Dickenson Cook Stoves

[Vino the Dog]

Yesterday, sun came out, and I shut down the Dickinson to add 3' of flue pipe. Now it extends 2 ½' feet over the boom. Cutting three feet off the boom won't make the boat sail any better, so this is not a solution, but another good experiment. Will report the results after observation.

Meanwhile, let me show you what else happened:

I had not cleaned the pot for two weeks, so decided to vacuum it out, check air holes, fuel feed and clean the mica view port. The soot build up was substantial, but a very fine particulate, easy to suck up. I was focused on the job, so did not look up until my friend began to cough. When I looked up after less than ten minutes, the entire cabin was filled with dark, black, soot from the exhaust of the vacuum cleaner. I never imagined that fine soot could pass through a vacuum cleaner filter and fill a room with smoke. I suspect something similar to this may be one of the reasons why many who have had bad experience with Dickinson stoves absolutely HATE them.

Someone already posted that it took him over a year to clean his boat after a Dickinson experience. I thought he was exaggerating, but now sorry I suspected his comment. I believe it virtually impossible to ever clean all the filth from this. Obviously, I can clean it up enough to live with, but this stuff penetrates deep into EVERYTHING.

After leaving the boat for a couple hours to let the smoke settle, I spent three hours cleaning the dirtiest places, and vacuuming the rugs, then put blankets over them so my dog could sleep without inhaling the remaining soot that can't be removed without having the rugs cleaned. I love my dog and don't want him to get terminal lung cancer from breathing soot.

For you who like to ridicule - yeah, I already know... it is my fault cause I did it wrong.
I am just showing what happened. You are welcome to draw your own conclusions.

Attached photos:
1. Extended flue pipe. 2. Soot at the base of the flue. 3. Soot filling the air of the cabin, from the exhaust of the vacuum cleaner. This is NOT a dirty camera lens, it is just how the camera recorded what was in the air. 4. Soot on a new Bic lighter. 5. Soot on the cabin ceiling after wiping with a sponge. 6. Soot on the top my sewing machine (Have you ever tried to clean soot from a complex machine? Can't be done without disassembling the whole machine to clean each little part.)

[JPA Cate]

Gosh,

I read your story with great trepidation because I, too, would f*** with stuff, maybe changing more than one thing at a time (Oh, when will I ever learn?).

I really hoped that when you got around to experimentally extending the flue, it'd work right, and all your trial soon be over. ....DANG!.... Now, why didn't that work? Too much fuel to the air? still? Is it possible it still needs an air boost? [My simplistic thinking is that too much fuel = soot, but may be wrong, I'm not good at this stuff.]

Good luck with it mate.

Ann

[cburger]

I have been having problems with a chronic throat problem that gets so bad that I can't talk, had to go to the specialist Dr. to have a scope put through my nose to have a look see, good news is no evidence of cancer. I have come to the conclusion that the Dickinson is effecting my health as I have evidence of soot in the cabin again, the bitch is getting ready to get really cold in NY again and will need the damn thing to stay warm. I am convinced that the issue is the flu as I am not able to have a straight run of pipe and have two 45's within the first 2.5' of the run. Evidently with the special baffle, barometric damper installed and the combustion assist fan running as Dickinson recommends the combustion is not as clean as it should be. Thinking about ripping the thing out and going to a wood stove like a Little Cod.

[Vino the Dog]

Don't none of you folks think for a moment that I am wallowing in self pity and anger over the extreme disfunction of my Dickinson installation. That ain't my style. I prefer seeing misfortune as incentive to learn something new. Maybe I am working out bad karma from beating my horse in a past life? Just crank up a little Zydeco on the CD, grab a cold beer, and rock & roll while working on the problem.

The flue pipe extension had very little effect. Some benefit at mid level, a small increase in burn quantity at 3-1/2, but still filthy and draw down above 3. Best clean burn still is between 2-3, and this has been consistent through all experiments. Highest heat production varies from 2-1/2 to 4 and always filthy.

Yesterday, added another 3' extension on the flue to give total of 11' 10" (ridiculous on a sailboat without a pilot house). The results of that experiment totally surprised me. It did NOT improve anything at all! Actually made burn worse at all settings. After 3-1/2 hours, my steamed brussel sprouts were still to hard to eat, so I got out my 2-burner Origo alcohol stove and finished them just a little before the late movie ended.

Today, finishing washing all the upholstery and blankets to get the soot off from the vacuum cleaner fiasco. Next change will be the interior flue modification, but will make sure the stove area is sealed off from the rest of the boat and did buy a new vacuum with a fine particulate filter.

cburger, sorry to hear you are having problems. I have been doing some theoretic research and hate to say, but your comment may be more true than people realize. The soot has a large carbon monoxide and nitrous oxide content. Will start posting some information on combustion principles and equations as soon as I better understand them.

[Panope]

Originally Posted by Vino the Dog

The flue pipe extension had very little effect........

I had the same (perplexing) result when I experimented with different flue lengths. All lengths that I tried worked exactly same (worked great) so I used the shortest possible arrangement.

Steve

[Strait Shooter]

Originally Posted by Panope

I had the same (perplexing) result when I experimented with different flue lengths. All lengths that I tried worked exactly same (worked great) so I used the shortest possible arrangement.



Steve

My experience was the same. I only have 4 feet of flue. I also have two 45* bends in the flue. I kept it as low as possible when I found out that it didn't matter.

I do have to have an assist fan on full time. I also have a pilot house that the Charlie Noble sits below the top of. The stove still burns fine even with all this going on. Setting number one is plenty warm most of the time (the cast iron top heats up to 500*+). I've had it on setting number three when it dipped into the teens around here and had hatches cracked and a port open.

I've been following your plight from the beginning with this stove. Wish I could help more, I just wanted to state the other side of the coin. I really hope you (we collectively), can figure this out.

I have to adjust the assist fan continually for the first 20 minutes or so. If I get the fan adjusted improperly I get carbon. If I leave it to its own devices at start up, I get a run away locomotive as a stove, and I get carbon. I can deal with this by cranking the assist fan up all the way for about 3-4 minutes and the flame will suddenly die down below the metal ring (excessive fuel has burnt off). If I don't turn the fan back down, I get carbon. Adjusting the fuel, and air via assist fan is all I ever have to do. After the first twenty or so minutes it turns into a rock solid heating machine that you could let run 24/7 (and I have).

I remember someone saying that they used alcohol to warm the heater pot, and I'm going to try that next to see if I can get a cleaner start up. In also remember seeing something about adjusting the carburetor using the nut on top of the dial knob. You have a copy of the manual I'm assuming?

Wish I could be more help.

John

[nmuir]

Somewhat late to post to the thread, but.....

I have a Dickinson Antarctic stove - purchased second hand and a bit beaten up. Dickinson gave me great customer service for the input and little bits I needed.

Installed and it has worked well, albeit after I added a damper. I typically run it 72 hours straight with no problem. I do have a pretty straight flue with only a few small 45's. The stack is into clear air above the stern. I do think the right flue cap is important and makes a difference when the winds blows, but that is just my personal theory.

The stove also seems to take an hour to start burning properly and 'find its stride', but once there it is worry-free. Running it short runs at a time would no doubt be frustrating! I also think how warm or cold the fuel is makes a difference, and this might be part of why it takes some time to settle down.

We are very happy and have no issues with soot or blow-back. The ultimate comment is that it has the Admiral's vote of approval!

Good luck! I do understand there comes a time when enough is enough. I hope you can get yours running as well as ours before you get there.

[cburger]

I use methanol, denatured alcohol between 1-2 ounces over the diesel to start the heater up, makes a huge difference in the amount of soot on start up. Pour a little into a small coffee cup and use a turkey baster to squirt into the pot. Like others the height of the flu made no difference so I settled on a length that allows me to sail the boat in the winter with the heater working, fan has to run all the time and you have to be on top of making adjustments to the fan until the stove gets to temperature.

[Vino the Dog]

Ann, (& everyone else),
I too hoped extending the flue would produce a significant difference. Your “simplistic thinking” is not incorrect, just incomplete. Slightly closer might be; (Too much fuel per volume of air + poor atomization of fuel) – (flow rate of flue gas / frictional resistance – thermal damping) = soot. This, of course is also simplistic thinking, but suggests the variables are too complex to apply a simple solution to every boat. They work great in certain configuration of boats and not at all in others. Appears they work OK on fishing boats, trawlers, or larger sailboats with a pilot house but not so great on sail boats under 50' without a pilot house.

More experiments to do on flue, fan, and fuel flow, but so far the MAJOR differences in operation has not been ANY of the suggestions, experiments, nor installation instructions, concerning draft or fuel flow, it has been the temperature on any given day. Works great on a warm day, fails miserably when temperature drops low enough to really need it.

Many suspect flow rate, which seems obvious, but is not really. Dickinson talks about adjusting the metering valve to compensate for viscosity of different fuels by changing the flow rate, but flow rate only allows more or less fuel in. It does not compensate for burn characteristics due to the viscosity of the fuel. The amount of fuel in the pot is not what makes it burn clean, it is how fully the fuel is atomized. Liquid diesel does not burn at all. It is diesel vapor that burns.

Viscosity, is the measurement of internal resistance to flow of a liquid. Assuming an adequate air-fuel mixture and draft, fuel viscosity is the most important characteristic in getting complete combustion. It is the factor that determines what is required for adequate atomization of the fuel. If the fuel is too viscous, it is difficult to light, and will burn poorly, resulting in emission of carbon monoxide, nitrous oxides and carbon deposits. Soot is carbon from incomplete burning.

Dickinson solution to poor operation is blow more or less air on it or add or subtract fuel. There is no mechanism to prepare fuel for complete combustion beyond little sheet metal devices placed above the fuel entry hole. This technology appears to me, only slightly more advanced than burning diesel in a coffee can, which we commonly did to burn slash piles in the logging woods when I was a kid. Then when the slash piles burnt down, we would roast hot dogs. If I can get my stove working as well as burning a slash pile, I will consider it a success!

When you pour diesel in a tin can, an inch or two below the rim, you can safely light it with a match. The flame starts out a lazy, dark orange flicker emitting black smoke. As the rim of the coffee can heats up, the flame burns more seriously and it will burn kind of like a candle, long enough to catch wet wood in the slash pile on fire. Of course there is no flue to worry about and no forced air fan necessary as there would be if the coffee can was put in a semi-sealed box inside the cabin. The coffee can works flawlessly, requiring no adjustment, but only in certain applications.

While they do have some effect, adjustments of stack height, fan use, and metering valve are simplistic attempts to compensate for obsolete design.

Modern fuel oil burners are designed to mix the air and fuel in a way that the turbulence of the air helps to atomize the fuel. The fuel is frequently pre-heated to insure proper viscosity. The Dickinson stove burner is an open pot with holes punched in the side and raw fuel flowing into the bottom through an open pipe. There is no pre-heater for viscous fuel and no atomization. All preparation for the burn is evaporation achieved by those little sheet metal pieces stuck in and around the open hole the fuel enters through. Coffee can technology. Works great if everything is just right. Works lousy if not.

Attachment is a diagram of modern, commonly used oil burner. Look at the air flow and vaporization characteristics, then think about what Dickinson does with a pipe into the bottom of a pot with a bunch of holes poked into the side.

[cburger]

Pot burners like Dickinsons have been around since the turn of the century and the very reason I went for this type of equipment is its absolute simplicity, its like 2 degrees here tonight and I certainly don't want one of the more complicated types of diesel heaters that are on the market with more complexity to break down as well as higher amp draw.

[Vino the Dog]

cburger,
I understand and appreciate that. I am withholding my final opinion until I have one. Meanwhile doing research. Mine stove does not work yet. If/when it does, I may have a final opinion to share. Until then, please take everything I post as nothing more than sharing what I am learning and when I express an opinion, it is related to immediate experience and what I find out. I post for anyone interested to draw their own conclusions and totally respect the opinions of those who have a different experience than mine. Everyone has different standards, expectations, and tastes. That is what makes life interesting. Glad you decided to get back into the discussion.

[Vino the Dog]

How diesel burns as a liquid fuel.

All liquid fuel must be changed to a gas before it will burn. It is the vapor that burns, not the liquid. Thus a liquid fuel will not burn below a temperature specific to that liquid. The lowest temperature an evaporated fuel can ignite when mixed with air is called its “flash point”. The viscosity of a fuel oil increases with decrease in temperature, which makes it difficult to flow or pump. Low temperature not only effects flow rate, it also effects the ability to vaporize the fuel above the flash point. To overcome this in industrial applications, preheating is commonly done by either heating the storage tank or heating the fuel as it flows out of the tank.

At this point, I suspect one of the reasons I have so much problems with my cook stove is that the day tank is located in a lazerette where it does not get heat, and therefore, even with adequate flow, does not get hot enough to vaporize. This will be subject for a future experiment.

Combustion is possible only with an adequate supply of oxygen. In our case, the combustion is called “fire”, which is “rapid combustion” producing heat and light. In fire, air is the source of oxygen, but oxygen is only 20.9% of the air. The remaining 79% is nitrogen, with traces of other elements. Nitrogen is not part of the combustion process.

Nitrogen reduces combustion efficiency by absorbing heat from combustion of the fuel and diluting the available oxygen. It is present only to get the oxygen needed for combustion. It reduces the heat available for use and increases combustion by-products, which have to move up the flue to allow more of the combustible air/fuel mixture.

For ideal combustion, air flow must exactly match fuel flow to give the perfect amount of oxygen needed to react with every molecule of fuel. This perfect amount of air is termed “stoichiometric air” and combustion under such perfect conditions is called “stoichiometric combustion”.

A basic equation to show composition of flue gas resulting from stoichiometric combustion of a hydrocarbon fuel using air as the oxygen source is simplified to:

fuel + oxygen + nitrogen → water + carbon dioxide + nitrogen

Unfortunately, complete combustion is virtually impossible outside a laboratory where every variable is controlled accurately. In addition to air/fuel ratio and matching flue characteristics, the quality of combustion is dependent on the design of the burner. Combustion analyzers can test the efficiency of the burner.

When burning diesel, “pyrolysis” also occurs before combustion. Pyrolysis reactions require constant energy input from the combustion, lowering the percentage of heat recovery. Lack of sufficient oxygen or any other poor burning conditions result in noxious and carcinogenic pyrolysis products emitted in smoke. “Non-radical intermediates” such as carbon monoxide are products of incomplete combustion. During the incomplete combustion taking place in our stoves, nitrogen also combines with some of the oxygen to produce oxides of nitrogen, and carbon monoxide, both of which are highly toxic pollutants. Sulphur also combines with oxygen to form sulphur dioxide.

This is what we breathe when the stove experiences back draft, leaks, or any time you can smell the exhaust from your flue. It is what dominates the taste of something baked in a poorly operating stove and what covers everything in the boat in instances of smoke saturation such as I have had to deal with three times now, and it is that common diesel smell that so many sailors are readily identified by when walking into a restaurant in a new port.

Any of you with a background in chemistry or thermodynamics, please correct any errors in the above. I really would like to know.

Thanks,

[Panope]

Vino Dog,

Thanks for sharing your findings concerning this mystery.

I will keep posting any experience that might be relevant in the hope that it may give you another clue.

My day tank is mounted very close to my furnace. Although the furnace always lights and burns clean even when the boat is below freezing, I do notice that the flame height increases after several hours of running. In my case, the fuel line from day tank to the furnace is very short, so the "warm tank" idea is surely a factor.

I am thinking that because the fuel flow for these units are so small, that (for installations with long fuel lines) by the time the fuel travels the length of the line, the temperature difference may disappear. This assumes that a good portion of the fuel line is in "heated space"

If your fuel line is in "unheated space" you might consider further lengthening your line by adding loop or coil of copper tube somewhere in a warm area.

Steve

[Vino the Dog]

Since my last post, having discovered the second extension of the flue pipe was counterproductive, I removed it, going back to the first extension. Then, I pulled out the interior section of the flue to extend the first section above the stove top, which was only 10” before beginning the 45 degree bend, now up to 13” before the bend, the maximum I can get without the flue in contact with wood. The theory behind this is that at least 12” straight flue is required to allow flue gases to accelerate before reaching any bends.

This task was preceded with a thorough cleaning of the entire flue pipe, at which time I used my brand new special purpose vacuum cleaner with its fine particulate filter bag to suck up the soot. This helped prevent the entire cabin filling with soot, but still required a couple hours cleaning around the galley. Turns out that even if you can't see it and do use a fine particulate filter, a lot of soot will inevitably blow out the exhaust port of a vacuum cleaner.

Now, I am curious to know; how many of you clean around your stove immediately after cleaning it, and do you use white rags so the quantity of soot is easy to see? What are the results?

I found, that even with extreme care taken, the soot extends clear through the cabin and into the stateroom, penetrates louvred vents in cabinet door and lands on everything exposed.

You may (or may not) be surprised to find... increasing the length of the first flue pipe above the stove made no difference at all!

Next will be fiddling with the fuel metering valve, which I already know is getting adequate fuel flow, but have only tested it under fairly warm, daylight conditions.

Attached photos:
1. Ridiculously high stack for a sailboat, approximately equal to cousin Mel's fishing boat (his stove works very well)
2. Highest burn with interior flue modification,
3. Lowest burn (consistently alternates between these two levels, always draws down to lowest with any use of the fan).
4. Full bag of shop towels saturated with filth from cleaning only the galley area.
5. Example of filth deposited on counter top.

[Vino the Dog]

Panope, thanks for your info. My fuel line is below cabin sole, in unheated space. Suspect this is indeed part of the problem and thought about a couple of copper coils between where it emerges above the cabin sole and enters metering gage. I have three different metering gages, each have slight differences. Will exchange them and use the one that works best first, then make the "fuel preheater".

I totally appreciate your contribution to this discussion. And, looked at your blog. The work on your boat is excellent! Hope some day to have the opportunity to see it in person.
thanks

P.S. forgot to post pic of the modified interior first section above stove. here is its.