Author Topic: Upgade from drip system to hot oil vapor/air blower  (Read 1041 times)

Rapidrob

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Upgade from drip system to hot oil vapor/air blower
« on: December 15, 2019, 09:04:10 pm »
I've been running my stove I built as a drip system for several years now. It worked very well but had one draw back, the stove took more than an hour to reach 250 degrees F to turn on the circulation fan.
I needed heat fast to warm my shop.
I saw how to make a forced air drip feed system that is so simple to make its amazing.
The amount of heat the burner produces has to be felt to be believed. The burner is a simple steel pipe with a 90 degree bend firing into a Dodge Truck rear brake drum.
Oil is dripped into a 1 1/4"  steel pipe via a 1/4" pipe cut at  a 45 degree angle and the cut is placed towards the brake drum.
The pipe is directing air flow from a Hot Tub Bubble Blower. The blower is controlled by a Harbor Freight 120 volt motor speed control.
The rushing air passing the 45 degree 1/4" drip pipe end causes a low pressure to form. This pulls the oil out of the pipe as an oil fog and blast it into the red hot brake drum where it flashes into white/blue flame. The burn is complete leaving no ash and there is only smoke at start up.
Starting is by a shot of Diesel in the brake drum and light. The flames heat the end of the burner until it is hot enough to flash the oil fog to self ignite and spread the heat into the brake drum and stove body.
The stove now reaches 450 degrees F in 8 minutes! And the stove weighs 450 pounds. Adjusting the drip feed keeps the stove at this temperature all day long.
Running full oil feed will heat the stove to excessive temperatures in 20 minutes . I stopped the feed at 650 Degrees F.
The heat melted the copper Diesel feed start up line. I need to replace it with Stainless Steel tubing.
I will also install a Fail-Safe Blower Hi Limit control that will kill the blower power and stop the air flow.


'Nam  Vet
President NM MILSURPS

smichaelR22

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Re: Upgade from drip system to hot oil vapor/air blower
« Reply #1 on: December 17, 2019, 04:37:04 pm »
nice work! 

smichaelR22

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Re: Upgade from drip system to hot oil vapor/air blower
« Reply #2 on: December 17, 2019, 04:37:52 pm »
about what gallon/hr are you running at? 

Russ

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Re: Upgade from drip system to hot oil vapor/air blower
« Reply #3 on: December 17, 2019, 09:12:10 pm »
Wow, yea that sounds like it is putting out some serious heat.  Thanks for sharing!

Rapidrob

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Re: Upgade from drip system to hot oil vapor/air blower
« Reply #4 on: December 17, 2019, 10:29:48 pm »
Fuel burn is about 5 gallons in 9 hours with this burner at the air flow set to minimum. If I was to restrict the air flow more I may be able to get 11 hours. The air flow now is so efficiently burning the oil that you have to keep the fuel drip at a slight trickle or the fire will be blown out by being too lean. There is no ash in the brake drum as it is "Cherry Red" all of the time as it is running. There is a slight odor of combustion as my fire door is not air tight.
This burner is a prototype and I will see just how well /not is works. The blower is quite,the oil burning is a fairly loud roar in the stove. You can hear it clearly outside.

 
'Nam  Vet
President NM MILSURPS

Oilburner

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Re: Upgade from drip system to hot oil vapor/air blower
« Reply #5 on: December 19, 2019, 06:27:31 am »

Seems like you got it running nicely.
I have always preferred forced air ( blown) type setups over draft for the reasons of cleaning and flexibility in the power you can get out of them. Draft is always limited in that you have to have a certain size fore to create enough draft and heat or that you max it out. Not saying it doesn't work, clearly it does but forced air works so much better.

You are averaging roughly about 20 Kwh out of the heater at the fueling rate you are giving it which is the same as a mid size wood stove will produce. The nice part is you can easily quadruple that at start up to get the chill off and then back it way down to sustain the Heat.
Being a heavy set up it will radiate the heat gently and not be too temperamental. I'll bet you are able to shut it down some time before you are finished in your shed and the stored heat keeps the place warm for a good while.

What size tank are you using and do you have to adjust your flow much as the fuel is used?  This is one reason I like a dosing type pump arrangement. The fueling is the same wether the tank is near full or empty. If you are working around it and giving it a tweak every so often insn't a problem, so much the better.

I am wanting to get started on the oil heater for my house but I'm a bit premature.
40O C here today and the 737, DC10 and other jet water bombers were flying over every 10 Min  for the fires burning not 20 KM away. Between the smoke that looked like thunder clouds only far more sinister and the Jets running low level steep turning passes overhead, place looked like the set of a doomsday Movie here today. Saturday is supposed to be worse with temps of 45oC plus.
 In American Terms that's ummm, Forking  damn hot!

With a bit of Luck the smoke won't be as bad tomorrow and I'll be able to see the back fence again.
Not really weather to be constructing oil burning heaters and firing one up would rightly have one shot by the Neighbours long before the police arrived to take me away.

Nice setup and I'm glad it worked out for you and hope the suggestions were of some help.

Rapidrob

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Re: Upgade from drip system to hot oil vapor/air blower
« Reply #6 on: December 19, 2019, 08:54:28 am »
I preheat the stoves burner with about 1/2 cup of old Diesel. This gets the brake drum burner and oil feed very hot with the air off.
Once the oil supply pipe is hot I have a parasitic pump that will give the burner a shot of oil via an adjustable timer. This way the same amount goes into the burner no mater what the oil level is in the supply tank.
I have on order a magnetic high limit switch in case of a run-away-stove. The oil feed and air will be shut off.
I found that a tank holding 5 gallons ( 19 liters) is about right. My tank can be removed from the stove in a matter of seconds for cleaning and the weight of a full tank ( steel paint can) is about what I can lift without spilling.
The tank is 250 m/m from the stove to heat the oil and always allow the oil to flow no matter how cold the oil is initially.
Once the stove is at operating temperature a thin sheet metal shield is placed between the tank and the stove.
The shield catches the air from the automatic  room fan and helps divert it into the shop where I work.
The forced draft blower is a Hot Tub bubble blower. (see photo) It is on a motor control for speed. The one I'm using is actually too powerful, and I could have used the 3/4 HP version. You could enclosed a 4-6" Muffin-Fan and have more than enough air through a steel pipe at the burner.
Sorry to hear about the fire.
I live at 7,000 feet on the side of Thunder Mountain and fires are a real threat . Smokey Bear was from an area 100 miles south of my home. I hope you and yours will be safe.
'Nam  Vet
President NM MILSURPS