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Oil burner consumption

Posted: Sun Jun 16, 2019 12:34 am
by Lopez Mike
I am considering buying one of the Beckman Boatworks forced draft oil burners for future longer distance travels. I'm quite happy with wood for most of my steaming but there are times when I just can't cram enough wood in the boat.

I'm looking for user experiences. I gather that the electrical draw is around 4 to 5 amps when firing. What I don't have a feel for is oil consumption. I realize that there are enormous variations in boat size and weight and power plant size and efficiency. But I can make an effort to correct for that.

My boat is under 2000 lbs., 25' overall, 3 x 4 single cylinder with a VFT-30, condensing but no vacuum pump. Easily driven.

Any experiences or just plain guesses greatly appreciated. I need to start planning for tankage.

Re: Oil burner consumption

Posted: Sun Jun 16, 2019 6:35 am
by TahoeSteam
Mike, on my 2200lb 22' launch I get about 8mpg or 1gal/hr of kerosene with 4 adults onboard, a 7hp compound, and a highly efficient monotube boiler.

On the 16ton 40ft big boat we get about 5-7gal/hr of #4 fuel oil (or vegetable equivalent), a 30-40hp compound, and 100sqft/hs Worthington watertube boiler (additional 45sqft/hs in economizer).

In fact, we just completed a 55 nautical mile, 9-1/2 hour trip in the Delta today and burned 47gallons of the sweet stuff.

For your get-up I'd think somewhere in the range of 1-3gph would suffice.

Re: Oil burner consumption

Posted: Sun Jun 16, 2019 6:58 am
by RGSP
My boat uses about 10 litres of kerosene in a day's steaming. 20' boat, around 3000lb displacement, Stuart 6A engine and a 3-drum water-tube boiler with feed preheater.

Re: Oil burner consumption

Posted: Sun Jun 16, 2019 7:42 pm
by Steam Captain
Hello RGSP,

Do you have any, at least rough mpg estimations to make your numbers more comparable with the ones posted before by the others?

Or if it is possible to write the heating surface + oil consumption + steam generation. This might be a good way for comparing - especially together with boat specs.

Re: Oil burner consumption

Posted: Sun Jun 23, 2019 10:02 pm
by barts
If you know how many lbs/hour of wood your plant consumes, you can easily calculate estimated oil consumption.

https://mha-net.org/docs/v8n2/docs/WDBASICS.pdf

Assuming about 7000 btu/lb of air dried wood and 140k btu/gallon of diesel and 7 lbs of diesel/gallon,

Estimated burn of 40 lbs of wood/hour is going to result in 2 gallons (14 lbs) /hr of diesel.

- Bart

PS: So 16 gallons of diesel would permit 8 hours of steaming, and occupy perhaps 2.5 cubic feet of space, as compared to the wood, which (assuming dry fir) would occupy perhaps 17 cubic feet.

Re: Oil burner consumption

Posted: Tue Jun 25, 2019 4:12 pm
by fredrosse
The FAQ section of this forum has details of the power plant end of steamboating. Estimating the power needed according to hull size displacement and cruising speed, figuring the power available from steam engines, the engine's steam consumption, the sizing and performance of boilers, and their fuel consumption.

Re: Oil burner consumption

Posted: Tue Jun 25, 2019 5:48 pm
by Steam Captain
I understood Mike like he wanted exactly not to ask for calculations, as I am sure he is able to do himself, but get solid,practical experiences with oil burner consumptions.

Re: Oil burner consumption

Posted: Sun Aug 04, 2019 1:20 pm
by malcolmd
Befur (27ft) uses a 1.75Gph burner nozzle on Diesel and runs a duty cycle of about 75:25 (on v off), driving a Leak Compound.

recent details of Burner/consumption here: https://sy-befur.co.uk/2019/08/03/a-goal-achieved/

Re: Oil burner consumption

Posted: Mon Aug 05, 2019 5:06 am
by Lopez Mike
Thanks Malcolm. Figures out to around 3 g.p.h. in imperial units. And comparing boats my little launch should use more like 2 or less.

Makes me appreciate my 25' I.C. powered cruising boat that burns just over a liter per hour at 5 kts.

Which supports my long standing assertion that pursuing efficiency at the expense of simplicity doesn't make sense, at least for me. Our steam boats are floating energy crime scenes. So what? When I'm moving silently along at five knots or so, I care not about entropy/enthalpy diagrams.

"Peel me a grape my dear!"

Re: Oil burner consumption

Posted: Mon Aug 05, 2019 8:02 pm
by RGSP
Lopez Mike wrote:
Mon Aug 05, 2019 5:06 am
Which supports my long standing assertion that pursuing efficiency at the expense of simplicity doesn't make sense, at least for me. Our steam boats are floating energy crime scenes. So what? When I'm moving silently along at five knots or so, I care not about entropy/enthalpy diagrams.
Yes mostly. My exception covers the difference between a high-pressure twin, and a compound twin (assuming condensing, which is essential for many of us for water quality reasons - e.g. salt). The simple twin will need a substantially bigger boiler than the compound twin, which is very significant in relation to the displacement of a small-ish launch.

I don't then think that feed water heaters or economisers are worth the extra complexity, and I can't prove it at the moment, but I strongly suspect that going to triple rather than double expansion compounds has a negative effect for our general size of launch engines, taking imperfect cylinder insulation and cylinder wall condensation into account.

"Falcon", a late Victorian launch that many of us know, used to have a quadruple steeple compound engine, which was certainly not the right engine for the boat. She now (as of this season) has an excellent twin compound, and I will be interested to hear how coal consumption compares between the two engines.