Heat Exchanger...Who makes or sells these?

[Ryedale]

Setting up my EKO 40 super, and a 1600 gallon tank this summer,
A guy on youtube talked about his storage tank having a "bun" in it

I'm thinking tube "bun"dle, but he sent a closed ebay auction ID to me, and said he didn't know the manufacturer, but it looked like this

Any help would be appreciated. I'm also open to other suggestions on immersion type heat exchange.
My 1600 gallon tank is a horizontal oval, 11 feet long, 4 feet high, by 6.5 feet wide. Access is through a manhole on top, and it has one drain on the bottom.
Material of construction is 304 or 316 stainless steel.

Thanks for any help

Here is the pic of a "bun" I guess... and the tank is the one I picked up this past weekend. It was a bulk milk transfer tank for the dairy industry. The dark blocks on the outside of the tank are old cork insulation, which is now scraped off, and the Carbon Steel rings and strips are for stregenthing, and insulation support. the tank it's self is smooth polishied and open inside, very nice. it had some brushed on coating/adhesive to hold the insulation, but it comes off with solvent pretty good, so I can clean it up if I wanted too. it's at least .100 to .125 wall thickness, so quite sturdy, but not too heavy.

Andy

 

[Vtgent49]

I have a Vaughn Solar DHW 80 gal tank with a similar coil inside it. Mine is finned also, for extra surface area. It would be available from them as a replacement, but I think they buy them from somewhere.

This easily transfers 30+ degrees at any of the 3 speeds of my Grundfos circulator. I.D. is 1/2"

http://www.vaughncorp.com/html/solar.html

 

[DaveBP]

Is there a manufacturer's nameplate or other info stamped into the tank somewhere that might indicate what kind of pressure it is rated to take? It may only take gravity pressure so you would be limited to using it as nonpressurized storage.

Look at a few milk trucks and see if you can determine how much cradling they use to support its weight. That's going to be over 7 tons when full. Of course, you won't be bouncing it down the road, so you won't need shocks.

Looks like an excellent start

 

[Ryedale]

This tank will just be a heatsink, and be unpressureized. I will be creating many "saddles" to bear the weight of the water. Yes very heavy.
I think whoever removed the insulation and jacket, also removed the manufacturers nameplate data. I do think it's quite old, as cork hasn't bee used as insulation for many years.

 

[leaddog]

Those coils can be bought from alot of the OWB dealers so if you keep looking around you should locate them. The tank was a good find. To bad the insulation came off as that would have been a good start on insulating. Remember that that tank isn't made to be pressurized and has to be an open system. I'd sure hate to see a big split in it's side and water alover the place.
leaddog

 

[WoodNotOil]

Are you planning to use the coil for DHW or for charging and drawing heat from the tank? You could always use a plate hx to charge/draw through to separate the pressurized heating system from the unpressurized storage. I would think it would be hard to calculate btus transfered through coils like that, so sizing them for charging and drawing might be difficult. I suppose you could go the copper coil like the STSS tanks route, but you would have to fit them through the manhole and solder them together inside the tank. Let us know you thoughts on hx. A very interesting project.

 

[Ryedale]

Are you planning to use the coil for DHW or for charging and drawing heat from the tank? You could always use a plate hx to charge/draw through to separate the pressurized heating system from the unpressurized storage. I would think it would be hard to calculate btus transfered through coils like that, so sizing them for charging and drawing might be difficult. I suppose you could go the copper coil like the STSS tanks route, but you would have to fit them through the manhole and solder them together inside the tank. Let us know you thoughts on hx. A very interesting project.

I looked into the STSS tank and HX's I like the HX but didn't like the tank. I really didn't have a good place for the tank, and it would have killed a bunch of space in my basement.

I'm installing the stove in the basement of a 2 story house, but the tank will be in my exisisting pole barn 50 feet away from the house. I'd like to have them closer, but it didn't work out without adding another basement annex or room. Thought of putting the boiler out there too, but then would need another chimney, and still need a burried line-set to the house.

I don't mind soldering together a coil like the STSS, as I think they are the best bang for the buck. I'm really new to Hydronics and don't want to make a big error, almost to the point of being in gridlock, it's my curse of being a perfectionist, but I think I'm in good company here at Hearth.com.


I watched this video...

http://www.youtube.com/watch?v=xX-RcXHgeYQ

he talked about a "bun" in his 300 gallon tank, so I though even if I needed two exchangers I could reject heat from the boiler into the tank through the bun, or ssts style HX.
My newest thoughts... even as I write this, is to use a plate HX, one side the boiler, the other would be my furnace coil, tank, and additional HX for domestic hot water on an additional loop. I guess I could use a plate HX exterior to the tank, and simply pick up circ water from the tank, and return it directly into the tank with no HX in there at all, a simple open loop, perhaps take cold off the bottom and dump hot back on the top.

I know some people run their forced air system coil directly off the boiler to give the house heat first if needed, then store it, I'm thinking of just rejecting all my heat to the tank, and then flywheeling off the large volume, even if the boiler is off. this would allow me to get my domestic off the tank too, using a mixing valve arrangement.


Thanks to all for the thoughts and comments. keep em coming, I appreciate them.

SSTS style HX PIC

 

[WoodNotOil]

I think the key to the finned coil in the picture in your first post working is the length of it. The whole idea is to keep a tank stratified so you want hot to top and cold to bottom. So you want the coils to go almost to the bottom of your tank. You can then have the charging water go in one direction and the drawing water go in the other direction (see my site in my sig for a simple way to do this). The fins allow one of those coils to have a lot of surface area without a lot of piping. So one of those would do the job of a whole lot of regular copper coil. The difficulty is calculating how much transfer potential you have. I think it is an idea worth pursuing.

With a plate hx you would need dip tubes to pump the water in and out of the tank and through the hx. The flow would go top to bottom for draw and bottom to top to charge. With this application you want to minimize mixing by point the two away from one another at least and possibly even having a perforated pipe to slow down the water and disperse it evenly.

 

[Ryedale]

I think the key to the finned coil in the picture in your first post working is the length of it. The whole idea is to keep a tank stratified so you want hot to top and cold to bottom. So you want the coils to go almost to the bottom of your tank. You can then have the charging water go in one direction and the drawing water go in the other direction (see my site in my sig for a simple way to do this). The fins allow one of those coils to have a lot of surface area without a lot of piping. So one of those would do the job of a whole lot of regular copper coil. The difficulty is calculating how much transfer potential you have. I think it is an idea worth pursuing.

With a plate hx you would need dip tubes to pump the water in and out of the tank and through the hx. The flow would go top to bottom for draw and bottom to top to charge. With this application you want to minimize mixing by point the two away from one another at least and possibly even having a perforated pipe to slow down the water and disperse it evenly.

I guess I wasn't aware of the fact that you are wanting to keep the tank stratified, so less mixing is good to get the hottest water for the draw loop?

I was thinking of a pipe like you said with hundreds of drilled holes in it, but the area of the holes being less than the total area of the pipe, so there is still some "squirting" action but very little. IE perforated pipe.

 

[pybyr]

I know some people run their forced air system coil directly off the boiler to give the house heat first if needed, then store it, I'm thinking of just rejecting all my heat to the tank, and then flywheeling off the large volume, even if the boiler is off. this would allow me to get my domestic off the tank too, using a mixing valve arrangement.

if you do a primary/ secondary piping & pumping arrangement, it does not have to be either/or- send heat from boiler to house when needed, from boiler to tank when the house is satisfied, and from tank to house when house needs heat and fire is out

 

[WoodNotOil]

I think the key to the finned coil in the picture in your first post working is the length of it. The whole idea is to keep a tank stratified so you want hot to top and cold to bottom. So you want the coils to go almost to the bottom of your tank. You can then have the charging water go in one direction and the drawing water go in the other direction (see my site in my sig for a simple way to do this). The fins allow one of those coils to have a lot of surface area without a lot of piping. So one of those would do the job of a whole lot of regular copper coil. The difficulty is calculating how much transfer potential you have. I think it is an idea worth pursuing.

With a plate hx you would need dip tubes to pump the water in and out of the tank and through the hx. The flow would go top to bottom for draw and bottom to top to charge. With this application you want to minimize mixing by point the two away from one another at least and possibly even having a perforated pipe to slow down the water and disperse it evenly.

I guess I wasn't aware of the fact that you are wanting to keep the tank stratified, so less mixing is good to get the hottest water for the draw loop?

I was thinking of a pipe like you said with hundreds of drilled holes in it, but the area of the holes being less than the total area of the pipe, so there is still some "squirting" action but very little. IE perforated pipe.

With mine I found that the holes need to be farther apart close to where the water enters the pipe and then progressively closer together. The pipe should extend most of the length of the tank. Once again this is just for the plate hx application and would not apply to the use of coils.

There is a section on stratification on my site where you can read about it in depth. The short answer is that you have a hotter usable temp at the top of a stratified tank than you would with a mixed tank.


Pypyr is right on with how to pipe this thing. A P/S piping would allow you to choose heat sources or a hydraulic separator would as well. You could also do a parallel hookup like the Simplest Pressurized Storage sticky, just substituting in the plate hx separating the tank from the pressurized heating system.

 

[Fred61]

My old Wood Gun had a heat exchanger for DHW that was similar to the one in the photo only finned. I should have salvaged it when I junked the unit but by that time I had had enough of the beast. One other component I think about and could have used is the electric damper motor. Perhaps if you contacted the folks at Wood Gun, they could probably get one for you.

 

[WoodNotOil]

My old Wood Gun had a heat exchanger for DHW that was similar to the one in the photo only finned. I should have salvaged it when I junked the unit but by that time I had had enough of the beast. One other component I think about and could have used is the electric damper motor. Perhaps if you contacted the folks at Wood Gun, they could probably get one for you.

Most DHW coils would only stick down a foot or two and I would think you would want it to go to the bottom of the tank if possible.

Addition: I was just googling these things and found this site http://www.energytransferinc.com/hot-water-coil.html . I think they do custom coils. You might get a quote from them and discuss with them the application and btu load you are trying to transfer.

 

[Fred61]

My old Wood Gun had a heat exchanger for DHW that was similar to the one in the photo only finned. I should have salvaged it when I junked the unit but by that time I had had enough of the beast. One other component I think about and could have used is the electric damper motor. Perhaps if you contacted the folks at Wood Gun, they could probably get one for you.

Most DHW coils would only stick down a foot or two and I would think you would want it to go to the bottom of the tank if possible.

Addition: I was just googling these things and found this site http://www.energytransferinc.com/hot-water-coil.html . I think they do custom coils. You might get a quote from them and discuss with them the application and btu load you are trying to transfer.

When you have a steel or stainless tank, you can add a bulkhead connection any place it is needed. Top, middle or bottom.