Radiant Superheater Types.

[mgjParticipant @mgj]

I was going to take the quick solutiuon and buy from Blackgates the welded spearpoint superheaters for Metre Maid. However, they don’t do them any longer, and I am having a lot of trouble getting some made – its actually quite difficult to get them to the right dia, and still get enough swerve at the far end to achieve a decent weld, and still have them fit down the flues.

 

The alternative is to use the concentric type which I can get welded very easily, and will be far easier to get down the superheater flues – and I can keep the areas constant quite easily..

 

Is there any advantage with the welded spearpoint type, that anyone knows of, or are concentrics OK. Or when designing them, is there anything I should watch out for particularly.

 

Essentially I was going to pass the wet steam down the centre of a 5/16 tube, turn it round at the far end and bring it back round the outside in a bit of 1/2″. Put holes in the 5/16 tube – x150% area to minimise losses at the firebox end turning through 180 deg, and bring it back down the outside. The cap at the far end would be finned of course, and I’ll get it as far as possible into the firebox to maximise radiant area.

 

Anything else needed, since I have no drawings. .

[mgjParticipant @mgj]

[Hugh GilhespieParticipant @hughgilhespie56163]

Hi mgj

 

I wonder if the advantage of the spear point design is because it minimises the loss of cross section in the flues? Two 5/16th od tubes have about 20% less cross section compared to a single 1/2 inch od tube. Of course, if the flue diameters are much bigger it probably won’t matter.

 

Regards, Hugh

[mgjParticipant @mgj]

Flue diameter is just over 5/8 – its 3/4 od tube.

 

This is new territory for me, but I was wondering if the spearpoint design could cause losses by that very sharp return bend.

 

Mind you, the concentric type with a “chamber” at the far end is hardly the “super flow” set up either.

 

Could be a case of any (effective) superheat is better than none?

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