Tim, What is your goal with the burner tips? Are you trying to create a pressure spray into the flash evaporator?

Have you looked into hot water pressure washer fuel nozzles? Oil-fired hot water washers have gph flow rates from .5 gal to 2.5 gal at 100psi. I have a chart that also gives the flow rates at 80, 120, 140, 160, 200 and 300psi.

I don't know the thread size or pitch. It doesn't look like a standard npt pitch.

Have you checked Spraying Systems for tips? They have nozzles for just about every application. Unfortunately their website is a bit hard to navigate but their tech support folks should help. Check out http://www.spray.com (I think).

I love your flash evaporator idea and will be building one soon.

Thanks for sharing it with us.

Todd

Reason for interchangable orifice inserts --

Don't actualy want to produce a "spray" as the burner tips are designed to do, just want to set the oil flow to a pre-deturmined amount and make a restriction to create pressure (oil burner nozzles were just the first flow control device that I thought of before considering the possible consequences of using a "spray"). From the ball valve tests, the water will flash evap just fine without actualy creating a "spray" of oil. A solid "stream" seems like it would be MUCH more difficult to accidentaly ignite than a "spray". Even the ball valve tests created a small amount of oil vapor, I suspect a spray nozzle would cause even MORE oil vapor. this is one of the reasons for trying to find some other existing selection of orifice inserts rather than using oil burner or any other type "spray" nozzles. May eventualy be able to just drill the correct size hole in a pipe cap or plug.

The interchangable orifice inserts are used to limit the oil flow so you can produce the 150 pound pressure inside the heater pipe to keep the 300 degree water in the oil from boiling until it emerges from the output orifice. (300 degree being an important requierment, most spray nozzles are not intended for this high temp)

It is just easier to do this early testing using some readily available interchangable orifice nozzle to deturmine flow rate/temp cyceling. It would also be nice if I can design a single unit that can deliver any flow rate anyone would want just by changing the output orifice and the heater element. This would allow you to easily change the gallon/hour of your existing dehydrator as your needs changed.

For this unit to operate as a stand-alone unit you need around 150 pounds pressure inside the heater pipe and then balance the flow rate and the applied heat, It is easier to control the applied heat using a simple thermostat than it is to apply max heat and control the flow rate by some mechanical means of adjusting the output orifice size.

I picked up one LP nozzle today from my local scrap yard. It is from a LP heater that is rated at 30,000 btu (may be able to use the btu rating to deturmine flow rate at some point). It is a #53 orifice (.0595") so is a bit big for my needs (8.5 to 20+ gallon/hour ??) but it will at least allow some base-line flow-rate tests.

Ah, understand now. Very good idea. Check out your local agricultural supply house for some spraying systems tips. Granted, they are typically designed for gallons per minute rather than gallons per hour.

The good thing is your oil is already filtered. Otherwise these tips would clog incessantly. Your 8.5 to 20 gph translates to .14 to .33 gallons per minute. They may be able to achieve that. Please keep us posted.

Todd

At the risk of being obvious, why not drill a hole in a pipe fitting if you're not interested in a spray pattern? A set of small numbered drill bits is pretty cheap, and would give you quite fine increments to play with.

It sounds easy when you say it but I have tried it and it ain"t.. We are talking about SMALL holes here, 30/000 inch and less, I have never had much luck drilling these, usualy break several bits trying, the last broken bit almost always stays jammed in the almost drilled hole. Once I get enough flow rate info from verious sized orifice holes it may be reasonable to drill them, depends just how small the holes end up.

Yer right, drilling tiny holes requires a drillpress or lathe.

I can't even do it then, I have used both of these as well as a precision jewlers drill press and still broke bits, even tried tungston carbide bits used to drill the holes in printed circuit boards. Also tried drilling partualy through with a somewhat larger bit and drilling the final hole with the correct size, sorta worked, maybee - still broke bits. Just easier to find something already available.

I went by the salvage yard again today to check gas water heaters for orifice inserts, they don't use em, they apparently are built inside the regulater unit. I did find a couple smaller orifice inserts from back yard bar-B-Q grills. These are # 60 (.0400) and #64 (.0360). the threads on these inserts are smaller than 1/8 inch pipe, haven't researched what threads they are yet but they seem to be standard for all the back yard grills that I looked over.

I took a few minutes and tried different thread taps to deturmine the size and number of threads of the B-B-Q grill LP orifice inserts. It appears they are a standard straight 5/16 - 24 thread.

I like the flash dewatering idea. Just doing a little brainstorming. I wonder how well it would work to use a pump that is rated at 2-3gph at 90-100psi, like a furnace fuel pump. Since you are planning to regulate the heat thermostatically, use a pressure relief valve set at 90-100psi instead of an orifice. Then to gather the oil mist direct the output thru a small amount of fibrous material, like fiberglass or steel wool. Steam should still escape once the material heats up. Sort of similar to the way the fuel alcohol stills worked, the condensable mist would cling to the material, gather together and drip down. Just a thought...

A furnace burner fuel-oil pump should work just fine, they do this exact same task for an oil burner. The burner motors are usualy 1/7 HP or less and these are also turning a squirrel cage blower so I suspect that most any comperable sized fan motor would work to turn one of these pumps. The pumps are shaft driven so the motor could be 110 volt AC, 220 volt AC, or even 12 volt DC.

Depending on the model of pump you use they can output up to over 7 gallon/hour at an adjustable 100 to 200 PSI, they operate at any speed up to 1750 rpm (3 g/m) or 3600 rpm (7 g/m)depending on the model.

Pressure relief valve -- HHMMM -- Have to think about this a bit, need to somehow insure the oil gets adequately hot before the pressure is released, I suspect this requires a controled flow rate, the only way I know to do this is through an orifice ?

Fiberous material -- From testing I don't think this is needed for the bulk of the oil, The bulk of the oil deliberately never gets hot enough to become vapor ( want to keep it below it's flash point temp) and just flows out the oriface as hot oil ( this is another reason to NOT use a SPRAY nozzle as the orifice). It may be a way to better trap the small amount of oil vapor that flows off in the water steam, will have to do some sort of testing on this.

The fuel oil pump I had in mind was THIS ONE ON EBAY.
Rated 90psi and 3gph at 14vdc. With the relief valve set at 90psi, the pump capacity should control the output to 3gph. Just need to ensure the temperature was regulated. The output from the relief valve could then be directed through different tubing or packing designs till you find something that gathers the oil mist without also condensing the water.

I've got a link somewhere for the above listed pump on a website too. Look again for it later.

nozzle control. Try some used old type (easy to disassemble) bosch diesel injectors? remove the spring inside along with the spacer, think that will allow it to be constant flow.

JOAT -- The pump you referanced works ok, I have a couple. They are a true gear pump, just very tiny and thin gears. 90 pounds is the highest pressure I was able to get from them, at this pressure the small motor has to work pretty hard and gets warm, they are specked as "intermittent duty" so don't know how long they would survive running full time, I don't think I was able to get more than a bit over 2 1/2 g/h at 90 pounds from these. I use them to pulse oil at open head pressure into my wood stove.

Here is a link to an ebay sale for a "suntec" pump. These pumps are standard on a lot of oil burners and are the type of pump I was describing in the above post ( I did not research this particular part number ?).

Here is the Suntec manufactures web page.

Also, from testing I find that the flash evap works better at around 150 pounds pressure than at 90-100 pounds. you get a bit more flow and the steam just seems to be of a greater volume and more consistent than with a lower pressure.

You will still have to use an orifice for flow control, The basic idea is to keep the pressure high while heating the oil/water, the orifice is the output restriction that keeps the pressure high. At high pressure water does not boil unless heated to around 315-320 degrees so when the hot (300 degree) oil/water comes out of the orifice into normal pressure the water instantly boils off as steam.

jmj -- Unfortunatly I don't have any of the bosh injectors and not many older diesel cars around this area, would have to search out a source and still end up paying for them. I do have a fairly consistant source of salvaged LP gas appliances to pull nozzles from so I will use these for testing for now.

How about using a gasoline fuel injector with a pulse circuit to drive it? Then you can vary the flow rate as you see fit.

Use a gear pump to pressurize things, tee off to the heater and the fuel injector for the heated section. Feed the third tee leg to a pressure relief bypass to regulate pressure.

Investigate pilot light orifices, too.

Natural gas is bigger than propane, but all are available cheap, and often on teh side of the road in abandoned water heaters.

Tim I'm new here, but was just thinking if you could use the furnace pump, then use the squirl cage fan to draw a small vacumm on a sealed recovery tank to pull the steam oil vaper out in to a seperate container. At least for a home version of this.

Keep up the good work, Jeff

Gasoline engine fuel injector -- I will have to think about this a bit, may have some application with veriable rate heat from exhaust. It seems a bit overkill for a fixed rate unit, realy no need to very the flow rate unless the amount of heat is changing a lot. I don't know if these injectors would survive the 300 deg f heat. Also need to research the fuel line connection, all that I have played with just use an "O" ring and a friction fit, some do have hold-down tabs but The pressure on these is only around 55 pounds, not sure how everything would wprk with 150 pounds. May not even be able to get them to open at this pressure, will need testing.

gear pump and bypass -- This would work just fine and may be the easiest way to go if you need a realy high flow-rate ( over 7 g/h). It is not the least expensive by far. oil fired burner pumps already have the bypass built into them and new ones are available regularly on ebay for under $25.00. Actualy, even for higher flow rates you could just run several of these pumps to get the required flow rate.

Pilot light orifices -- wondered about these - Looked at several from water heaters but did not find any numbers to deturmine size, I suspect one size fits all pilot lights that burn the same fuel. Boy, you are sure right about a natural gas orifice being bigger than LP, A LOT BIGGER. even the ones for home water heaters have huge 1/16 inch or bigger holes in them, way too big for now, would be a realy high flow rate.

Vacuum -- From this early testing I don't think this is nescicary. The oil/water is under 150 pounds pressure as it emerges from the orifice, the water flashes into steam and increases many times in volume adding even more pressure. This pressure will follow the route of least resistance, due to the gooseneck oil outlet being some distance under the surface of the oil the least resistance will be up and out of an opening in the top of the flash tank and down into the steam condensing tank, just below the surface of the condensed steam water.

Gotta clean and filter another 250 gallon or so of oil before I get back to testing.

Hi, Tim--
For spray-nozzles, try makers of furnace nozzles for diesel fuel--Some makers like Delevan, make nozzles with a hole around quarter of an inch, and all sizes and spray-angles/pressure ranges up to that size.

For cleaning the tallow/glyc glop after you have drawn off the good oil, just place in cone-bottom reactor, heat the whole lot up to say 50 degrees, while mixing, then add a little more glyc, mix a while more, settle overnight at between 40-50 degrees, then drain the glyc/crud/water. Dry the oil left (which shouldnt take long) and titrate/react in the usual way.

How about Carbeurator jets? You could either go large with a set from "Holley" or go small with mikuni 2-Stroke carbs? Use an electric fuel pump for injected engines (high Pressure) and run the BD through steel or braided stainless fuel line. Try http://www.Jegs.com or http://www.Summitracing.com for all kinds of fuel pump jet/nozzle accessories. We are pumping fuel here so instead of modifying items that are not designed to do what you want, just get the items that have millions of dollars in engineering already done to produce your desired results. I am not trying to be a weiner here, but as I started reading this thread that is the first thing that came to mind. If you need smaller diameters than fuel jetting provides, take a look at some torch tips for Ox/acetylene torches. hell most even come with tip-cleaners, the are already threaded in NPT so there leak proof. Maybe even look into "NOS Systems" they are a Nitrous oxide kit company they have almost anything you could ever want for this task. (I am a serious gearhead, so most solutions I suggest are from the automotive industry) I hope this has been helpful.

I have a bit of concern about the ignitability of our heated oil. I've dealt with combustibles for years but was fairly shocked when I was at the OSHA Institute and they demonstrated that when a combustible is sprayed in a mist, the flashpoint is much lower. The atomizing of the spray really makes a difference.

Granted, it is heated but no ignition source is present (hopefully) and the auto-ignition temp is way up there. But, the span between the boiling point of water and the flashpoint of the vegetable oil may not be as much as at face value.

As for the pump flow rate, I regulate the flow through my stack of bag filters by adding a T which diverts excess veggie back to the drum of 'dirty' oil. A gate valve gives plenty of adjustment.

Todd T