Onboard Condenser

[JonRiley56]

Hey Den,

Sorry I didn't post this sooner. I bought the coil from a
Guy who makes them for moonshine stills.

I put a link to his website in the "for sale section"

Jon

[Lopez Mike]

At the risk of a snub, why an inside condenser rather than a keel unit? Seems like a lot of trouble and complication. And doesn't it need yet another pump to circulate the salt water?

Mike

[JonRiley56]

Hey Mike,
You make a very valid point. The bottom line is that I am scared to death of having
Some joint outside of the boat start to leak and I end up with saltwater in the boiler without knowing it. Almost all my use will be in saltwater.

My steam drum and mud drums are black iron and my
Water tubes are stainless. Corrosion scares me.

I am going to use a live well or raw water wash down pump
Run off a battery. I may try putting a scoop on the intake
And see if there is enough convection flow so that I don't need the pump.

Jon

[Oilking]

Jon,
During my time on a Knox class DE, the only time we missed an underway commitment was when the machinistmates left the main condenser drain open and pumped the bilge into the hotwell when they lit off the air ejectors! We ended up dumping both boilers and flushing the hotwell.
On the old Fletcher Class the aft plant had a leak in the condenser tube sheet. We would get underway on both plants, then lock shaft and shutdown the aft engine once out to sea.
At sea chloride comes from two places, the condenser, or the evaporators(make-up feed).With the exhaust on the inside of a continous coil, you should have perrty much eliminated the risk of contamination.

Dave

[DetroiTug]

Jon,

A steam leak to cold water will make a lot of noise. The cold water shocking the steam (like submersing a hot piece of steel in coolant). That's how I knew the check valve at the boiler was not working. Sounds like someone pounding,tapping and dragging a hammer on the bottom. I also have the exhaust split, it can be ran out the stack or through the hull or both. When I run it out the bottom, it sounds like a cement mixer.

-Ron

[farmerden]

Jon I have a keel condenser and run in salt water. A few years ago my boiler water started to taste salty.I pressurized the whole system and sprayed soapy water everywhere and alas could find no leak. In the picture,behind and below the green alternator you will see a copper coil-like flex connection.For some reason in my quest to find the leak,I filled the bilge up with water and sure enough there was the stream of bubbles coming from that!! Now my bilge water is also salt and that line was running under a vaccuum and there was the source of the salt water.So don't ever think all leaks will occur on the outside!! "If it's made by man-It will wear out!!" [img]http://i279.photobucket.com/album ... .jpg[/img]

[Lopez Mike]

Others may dispute this but my personal experience has been that getting some salt water in the system is no big deal as long as you don't make a habit of it.

Corrosion isn't the problem as much as buildup of deposits. I have used salt water as makeup in a pinch. Just flush things out well when things are fixed.

I think you will get much more corrosion from low pH and a lot of oxygen than from a bit of salt intrusion.

The added complication from designing in an inboard condenser has never seemed worth the hassle.

Mike

[barts]

The only reason I'd go to an inboard condenser would be to reduce the chance of damage due to logs, beaching, etc. The large boat will have a nice heavy pipe well protected by the keel... or just part of the keel being galv. steel and a condenser .

[DetroiTug]

Salt vs low PH? Based on witnessing steel bodied cars running in winter salt versus steel bodied cars ran in areas where salt is not used (instead cinders), the steel bodies exposed to salt deteriorates much more rapidly. Back before they used surface coatings that they use today, galvanizing etc, I've seen car bodies rust right through in as little as three years.

I pull right out of the lake, and I removed some fittings a few months ago in my boiler, all I seen was a thin powdery brown dust-like coating, no rust that I could see.

I read where Bill Durham was talking not too long ago about salt water under any condition is the cardinal sin of boiler water (something to that effect). Himself seeing boilers destroyed from intermittent saltwater use in as little as five years.

-Ron

[Lopez Mike]

Sure, salt can eat steel up in no time if there is oxygen too. The conditions inside a boiler are way different.

And yes, salt inside is bad in the long run but I don't see it as causing the boiler to be damaged by a busted condenser. That means, of course, that you fix the problem and flush it all out.

Personally I think you are just as likely to have a leak in your condenser/heat exchanger as you are to have a problem with a keel cooler. As Bart says, just don't go whacking in to things with it. I beach my boat regularly to pick up passengers. I just remember which side of the keel it is on (port) and run her up on the sand on the starboard side.

Mike