much it blows it out - will take picks and post tomorrow.

Share this post


Link to post
Share on other sites

If "big flame smokes" that's because you are not adding enough air to keep up with the fuel. Anytime you see or smell smoke, that's a sign that your fire wants more air. You need to make adjustments relatively slowly. Add a little oil until you start to see a bit of smoke; then add a little air. Then add a little more oil, and a little more air, and so on, until you're getting the heat you want. (Making incremental adjustments will also help you avoid flooding the forge.)

If the flame you have now isn't heating your forge to the temperatures you want, then yes, a bigger flame would be better. I need to see your setup to understand your question about nozzle size. But if you mean the tuyere, yes, reducing the size of the tuyere will add back pressure to your system, which may be preventing your blower from delivering enough air to burn the amount of oil you want. What sort of blower are you using?

A properly tuned oil burner is good at delivering fires-of-Hades temperatures. Most of the homemade burner designs do not run as well at medium temperatures. They tend to want to run near wide open. The amount of radiant heat that comes out of a properly running oil burner can be literally scary.

Share this post


Link to post
Share on other sites

Oh, and once again: how much oil are you using per hour, ballpark? And what are the internal measurements of your forge? Guesstimate if you have to.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.