[Steam-engine] Re:sediment in mud ring or suspension?

[HISTMACHRY at aol.com]

Charlie,

Regardless of the boiler type the cold water from the injector should be kept 
away from the hot firebox. Even if the historic/old location of delivering 
water to the boiler was anywhere but away from the firebox, and it was my 
boiler, I would relocate the point of delivery. The blowdown you see near the middle 
try cock is to "skim" the surface of the water to remove solids on the 
surface. This assumes of course that the mean water level is at the middle try cock. 
Blow down valves at the mudring remove the sediment that settles there, as 
the boiler settles down from heavy firing,  or other activity like water being 
feed into the boiler, whistle if safety valve going off, etc. Another blowdown 
is the Continuous Blowdown, where  water is constantly being removed from the 
boiler, and removing a portion of the total disolved solids in the boiler. 
This of course requires for feedwater delivered to the boiler.

If the tubes are covered in scale water treatment can loosen the old scale, 
where it can then be washed out of the boiler. There are also mechanical tube 
cleaners that impact the inside of the tube, the resulting vibration causes 
scale to come off the outside of the tube. I have used a blunt tool in a chipping 
hammer to vibrate the exterior sheets of the firebox to remove scale from the 
inside surfaces of the firebox, it doesn't remove all of the scale but does 
remove the loosest stuff. 

Robert Yuill