Simple Condensor Design?

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cyberbadger
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Simple Condensor Design?

Post by cyberbadger » Wed Mar 24, 2021 9:03 pm

When I operate with my Kerosene atomizing nozzles I no longer get any benefit from the puffer arrangement in this configuration. Dumping the exhaust overboard is pretty, but not particularly efficient.

I'm running a 6HP Twin 3"x4", and without adding an airpump I'm wondering if I would get any benefit to having the exhaust run down a long pipe under the water surface along one of the pontoons. My length is 24', I'm guessing at 10ft of 3/4"-1" copper pipe?

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Re: Simple Condensor Design?

Post by barts » Wed Mar 24, 2021 9:13 pm

cyberbadger wrote:
Wed Mar 24, 2021 9:03 pm
I'm running a 6HP Twin 3"x4", and without adding an airpump I'm wondering if I would get any benefit to having the exhaust run down a long pipe under the water surface along one of the pontoons. My length is 24', I'm guessing at 10ft of 3/4"-1" copper pipe?
It will be much quieter....

Your best move would be do condense the water and bring it back aboard. into a hotwell, and pump it back into the boiler, controlled by a float. No bypass to adjust, and much better control of boiler water purity/chemistry.
That condenser will be plenty in cold water while moving; not enough in hot water standing still at the dock.

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Re: Simple Condensor Design?

Post by cyberbadger » Wed Mar 24, 2021 10:47 pm

barts wrote:
Wed Mar 24, 2021 9:13 pm
It will be much quieter....
....
That condenser will be plenty in cold water while moving; not enough in hot water standing still at the dock.
There was another thread where I believe Mike Lopez had 6ft of pipe and thought it might be giving an extra 1psi. (I'm not sure if this was used in the simple way I am imaging doing it)

I was hoping I might get a little more power from the difference in pressure across the engine. If it's only 1psi and nothing near 14psi I don't think I would even notice it.

I'm at a point where additional equipment really needs a good justification for it's wet and dry weight. I put a steampump onboard, but took it off because I couldn't justify the 200lbs of worthington pump that I didn't really need.

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Re: Simple Condensor Design?

Post by cyberbadger » Wed Mar 31, 2021 7:26 pm

If I end the 6-20ft exhaust line underwater with a steam trap would that allow a vacuum to develop while removing the condensate?

I am looking for a passive way to remove the condensate from this condensor...

High-Flow Iron Steam Trap 3/4 NPT Female, 125 PSI Maximum, 5" Long
https://www.mcmaster.com/4897K28/

-CB
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Re: Simple Condensor Design?

Post by Oilking » Wed Mar 31, 2021 8:07 pm

The vacuum in a condenser is created by the reduction in volume of the condensing steam. A pump will be required to extract the condensate and maintain the vacuum. If your goal, as in Mikes case, is to reuse the water in order to extend his range, then a simple tube of the right length will work fine, but it will require exhaust back pressure great enough to push the water out of the condenser. I've wondered if the added complication of running a vacuum condenser is of much value unless one is running a compound anyway?

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Re: Simple Condensor Design?

Post by barts » Wed Mar 31, 2021 8:48 pm

Oilking wrote:
Wed Mar 31, 2021 8:07 pm
The vacuum in a condenser is created by the reduction in volume of the condensing steam. A pump will be required to extract the condensate and maintain the vacuum. If your goal, as in Mikes case, is to reuse the water in order to extend his range, then a simple tube of the right length will work fine, but it will require exhaust back pressure great enough to push the water out of the condenser. I've wondered if the added complication of running a vacuum condenser is of much value unless one is running a compound anyway?

Dave
I've run Otter (single) w/o a vacuum pump for decades - it works fine, and lets Otter run in salt water. On a single, the amount of power gained by removing some back pressure is likely pretty minimal, although an indicator diagram would help determine this. The vacuum pump takes power to run as well. On compounds, the larger LP makes the presence or absence of vacuum noticeable.

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Re: Simple Condensor Design?

Post by cyberbadger » Thu Apr 01, 2021 1:06 pm

I keep hearing, "No you need a pump!"

At some level this is not true, I have taken a steam hose and put a few inches of the hose into a bucket of cold water.

No pump is necessary, and all the condensate leaves the hose.

Now, that only works until you super heat the water in the bucket and it gets to a rolling boil.

But once in a lake, it is impossible to noticeably heat up the lake in that manner.

So what I'm going to try is a length of pipe leveled slightly so gravity can do it's job. Underway (which is all I care about), there should be an additional suction force pulling from the water movement.

There is probably optimum length and size to make the pipe to achieve a vacuum, not sure if one or two check valves would do anything.

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Re: Simple Condensor Design?

Post by barts » Thu Apr 01, 2021 3:49 pm

I would still bring the condensate back aboard and put it in a hot well, because:

1) The condensate is (modulo steam oil, if any) pure water, free of minerals, etc. If you keep putting lake water in the boiler, you will need to blowdown more frequently as the minerals will concentrate in the boiler.
2) Any oil that's carried over will pollute the lake; you may well leave a sheen on the surface idling at the dock - which can lead to some uncomfortable conversations best avoided.
3) A hot well with a float will mean that tending the pump bypass valve is a thing of the past - the bypass is the float valve.

No pump is needed, the amount of induced backpressure is probably one or two psi.

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Re: Simple Condensor Design?

Post by cyberbadger » Thu Apr 01, 2021 4:09 pm

barts wrote:
Thu Apr 01, 2021 3:49 pm
2) Any oil that's carried over will pollute the lake; you may well leave a sheen on the surface idling at the dock - which can lead to some uncomfortable conversations best avoided.
That is an important point that I did not think about, however probably similar to a 2-stroke internal combustion outboard.

To be really honest, a good puffer arrangement probably throws some steam oil up the stack and it probably eventually ends up in the body of water.

The Chautauqua Belle is also single expansion and has escape stacks that are filled with loafa sponges to capture the steam cylinder oil.

It doesn't seem like it is something that makes enough sense in my application at this time for the whole package. (I'm sure there are economy efficiencies that can be gained.)

My current boiler treatment and blowdowns is much better then the Belle, they don't use anything and I doubt they do blowdowns. I can see the magnetite on the interior of my boiler that has developed because of my boiler treatment.

I have no interest in pumping steam oil into my boiler.

-CB
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