Incinerating Toilet

Discussion in 'Boat Design' started by rfleet1066, Apr 7, 2022.

  1. rfleet1066
    Joined: Feb 2012
    Posts: 173
    Likes: 35, Points: 28, Legacy Rep: 46
    Location: New Kent, VA USA

    rfleet1066 rfleet1066

    Incinerating toilet?

    I thought it would be a good idea to use one on the vessel I was building, ‘The Sebastian Marie’, a 97 foot river boat. I ordered one that uses 12 volts dc and diesel fuel. It was over six thousand dollars, but I thought about eliminating (no pun) the need to store, treat and discharge black water.

    The unit arrived and was installed in the spaces below the wheelhouse. It won’t go below with the wheelhouse installed, so for all intents, any maintenance or repair will be done in place below.

    The advertised specs said it required 12 volts DC. Not so fast. Actually it requires two 12 volt batteries because one part, (the auger) requires 24 volts. That means two charging circuits, too, to support it. Or perhaps, one could switch from parallel for charging to series during cycle…..but I used two charging circuits to keep it simple.

    During the boat building the unit tested fine. Not long after the vessel was launched, the troubles began. The control circuit board failed. I ordered a replacement and a spare. The replacement failed within six months and I decided to build my own controller from readily available components. The wimpy membrane operator’s switch panel was replaced with industrial grade Allen Bradley brand switches.

    At or about the same time, the burn chamber failed. It’s stainless and started separating at the weld joints. I ordered, received and installed the replacement. Go back to line five. This has to be done down below.

    Another problem was wind blowing down the exhaust pipe and causing backdraft, and overheating. I solved this by installing a wind direction turning exhaust cap and to be sure, an inline draft inducer to make double sure it can’t backdraft.

    Then the second burn chamber failed. Looking into the inspection port, I could see the internal components separating at the welds, again. I ordered a third burn chamber. Upon careful inspection, it was revealed that most of the welds on the chamber were ‘fuse welded’. That’s when components to be welded are fitted closely enough for a tig process using no filler metal. It’s quick and pretty, but structurally not near as sound as if filler metal was used.

    But, this has to stop. The labor and pain factor of changing out these chambers has ended. The third chamber received was lined with firebrick and an Inconel plate fitted in the bottom in line with the diesel burner blast.

    The unit is flawless now. If the auger is scraped down every few days, all material goes to the burn chamber, gets warmed up to 800 degrees stack temp for the operator selected cycle…….15 minutes for urine or 40 minutes for (more?) solid waste. The result is, everything is reduced to carbon in the consistency of cigarette ash. I clean it every 4 months and a three gallon vacuum will retrieve about ¾” ash in the bottom of the canister.

    The result is good. The path provided a plethora of problems. Be advised, one does not build a boat to save effort or money.

    Ryland Fleet

    Attached Files:

    bajansailor likes this.
  2. fredrosse
    Joined: Jan 2005
    Posts: 437
    Likes: 80, Points: 38, Legacy Rep: 56
    Location: Philadelphia PA

    fredrosse USACE Steam

    Looks like the manufacturer gets to improve its product at your expense? Did they stand behind replacements? Too bad such an expensive device isn't properly developed.
  3. rfleet1066
    Joined: Feb 2012
    Posts: 173
    Likes: 35, Points: 28, Legacy Rep: 46
    Location: New Kent, VA USA

    rfleet1066 rfleet1066

    No, the manufacturer was happy to continue selling replacement parts. The circuit boards were over three hundred bucks each, the burn chambers around nine hundred. I'm not sure what it cost me to design and build the controller, but it does not fail and has plug-in relays and timers. The switches have replaceable contact blocks. I think they put this product on the market not having data on service life of the components, some of which were poorly designed and constructed.
  4. Will Gilmore
    Joined: Aug 2017
    Posts: 892
    Likes: 393, Points: 63
    Location: Littleton, nh

    Will Gilmore Senior Member

    Has a competitor been born? Perhaps their failures have opened the door for someone else's success. Recoup losses and actually gain some.

    What would you charge for your new and improved version?
  5. philSweet
    Joined: May 2008
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    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    I see a combined diesel tier-4 regen/incinerator chamber in the offing:D

    (you know what diesel exhaust fluid consists of, yes?)
    Lloyd Too likes this.
  6. kapnD
    Joined: Jan 2003
    Posts: 1,259
    Likes: 385, Points: 83, Legacy Rep: 40
    Location: hawaii, usa

    kapnD Senior Member

    Rfleet, you must be that company’s best, and possibly only customer!


  7. Flotation
    Joined: Jan 2020
    Posts: 175
    Likes: 34, Points: 28
    Location: Canada

    Flotation Senior Member

    I was one step away from googling "incinerating head" to find an answer to this question until i changed my mind.
    Will Gilmore likes this.
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