Waste Exhaust Heat - Geniuses Requested

[LowGear]

Hi Lowgear/Casey
2nd time I've heard you ponder engine waste heat usability in your not needing much space heat environment.
Just suggestions:
Dry something. Remember Liberty Orchards "Applets and Cottlets" out of Washingtion State? They have to evaporate reduce then dry their fruit juices. Same for kiln drying of woods and all nuts. Dried flowers, plants and herbs, etc.
Evaporate distill some thing: you probably don't need this but water purification comes to mind. Hmmm. Alcohols - motor fuel of course.
I am not joking or being off the wall.
Any process created energy or material crosses over from being a waste to a resource just but creatively coming up with a useable use for it.
My chainsaw and sawmill blade kerf "wastes" is the resource used for animal bedding. Used bedding and manures enrich our nutrient washed out rainforest garden soil.
My "waste" engine heats will now be the solar derived energy resource used to reduce my unusable 40-60% moisture gasifier woodfuel down to a gasifier useable 20%.
Only been 7 actual sunny solar drying days here in the last 40 here - all woods outdoors has fallen behind drying with the +30 inches of rain in the meantime.

You are a smart man - you'll think of somthing. Just think of that heat blowing away unused as $$$ blowing away in the wind.
Like your new engine picture.

Regards
Washington State Steveu.

Look Out!  Brain Storm Occurring

I take the exhaust pipe almost directly out of the engine and put a long sweep 90 on it so its pointed straight up.  I then braze a copper chamber on that with the exhaust about 6 inches from the flat top of this chamber.  Then, a few inches below that is an exhaust pipe that travels downward and out to the mufflering system.  Next comes the BS or I mean Brain Storming!  I put 4 inch hole in the top with a 4 inch pipe adapter where my cooking pot or methanol still will set.  I clean it every time I clean the pot.  And when I'm not cooking I'll put a 4 inch copper pipe plug into the adapter hole.  This chamber might even be a great place to put some copper coils in to heat water for fuel warming as well.  

Fellow Brain Stormers:  I expect you to come up with enough nays to keep me from getting too excited about doing this!

How hot is that going to get?  

How hot is the exhaust gas about 18 inches from the head?

Just in case you don't see the copyright logo you may come to realize this drawing is not copyrighted.

Casey

[spencer1885]

I think your looking at  around 150c.
Never run the exhaust up from the engine as the crap will build up choking the engine, if your burning waste oils.
Matthew

[LowGear]

OK!

300 degrees Fahrenheit.  So distilling may call for the high heat plug to be left in once the initial heating has been accomplished.  And beans may call for higher heat.  Too bad the run over to the bio-diesel cooker is 36 feet?.

Crap in - Crap out as was once the motto of database operators.

Here's the new and improved Mk II.

Casey

[mike90045]

I think your looking at  around 150c.
Never run the exhaust up from the engine as the crap will build up choking the engine, if your burning waste oils.
Matthew

How strict is this rule for diesel or bio-diesel ?   

[Crumpite]

I think your looking at  around 150c.
Never run the exhaust up from the engine as the crap will build up choking the engine, if your burning waste oils.
Matthew

How strict is this rule for diesel or bio-diesel ?  

The figure I saw quoted was 800 Deg. F (in theory !) I'd guess that the output gas temp from a fully warmed up lister would be a *lot* hotter than 150 C.

You will get crud even from diesel or biodiesel, but only on startup.
You can get around all of this by having a T-trap at the outlet, where any crud just runs down the tee and collects in a lower catch cup.

It can be quite a job designing a heat exchanger for diesel exhaust since it's so filthy, you need to clean it frequently !

Crumpite

[LowGear]

First: 

(IMHO)

I can't see how this has anything to do with the International Mental Health Organization. 

B:  I hate to see good minds trapped inside a copper can but this is just a paper and not the Holy Grail:
http://www.unene.ca/un702-2009/lectures/HeatExchangers1-16pages.pdf

III:  Moving On:  Mac and Cheese is a lot more than the vast majority of diesel burners are doing with their hot air at this time.  But let us get this straight right from the start.  I am a beans and rice kind of guy!  "Pull my finger."  And reclaiming methanol through a reflux distiller is an honorable attainable objective.

Fourth: 

This chamber might even be a great place to put some copper coils in to heat water for fuel warming as well.

I guess this feature in the original requirements document was overlooked.  This does meet the "a liquid filled tube and shell heat exchanger. There is a reason why that kind of a system is used throughout industry." criteria offered by some.  It could also serve to heat water for the engine room showering facilities.

Fourth-a:  Now this Witte uses an evaporation system of cooling to get it up to running temperature "boiling" for runs lasting longer than "show and tell" or You-Tube moments.  Word has it that this 1250 cc single needs to have a bit of load on it to get up into this heat range and I'd hope we all agree that a diesel engine running at 212 is happier and has less "coking" than some primitive design running on a 180 degree thermostat centered cooling system.   A simple (normally open) thermostat could control the flow of this heated water from the primary coil allowing the secondary coil to be used for hot water.

I wonder how well a 3/8" solid copper rod would transfer the heat.  If one end is exposed to a constant 300 F how hot would the other end be at a length of 24 inches?  Too much to hope for?

Casey

[mike90045]

I wonder how well a 3/8" solid copper rod would transfer the heat.  If one end is exposed to a constant 300 F how hot would the other end be at a length of 24 inches?  Too much to hope for?

I think 5/8" - 1" would be better. As good as copper is, 3/8 won't carry that much.

[LowGear]

Hi Jens,

Yeah, I know.  I had to google it so I went with the interpretation that was the most fun.

Hi Mike,

Since it took me a week to get my arm back from that first start attempt I completely understand and envy electric start machinery.  It's just been this last couple of weeks that it has sunk into me that these single lungers are actually bigger displacement than my mini.

In general SteveU's kick in the pants has got the little gray cells agitated but the engine is still a year away from smokin here at Camp Aloha.  What I do know is that whatever heat collector (better?) I adapt to the Witte it must be easy and quick to clean like unscrewing a cap and washing it down with a pressure washer.

Casey

[Crumpite]

Did you see the thread about using an old gas hot water heater as a heat exchanger ?
Just pop the top off and run a pressure washer or brush through it.
Not as efficient as a custom tube and shell exchanger, but it's cheap and better then the ideas discussed so far. (IMHO)

I like your sense of humor !

Crumpite

[LowGear]

Not as efficient as a custom tube and shell exchanger, but it's cheap and better then the ideas discussed so far. (IMHO)

Sorry, I'm not being roped into building one to the above technical document requirements quite that easy. 

But I have been cruzing the brass fire extinguisher tanks on Ebay.  Nice threads. 

Casey

[Crumpite]

Ahh, you've caught on to my clever scheme !

Curses, foiled again...



Crumpite

[LowGear]

LowGear,

As I recall, you have a biodiesel (or at least a WVO) setup.
Biodiesel requires the batch to be heated to 130f prior to reaction.
You could use the waste heat to A] Heat you biodiesel reactor, or B] Help heat and dewater your WVO.

veggie

from http://www.microcogen.info/index.php?action=post;topic=1082.0;num_replies=5

Dewatering is going to rely on old Sol himself.  My batches are like 20+ gallons so there are wheels on the back of that tank.

The cooker is close to 35 feet away as the worm crawls but more like 70 as the old man digs his way through the lava rock.  PEX is rated for 210 degrees in non pressure applications so I think I'm pretty safe there but getting it insulated against heat loss for that long of run??  My guess is about 60 degrees for ground temperature at 6 inches depth here.  Here's a photo of what happens when you dig a 24 inch trench for wiring.  How would you insulate 3/4 in PEX in ground?  In air?

Casey

[LowGear]

I absolutely agree that nice toys make great tools.  The last ditch I hand dug was hundreds of feet long but only about 6-8 inches deep.  You can see it crossing the "trench" in the bottom photo.  One 16 foot section took 24+ man hours to dig.  So while this 90+ foot by 24 inches trench may have cost $1600 I didn't die in it next decade before completing it.

Now to find some insulated PEX.  The stuff I learn on this site never ends.  Thanks to you all.

Casey

[vdubnut62]

Wow! a breaker on lava rock has got to make a long day!!
Jens you get bored with digging holes all over the place- eventually.Here is a pic of my old hoe.
Ron

[DRDEATH]

Casey I have been think about the gas hot water idea. The negative side is how much heat would you get from the exhaust going up the center. I think I am going to build a base that a hot water tank will sit in then blow the exhaust into the base. It will heat the bottom of the tank and up the center. As for cleaning I would suppose a good wash down on a regular basis down the center should just about keep it pretty clean. You could just remove the exhaust pipe and let the water run out there. I havent tried it yet so I suppose there could be some bugs in that idea. If everything was hot when washing it would be close to steam cleaning. DD