As delivered the Aster Big Boy Burner was a three element burner, but as you can see it is now a
two element unit that puts out way more heat energy than the locomotive can use.
That is a Charm-Glow gas lighter in the vacant third hole in the burner body.
That is how I light up the locomotive during regular operation.
Art Walker and others were referencing the
use of ceramic burners in pot boiler configurations whether they were vertical
or horizontal. Someone, I forget who, sighted the problem of making a
poker type ceramic burner. He would be right as it is a problem, but there
is another approach.
One must ask the question "What is so special about
ceramic burners that
I would want to build one"? The simple primary answer is that they
roughly 100% more efficient than the standard blue flamed, Benz-O-Matic type
burners (whether gas ring or poker type) that are commonly found in Aster,
Roundhouse, Pierce, and AccuCraft gas fired locomotives. Why is this so?
In high school physics we learned that there are three ways that heat travels;
conduction, convection, and radiation.
The standard burners I mentioned above only use two of these paths to conduct
heat to the boiler's flue; conduction (poorly) and convection (hardly at all).
Only the properly operated ceramic burner utilizes the principal of radiation,
and as a result becomes very efficient in converting gaseous fuel into easily
transferred heat energy. The key to this discussion is not the materiel
that the burner is made from, but rather can the burner be made to radiate using
whatever materiel that the burner is made of. The answer, especially in
the case of poker burners, is an unqualified yes!
Five years ago I built the first (that I know of) radiating
for my Frank S. locomotive. It all started with a device that I christened
"Turbulator". The first Turbulator was a piece of 20 mesh
fabric that I bent into a triangular, yet helical, shape, and then sewed it
onto the end of a standard Frank S. blowtorch type poker burner. The
"thread" was .015' diameter stainless steel wire. The turbulator
was about 1 1/2" long. When the burner was operated, and the system came up to
temperature, the Turbulator (being located out in front of the bright blue
flame) started to glow a dull red.
As conditions in the flue stabilized I
found out that by turning the gas flow down that the Turbulator's color changed from dull red to medium orange! Huh! How can that be?
be know, the first amount of gas flowing out of the burner was in excess of
needs, and it was not all burning up in the blue flame, and further, it was
COOLING THE TURBULATOR as it passed on to the smokebox and out of the stack.
By reducing the amount of gas flow, thus conserving the supply, the
Turbulator came up to temperature (medium orange) And RADIATED all of the
heat generated by the burner directly into the dark colored walls of the
flue (Law of the Black Body).
I know someone is going to say "All of
heat"? Yea, it is an exaggeration, but in one on one comparison with
the non-turbulated burner, not by much. In fact one could now hold one's hand
directly over the smokebox stack without feeling much waste heat emanating
from the stack. The Frank S. runtime went from 35 minutes to 65 minutes
using the same amount of fuel! Since that time I have built many radiant poker burners, and
the designs evolved into the present types that I have fabricated for Aster
Hudsons, K4s, C&S Moguls, Western Marylands, Climaxs, Big Boy, and Rubys and
butane Janes. My personal Big Boy runs with much power untapped on two
radiating poker burners instead of the three standard burners supplied. In
fact the third hole in the burner holder in the Big Boy contains a Char-Glo
gas barbeque lighter element that allows the burners to be lit with the push
of a switch!
The "magic" materiel that I use to make the
radiating poker burners is
stainless steel mesh of about 40 to 50 denier that is tightly wrapped around
the poker burner's slots and is held in place by either a tightly fitting
sleeve ala Ruby practice (I developed this configuration for AccuCraft in the
spring of 1997), or by binding it in place with .015" diameter stainless steel
wire wrapped around the poker like barrel bands. Just this much work will
improve a "bad actor" burner, but it will not radiate heat.
The radiant component is supplied by cutting a strip of #20, or so, stainless
steel cloth long enough to cover all the burner's slots from end to end, and
wide enough to equal 3/4s of the circumference of the cloth wrapped poker
diameter. This piece of cloth is rolled up into an arc approximately the
same diameter as the poker burner, and is then sewed onto the poker using the
lowest second course of stainless steel threads (running fore and aft) as the
attachment point. This configuration resembles the top cover of a
Conestoga Wagon, and there is an air space of about an eighth of an inch between
the top of the cloth wound poker and the bottom of the 20 mesh cloth.
In practice the burner is lit on the lowest fuel valve
consistent with keeping the flame lit in a cold flue. Once the flame
steadies out the fuel control valve is opened slowly until the "Conestoga
Wagon" top starts to glow red. At this point the operator lets the glowing
mesh temperature stabilize, and then opens or closes the gas control valve
until the desired color is achieved. Consistent with the load imposed on
the locomotive, the darker the color the better as lower mesh temperatures
improve the life span of the incandescing mesh.
At the Summer Steamup in Sacramento this year I provided a
seminar on radiating burners. I borrowed a radiating burner that I had
fabricated for Sam DiMaggio's Aster K4s as my demonstrator, as well as an
example of the first Frank S. unit with a newer model of the original
Turbulator attached. Sam did not time the runs of his K4s, but he did repeatedly time his Aster Hudson which has a nearly identical radiating
poker burner in it. His run times, with the Hudson, on the same amount of
fuel, pulling the same load, more than doubled to in excess of 65 minutes
including starting from a cold boiler with no topping up the fuel tank prior
to gaining the right of way.
Now that the cat is out of the bag I hope that others will
with stainless steel radiant poker burners in their locomotives. One more
thing! Once a poker burner is converted to a radiant type its dynamic fuel
requirement drops so low that the burner becomes SILENT (or nearly so). This is a disadvantage to those who have learned to operate their
locomotives by ear. From now on they will have to learn to drive a
locomotive by the boiler pressure gauge and by observing the locomotive's
behavior both with and without load.
I hope that I have not confused anyone, and that this
help to further the enjoyment of the hobby. Obviously there is more to
stuff than I have written, but I have covered all the principles. Others
can duplicate what I have done over the past five years in their own shops
using only hand tools and following the above guidelines.