Chains instead of turbulators

The idea of turbulators is to maximize contact of the hot flue gases with the outside of the tubes in contact with water. Laying the chains on their sides probably would work pretty well, but it may not achieve the optimum result.

I did this with a recent boiler. Ran a single long chain in two tubes. Not sure it was exactly centered, but did all the tubes the same. The bottom line is what the stack temperature was. It was significantly lower.
The beauty of the chains is they disrupt flue gases and get them in contact with the tube walls. In a perfect world, they probably should be perfectly centered.
In our case, the stack temp dropped so much that I was happy as they were.
The current units we are testing have sheet metal turbulators in them. I will change over to chains based on my recent experience. They should last a very long time and as you say are a lot easier to remove. One has to play with diameter of the chain to fine tune it.

In my boiler chains work great and they also work great to clean the tubes if you use a drill to spin them at the end, on vertical tubes of coarse. I welded a small pipe or a bolt that I could chuck into a cordless drill.

I think you're approaching this from the wrong direction. Instead of installing "crud proof turbs (chains), my approach would be to locate the reason for plugged tubes. Is your wood dry, does your unit idle a lot or are you loading too much wood for the heat load. A full load of wood baking in the firebox will produce more creosote than a small, more charred load.
I tested chains vs. oem turbs and found no difference in stack temperature. The reason I decided to go with chains was ease of handling when cleaning.

In my experience, it does not take much to cause turbulators to get stuck. And they tend to wear out. The cost is kind of high for what they are, some spindly sheet metal. Chains bring a lot to the table.
A small transitory start up issue will get sheet metal turbulators stuck. Not so with chains.

Going into year 4 now, I have never had issues with my sheet metal turbs sticking, and haven't noticed them wearing any. Must be some design & manufacturing differences between boilers. Also seems like the OP is experiencing some significant build up if it reduces the airflow much.

Turbulators in the Jetstream were over 30 years old with little sign of wear.

I feel compelled to because I think the chain turbulator originated with me back in the 2006-07 heating season, or at least I wasn't aware of the idea from any other source, and if it did originate with me, I think it is the best and most innovative idea I ever had with regard to a gasification wood boiler. Certainly not perfect, but they work, and work well.

frolingdual said:

After several problems with my turbulators getting stuck and reducing airflow I have removed and put chains in.
So far great improvement. I am wondering if it is best to hang them centrally in the tube though?At present I have them such that one chain is used per two tubes and hence lay on the side of each tube.

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Sounds to me like you have a problem with creosote, not turbulators.

Dirty fire tube just fly ash .Turbulators come out easy.

I'm doing a turbulator test (see recent thread) in the next couple of days. Reading this, I'm mightily tempted to add a second test using chains. I'll look and see what I have lying around.