Simple exhaust heat-x

[Crofter]

I was thinking more of a short blast rather than a sustained temperature but once it got going perhaps it would take off by itself so I guess stainless might be a necessity. Steam on the other side might be an issue too. Manual clean out.......dirty job? you bet! That grime is next to a tattoo to get off your sorry hide!

Mobile Bob did some hinting at an easy cleaning exchanger prototype he was conjuring up but he is playing those cards close to his chest.

[billswan]

Guys, personally with what experience I have gained trying to pull heat out of exhaust on a diesel I see no way to keep the heat exchanger clean except to build it so that the exhaust leaving it is still well above the boiling point of water. I believe bob said as much back on some of the other threads dealing with this subject. Excuse me bob if I am wrong, not trying to miss state you.

I am hoping to take take a third try at building something that will get more of the heat but not plug up.
1st try was in the pix a few posts back.
2nd try is in use as i type but it is too ineffiecent loses heat out the exhaust but I have yet to clean it.



It is a tube in a tube with water around the inner exhaust pipe about 4 feet length of effective heat exchange.
Water in at the brass fitting and water out at the cast iron fitting.
And a removable plug to allow a brush in on the left end.
Brass air relief on the top.
Exhaust in at the pipe pointing at the viewer of the pix.
For my third try I believe I will build something to add on after what is in the pix above to try to capture some more of the heat from my 10/1................

Billswan

[oiler]

My heatex is very similar to yours, but 6 feet long and still very inefficient................ Inner pipe is 2"

[wagspe208]

Guys, personally with what experience I have gained trying to pull heat out of exhaust on a diesel I see no way to keep the heat exchanger clean except to build it so that the exhaust leaving it is still well above the boiling point of water. I believe bob said as much back on some of the other threads dealing with this subject. Excuse me bob if I am wrong, not trying to miss state you.

I am hoping to take take a third try at building something that will get more of the heat but not plug up.
1st try was in the pix a few posts back.
2nd try is in use as i type but it is too ineffiecent loses heat out the exhaust but I have yet to clean it.



It is a tube in a tube with water around the inner exhaust pipe about 4 feet length of effective heat exchange.
Water in at the brass fitting and water out at the cast iron fitting.
And a removable plug to allow a brush in on the left end.
Brass air relief on the top.
Exhaust in at the pipe pointing at the viewer of the pix.
For my third try I believe I will build something to add on after what is in the pix above to try to capture some more of the heat from my 10/1................

Billswan

This i what I had in mind to capture some of the heat. Did you have this setup running yet? Easy to make.. If you had it running, how did it work? Well, fair? Crappy?
Thanks
Wags

[billswan]

Wags

Here is a second pix of the unit before I slid it together and welded it up.



As you can see it is just a piece of 2 inch tail pipe with washers welded to it to make the water move back and forth as it passes through. The washers are welded to the inner pipe and not the outer pipe. Works fairly well. Would work better if it was twice as long. It has about 300 to 350 hours on it and so far so good . I will find out fast if it has any problems as I have put 14 hours a day on it in the last 10 days and am planing to go to 24/7 operation when the cold gets here and that is not to far away. If you do build one you should probably use stainless steel, this is not ,I am not a math wizard like some of our members so I am stuck with trial and error.......


Billswan

[wagspe208]

I was planning on SS material.  I assume the straight section of tube to the far left is a cleanout?
I like the cut washer idea. I was thinking of how to make the water swirl. There you go.
I was hoping to use a similar heat exchanger, some hose, a small water pump, and a radiator and fan to heat (not to 70 or anything) a 30 x 30 secton of my shop. I now use LP to keep it at 50 F in any temp. It is where my engine machines are and I hate to let the temp swing hugely. From 50 it warms up pretty quick.
Any math geniuses know the heat output possible with an exchanger like this?
Thanks
Wags

[billswan]

Your engine better be higher than that tube. A little water leaking into the exhaust because of corrosion and finding it's way into the head will ruin your day in no time flat.

Can't argue with you jens water with antifreeze is bad for almost every thing it is not supposed to be in contact with and my 10/1 is below. But it is not old enough to be rusted out yet and sooner or later I will build something out of stainless to replace it.

Wags I will post to you later have to go now..............

Billswan

[sailawayrb]

http://polarpowerinc.com/products/heat_exchanger/heat_exchanger.htm

http://www.ejbowman.co.uk/products/ExhaustHeatExchangers.htm

[billswan]

http://polarpowerinc.com/products/heat_exchanger/heat_exchanger.htm

http://www.ejbowman.co.uk/products/ExhaustHeatExchangers.htm

Wow lots of info in those 2 links!

Billswan

[billswan]

I was planning on SS material.  I assume the straight section of tube to the far left is a cleanout?
I like the cut washer idea. I was thinking of how to make the water swirl. There you go.
I was hoping to use a similar heat exchanger, some hose, a small water pump, and a radiator and fan to heat (not to 70 or anything) a 30 x 30 secton of my shop. I now use LP to keep it at 50 F in any temp. It is where my engine machines are and I hate to let the temp swing hugely. From 50 it warms up pretty quick.
Any math geniuses know the heat output possible with an exchanger like this?
Thanks
Wags

Wags
Yes the straight section is a clean out. The end is plugged with a expanding pvc clean out plug the end runs cool enough that you can hold the last 4 inches with a bare hand so the rubber seems to hold up just fine.

My 10/1 running at 1000 rpm and generating about 3900 watts ( 211 volts and 18.5 amps)  is heating a 54 X 75 shop. I have been running it 14 hours a day + or - . Less today as it needed an oil change and right in the middle of it an neighbor showed up and distracted the process.

Now here are some numbers for the math geniuses to look at.


The outer tube is 49.5 inches long.
The temp at the exhaust pipe about 1 inch past the coupling on the 10/1 is 590 degrees Fahrenheit. I used a infrared temp gun.
There is about 5 feet of pipe with 2 bends going to the exchanger and at about 7 inches up stream of the water section the temp is down to 515 degrees.
About  6 inches after the cooling section in the middle of a 90 degree bend the temp is 315 degrees.
So that makes about a 200 degree temp drop.
The water temp in is about 77 degrees.
And the water temp out is about 82 degrees.
This was all with the same temp gun and after the unit had run about 4.5 hours.
Water flow is not known but estimated at about 3 to 4 GPM.

There is a heat exchanger for the coolant and the 3900 watts go's to a water heating element and all the heat is piped into an in floor pex  tube system. Air temp in shop about 60 degrees F.

Of  course there is a lot of heat that radiates off the engine the pipes and the st head that also heats the air in the shop.

Billswan