Economizer Tube Failure

Remy 21-May-11 (17:47) post about a similar experience.

The tube failures were traced to a heat-treating step in the last stage of fabrication. The tubes were placed on refractory bricks in an annealing furnace to keep them a few inches above the furnace floor. Unfortunately, a metallurgical imperfection occurred everywhere the brick contacted the tube, thus compromising its mechanical integrity!

Now you have heard... the rest of the story!

Regards, Phil Corso
 
N

Namatimangan08

Water hammer. I think you have heard about this phenomena. Water hammer causes explosion rather that implosion. What I'm predicting here is the opposite of water hammer. We can call it the formation of low pressure region near vacuum state. It can cause implosion since it creates almost vacuum state inside a constant volume flow conduit. This conduit is exposed to ambient air pressure. The nature of air is that it moves from high pressure to low pressure region.

Think about this simple experiment. Take a straw. Fill it up with water in full. Using your finger close the other end tightly. Now you can rotate whichever direction you want. The water in the straw remains there. Why? It is in pressure equilibrium with ambient air in all directions. No net pressure reacts on the straw.

Next, suck the other end. See what will happen? Yes. The straw turns flat. Why? When a quantity of water is removed from the straw says 2mm3, then an equivalent volume of vacuum state will be created inside the straw. Ambient air pressure "sees" this. Thus, net pressure will react to bring your straw-water system to a new equilibrium state. In this case, the straw is flattened...

I think this is the "physic" that caused one of your boiler tubes "dent"....
 
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