Monday, January 9, 2012

Let there be light! And heat!

You may have one of these fairly ubiquitous Dickenson Newport heaters aboard.  I hope you are familiar with the process for lighting it, but if you are not or you struggle to get it lit, here is the process we have developed on Eolian over the years:

This is a "pot burner" type of heater.  That is, the diesel is admitted into the bottom of a "pot", where the heat of previously burned fuel vaporizes it.  Once going, it is diesel fuel vapor which is burning, not liquid.  But to get it going, it is liquid diesel which much be ignited.

Go to the head and get 4 squares of toilet paper.  Roll up three of them into a loose roll, leaving the fourth as a tail.

Open the door on the Dickenson, and use the rolled up toilet paper to wipe off the soot from the last use from the inside of the glass

Drop the paper into the heater.  You will note that there is an internal baffle device in the burner - this serves as a heat reflector which, when hot, will provide the heat to evaporate the incoming liquid diesel.  But now it is just in the way.  Using a poker, try to get the rolled up portion to go at least partially beneath the disk at the bottom of the baffle, leaving the tail accessible for lighting.  Do the best you can - usually you can't get more than one end under the disk.

Turn the oil valve all the way on (to number "5").  Note that there may be a couple of stops that prevent you from turning the knob this far in normal operation.  But if you pull up on the knob, you can turn past the stops.

Do something else for 2 minutes.  Do not lose track of the time!

Using a BBQ lighter, light the protruding tail of the toilet paper.  Close the door.  You will need to turn on the combustion air fan all the way to get enough air down to the paper to keep it lit.  When the burning paper ignites the oil, it will be obvious - the flame is a rich bright yellow-orange instead of the pale yellow and blue of the burning paper.

As soon as the oil lights, turn the oil valve back to number "1.5".

If the burning paper fails to ignite the oil, turn off the oil valve.  There is very likely enough diesel in the pot, it's just that the flame from the paper didn't reach it, or the diesel did not yet wet out the ash in the bottom of the pot far enough to reach the paper.  Roll up some more toilet paper and try again, leaving the oil valve closed.

When the oil ignites, turn the combustion air fan down one notch.  When it is all the way up, it will force smoke and fumes into the cabin.

How much combustion air the heater requires once it is settled in is a variable depending on the stack length.  Ours (stack is approximately 36") requires none.  If the flame is burning cleanly (no trailing soot tendrils off the tips of the flames, yellow in color - not orange), then adding more air just means you are pushing valuable heat up the stack.
Some notes:
  1. Before lighting the heater, be sure that there is nothing combustible near or above the Charlie Noble outside.
  2. In the unhappy event that you get too much oil in the burner before getting it lit, your first clue will be that the flame grows much more quickly than normal, and to a much higher level.  Should this happen, turn off the oil!  If you suspect it might be happening, turn off the oil!  In our heater, the oil burns off harmlessly when this happens, tho with a frightening pulsing roaring sound, and the heater does get very hot.  Standing by with a fire extinguisher would be prudent if this happens.
  3. The oil valve is very non-linear in controlling the heat output.  Normal operation will be only be between the "1" and "2" marks.
  4. The oil feed and combustion air should always be adjusted so that the flame remains above the top ring of the baffle.  This is the way the burner is designed to operate.
  5. If you should ever be moved to clean the heater, be advised that the collection of ash and crud in the bottom of the burner is an important part of the combustion process - it serves as a high surface area diffusion plate/evaporator, much like a candle wick.  If all the material on the bottom of the burner is removed, the heater will be difficult to light until this layer gets re-established.



Salty Bob said...

I recently decided on the propane version of the same Dickerson heater. After reading this, I am delighted with my choice. It barely sips propane and lighting it is as follows: open door, turn on the gas, light the flame and close the door. Because it has the new style double flu, we have zero moisture build-up in the boat and it dries everything out, including us, quickly. Sail on sailors!


bob said...

Salty -

There is no doubt that LPG is a simpler fuel to use in a heater, both because it is a gas and because it delivers itself to the heater, due to its vapor pressure. And with a stack to vent the products of combustion to the outside, the water vapor in those products of combustion does not enter into the cabin.

So how long does a 20 lb cylinder last you, heating day and nite in the winter?


Salty Bob said...

Bob: Belive it or no, we only have a 2½ gallon can in a propane locker. We are on the boat every weekend and use the heater almost everytime we're aboard. (My dear wife never gets warm enough.)We cook full meals on the stove too. We had one bottle last us more than 3 months this last fall. That works out to about 12 days of steady use for 2½ gallons.

s/v Chaika said...

We quit lighting ours with toilet paper and squirt a bit of stove alcohol down instead. Easy to light with a long lighter, and we figure it avoids the build up of ash from the toilet paper.

Deb said...

Bob - been enjoying your blog immensely. Lots of really helpful information. I especially look forward to trying the ricotta cheese recipe. I've been making yogurt with great success but I've never tried ricotta cheese before.

Thanks again,
S/V Kintala

bob said...

Deb -

Why thank you very much for your kind words!

(Ricotta is easier - less waiting...)


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