How to argue that a grease pan on fire is or is not a good oil burner?

cowdog

Today I did some experiment with silica gel heavy oil burner, and it indeed burns if the silica gel is preheated to red hot before adsorbing the heavy oil. Silica gel is a good wick for heavy oil.

Smokes a lot though, but I suppose this can be improved by leaner oil/air ratio and an insulated firebox.

However, my friend watching the experiment argued it's nothing different from a grease pan on fire, the flame does not even look like oil burner flame.

So, why is a "grease pan on fire" not a good oil burner? What are the key characteristics / performance measurements of a good oil burner?

Jamie Hall

My first reaction was "say what?"! But on reflection, it's not as off the wall a question as one might think. In fact, at the risk of oversimplifying, I think one could sum it up in one word: control.

That is a little simplistic, I'll grant, however by control I mean that the heat output of a good oil burner is known and constant, or if variable, variable over whatever range is available at will. That the air to fuel ratio is controlled at all times to maintain a close relationship, and one that is as close as reasonable to optimum for most efficient conversion of the energy in the fuel to heat. That the combustion flame characteristics (overall size, dimensions, etc.) are reasonably constant.

Steamhead

Also, how would you shut down such a device quickly if something went wrong, as the safety controls on standard oil burners do?

cowdog

Steamhead said:

Also, how would you shut down such a device quickly if something went wrong, as the safety controls on standard oil burners do?

Shut down both oil drip and air supply?
I think for slightly larger burner we need to blow air into the silica gel, so air supply is the constraint here, we can design the burner so outside air don't easily flow into.

Standard oil burners shut off oil flow. 

Steamhead

cowdog said:

Steamhead said:

Also, how would you shut down such a device quickly if something went wrong, as the safety controls on standard oil burners do?

.........................Standard oil burners shut off oil flow. 

Standard burners shut off oil flow, air supply and (where ignition runs all the time burner is running) ignition if something goes wrong.

EBEBRATT-Ed

To be a "good" oil burner the fuel has to be atomized (broken up into small droplets) by some method, pressure atomization for light oil, air atomization, steam atomization or centrifugal force (rotary burner) for heavy oil or a vaporizing "pot type burner" which vaporized the oil with heat

Once it's atomized it has to be mixed with air before it is ignited, the better the mix the better the burn.

You can't just dump it in a pan and set it on fire. Will it burn without being mixed with air first? Yes.

But it will make more soot and smoke than heat.

The only burner that used heat alone to atomize (actually vaporize) the oil which was marginally successful and never popular was the "pot type" burner

And even those could only burn kero or #1 oil

Jamie Hall

To follow up just a little on @Steamhead 's comment -- which is a critical part of control. You need to be able to shut the burner off -- completely -- virtually instantaneously in the event of a problem. As has been noted, in "standard" burners one shuts off the fuel and air flows, but it must be noted that not only is the fuel flow shut off -- but there is no remaining fuel. I have an impression that your silica gel arrangement is going to have considerable fuel in it after the drip or other flow is shut off. It might be possible to design a fail safe system to also completely remove access to additional air -- but it would have to be such that it activated on loss of power.

BDR529

Now put it in a sealed vessle and see what happens.

cowdog

Jamie Hall said:

I have an impression that your silica gel arrangement is going to have considerable fuel in it after the drip or other flow is shut off.

You are right, because silica gel is porous and will adsorb oil on its surface, 10-20% to its own weight, so there will be some oil left in there after drip is shut off.

The best work condition is not to saturate the silica gel, rather keep the silica gel relatively dry so air and oil will react on its surface, which requires drip speed control and maybe mechanical stirring of the silica gel. In this condition, not much oil is left on the silica gel.

retiredguy

When you say heavy oil, are you speaking of Bunker C or #6 oil. If so, how do you get these 2 oils to drip? I would like to ask what are you trying to accomplish or invent? When burning oil as a fuel you need to vaporize the oil first as a wick can do, then add a controlled amount of air to mix with the flame to produce a "clean burn" with the least amount of excess air. When it comes to burning oil with a wick to produce heat or light, my only memories are being with my Grandfather at his camp in the 1950's, and him using his wick stove to cook dinner and his lantern for lighting.

cowdog

retiredguy said:

When you say heavy oil, are you speaking of Bunker C or #6 oil. If so, how do you get these 2 oils to drip? I would like to ask what are you trying to accomplish or invent? When burning oil as a fuel you need to vaporize the oil first as a wick can do, then add a controlled amount of air to mix with the flame to produce a "clean burn" with the least amount of excess air. When it comes to burning oil with a wick to produce heat or light, my only memories are being with my Grandfather at his camp in the 1950's, and him using his wick stove to cook dinner and his lantern for lighting.

Yes. Bunker C or #6. There needs to be a preheater. I want to invent a reliable heavy oil and waste oil burner affordable by even the poorest Americans.

retiredguy

@cowdog said "Yes. Bunker C or #6. There needs to be a preheater. I want to invent a reliable heavy oil and waste oil burner affordable by even the poorest Americans". I have to ask WHY? Where are they going to get the fuel in any quantity and what will be the savings and payback. It sounds like a waste of time to me but that may be your dream. Burning heavy oils are only cost effective in an industrial setting and only if you can burn enough of it. Other than that, the maintenance is way too costly.

ratio

It's already been done. Google "Babington burner".

cowdog

ratio said:

It's already been done. Google "Babington burner".

Babington burner is a good design but based on different principles. Silica gel is like a wick with microscopic surface area.

cowdog

retiredguy said:

@cowdog said "Yes. Bunker C or #6. There needs to be a preheater. I want to invent a reliable heavy oil and waste oil burner affordable by even the poorest Americans". I have to ask WHY? Where are they going to get the fuel in any quantity and what will be the savings and payback. It sounds like a waste of time to me but that may be your dream. Burning heavy oils are only cost effective in an industrial setting and only if you can burn enough of it. Other than that, the maintenance is way too costly.

I don't know, maybe off craigslist? If there are people who want to buy, there are people who want to sell, right? The savings could be 40% of their fuel cost compared to #2 heating oil.

bburd

Most industrial and large commercial facilities designed for heavy oil (#4, 5 or 6) have converted to #2 or gas due to air emissions regulations.

EdTheHeaterMan

I drove a 1955 Mercury to high school in 1973. Now that was a real oil burner. You could see me coming a mile away and smell me for 15 minutes after I passed by. I used to get about 30 miles to the quart.

Does this qualify for this discussion?

cowdog

bburd said:

Most industrial and large commercial facilities designed for heavy oil (#4, 5 or 6) have converted to #2 or gas due to air emissions regulations.

Good point, after losing the industrial/commercial customers, we can market 4,5,6 to residential instead?

cowdog

EdTheHeaterMan said:

I drove a 1955 Mercury to high school in 1973. Now that was a real oil burner. You could see me coming a mile away and smell me for 15 minutes after I passed by. I used to get about 30 miles to the quart.

Does this qualify for this discussion?

Yes, and how did you source cheap oil? Did you get a 55 gallon barrel of waste motor oil and top up with WMO every 30 miles?