Steam water heater

[DetroiTug]

Well, for a few years I've been trying to figure out how to get hot water on the tugboat without parboiling myself. I was originally going to mount a small tank under the sink and run a steam line through it. The tug has two 10 gallon plastic water tanks, one is for fresh water, the other was for the sink drain or gray water, and it had a pump to empty it. I found out that the latter wasn't needed. So I yanked the old tank and bought a new one to replace it. The sink drain is now piped in to the same through hull (I know this is all sounding like a three stooges episode) as the ejector with an isolation valve in the drain below the sink so I don't blow bilge water back through the sink drain when using the ejector. So I had the bright idea - make the new tank for hot water - install a steam coil in that. So that is what I did. However, I had to add another on demand pump for the hot water as it is a totally different system than the cold.

The coil is 1/2" and I'm running 1/4" copper over to it, the idea here is that the half inch copper will have more surface area to heat the water. Then the exhaust line for this will be 1/4" and tie in to the exhaust for the southworth steam pump. I think I will be able to control the temperature by feeling the line coming out, once it gets warm that means the water is warm as well and turn the steam off. The tank will be insulated so it should keep it warm for a while. Will install a thermometer in it as well just to be on the safe side.

Will report back how it works as I'm going to give it a try soon.

-Ron

[Mike Rometer]

A rather large Windermere kettle!

[DetroiTug]

Yes, exactly

-Ron

[Lopez Mike]

I have this terrible vision of the heater going unsupervised due to navigational distraction and melting down. How much heat is that plastic rated for? UHMW?

[DetroiTug]

I share the same vision

I'm not sure what kind of plastic it is, looks to be the same kind milk jugs are made from. I have no idea on the temperature rating, but if it got that hot I'd rather it rupture and dump in to the bilge as it would burn someone badly. The idea here is to simply warm the water for showering, shaving, washing dishes etc.

I'll just have to pay close attention to it and monitor the temperature rise. I have a feeling it's going to work pretty well.

-Ron

[Mike Rometer]

My mind is running along the lines of a steam valve operated by bi-metal strip, or similar, to control the temp.

[DetroiTug]

Mike,

Yeah I thought about that and I'll bet there is some existing control that would work.

I found a few here, at 600 to a 1100 dollars it's a little out of the scope of project funding

http://www.mcmaster.com/#temperature-co ... es/=xun6sp

-Ron

[Mike Rometer]

How about making up something using the wax insert from a car thermostat? Generally the temp range is a bit high, but perhaps some form of adjustment might be possible.

[DetroiTug]

Mike,

That's possible. Mount the sensing side in the tank and then mount a stop valve to the outside. I may experiment with that when I get time.

Looks like if the expansion unit was removed from one of these it could be made in to a cheap control unit. Mount it in the top of the tank to prevent leakage. Then extend it to the bottom of the tank. Have a rod that controls a modified straight push needle valve. I think a low temperature (160°F) thermostat with springs removed or lower tension springs could be calibrated to about 140°F pretty easily.

-Ron

[Steamboat Mike]

Ron,
Very interesting journey on the path to creature comforts aboard the steam vessel.

Storage systems are by nature complicated, the more you try to fine tune the operation the more complex and, therefore, expensive the system gets to be. May I suggest another line of thinking, a parallel universe of steam heated water? That would be the concept of demand heating. This is actually quite simple on a steam vessel.

When I read the sentence in your post about wanting the water for showering, among other things, the (dim) light bulb in my head began to glow. When I fitted out Catawissa I put a 3/8" steam ejector onboard to drain the bilges and provide wash down water for general cleaning. I never hard plumbed it into the bilge, in the rush to complete the boat for launching I figured I would get back to that later. As you may have guessed, later never came. The ejector is mounted on the side of the boiler with two hoses. Each is about 15 feet long, the intake has a coarse Perko bronze bilge strainer, the delivery has a male hose thread adapter. This has proved to be very useful for all kinds of things. Pull in to a dock that the geese have been partying at all day and just fire up the ejector with the handy hose nozzle accessory and squirt the offending "goose ash" away to enjoy a sparkling clean dock. Very useful for pumping your own or others boats of accumulated rain or other water. Another nearby boat have an empty boiler and no fire? Fill them up with warm ejector water. Using the ejector for so many things naturally lead to my using the hose for wash down without the nozzle and just my thumb over the hose end. Eureka! The more you throttle the water to get the last bits of dirt to go downstream the hotter the water got. This makes sense if you consider that the amount of steam remains constant but there is less water absorbing the heat. This lead to the most important steam appliance on the boat when cruising, the steam shower. My wife C'Anne declared it the most important scientific advance in steam cruising of all time. I made a shower from a replica antique tub-on-legs conversion piece found in a yard sale. It has a long stem that would hook up to the faucets on the tub and a large brass shower head on a return bend at the top.The stem is mounted in a weighted lamp base. When set up it resembles a large brass sun flower. There is a globe valve on the stem at the base that can be used to throttle the output for any temperature between tepid and quite hot. The higher the boiler pressure the higher the range of temperature of the delivered water. Scalding is unlikely because if the output is throttled too much the ejector stream will break and steam will dribble out of the shower head after it pushes all the water out that is in the hose. Another thing to remember is to start the ejector with the throttling valve wide open, this will allow the ejector to pick up and start the water at the cool end of its range. Adjust the flow carefully as there is a considerable lag between adjustment and temperature change. Endless hot water as long as there is steam. The whole thing breaks down to pieces for storage. Set it up on the dock and watch other boaters line up with soap and towels in hand. I have used it "at sea" in the middle of a large lake, just let the water accumulate in the bilge for later disposal. For dishes and othe galley work just fill up a bucket and wash away.

There is one caution of a potentially serious nature. In Catawissa the cockpit sole is just below the waterline. It is therefore possible to slowly sink the boat while you are not there. If the hoses are full from being used and the nozzle end is left on the sole with the intake still over the side you have a perfect, very silent syphon set up that will very slowly, very surely sink your boat. You do not need to ask how I have this knowledge, I figured it out luckily before the water was very deep over the floor plates. Sooner or later you will be distracted and walk away from your (sinking) boat. There should be a vacuum breaker in the delivery side of the ejector line. This would help, but you are still relying on the valve to work every time. Just be aware of the hazard, I have not sunk the boat yet. The problem arises when tied up to the dock and the boat is unattended.

This has proved to be a very simple, effective and versatile system for hot water aboard that makes longer than day cruises a delight, with very little additional equipment required.
Happy steaming, best regards, Steamboat Mike.