I think if one is operating a "CLASS 1" type of boiler as mentioned above, the remarks are mostly correct.
However there is another "class" of boiler commonly refered to the "Monotube Boiler" in some cases, its refered to as a flash steam boiler and its much safer to operate. This is basically a coil of tubing that is directly in contact with a burner of some sort, examples would be a waste oil burner/liquid fuel burner or solidfuel burner.
In the picture below we see DanB in the foreground, observing his "Steam Generator-set" burning wood chunks. This is a Class 1 type of boiler, you can see the licenced boiler operator in the background, he's demonstrating "proper operation" to DanB.
We used to have a "Mechanical section" on the old board, and have "Other" on the new board here. (which we could rename, to mechanical, by the way) This picture was in my hard drive from a while back and I Just happened to have it, so I posted it. The original thread this photo comes from appears to be lost, at this time.
We've covered lots of ground here on fieldlines, here's a picture of one of my projects.
I TIG welded and machined the aluminum myself. The box houses two 12volt Iota Ballast's at 40watts apiece running two 5ft T8 fluorescent bulbs(on 12 volt DC). The housing was designed to be waterproof and remove heat from the ballasts, which it did well on both functions. Its a story I wrote in my diary long time ago.
Here's something interesting to checkout a Gauss Meter-
In any event, I wanted to get to my main point. There are some who have considered the possiblity of using cheap unrefined fuels, one way to do that is external combustion. So now a new class of steam engines are in development. So called flash steam engines, and the Rankine engine cycle, each are both relative to Carnot efficiency, but operate thru different means. For example, your not going to see a "4cycle Rankine steam engine" However with both types of engines the use of dynamic adjustments such as Cut-Off and Angular setting, for steam admission, using such techniques an expander (steam engine) can exceed the 3% eff number quite easily, but a Donkey Pump engine that has steam admission continuously on its power-stoke with no provisions for expansion of steam in the cyclinder, of coarse 3% would be accurate. But almost all modern steam engines built have such provisions.
The monotube boiler is not simular to a "storage boiler" and eliminates a storage drum of anysort, and the ballistics are completly different. Since the monotube has very limited storage capacity in its basic form, its also much harder to regulate its output. Powering a gen-set you can get away with it easily, since for the most part, the engine runs the same rpm over time.
True Flash Steam engines may be 4cycle and dont need live steam generated from a monotube, so there even safer, but the engines tend to be very experimental at this time. I work with such type of engines.
These type of systems are built by people who have attempted to do this for years, the primary concern is Safety, these newer steam engines are more safety redundant nearly to the point of "explosion proof". But there is one hell of a learning curve, if you havent been directly working on experimental steam engines for like ten years, there's alot of getcha's with a gotcha. Just starting from scratch is very risky, its best to work with someone who has the needed experience.
On another note, I just recently passed my ASE Master Tech Certification (they expire every 5 years) my experience spans 17 years, as a automobile master tech. At somepoint coming up here, Im going to take the Boiler Operators Exam, been studying for it for years.
JW
