Heat Exchanger End Flange Decapitation
Hello HeatingHelp.com Community! : )
This was my first encounter in scrapping an abandoned chiller tube.
I had four different local scrapper guys take a look …. and they all walked away from it! : (
This caught my interest, ….. so I decided to try my hand at it.
The tube was 2ft in diameter x 10ft long and a 1/4" steel tube wall thickness.
The inside of the tube was packed full with thick walled 1/2" copper pipes.
These pipes terminate (brazed) at each end of the tube into a 3/4" thick flanged copper bulkhead.
These flanges extend 2" beyond the tubes outside diameter and are 1" thick.
Aside from the two 2" in/out pipe ports on the domed end caps, there were two 3" in/out flanged pipe ports attached directly to the tubes wall, vertically ,very near the tubes ends.
These vertical flanged ports created an obstacle to passing my circular saw, leaving an unreachable cutting area 12" long in circumference.
To get around this, I had to remove the saws contact base plate (shoe) and split the front blade shield off (now my saw looked more like a big disk grinder with an 12" - 82 tooth carbide tipped metal cutting circular blade). ……… scary indeed! : (
Since trying to cut upside down the bottom half of the tube with this large spinning blade ….. would be lethal : ( ….. I had to release the tube from its mounts and rotate it.
After cutting all away around the steel tube, I then used a 14" saw zaw blade to cut at the copper tubes inside ….. again having to rotate the tube to reach thru to all the tubes.
All this worked out ok …. but thinking: …. what would be a better way to do this ?
Keep in mind, the solution would have to be in the realm and affordability of the typical "junker" or "metal scrapper" guy. : )
Pics below set the stage of the industrial scale steel cutters using diamond grit steel rope.
My thoughts are, …. that I can make such a cutting tool rather simply with mostly all "off the shelf" standard components and a simple frame fabrication.
Basically, …. a motor drive to spin around a diamond grit "loop" with an "auto loop tensioner" as the loop cuts thru the steel and copper.
Once attached to the heat exchanger tube, you can let it run by itself without holding anything.
….. your thoughts on this?
Thanks!
Comments
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excavator with a deo claw on it?
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or cut the tubes with a torch on both sides of each bulkhead one layer at a time
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………. for commercial sized hot water tank scrapping as well?
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They are difficult to cut up Torch won't cut copper. There is no easy way to do this.
I have cut up huge fire tube steel boiler but those tubes are much bigger they have 2" or larger tubes and are all steel.
The first one I did we we stuck our torch in the tube at an angle and cut around the tube from the inside out. This was a slow procedure.
We then found it was easier to cut the tube sheet which in the boilers were steel and we would cut the tube sheet in a circle or a square around each individual tube and then remove the tubes with a small piece of tube sheet attached to each end this proved to be much faster
What are you tube sheets made of I would thing they are steel and you could do the same thing?
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The "boiler" tubes (inside the very large steel containment cylinder) you refer to were 2" steel tubes?
……. my interest in this scrapping job was for the very valuable copper tubes inside!! (over 160 10ft long 1/2" "K" copper tubes) $$$$ : )
….. "steel only" scrapping is hardly worth the salvage scrap money you get.
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" …… They are difficult to cut up Torch won't cut copper. There is no easy way to do this."
My thoughts are: …. what would be easier than attaching a "loop" around the large steel cylinder and come back in a hour to see the 2 ft diameter flanges laying on the floor? : (
…… and all the 160 copper heat exchanger tubes ready to be pulled out freely!
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could you get them outside and use a plasma cutter.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
That was the first thing I tried!
Harbor Frieght plasma cutter (cuts out to 5/8")
What a mess that was! : (
You ever try cutting with one?
The eye protection is so dark, you have to have a lot of experience working thru that dark shield.
I was all over the place cutting. : (
I could not produce a reasonable cut line.
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…….. the 12" circular carbide blade cut very well , but forces you to rotate the entire 2' x 10' containment cylinder (so your not trying to cut upside down).
Still loaded with all that copper inside ……. its extremely heavy!
….. and rotating this extremely heavy cylinder with its bolted down mountings removed is extremely dangerous as well (can roll off its perch and free fall to the ground).
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The big flanges at the end of the tubes are the tube sheets. Are they steel or copper? I am betting they have to be steel.
What we did with the boilers was cut the tube sheet around each tube with a torch. We got decent $$$ for the steel but the job wasn't done specifically for the scrap the boilers had to be removed
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The thru bolts area on the flange is 1" steel and the bulkhead where the copper tubes emerge is 3/4" thick copper.
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…. I never heard the term "sheets" for the flanges : (
What was that derived from? "Pile sheets"?
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are the tubes also attached to the spacers in the middle? if they just pass through you could cut layer by layer cutting a v from the top using the circular saw and moving in to cut another pass at the end of the cut from the previous layer sort of like you're cutting a tree with an axe
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Their not attached in the middle of the pipe, but are surrounded by a wire placement grid.
You can pull each tube out easily from the open cylinder ends.
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"……. if they just pass through you could cut layer by layer cutting a v from the top using the circular saw and moving in to cut another pass at the end of the cut from the previous layer ….. " - Mattmia2
Are you suggesting cutting the full length of the cylinder multiple times?? (10feet)
: (
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This is a more robust design for the diamond grit cutting tool.
The heavy drive motor is ratchet strapped to the heat exchanger cylinder.
Now only the slide rails need only carry the sliding "slack take-up" pulleys without the heavy weight of the drive motor.
Start Cut:
End Cut:
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Hello Rick,
Do not drive yourself crazy.
You do not need to develop a diamond studded cable saw like the ones they use to cut marble, granite and sandtone.
Save yourself a lot of work and purchase some 24 inch Reed Tool Sawzall blades from Amazon that will cut up your copper.
Amazon
Reed Tool Z2414 power hack saw blade. 14 teeth per inch. $21.43USD plus tax and shipping for each blade.
Purchase gallon of Fluid Film and a small one gallon plastic sprayer and lubricate the blade as you work.
Donations of dark molasses cookies are gladly accepted.
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Hi leonz! : )
I tried several of the saw zaw metal cutting blades on the shell cylinder..… took forever to make any cut progress at all! ...... (all work and little cutting!)
Just was not the way to go with this at all.
: (
The carbide circular blade cut fine, but too dangerous and problematic.
I think the diamond grit cable offers all the safety and benefits!
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As you have the bundle removed from the shell, cutting the copper at the U bends through the U bends one at a time is simpler than trying to crosscut it. Scrap dealers are only interested in the weight of the scrap not what it looks like or the length.
Spray the copper at the U bends with the straight Fluid Film and then cut it with a small metal blade.
By doing it that way you are only cutting one tube at a time and clearing the teeth at the same time, your cross cutting it is complicating the work because of doing multiple tubing cuts versus a single solid piece that has been your problem the entire time.
Once you see how easy it is to do it will be a fast chore.
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Disagree! : (
Cutting the copper is not a problem..… it's the steel shell and access to it.
..…what is "U" bends your referring to??
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By doing it that way you are only cutting one tube at a time and clearing the teeth at the same time, your cross cutting it is complicating the work because of doing multiple tubing cuts versus a single solid piece that has been your problem the entire time. - Leonz
You think cutting 160 copper tubes one by one is easier than cutting all them at the same time?? : (
You would be there for a week cutting!
Cutting the tube's all at once is easy!!
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i had assumed yo removed the outer jacket but it would seem the safer but slower way to do that is to cut it in to about 1/3 diameter sections then cut those to whatever length is manageable and remove the top 2/3 or so then you can cut the tubes layer by layer. there is a reason no one wanted to scrap it, unless you can get heavy equipment to it or at least a cutting torch, the labor probably isn't going to be worth the value.
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There are no "U" bends in a commercial chiller.
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Hi matt! : )
" ……there is a reason no one wanted to scrap it, unless you can get heavy equipment to it or at least a cutting torch, the labor probably isn't going to be worth the value." - matt
Disagree! : (
Did the first one with just a 12" circular saw (1/4" steel containment shell) and reached in with a long saw zaw to release the copper pipe ends from the copper bulkheads at each end.
Took 1 1/2 days (really only one day …… running around 1/2 day getting blades!)
Came out of the scrap yard with $2,480.00 ……. I'm happy with that! : )
NO heavy equipment needed! : )
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……. after "decapitating" the end flanges, you simply pull all the copper tubes out by hand and load them on the truck.
Now that I have first hand knowledge of the "nature of the beast" and the real dangers for bodily harm in doing so, the diamond grit cutting cable paradigm looks to be the best and safest way to go by far.
I'll be fabricating the above pictured "cutting rig" soon , a simple pulley and framework of 1" copper pipe and fittings ….. (all sweated together with nickel bearing solder)
I'll let ya know how this all works out.
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…… footnote:
The cut off end flanges are 24" diameter, 3/4" thick copper and ringed (braised) around it a 2" x 1" thick steel flange.
Since the steel is attached to the copper ….. its copper scrap value is greatly diminished.
While I was at the scrap yard, I saw a 4 foot end flange in the low end metals bin! …. its of no significant value!
See in the "end cut" pic above ……. the diamond grit cable is standing vertically to the left side of the drive motor? …. much like a band saw!
I'll use that attribute (diamond grit band saw) to cut off the undesirable steel flange ring sitting on a lazy susan ……. and recover just the massive copper disk!
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Question:
Is there a simple low cost chemical solution to drop all the copper tubes in a bath …… to bring them up "shiny bright?"
What , if any, would that be?
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Maybe I'm missing something. Cut the shell behind the tube sheet all the way around. 6" angle grinder with a pack of disk will do that. Once through the shell, cut through the tube bundle with a long sawzall blade.
Those rope saws a pretty cool though. For your DIY version, don't underestimate the torque on the drive section.
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Hi Kaos! : )
"Cut the shell behind the tube sheet all the way around. 6" angle grinder with a pack of disk will do that" - Kaos
Tried that! ….. yea, that will do the job …..but that's a lot like work! : (
Grinding a 2 foot , 1/4" thick steel cylinders upside down on your back takes all the fun out of the job!
Saw Zawing the tubes is easy, …. until you get a powerful kick back as the blade hits the other tubes or is pinched.
With just me and a girl helper, I had to think of ways we can easily do all this.
…… what's easier than placing a looped cable around the cylinder and let it cut both the steel cylinder and all 160 copper tubes …… all at the same time?
With a small motorized tensioner …… you could have a seat in the corner and just watch! : )
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"Those rope saws a pretty cool though. For your DIY version, don't underestimate the torque on the drive section." - Kaos
Yep! ….. will be talking to the cable manufacturers tomorrow for the recommended speed and torque requirements.
In the plain jane version, you have to constantly be there to manually increase the cable tension as the cable cuts.
For the motorized auto-tensioner version ……. you set and forget it!
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" Maybe I'm missing something. " Me too…
Scrappers would not touch it…
Assuming proper ventilation can be achieved, Oxy-Acetylene cutting torch would make short work of 1/4" steel stuff gaining access at one end (or both ends if needed) to cut the copper with a Sawzall.
By the time you engineer and build a home brew diamond cable saw the job could be done.
Oxy-Acetylene is such a useful tool, not just for scrapping stuff.
What else are you going to do with a home brew diamond cable saw ?
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
Hi! : )
"Assuming proper ventilation can be achieved ….. " -109A_5
It could …… but the risk of even a short ventilation failure would be catastrophic! (Motel environment with guest rooms right above ya)
About 3 years ago, their maintenance guy ran a small gas powered electric generator to run the basement sump pumps during a power outage near the outside basement door. The fumes got up into the guest rooms and tripped the fire alarm system.
The fire marshal made them empty the entire motel (180 guests) !! This lost major revenues for the motel for two days until health inspectors deem the building safe.
"What else are you going to do with a home brew diamond cable saw ?" - 109A_5
The first thing that comes to mind…. is the severing of the large commercial hot water tanks we have into easily manageable sections for disposal.
It takes 4 "big guys" just to carry these tanks down the stairs when new.
…… and after years of sediment build up …. its even heavier to carry out!
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……. another use?
The very large three phase electric motor that drives the compressor for this abandoned chiller system ….. is massive!! (just the end shaft bearings are 6" in diameter!) …. i'm guessing its around 1500 pounds!
As I had planned to salvage the copper (1/4" thick gauge wire) from … its a lot of work. : (
so …… I intend to cable cut this monster into three sections ….. making it easier the extract the copper windings and to carry out the steel components.
The all steel compressor attached to the motor is equally as massive! …. I hope to slice that down to size as well! : )
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As the copper tubing and the end plates of this shell and tube heat exchanger were pushed and pulled in place is their any reason you cannot grind both ends to break the bond of the gas welded end plates and push several threaded rods through the tubes and fit them with round end plates of thick flat steel with holes lined up with the tubes and then thread nuts on the threaded rods and pull the tube assembly out using a chain come along winch and sheave blocks to increase the pulling force?
You are going to need a dry ice sand blaster to clean that copper up if you are trying to obtain a higher salvage value and eliminate any pitting damage.
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" ……..is their any reason you cannot grind both ends to break the bond of the gas welded end plates and push several threaded rods through the tubes and fit them with round end plates of thick flat steel with holes lined up with the tubes and then thread nuts on the threaded rods and pull the tube assembly out using a chain come along winch and sheave blocks to increase the pulling force?" - Leonz
Yes! ……… sanity! : (
Leon, If you just slice the end flanges off the cylinder …… all the tubes can be slide out one at a time with just two fingers!
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..….. you have to remember my only helper is a skinny girl!
This is the building I told you about with the severe negative pressure throughout the building.
When she walks thru a doorway the negative pressure draft pulls her backwards! ....... makes her "moonwalk" til she overcomes the draft! : (
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Well that skinny girl with the right training, experience, a torch, a Sawzall and a small sledge hammer, that heat exchanger would come apart like a cheap suit. And she probably would enjoy it. The hardest part for her to manage may be the Oxy-Acetylene tanks depending on their size.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System1
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