Talk:Thermic siphon

Expansion (+ diagram) required

I know this is only a small article, but it needs some additional explanation for non- 'rail nuts'. For example 'throat sheet', 'crown sheet'...huh? If there was ever an article that needed a diagram, this is it!

EdJogg 20:34, 15 November 2007 (UTC)

I have added some clarification. Biscuittin (talk) 08:43, 3 April 2008 (UTC)

That's much clearer, thanks. But I still think a diagram would be useful, as I'm having difficulty imagining what they look like.

EdJogg (talk) 10:49, 3 April 2008 (UTC)

I've added an external link but it only shows a small part of the thermic syphon. I'll see what else I can find. Biscuittin (talk) 16:40, 3 April 2008 (UTC)

It's a good start, and some unusual pictures. The refs are good finds too. I'm usually surprised at what I can find once I start digging... EdJogg (talk) 23:47, 3 April 2008 (UTC)

Accuracy

Quote:

"Fresh cold water introduced from the injectors is pre-heated by passage through the syphons before arriving at the crown sheet".

I don't agree with this statement. The feedwater will have been pre-heated (by being mixed with hot water in the boiler barrel) before it gets anywhere near the thermic syphons. The thermic syphons are not feedwater heaters, they are just part of the boiler heating surface. Please discuss. Biscuittin (talk) 08:41, 3 April 2008 (UTC)

Arch tubes

Locomotives with wide fireboxes often had arch tubes to support the brick arch. I've never seen an arch tube but I think it was a simplified version of a thermic syphon. Does anyone have more information? Biscuittin (talk) 08:48, 3 April 2008 (UTC)

Simplified to the point where it wasn't a siphon. It carried water, it added radiant heating area, but because of the shallow angle needed to support the arch, it wasn't as effective as a true syphon for thermosyphon circulation. A thermosyphon needs more height difference between the ends. Andy Dingley (talk) 20:02, 22 September 2010 (UTC)

Syphon or Siphon

We should choose one spelling and use it throughout. Since most of the examples in the text relate to British applications, maybe the UK spelling should be used?--Theodore Kloba (talk) 19:13, 22 September 2010 (UTC)

Probably, but who's going to choose which? Andy Dingley (talk) 20:03, 22 September 2010 (UTC)

Leader picture

I don't want to appear 'dense', but what in the picture of the Leader boiler are the thermic siphons? I think the caption needs a little more explanation, or the photo edited in some way to highlight them. -- EdJogg (talk) 14:10, 24 September 2010 (UTC)

They're the great big things that a Leader has, that other boilers don't! Look at the picture of the Nicholson syphon, then look for the thing that looks the same. Maybe juggling image order would help?

This article still needs a lot of expansion of locomotive syphons pre-Nicholson (Ahrons would be a good source). At one point it even claimed that he'd invented them. Andy Dingley (talk) 15:25, 24 September 2010 (UTC)

Ahhhhh! NOW I can see what I'm looking for! Thank you. That is actually a quite helpful photo, but you do need to look closely. At default resolution, the pipe at the bottom of the nearest syphon could be 'just a pipe'. Also, as the rest of the syphon is sort-of 'firebox-shaped', and the shadow is such that you cannot see how thin it is, it just looked like the side of 'a firebox'. It also helps to understand that you are already 'inside' the firebox -- presumably there is an outer casing to be rivetted on later, so that might be worth mentioning. (This might result in a long caption, but sometimes 'a picture paints a thousand words' needs some help!)

Definitely changing the photo order will help. You have a good understanding of my (limited) knowledge of boilers, but I don't think that it's unreasonable to say that my understanding will be somewhat higher than the average (non-technical) reader here, so if I can't understand something technical then it certainly needs more explanation! (Reading the section on steam locomotives also helps! Ahem.)

EdJogg (talk) 09:31, 25 September 2010 (UTC)

I suspect it's not about arcane knowledge, just that my preferences set thumbnail sizes to be bigger! Andy Dingley (talk) 18:43, 26 September 2010 (UTC)

Why "siphon"? What propels the water through the siphon?

There's no explanation of just how these devices work. Is it that the heated and thus expanded water rises? Are bubbles and steam created? There doesn't seem to be a pump involved... Dan Griscom (talk) 02:19, 26 October 2013 (UTC)

Thermic syphons are thermosyphons. Might be worth making this more obvious in the text here. A _lot_ of steam is created, as thermic syphons are placed in the hottest part of the firebox, with lots of radiant heating directly from the fire. Andy Dingley (talk) 06:30, 26 October 2013 (UTC)