Dickenson Heater Report

[Roger Long]

I finally fired up the Dickenson Newport heater. There definitely is a learning curve to starting them up and one point on that curve is having the glass window soot over so that it obscures the fire as well as a cast iron stove door would. After that, whatever is going on inside is sort of a mystery but it did get warm. I was able to confirm that the flames were above the burner ring before the view was obscured.

I ran it for about an hour and am a bit concerned not to be able to see any evidence of the water coil getting the least bit warm. The flue is too hot to touch more than a lick so there is plenty of heat but, with the circulating pump running, the copper pipe between the stove and the PEX tubing loop to the hot water heater didn’t even lose its chill. I could hear water running through the tubing at the circulating pump aft and tried throttling it down to minimum flow but no change.

It’s only a short trial and I’m still at the stage where I could have air in the system so I won’t lie awake all night. The hot water part of this was half the cost of the whole system so I sure hope it works.

http://www.rogerlongboats.com/10Winter.htm

Until the window soots up, the flames sure are pretty.

 

[DeniseO30]

Roger... my guess is the heater has to operate quite a long while to heat water. Looking at the coil it's very small. the heater only has a high output of 16,250 btu must only give maybe 20% of that to water heating? the specs on the coil's btu transfer to water don't seem to be included in the manual. (I can guess why) I would not expect it to work anything like a "tankless" water heater design. Your working with a very small amount of heat and large volume of water. You may want to try a tank by-pass and see how the water heats just flowing slowly through the coil. If you have air in the system you may need to determine where it's getting trapped and where to put vents.
the burner setting seem to be critical also.. Twas always a problem with those type of burners.

From the manual:
Flooding Burner
A vaporizing oil burner of this type can be flooded if care is not taken to prevent excess oil
entering the burner when lighting. By following the lighting instructions flooding will be
avoided. A flooded burner that is still burning should be turned off and the heater monitored
until the oil has burned off. Use the combustion assist fan to add air to fully combust the
excess fuel.
Causes of burner flooding:
Fuel entering the burner faster than it is burning.
Increasing the fuel supply too quickly without use of the combustion assist fan.
Poor draft and/or ventilation.

Very impressive engineering job!

 

[Roger Long]

my guess is the heater has to operate quite a long while to heat water.

I was expecting to only have hot water on long rainy days at anchor with a day or so to get the tanks warm. That's when I'm most likely to take time for a shower, washing some clothes, etc. Not finding the coil output pipe even warm after an hour makes me wonder if that might be rainy *weeks* at anchor, though.

There have been semi-substantiated reports of people getting hot water from these heaters so I'm hopeful.

 

[palacegrand]

Roger, as always a phenomenal looking job. Your photos that you document your projects with are soooooooo helpful to the rest of us.

Regarding the lack of water heating, my initial reaction was an air lock somewhere. One tiny little bubble .....
But then I started wondering along the lines of Denise's hypothesis, such a small percent of actual btu's. Did you have the small circulating pump running? Maybe it's moving the water through the coil too fast? Or not fast enough?

just my 2 cents
jcm

 

[DeniseO30]

Roger, if you hear water moving in the circulator, it's air. Also a circulator is not a pump in the traditional sense, it only moves water if water is on both sides. It's not a pump that pushes water up with or against pressure. Air, of course will always gather at the high spots.

 

[Roger Long]

I tried scooping Sterno out of a can today and putting a tea spoon on the bottom ring and another on the top platform of the removable burner frame. I also smeared some on the super heater ring.

It worked very well with no smoke in the cabin or need to reopen the door. However, the Sterno seems to leave an ash residue that became the substrate for a large build up of soot where I put it on the superheater ring.

I still haven't found the magic combination that keeps the window from sooting up but I can see progress. I learned that , by turning the oil off briefly and back on just as the flame die down, you can open the door (with gloves) and quickly wipe the window with a paper towel. However, soot flies every where. And I was worried about stove ashes Normally, I wouldn't worry too much about seeing the fire, but I needed a clear view today to assess what I was doing.

BTW, am I correct that, when the manual refers to flames being above the top of the burner, they mean the main body and tops of the flames? It looks like the base of the flames will always be below the top burner ring and just inside the pot.

A hint I got from a visitor today about dealing with the fine soot (with a cold stove): Spray a paper towel with Windex and hold under and in front of the opening. Most of the soot that flies out will stick to that. Then spray the inside
with Windex to fix the soot before trying to remove it.

 

[Roger Long]

Roger, if you hear water moving in the circulator, it's air. Also a circulator is not a pump in the traditional sense, it only moves water if water is on both sides.

I understand that about the circulator pump. Mine is one of those single moving part El Cid units intended for solar collector circulation. I think I've gotten all the air out now. I have a bleed fitting (not shown on my schematic) at the top of the inlet to the hot water tank heat exchanger which is downstream from the pump. This is well below the bottom of the bulkhead tank so I have reasonable head pressure to push the air out but the convoluted tubing runs forced by existing boat architecture leave plenty of places for air to collect.

I heard some noises from the circulating pump today that sounded like air bubbles going through and these seemed to follow the water coil boiling and bumping. It doesn't seem to me that a steam bubble could last through 12 feet of tubing. Am I wrong about that?

BTW I did use the PEX tubing with the O2 barrier. I don't know where air could be getting into this system. The bulkhead tank acts like a large expansion tank for the circulating loop and keeps a good head on it. This head is equally distributed to both sides of the circulating pump so it doesn't have to work against it.

 

[Roger Long]

Regarding the lack of water heating,

See "It Works!" post.

 

[Roger Long]

Don (at Dickenson),

I found the hinge mount bolts with better light but they are immovable without unmounting the heater for access to the fan controls to disconnect and removal of the shroud.

However, with the heater cold, I was able to turn the door closing screw enough to bring the door tight. It got a bit easier with repeated cycles as the "Z" bracket that holds the hinge is evidently bending slightly. I fired up the heater and it burned perfectly, was easy to adjust, and fairly forgiving with no sooting evident. Door air leakage was the problem.

The brass thumb screw is showing signs of thread flattening and deformation due to the high loads so needs to be replaced. The harder S.S. socket appears to be OK. If you will send me another thumb screw and retaining clip, I think I will be all set. Since this heater will always be operating with a great deal of strain on the door closure, a spare screw would probably be in order.

The superheater core appears to be fitting the bottom well and the burn is good. It got pretty well cooked though so it might be good for you to send me another. Use your judgement.

Thanks and best regards,

Roger Long

 

[sailingdog]

Roger—

What we all really want to know is does it roast a mean marshmallow???

 

[DeniseO30]

geeze.. sorry that thing is built so shabby Roger. Were the hinges bent? At least you found where the air was getting in!

 

[Roger Long]

geeze.. sorry that thing is built so shabby Roger.

It's actually built pretty well. The hinges have slots and are supposed to be adjusted during assembly. I've learned over the years that even the best quality control slips up occasionally. There's always the day that someone shows up at work with a hangover or the morning after their wife ran off with someone else.

It's certainly better quality than much of the stuff I had to trust my life to back when I was flying small aircraft. If I were doing this project again I wouldn't consider a different heater. The only thing I would do differently so far would be to put a hooded opening in the metal stove mount that would take a small computer fan to pump some air into the head. The back of the Newport is much cooler than I expected from people talking about their experience (evidently with a different type of heater), a good design feature.

The temperature gradient people have been talking about is very dramatic, especially with that bulkhead tank. I need to find a place for a fan and duct to suck air from the ceiling down to the floor but that's a separate issue. BTW I had my electric hot water heater going today and the natural convection bulkhead tank gets hotter than the electric after about three hours. With all the radiating area, I think it will stabilize at a reasonable temperature.