Venturi burner jet hole question

[BlackKnight0739]

I'm building a venturi burner using this guy's design here, and I've been able to do everything else in the design except drill in the jet hole that blows the propane into the venturi itself. His design calls for a #57 drill bit, which I can't seem to find any in stock at Home Depot, Harbor Freight, Sears, or even Lowe's (all of the tool shops within easy driving distance of me). When I looked up the thickness of a #57 drill bit (to see if maybe I could just use something close in size) I found that a #57 drill bit is 0.043" and the smallest bit that I have is 1/16, or 0.0625"

Do you think .0195" is a big enough difference to affect the venturi's operation? I can maybe see it having a problem at extremely low psi, like 1 or less, but otherwise I can't see a huge problem. Am I right or wrong in that assessment?

By the way, if this thread is somehow in the wrong area, please let me know; I'm pretty new here :)

[Frozenforge]

Unfortunately real tool/hardware stores are scarce these days! Try Mcmaster Carr, they carry the drill bit you need. Dont use the 1/16 its way too big. It makes a huge difference. I would highly recommend checking Ron Reils burner build as this burner is the same as his but he has several improvement you can incorporate.
You have to create a small high velocity jet of propane for naturally aspirated burners to work efficiently so even a small burr left on the edge of your hole can cause a problem. If you can use the mig welding tip as suggested in Rons burner build it makes a fine high velocity jet of propane.
Small changes make a big difference with NA burners but once they are tuned they are wonderful

[BlackKnight0739]

Thanks for the MIG tip idea! I happen to have a couple lying around, I'll just thread that into the brass pipe and be good to go!

[Fatfudd]

MIG tips work great but you need to size those also. On my small forge I use a .023 tip which has a 1/2in tube body. On my 3/4 tube body I use a .030 tip. It make a big difference which one you use.

[BlackKnight0739]

How would I know if the tip I have is too small for the burner body I'm using?

[timgunn1962]

Too big on the gas jet and the temperature will be low with lots of Dragons Breath; too rich (reducing)

 

Too small and there will be no Dragons Breath and a massive scaling problem; too lean (Oxidizing)

 

Broadly speaking, the jet size will set the air:fuel ratio, which will vary the temperature of the flame.

 

Varying the gas pressure effectively varies how big the flame is.

 

There are several designs for chokes that will work with your burner. It's worth building one. The choke gives scope to adjust the air:fuel ratio.

 

Ideally, you want to have an air:fuel ratio that gives a flame temperature at, or just above, the maximum you will ever need with the choke fully open. You can then choke it down to get a lower temperature, and a reducing atmosphere, when you do not need it that hot.

[ThomasPowers]

Or to put it a different way: it doesn't work right.  NA burners are *very* picky in how they are built.  Making even what you may consider minor changes can ruin the tuning of such a burner.

[Frosty]

You really need to do some more reading. While that design burner WILL work it's not a very good design. The nipple extending the intake bell reducer does nothing for performance besides degrading induction.

 

Go to Ron's pages, he actually knows what he's doing. The plans you're using are full of additions to make it work by someone who didn't understand how the things work. And no, don't try asking Ron questions, he got so fed up with people asking questions without bothering to read the material he stopped answering anybody's questions and in fact stopped participating in web fora, lists, etc.

 

Your last question. NO threading the cross pipe and installing a mig tip in your set up isn't going to help. It will in fact make it not work worth spit.

 

Frosty The Lucky.

[BlackKnight0739]

I read Ron's pages, that's how I got the idea to use a MIG tip (in addition to what Frozenforge said); Tweco is a brand name and the measurements he gave on his page are MIG wire sizes, so I figured it'd work just fine. I've also read on other forums that people use them as well. Are there other pages or places I can read up on venturi burner designs that you know about? Pictures would also help out, as I don't know a lot of the terminology yet lol so I may be looking up the wrong things when I try to Google it.

 

When you're talking about the nipple extending the intake bell reducer degrading induction; are you talking about the brass nipple extending out, or the iron nipple he screwed on in lieu of a set screw? He does both at one point or another in the procedure, I'm just trying to see if I'm on the same page as you are :)

 

Thanks for all the feedback so far! I really appreciate it :)

[Frosty]

I haven't looked at Ron's plans for a long time, years. does he actually put a mig contact tip on the cross tube? How far down the burner tube does he let it extend?

 

Ron and I haven't been on the same page for a long time, we're good friends we just differ significantly in burner design. He spent a LOT of effort and time developing his linear inducer burners and I spent almost a whole day developing an easy to make ejector inducer. For another example, I had a little issue when he actually said screwing a nipple into the intake bell was a viable alternative to using a set screw.

 

The deeper in the induction device the primary supply is the lower the entrainment. Okay, that's the kinda technical way of saying, the farther into the burner you put the jet the less efficient it is.

 

What dia. mig tip are you using?

 

Oh yeah, you can find my earliest concept drawings by searching "Frosty T burner". Be aware though it's an entirely different device than you're trying to get to work. A world easier to make and adjust but it's probably the main reason Ron and I don't talk burners. Mike Porter and I do occasionally but we all have our own style and all work just fine if you build and tune them correctly.

 

Frosty The Lucky.

[BlackKnight0739]

I'm starting with a .023 MIG tip, because I figure I can always go bigger if it turns out to be a problem :) Ron's designs and various modifications are all arranged in a very complex mess, I might have to go to ABANA with a redesign concept, so it's all organized and easy to follow (but I'm starting to ramble lol). After some crazy searches, Ron recommends an 1 1/2" x 1/4" tip, preferably a nozzle type tip. He recommends tapping and threading so you can easily swap out tips if need be while tuning, and then silver solder it in place to prevent unnecessary gas leakage past the threads once you figure out what will work best for your setup. He also said to increase the bell intake to 2" to compensate for the deeper inset.

 

I found the thread pkrankow made of your design, I'll take a look and see what the differences are! The main reason I went with a venturi burner is because I understand the Venturi principle the best (and there's far fewer moving parts for me to mess up lol)

[Frosty]

Yeah, Ron was a middle school science teacher and I think he just got used to trying to make things fool proof even to the detriment of the project.

 

So, tell me how looking at couple different sets of drawings or pictures will tell you the differences? If you believe how it looks means anything you don't understand naturally aspirated burners at all. If you did you might notice there isn't a venturi in any of them. Do you know what a venturi is for?

 

Forgive me if I seem short but I've described in detail how to make these things many times and helped many guys trouble shoot and tune all kinds of naturally aspirated burners. I'm just running short on enthusiasm for repeating myself for folk who haven't done much if any research. Telling me what Ron has in his plans when you don't know how it works is wasting both our time and my patience.

 

Frosty The Lucky.

[Fatfudd]

Frosty is actually offering some excellent advice, do more research. I gave up on Ron's approach too, and developed my own, but it took lots of experimentation. The burner output is affected by a whole series of variables which need to all be in-sink to work properly.

[BlackKnight0739]

I'm a visual person, text alone doesn't normally help me learn anything; text with supporting pictures does. And I am doing research; asking experienced people is research, no? The only reason I'm asking the questions I am is because all of the pages I've found on the subject are pretty vague. The answers I've gotten in this thread are the most specific answers I've found as of yet :) So thank you all again for helping me out!

Frosty, I have no problems with your being short, I understand where you're coming from! I'm in the Navy as a nuke electrician (which means reactors, not bombs so no worries about me on that end lol), and teaching people about my job was one of the roles I was assigned. After about the 300th walkthrough my enthusiasm was also run out. I understand the principles behind the venturi effect, we used it all the time in the Navy, from using a widespread water fog through a doorway to desmoke a room after a fire to venturi-based steam flow detectors.

Update: I got the burner to light without chuffing, but it's too bright outside right now for me to really see the flame so I'll have to wait until it's a little darker for more tests. But from sound alone (and the shimmer from the flame) it runs pretty decent from somewhere around 5 psi to 25 psi (Got sent on an errand, so I didn't get time to play with low pressure testing). I'm going to play around with it a lot more, but for now I wanted to see if what I built was at all sound.

[Frosty]

Sounds more like asking experienced people is the modern alternative to doing research.

 

You're a nuke so regardless of what you claim here you can indeed learn from the written word. I have a couple close and dear friends who were and are nukes, one a bubblehead, the squid was on the last deployment of the Enterprise, he and the black gang spent about a year "rebuilding" the reactor and power plant so it could make it's last deployment cruise then probably go to the breakers. Neither of my guys would've been allowed near the plant if they couldn't learn from reading.

 

I hear your reasoning all the time in one form or another and to an old fart it sounds like excuses. I'd be honored if you'll prove me wrong so here it is.

 

The ratios to  make an induction device operate, be it a steam powered bilge pump, room fogger, the vacuum generator in a storm drain vac truck (the Aquatek was the old one at work). or the NA inducer/mixer in a gas range follows.

 

All significant ratios are based on the throat diameter. The throat being the narrowest point in the tube after the induced (whatever) intake(s).

 

Tube length should = 8-9 x throat diameter.

 

Intake area = 2x the throat cross section area.

 

Jet setback should be no less than .5x throat dia.

 

For the purpose of illustration I will use a throat diameter of 1" for the purposes of simplicity.  Tube length = 8-9", intake port(s) = 1.57" sq/in. jet setbsack = 0.5" +.

 

That ratio set and the example of the Bunsen and the Fisher burner is what Ron and I used to make our burners. the early days of the internet is how Ron and I got to know each other and early on in our tinkering I found a patent for the improved gas forge. The improvement wasn't about the burner but a recuperative wall design. There was a picture of it with the burner ad the burner was a linear induction device the same in principle and materials as Ron's EZ.

 

I was misled into going with the linear for a while till I discovered there is indeed almost30% better performance using the ejector design. Ron refined his linear till his worked nearly as well as a commercial inducer and I made the T. The "Side arm" is the result of a misunderstanding of how I was going to mount the T but it works very well so. . .

 

Ron and I didn't have anyone but each other to ask questions, we reinvented the wheel on our own power.

 

Frosty The Lucky.

[BlackKnight0739]

Thank you! These numbers were exactly what I was looking for! I didn't think to use Bunsen or Fisher burners as an example!

How long had you and Ron been smithing before you met, if I may ask?

[Frosty]

I've been messing with fire and hitting things with hammers since I was maybe 10, I don't know about Ron. We met via theforge list and maybe he was subbed to the old Artmetal list too, it was right after the internet went public.

 

Frosty The Lucky.

[BlackKnight0739]

No wonder you understand this so well :) Hammers were never my strong suit, I grew up a computer nerd. It wasn't until about a year ago that I took up anything more physically strenuous than a screwdriver for anything (other than while at work), so a lot of this is very new to me.

I'm working on learning how to silver solder before I build a burner based on the ratios you gave me.

[horseshoe182]

engineering suppliers will (should) stock every drill size, hardware stores just stock standard drill sizes and usually inferior quality too. and welding supply shops will stock a vast array mig tip types and sizes.  

 

cheers Michael

[Ian Wille]

To Build on what Horseshoe182 suggested, look for MSC Industrial Supply or Grainger. Both supply houses sell to the manufacturing industry will have those drills, mig tips, and special plumbing supplies in stock. And there will probably be one within a reasonable driving distance.

[Frosty]

No wonder you understand this so well :) Hammers were never my strong suit, I grew up a computer nerd. It wasn't until about a year ago that I took up anything more physically strenuous than a screwdriver for anything (other than while at work), so a lot of this is very new to me.

I'm working on learning how to silver solder before I build a burner based on the ratios you gave me.

 

Ah yes, hammers and computers aren't a good combination when one is trying to learn to use a computer. I still have my Commodore 64 in the basement. Right after I bought it I took all my hammers out of the house and put them in the back shed, the temptation was strong.

 

Frosty The Lucky.

[ThomasPowers]

Depending on where you live; it's 60-70 miles each way from my shop.

[BlackKnight0739]

Ah yes, hammers and computers aren't a good combination when one is trying to learn to use a computer. I still have my Commodore 64 in the basement. Right after I bought it I took all my hammers out of the house and put them in the back shed, the temptation was strong.
 
Frosty The Lucky.

lol I understand that feeling completely!

Thank you everyone for the info on engineering supply stores, Grainger and MSC Industrial! I will definitely keep that in mind when I'm searching for more tools!

I'm currently in the middle of trying to build your T-burner Frosty, I'll definitely post pics and videos when it's complete! I got a Reil burner to light successfully, and now I want to see the differences in performance for myself to see which I prefer. Thank you again for all the help you've given me so far, I really appreciate it!

[rustyanchor]

If you are on a ship, go talk to your HT or MR shop, I would bet there is someone that would be happy to drill your jet. On the shore side SWRMC (used to be called SIMA San Diego) has folks that can do a drill job. AIMD on an air facility.  

There is usually someone around every shop or facility that would be really interested in your forge build and may be able to show you silver soldering or other things hands on.

[Elijah Perry]

On 4/23/2014 at 1:27 AM, BlackKnight0739 said:

I'm building a venturi burner using this guy's design here, and I've been able to do everything else in the design except drill in the jet hole that blows the propane into the venturi itself. His design calls for a #57 drill bit, which I can't seem to find any in stock at Home Depot, Harbor Freight, Sears, or even Lowe's (all of the tool shops within easy driving distance of me). When I looked up the thickness of a #57 drill bit (to see if maybe I could just use something close in size) I found that a #57 drill bit is 0.043" and the smallest bit that I have is 1/16, or 0.0625"

Do you think .0195" is a big enough difference to affect the venturi's operation? I can maybe see it having a problem at extremely low psi, like 1 or less, but otherwise I can't see a huge problem. Am I right or wrong in that assessment?

By the way, if this thread is somehow in the wrong area, please let me know; I'm pretty new here

Sorry for the necropost, but I had the same issue and found a set of dremel bits with a 3/64" (0.0485") at home depot, very close to a #57, hope it helps.