The Steamboating Forum

All,

Now that I have elected to go non condensing to get on the water as soon as I can, I have to fogure out what to do woth the exhaust.................

Any suggestions ?

jon

When Otter was non-condensing, I just exhausted out a through-hull that exited above the waterline. I used water heater hose for this; it worked well enough and never gave any problems. Do be careful to not oil the engine interior as this will produce a slick.

- Bart

Hi John,

As you aren't condensing and you have a watertube boiler I would recommend you exhaust up the funnel- you are going to need a permanent draught through that boiler anyway- you may as well save the blower and use your exhaust. This also makes for a nicer image as you steam along on the water.

Install a decent silencer/oil seperator to make sure that the exhaust in the funnel is as dry as possible and no oil is going to pick up smuts and deliver them to your canopy/clothes/following boats.

Greg

Hi Greg,

What do you mean by "separater/silencer" ? Also, where do I take the exhaust into the funnel ? It looks like the exhaust coming out of my engine is a 1" line. I assume I need keep that size or larger to the funnel ?? Do I turn it up the stack ?

If you have any pictures I would be grateful.

jon

Jon ,

The exhaust should enter the stack at or near the bottom and point up it like the nozzle of a steam blower . It helps to have a slight restriction/venturi in the stack but this isn't essential .

The separator/silencer is just an empty cylinder : put the entry for the exhaust at one end angled so that the exhaust steam entering this cylinder is given a swirling movement and have the exit at the other end in the centre , centrifugal force will deposit at least some of any oil onto the cylinder wall , have a drain at the lowest point to take this oil into either the ashpan or a suitable container so you can dispose of it later .

Regards Edward

All,

If I take the exhaust out through the hull under the water line should I have a valve and check valve in the line ?

jon

You definately do not want to exhaust underwater. This arrangement, with no check valve, will occasionally slam water in reverse flow right back into the engine exhaust, possibly causing damage. With a check valve near the hull fitting, steam condensation will often cause loud banging noise as steam rapidly condenses and has reverse flow of cool sea water back to the check valve, slamming it shut. A second later, exhaust steam forces the check valve open again, and the process repeats. In the conditions where I have experienced this, it sounds just like a 5 pound sledge hammer hitting a steel tank in repitition.

Exhaust into the stack, into the air, or overboard above the waterline.

Thanks Fred !

Do I have to be concerned with how long the run is to the point it exits the hull ? If there is any upward run do I need to provide for a drain at the lowest point ? The simplest thing to do starting out would be to just direct the ~ 12" or so fo 3/4 pipe I have coming off the eshaust port straight upwards and let the engine puff away. The only concern I have with that is that anyone to the rear of the boat will likely be sitting in a cloud of steam.......... do you think that is an issue ?

If I take it out the transom it will go down from the engine, run about 6 feet or so and then come up and out the top part of the transom. With that set up do I need to provide for a drain or will I be OK with disconnecting the exhaust hose after each run and letting any condensate drain to the bilge ?

thanks

jon

You are missing a good thing by not directing it up the stack. Free draft enhancement and a nice sound.

Mike is right with his comment, although the exhaust on my boat is thru a 1 inch copper tube which starts out at the very bottom of the boat, and is run up about 3 feet along the side of the paddlebox. I can direct the steam into the paddlebox, or vent upwards (with a 45 degree elbow fitting so I do not spray any passengers). When starting up I sometimes blow out some condensate because there are no drains in the exhaust line, have not had any problems with this.