Archive for The Unofficial Mamod and Other Steam Forum The Original Unofficial Toy Steam Forum
Established 2006
The biggest, most popular steam forum around! Accept NO imitations!
We have a growing community of regular posting members who chat about all aspects of toy and model steam.
|
mc_mc
|
Toy Steam Heat Source Experimental TestingWell I probably shouldn't be posting this now having almost finished off an entire bottle of the Jacobs Creek red stuff (very smooth), but here goes anyway, the wine might actually add something after all  .
I have been doing some scientific experimentation to determine the toy steam fuel with the greatest heat output.
On test were: meths evaporation burner, ethanol gel fuel and mamod solid fuel tablets.
Theorem under test: Methylated spirits is the best fuel for generating steam for toy steam engines in terms of heat output.
Experiment Apparatus: A open vessel containing 5ml of water is suspended over the heat source by a 'lash up' of intricate lab equiment (see picture).
Experimental Methodology: A fixed quantity of room temperature water is placed in the warming vessel (15ml measuring spoon) and subjected to a heat source and a timer is started. Once the heat has boiled and evaporated the entire volume water then the timer is stopped. Since the water quantity is fixed and the boiling point of water (at the standardised atmospheric pressure) is constant then the time taken to evaporate the water should indicate the relavtive heating effectiveness of the heat source.
Test 1: Methylated spirits. The burner was filled and then lit and allowed to burn for 1 minute to attain it's mean output temperature. It was then placed under the water vessel. After 4 minutes 45 seconds the last of the water had boiled away.
Once the water vessel had boiled dry it was then cooled back down to room temperature with a wet rag ready for the next run. The vessel was refilled with another 5ml water for the next test (all test water came from the same jug and was kept at room temperature throughout)
Test 2: Solid Fuel. A foil lined tray had a single mamod solid fuel tablet placed upon it and was lit. Again a wait of 1 minute was made to let it fully ignite and get up to temperature. Once applied to the test vessel the water was completely boiled away in 4 minutes 15 seconds.
Test 3: Gel Fuel. The burner tray was relined with foil and this time a quantity of gel fuel was added, I attempted to approximate the same volume of the solid fuel table with the same volume of solid fuel. It was lit (the easiest of the three to light) and left for thirty seconds to get up to temperature (less time because it burns so quickly). The fuel was then placed under the heat vessel. After 4 minutes the gel had gone out leaving about half the water unvapourised. 
During:
After:
Test 4: Gel Fuel. Since the first gel fuel didn't give enough burn time to vaporise the water the experimenter decided to go for broke and empty the rest of the 35ml packet into the burner tray.
This time the gel succeeded in vapourising all the water in a time of 4 min 20 seconds
Test 5: Meths again. Just to make sure the first meths run wasn't a mistake the same procedure was repeated again. This time it took 5min 5seconds to evaporate the 5ml of water. (no idea why it was longer, but the flame does seem to get blown by the slightest draught)
Conclusion: From the experimental data obtained, it seems that solid fuel is the best fuel to use for boiling up water, it beat out the other fuel sources on test. The gel fuel burns too quickly and needs a greater quantity than solid fuel and even then does not equal the results obtained by the solid fuel. Meths seems to be the weakest (albeit longest burning) of three heat sources under test. The initial theory whilst not totally disproved by this experimental data has taken a severe knock.
Recommendations: More experimental data from other sources is required to establish a firm conclusion. The experiment could be improved by using a 'firebox' to shield the meths burner to allow the flame to be in a draught free environment.
|
IndianaRog
|
Mike, fascinating stuff...yet is seems to fly in the face of conventional wisdom and my own personal experience firing a Wilesco D455 vertical with recommended Esbit load vs. using a Bowman meths burner.
I wonder if instead of using the approach you did, if you took a specific engine meant for Esbit and did the following:
(A) Esbit test
1) fill boiler with a measured amount of room temp water
2) fill the tray with recommended Esbit load of tablets
3) time the burn from match lit until the flywheel stops turning on it's own...ie: all the usable heat output has been had from the Esbit
4) let things cool down and empty out the residual water in the boiler and measure it's volume
(B) Meths test
Once everything is cool to room temperature again...repeat steps 1-4 with a full Meths burner instead of the recommended Esbit load
=====================
I think this approach would do several things
- avoid drafts by presence of a firebox
- relate more to how we actually run these things (load up with Esbit or load up with meths)
- give a heat output measure in terms of both water evaporated per test run AND duration of that run in terms of how long it could keep the flywheel turning.
IF you had a pressure guage, you might also find the meths output gave you greater PSI for a certain duration...that was what I think was happening with my Wilesco D455...it was going about 2X the normal rpms I get with full load of Esbit. I have NOT measured pressure in this way, but hard to ignore an obviously screaming engine trying to vibrate off the table so much I had to add a wood base to hold it down!!!
You could use the gel fuel in the same sort of evaluation, but since it did not compete well in YOUR test...I think the remaining contenders are Esbit and meths. I'm betting the meths will win the above sort of evaluation.
If I find myself needing a challenge this week, I might just give the above a go myself. More replications than just one run of each would be desirable...average out the results to a more repeatable
conclusion.
Cheers,
Rog
|
mc_mc
|
I was surprised by the result myself. More data defiantly needed.
All good fun too!
|
IndianaRog
|
Mike, you didn't mix up your meths and Jacobs Creek now did you?
I'm sure Jacobs Creek would have relatively low heat output and if you drank the meths...well, been nice knowing you!!!
In all seriousity...I WILL run my version of the test this week...though I am handicapped with NO camera for a bit, but will have to apply the scientific process in word and deed.
cheers,
Roger
|
mc_mc
|
| IndianaRog wrote: | Mike, you didn't mix up your meths and Jacobs Creek now did you?
|
Unfortunately the Jacobs Creek doesn't ignite (I tested it). and it's even more expensive than solid fuel.
|
old_timer
|
Re: Toy Steam Heat Source Experimental Testing | mc_mc wrote: | Theorem under test: Methylated spirits is the best fuel for generating steam for toy steam engines in terms of heat output.
...
Conclusion: From the experimental data obtained, it seems that solid fuel is the best fuel to use for boiling up water, it beat out the other fuel sources on test. The gel fuel burns too quickly and needs a greater quantity than solid fuel and even then does not equal the results obtained by the solid fuel. Meths seems to be the weakest (albeit longest burning) of three heat sources under test. The initial theory whilst not totally disproved by this experimental data has taken a severe knock. |
I believe the issue here is, that by following the manufacturers instructions and filling the boiler with hot water, then the meths will give the best results as it gives longevity as well as sufficient heat to maintain steam pressure, whereas the solid fuel may give a hotter flame but will expire quicker.
To initially heat the water, I firmly believe an electric kettle is more suited to this task than any of the fuels you have tested.
|
oldstuff
|
Jacob's Creek, intricate lab equipment...funny stuff, mc. 
|
tarbyonline
|
Re: Toy Steam Heat Source Experimental Testing | old_timer wrote: |
I believe the issue here is, that by following the manufacturers instructions and filling the boiler with hot water, then the meths will give the best results as it gives longevity as well as sufficient heat to maintain steam pressure, whereas the solid fuel may give a hotter flame but will expire quicker.
To initially heat the water, I firmly believe an electric kettle is more suited to this task than any of the fuels you have tested. |
I would agree with this. My experience with solid fuel is that it gives a shorter run - probably due to the fact that solid fuel expends most of its energy shortly after ignition, where as meths has a more gradual release. It would be interesting though to see a comparison between different brands of solid fuel tablets (Mamod, Esbit, Hi-gear, MSS).
|
flywheel61
|
Long live Jacob's Creek, well for export anyway, .
Seems to me that the comparitive tests are not too unequal. Unless the tests Rog suggested provide startling differences I'd be looking to use the cheapest fuel source.
Cheers
Chris
|
SPOKESMAN
|
Great work Mc - I think it the burning time of meths which gives it an edge over solid fuel! great work though, maybe further tests may be needed!!?
|
tmuir
|
| flywheel61 wrote: | Unless the tests Rog suggested provide startling differences I'd be looking to use the cheapest fuel source.
Cheers
Chris |
Well for us in OZ Meths would have to be the cheapest source.
|
yosa
|
Great experiment. 
Having tried the Gel, I'm not too surprised at the result, and given a difference of 30 secomds (around 10 %) and allowing for variables, I would class meths and solid tablets as near enough the same, or at least not enough to matter.
Nice work mc. 
|
Mamodman123
|
Very interesting findings MC!
The reason I choose meths is the burn time and the lack of a horrible smell
The problem with solid fuel as when it burns away the flame gets less powerful!  and it stinks
Again, interesting stuff
|
Chris
|
Also in a loco you can top up the meths for continuous runs (with care!), but you can't top up solid fuel so easily.
I nearly always fill boilers with hot water, so the time it takes to boil isn't that important, but I like to get nice long runs and meths I think is better than for that. You can also buy meths relatively cheaply and very easily. Fuel tablets for me mean mail order or a longer drive. I can pick up meths in shops I go to anyway.
Maybe another experiment is to see what burns longest out of a vap burner and a couple of tablets. The gel fuel would be out of the running with that.
How about a cost per minute burn comparison?
|
|