Source for spiral turbulators?

[DaveBP]

I've been stumped in my search for a source for spiral turbulators for my Tarm boiler. Tarm used to offer the bent zig-zag type but I can make those myself. I'm just a little fascinated with the helical action so I wonder how much they might cost to buy.

Some of the brands that people own around this forum come with them but I haven't seen replacement tubulators on any websites. I haven't gone so far as to call dealers, though.

Has anyone bought a set of these from anywhere that doesn't require a wholesale license? I would be looking specifically for some that would fit into 80mm (about 3-1/8") I.D. tubes.

 

[timberr]

Dave,

Contact TARM, there pellet boilers have the spiral turbulator's not sure on the dimensions. MAybe they could be used.

 

[Chris Hoskin]

spiral turbulators used in the Solo Innova too. Give me a call on Monday and I'll let you know if they (or the Multi-Heat turbulators) would be a good choice for the Solo Plus. The Solo Innova turbulators are just under two inches in diameter and the Solo Plus tubes are about three inches. Anyone have any thoughts if that would work OK or would too much exhaust gas just 'slip past' the turbulators? Hmmmm.....

Chris

 

[jebatty]

Tarm Guy Chris: what does your data show as to stack temp drop with and without the turbulators? When I added my "chain turburlators" 3 years ago, Tarm advised I could expect about a 100F temp drop with turbulators (type not specified). The chain turbulators I made achieved every bit of that. Burning well seasoned pine slab wood, my stack temp typically is 380-420F (measured with a K-type digital probe in single wall black stovepipe, 18" above the Tarm flue outlet), with 450F approx maximum, and time to reload at 380F.

 

[kabbott]

Tarm Guy Chris: what does your data show as to stack temp drop with and without the turbulators? When I added my "chain turburlators" 3 years ago, Tarm advised I could expect about a 100F temp drop with turbulators (type not specified). The chain turbulators I made achieved every bit of that. Burning well seasoned pine slab wood, my stack temp typically is 380-420F (measured with a K-type digital probe in single wall black stovepipe, 18" above the Tarm flue outlet), with 450F approx maximum, and time to reload at 380F.

Just for comparison sake... My Varm runs about the same Jim. I have seen 46x F for a max when burning some dry pallet wood. The output exceeded the 30kw rated output
but I believe the Varm rating is an average not peak. My thermocouple is on the boiler itself not in the pipe but I don't think 18 downstream would make very much difference.
What amazes me is the dramatic drop in output with a 20-30 degree stack drop. Don't know how I lived without the thermocouple before... VERY HANDY.

When I get a chance I may pull the turbs out and check to see how much the temps rise... You got me curious now. :coolgrin:

Kris

 

[Chris Hoskin]

Tarm Guy Chris: what does your data show as to stack temp drop with and without the turbulators? When I added my "chain turburlators" 3 years ago, Tarm advised I could expect about a 100F temp drop with turbulators (type not specified). The chain turbulators I made achieved every bit of that. Burning well seasoned pine slab wood, my stack temp typically is 380-420F (measured with a K-type digital probe in single wall black stovepipe, 18" above the Tarm flue outlet), with 450F approx maximum, and time to reload at 380F.

Those are great stack temps Jim - I wouldn't want to see them much lower. I would expect you to see stack temps in the 500-600 degree range without turbulators all else being equal.

 

[jebatty]

When I get a chance I may pull the turbs out and check to see how much the temps rise…

I'll do the same to make sure my recollection from 3 years ago is correct.

 

[willworkforwood]

... The Solo Innova turbulators are just under two inches in diameter and the Solo Plus tubes are about three inches. Anyone have any thoughts if that would work OK or would too much exhaust gas just 'slip past' the turbulators? Hmmmm.....
Chris

Before spending $ on an undersized turb Dave, you might be able to get some helpful info by using multiple sections of chain, hung side-by-side. I recall that Tarms allow easy access to the tubes, so multiple experiments could be run, each with a different number of chain sections (and maybe also different link sizes). Chain is relatively inexpensive, or you might even have already have some from another project. Based on the results, you could either just run with the best chain combo, or perhaps take a shot at trying to match the best-performing chain weight/volume to a custom set of spiral turbs. I was told by the Econoburn factory guy that chain didn't perform as well as the EB spiral turbs, but now having said this, I'm wondering if they ran any trials using multiple chains. Hmmmm......

 

[DaveBP]

I have some 16ga. 304 stainless steel strips that I can shear to a couple inches or so wide and bend into a zigzag Brock-type strip turbulator. These would probably be as good as any other style. Most of the info I could find on the web is big industrial boiler oriented.

I've had my eye out for some big chain since Jebatty first reported on his experience but the elegance of the spiral twisted strips made me wonder how much they cost. I'll undoubtedly try the free route first because I have those stainless sheets standing behind the basement door and hydraulic shear and press available at work.

 

[leaddog]

You can just take those strips and place one end in a vice. Take a large cresent wrench and start turning on the other end. put as many twists in as you want. You will have to straighten them some so they will slid in but they work well and easy. If you cut them about 1/4in smaller than the tube dia they will work best. I made some for my sons older eko60 but went with chains as they are easier to clean.
leaddog

 

[Chris Hoskin]

the consensus around the office here is that the Solo Innova spiral turbulators would work, but the Multi-Heat pellet boiler turbulator is a bit wider and would work better. These turbulators rest on "shoulders" that keep the piece from falling down into the heat exchange tube and these would need to be widened by welding a small piece of flat or round stock across the top of the turbulator. For a less elegant, but much easier, solution, you could just slide a 3 1/2" or 4" bolt through the hole at the top of the tuburlator and let the piece hang from that. Cool idea.

 

[Chris Hoskin]

anyone have any thoughts about how much more effective spiral turbs would be compared to zig-zag? Any difference at all?

 

[kabbott]

anyone have any thoughts about how much more effective spiral turbs would be compared to zig-zag? Any difference at all?

I have no clue really... At first glance it would seem spiral would be better, However zig-zag may create more turbulence and be more effective. I would like to see some
data on each.

As far as the spiral... If one had a piece of tube the same size as the firetube you could shear a piece of metal and insert it in the tube, hold one end and twist the other.
The tube would help keep it straight.

 

[kabbott]

oops... double post

 

[BONE]

Hi DAVE
sorry for butting in, but do you think stainless washers cut on one side, or round blanks with right diametre hole in centre cut on one side ,opened up ,and formed around stainless bar ,ending up like a industrial food screw.Could quite easily be fab for a test piece.BONE