Post in 'The Boiler Room - Wood Boilers and Furnaces' started by 2.beans, Nov 8, 2012.
thank you, but sorry no prize.
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That is a very large plate and frame heat exchanger. Looks like it might be a DeLaval. I think that MR 2Beans will have no trouble maintaining very close approach temps.
the exchanger is a "mueller". when you say "very close approach temperatures" your meaning each side of exchanger will be very close to equal. one side being the pressurized and the other side being open.
Yes 2 beans. You will be able to get endless hot water (DHW) with that exchanger for sure. Something that large should function just like an instantaneous gas fired water heater.
So if you have 4 full baths, a dishwasher & clothes washer...well then all the ladies in your house wil be very. Endles showers/baths etc.
Pretty sure they will hold a vote & make the dishes & laundry your job though...sorry about the bad news.
Btw nice find, good luck & have fun with the project.
Great Find, but now is the time to give this boiler o2 control!
MR 2Beans, you will not regret buying that Garn. in my humble opinion, there is nothing simpler than a Garn and the bigger the better. With the storage concept on the Garn, you can't oversize the system. The bigger the storage the less you have to think about it. I built a 3000 gal system for myself and a 6000 gal system for my brother-in-law. If I were to redo mine, it would be 6000 gallons. .
When you hookup your boiler, add an exhaust temp guage just after the exhaust exits the boiler. i added a turbulator to my last pass, a suggestion from Tom Caldwell, and now i have exhaust temps exiting the boiler at about 250-300 F. I would love to see Tom's O2 system, but I believe there is deminishing returns when your exhaust temps are already so low.
2Beans, click on my name in the avatar, click on information and you will find my garn, if you want to talk further give me a call tonight.
Quite the heat exchanger! Every once in awhile I run into this size of plate heat exchangers at farm auctions. Any disadvantage to using an industrial sized heat exchanger in a residential application?
i took it out a house so im assuming it worked. i cant see any reason that it wouldnt. probably the only reason you dont see them in more houses is cost. no need to oversize the exchanger if you dont have to. this boiler started its life in a light house so im guessing thats where the exchanger came from as well.
It appears that the circ pump is cast steal as well as some parts on the exchanger. I thought that was a no no on Garns since they are an open system? I am hoping to soon plumb my Garn up and was under the impression that the circs should be SS or bronze. I figured it that was the case I would by a HX and keep the load side of things pressurized and use reg circs, and SS on my primary loop.
The GARN is all steel so with properly treated water you shouldnt have an issue with cast pumps or black iron pipe. as for the exchanger its all stainless. If domestic hot water then you would need stainless or bronze. [Or hot tub pool ect]
That heat exchanger will basically give you a 0* approach temp if you circulate enough fluid from the source side of the system. [the Garn] The Mueller and DeLaval I mentioned are virtually identical and that size unit probably came off a dairy farm and had maybe 30-50 GPM of cow temp milk on one side and the same amount of well water or chilled water going through the other. They are made to cool the milk in one pass so they have tremendous capacity to move heat.
The steel/iron body pump is not an issue. Every Garn we have ever done has an iron pump on it. No problems. If you are running 100% fresh water for domestic use, yes, then by all means use a Bronze or SS pump. I'm guessing that HX would sell for around $5K new.
All that being said, that type of HX has a gasket between each section and they are made to be taken apart for cleaning. You may want to contact Mueller and find out if the material normally used for said gaskets is suitable for use in a boiler system which will be running at 180*+ and will contain typical boiler chemicals.
Just a thought.
The heat exchanger was hooked up in the house when I picked the boiler up. Supposedly the heat exchanger was in the lighthouse that the boiler was in as well. That doesn't mean that it has the right gaskets in it. So that is a good idea to contact them to see if it is compatible with heating system. Thank you.
I added a turbulator to the garn, flue temps are between 400-450 if the temp drops below 325 it smokes a bit, if it's 250 it's almost out. Do you think my temps are too high?
Where did you get your turbulator, aftermarket or garn. 400-450 represents a good hot burn, depending on the stage of the burn, if toward the end 325 is normal, if in the middle the wood moisture content could be too high disrupting gasification, yes at 250 it is almost out. What was the water temp when these flue temps were monitored. keep in mind if these were before the last pass, the actual flue temp at the back of the appliance is lower. Turbulators should be sized carefully, as they can cause flow restricting backpressure that does show a lower fluetemp caused by reduced boiler output.
If your burning wood with the correct moisture content what should the exhaust temperature be at the back of the boiler? Without a turbulator.
I'm assuming it's a turbulator , it's an angled piece of steel that fits in the final section of the flue behind the thermometer. Gran supplied.
Check out this link. http://shop.garn.com/order-parts/flow-stabilizer-p-0062/
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