Screwed tobacco pipes made from welded steel tubes
Thread Content
We are designing the air preheater for a boiler. Due to space and layout constraints, the air preheater cannot be too large; therefore, we plan to change from straight tubes to threaded tubes. The tubes in question are sealed thin-walled tubes with dimensions of 51×1.5. Is it possible to turn them into threaded tubes? What aspects need attention in terms of the manufacturing process?
Seamless steel pipes work fine. Alternatively, instead of making the pipe threaded, welding a flow guide inside the pipe can achieve the same result.
The operating environment of air preheaters is very harsh. It is required to use seamless thick-walled pipes, with an anti-wear sleeve installed at the inlet of the flue gas. The poster used thin-walled tubes and had them pressed into threaded tubes. It doesn’t seem quite right.
Using tubes with smaller diameters will not improve the heat exchange efficiency; tubes with a diameter of 38 or 42 are sufficient, and there’s no need for threaded tubes!
When using tubes with small diameters in the design, the flow area for the smoke is too small, resulting in a smoke flow velocity that is too high and exceeds the recommended values
I know all of this you mentioned, but we’ve seen a user use an air preheater with threaded thin-walled tubes, and the wear wasn’t that severe. We can actually outsource it, but we mainly want to see if we can do it ourselves. It has been tested for a few days now, and the results are getting better and better
I’m not sure if it will work in a boiler, but if the wall thickness of the threaded tube is a bit thin, a wall thickness of around 3.5 mm is required
The wall thickness is a bit thin; it could be considered for processing into finned tubes.
Threaded tubes? They don’t seem necessary for air preheaters. The wall thickness of the tubes in tubular air preheaters is already very thin, so it seems difficult to replace them with threaded tubes.