Stainless siphon nozzle waste oil burner

Discussion in 'Burners and their construction' started by Guster, Mar 13, 2019.

  1. Guster

    Guster Silver

    I liked the idea of the siphon nozzle burners. Being able to be used for multiple fuels and having access to waste engine oil was a bonus. Unfortunately the Delevan ones were expensive to source. Then I found some on AliExpress for much less and free shipping. It arrived around the time I was making the little visemount hotwire cutting table. I'd collected a few parts already so assembly was quite quick.

    I may have mentioned before that I like working with stainless. I welded up some plumbing as well as a little vane holder to center the nozzle in the main tube.

    This is less restrictive than some other attempts to induce a vortex and produces a very nice looking business end.

    Welded a inlet and mount for the blower along with an end cap to secure the plumbing:
    _Jason, PatJ and oldironfarmer like this.
  2. Guster

    Guster Silver

    Picked a wet day to test. Atomises well though I added some diesel to the oil as I was worried it may be too viscous.

    Turns out the oil works well enough on its own. Though the addition of diesel produces a more stable flame. when burning in the open like this. Once inside a glowing furnace that will be less of an issue. Burnt up a cup of oil and the front of the burner was still ice cold. I could also make it much shorter and more compact and would love to try a slightly more powerful fan.
  3. oldironfarmer

    oldironfarmer Silver Banner Member

    How do you control the airflow to your burner?

    I assume you have a filter on the fuel line.
  4. PatJ

    PatJ Silver Banner Member


    That is a really nice piece of work there.
    My latest siphon nozzle burner tube uses stainless, and I really like that stuff because I don't have corrosion issues.

    One of my earlier burner versions was pretty short, perhaps 12" long (+ -), and any leakage of hot gases around the tuyere put everything connected to the far end of the burner tube in danger of overheatings (I had a rubber seal and it melted).
    I now use a burner tube that is at least 18" long; I will have to measure it to get an actual length.

    Looks like you have a serious cast iron melter there.
    And with speed control on the fan, you can dial it in to perhaps 2.5-3.0 gal/hr if you are going to melt iron.

    I like it a lot.

  5. Guster

    Guster Silver

    Aspiration is not currently controlled at all. The little blower is a bit gutless but does the job. Hence I wouldn't currently know if more aspiration would benefit the setup. I do have two 10000rpm universal AC motors which I was hoping to speed control using a speed controller but the both turn the wrong way. You can normally change the direction by swapping ends on one for the windings in relation to the brushes but the way these are manufactured is making that difficult. Alternatively I will find a DC motor and speed control it since simply swapping polarity changes direction.

    Atomisation/siphon air is first controlled through pressure regulation and secondly have flow control using a needle valve. The idea is to set the pressure to spec for the nozzle and then adjust flow to moderate the siphon.

    I pre-filtered the oil I tested with though the idea was to pump the oil through a normal automotive spin on oil filter. I acquired a remote filter adapter you can do this with. Mine requires I find a filter with M20x1.5 thread. I would still very much like to pre-filter my oil before decanting it to the fuel tank. Otherwise I may just filter it from the tank outlet. I do have a little 12v universal automotive fluid pump that should do the trick as well as a power steering pump.

    For a fuel tank I have an old party balloon helium tank which I welded a largish pipe nipple to use a pipe cap as a port for filling etc. Then plan to weld in a pick-up tube threaded 1/4"BSP for a small ball valve and hose barb. At the top I may also add a regulated compressed air inlet for a little(very little) flow assistance. This would also assist filtering if I chose to do it this way. The idea of making a mess quickly is always on my mind when it comes to vessels containing fluid and above ambient pressure.
    Last edited: Mar 13, 2019
  6. Guster

    Guster Silver

    Thanks PatJ. The design on this was borrowed from Myfordboy, SVSeeker and Brian Oltrogge amongst many other. I just added my spin on things.

    I took my measurements by eye in relation to the size of the nozzle. based around the other builds. Though it is all easily adjustable and modifiable. As I mentioned to OIF the current fan is a little weak and I'd like to play with it had I the ability for a bit more power and speed control. These nozzles are heat sensitive due to the internal o-ring so time will tell if I need to make changes. Keeping the nozzle back and out of the tuyere is key to avoiding circulated and radiant heat damage.

    At this stage my furnace is only rated to 1400C and happy to stick with aluminium and copper alloys. So far I've been using my LPG burner to my great surprise. Once I have my oil supply side sorted I do want to try this one as it will keep my fuel costs down.
  7. oldironfarmer

    oldironfarmer Silver Banner Member

    It is really easy to pressurize your fuel tank. That's how I'm operating, and I don't run my furnace when I'm not there. So I blow down the fuel tank to avoid coming in later and being able to see all my fuel.

    I just dump my crappy fuel into my tank and let the discharge filter take care of everything. I run my tank at 10 psi but just have a drip burner. I guess your tip might take more pressure.

    Is 1400C not plenty of temperature to melt cast iron?
  8. Guster

    Guster Silver

    There is really no reason not to just use the tank as a reservoir with just enough pressure to overcome the internal resistance of the filter(other than my preferences) I was already thinking about how to mount the remote filter block to the carry flange on the tank.

    I honestly never checked, thinking it to be much higher but you are right... 1200C should do that and I was hitting that temp with my little LPG burner during dry-out. :oops:

    This burner has the output to smash that and more to spare.

    Not even here a day and already Andy is leading me down another path. Guess I should add that to my list of things to learn more about. :eek:
  9. PatJ

    PatJ Silver Banner Member

    I never melted an o-ring, but I alwyas pulled the burner tube away from the furnace when I turned off the burner.
    I did not want to spoil an iron melt if an o-ring should happen to give out one day, so I made up an o-ringless design.
    I am not sure if I posted that build here or not.
    I will look for it.

    The SVseeker video is what got me started with siphon-nozzle burners.

    Yep, I did post the o-ringless burner build here:
    I don't use the fins on the end of the burner any more; I cut them off and just use a straight pipe.
    I got a little carried away with the silver solder when I soldered on the small piece, and I blocked the small hole completely, and had to drill it out.
    But it all works like a charm, and no more o-ring.

    Last edited: Mar 14, 2019
  10. Guster

    Guster Silver

    Thanks! That's a great modification using the existing component. Should be even easier to change the stainless one. Though I should have no issues making one from scratch either. You can also purchase the nozzle component seperately which can speed up making your own. I know a fellow NZer who lives around the corner who also made his own:

    I even pull the LPG burner away when I turn it off at the moment... guess I'm hoping it forms a habit. Having the burner mount on a pivot also made it easy. I guess I have one saving grace knowing that can hit over 1200C and I haven't optimised it yet either. Andy(Oldironfarmer) is nudging me to explore the larger MIG nozzles.

    Always good to have more ideas to play with.
  11. Tobho Mott

    Tobho Mott Silver Banner Member

    Nudge is a member here too, though he's been quiet lately.

    No list of homemade siphon burner nozzles and Delevan mods is complete without a link to Dave's kwiky all fuel burner!

    I've had parts for one of these for a couple years, but I like my Hot Shot drip burner so much I haven't gotten to it yet. In no rush to wear out my cheap little air compressor either, but I always thought it'd be fun to build one and see if I can get it working.

    Jason likes this.
  12. Guster

    Guster Silver

    Good to know, didn't see him in the member list though I rushed through it. Nudge has been offline for a bit. Either busy or on holiday I guess. Funny we've been chatting for months but still to meet in person.

    I saw the kwiky and should be able to machine that from stainless if I take a little time to design one. Done some small orifice jets on the lathe and stainless can be tricky without a sensitive drilling chuck. I'd love a little tap burner EDM for 'cutting' small accurate holes too - somewhere on my list of projects. The imported siphon nozzle I got was too cheap to pass up. Worst case I do a little surgery on it. :oops:
  13. Guster

    Guster Silver

    Getting ready to use my burner in full anger I decided to upgrade the supply a little. I had a spent party balloon helium tank that looked like a good candidate for an oil tank. Welded in a siphon tube along with a 1/4" BSP fitting to attach the hoses too. The inlet sits about 1/2" shy of the bottom, to leave the waste oil sludge where it belongs. To fill the tank I added a 1.5” hose nipple and pipe cap. To add a little positive pressure to the tank I found a 7/16” UNF nut fit the original tank plumbing and welded a hose barb/tail to the nut.

    I found a M20 threaded oil filter for the oil but its diameter was larger than the remote oil filter mount I got. I had the right M20 bolt so decided to make a new filter mount using some flat aluminium plate thick enough to hold a 1/4" BSP thread for a hose tail. Bored out the M20 bolt and tapped the end for a hose barb.

    With the tank done and filter mount done I wanted a way to mount or hold all the plumbing so I made a little cage for it all. Added a recess for the tank fill port and some holders for the burners.

    Lick of paint and some tread plate Removed all the controls from the oil burner and mounted some quick disconnect fittings along with a little ball valve on the oil disconnect.

    Oldironfarmer might recognise the stainless crucible pouring shank design sitting across the top. o_O
    oldironfarmer likes this.
  14. oldironfarmer

    oldironfarmer Silver Banner Member

    Man you do nice work! Sure puts my home made stuff to shame.:oops:

    A year after building my furnace I still have no place to store the burner except on the shop floor. I need to find somebody to cast me a bracket to hold it.

    Lets see some hot metal!!:D
  15. Guster

    Guster Silver

    Thanks Andy. Spent morning moving the handle bar on the furnace trolley back 10mm to make this fit as intended. :oops: Need to add another rail or something to hold all the crucible tools now.

    Then the rest of the day breaking down some old outboard motor castings, removing metal and plastic fittings from them. Also have about 2 crucible shots worth of brass ready. Best thing to do while it is raining outside. :(
  16. Jason

    Jason Silver Banner Member

    Wish I was melting metal... instead i'm dorking with stupid glass.:rolleyes:
  17. Petee716

    Petee716 Silver Banner Member

    Wow, nice kit.
    I have a valve on the bottom of my tank (it's a 50 gal hot water tank -not full) and tap off a couple of cups of oil before starting. I also back feed air down the dip tube for awhile to mix the various oil to be somewhat homogeneous. I haven't been too picky about my fuel sources, but I should be! I haven't added any oil in awhile so most of the original source water is gone, but I run about 20psi into the tank while in use so I'm sure I'm putting new moisture in there. I run a spin-on filter in-line to my burner as well. The only time I've had a plugged nozzle has been from trimmings from when I initially cut and connected the fuel hose. I have indeed melted my o-ring and even though I always pull my burner out when the compressed air is off, I do replace it from time to time due to deterioration.

  18. Melterskelter

    Melterskelter Silver Banner Member

    I have come to the conclusion that filtration is very important in running my siphon burner. Initially, I set it up with filters on air and fuel just BEFORE the quick connects to the burner tube itself. To avoid dirt in the lines, I was careful to cover the connections with foil when the lines were not connected. And it ran that way for quite a few hours and quite a few cycles OK. But then it started to become more difficult to maintain a consistent burn. On troubleshooting, I found dirt in the burner tip both in the atomizing portion and the fuel supply. The solution was to move the filters on the lines to the burner tube side of the connectors. That way the path from the filter to tip is never broken an tiny bits of contamination, hopefully, will not build up in the tip.

    I have run my burner through a couple hundred burn cycles and am on my second O-ring. I burned up my first one on the second or third cycle as I forgot to remove the tube from the burner on shut down. Radiant heat did its mischief in no time. Since then, my shut down sequence is:
    1) Fuel off
    2) Atomization air turned up to full full on
    3) Combustion air full on
    4) Pull tube and set aside with combustion air blowing full and atomization air blowing fully.
    5) Despite those precautions I keep a spare ring taped to the burner tube near the air-entry end.

    To make pulling the tube easy I silver-soldered a Tee extension on the hose clamp screw that secures the burner tube to a mounting bracket that positions the burner tube it the tuyere.

    I do use a a burner tube which is SS for the last couple of inches. But that same arrangement would gradually burn up over time until I made my tuyere with a slight step in the fire end so that the burner tube butts up against refractory. Previously the tuyere tube was of the same diameter all the way into the furnace and even though the tip of the tube as an inch or so inside inside the tuyere, the heat of the fire gradually consumed the SS tube tip.

  19. Nudge

    Nudge Copper

    "Then the rest of the day breaking down some old outboard motor castings, removing metal and plastic fittings from them."

    I don't bother breaking down any parts.... Just sit them on the top of the furnace and crank up the heat. It is a LOT faster and more satisfying.

    Nice looking setup!
    Guster likes this.
  20. Guster

    Guster Silver

    I wish I was melting metal(other than welding a lot) but it is raining again. :(


    Soon as I have some time I’ll make a stainless kwiky or nudge style burner without an o-ring. The nozzles minus the siphon body are very cheap on their own too so that might be another option to make a nozzle without an o-ring.

    That sounds exactly like my shut down sequence. But sure I’ll still manage to burn an o-ring with my luck. Another reason I was thinking of getting spare nozzles was to make for a quicker swap when fouled or burnt.

    This spin on filter is massive and should last me a long time. I need to dial down the tank pressure just to the point where it stops spurting oil out the nozzle too much.

    If you look at my furnace trolley it is super easy pulling the burner with the burner holder I made using an old umbrella holder that just happened to be about the right size. Letting me slide and pivot it out of the way.

    My next mission is to upgrade the fan motor with something I can speed control.

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