Arizona republican. [volume] (Phoenix, Ariz.) 1890-1930, 1909-04-30

The experts who had immediate
charge of this investigation were D.
T. Randall and II. w. Weeks. engi
neers of the technologic branch of the
survey. and they have just made their
report, which will soon be issued by
the geological survey as a bulletin. Mr.
Randall makes the statement that not
only can bituminous Goals high in vol
atile matter be burned without smoke,
but also that large plants carrying
loads that fluctuate widely, where boil
ers over banked fires must be put into
service quickly and fires forced to ca
pacity can be operated without pro-
ducing smoke that is Objectionable. Mr.
Randall maintains that il is not neces-
sary TO use any one certain patented
furnace to obtain smokeless conditions.
On the other hand, he declares that
there are many types of furnaces and
stokers that burn coal without smoke
Credit is to be given to any one
kind of apparatus only in so far as
the manufacturers require that it shall
be so set under the boilers that the
principles of combustion are respect
ed" says Mr.. Randall. "A good stoker
or furnace poorly set is of less value
than poor stoker or furnace well
set. Good installation is necessary
for smoke prevention"
And here is the secret of all smoke
less burning of coal. Mr. Randall
says: "Stokers or furnaces must be
set so that the combustion is COM
plete before the gases strike the heat
ing surface of the boiler. When
partly burned gases at a temperature
of, say $500 degrees Fahrenheit, strike
the tubes of boiler at, say $50 de-
grees Fahrenheit, combustion is nee
essarily hindered and may be entirely
arrested. The length of time required
for the gases to pass from the coal to
the heating surface probably averages
considerably less than a second, fact
which shows that the gases and air
must be intimately mixed when large
volumes of gas are distilled, as at
times of hand firing, or the gas must
be distilled uniformly. as in a me-
chanical stOker"
The surveys engineers do not be-
lieve satisfactory results can be OBJ
tanned in plants where the furnaces
are fired by hand. Although hand
fired furnaces can be operated with
out Objectionable smoke" says Mr..
Randall, the fireman is so variable
a factor that the ultimate solution of
the problem depends upon the me-
chanical stoker-in other words, the
personal element must be eliminated.
The small plant is no longer depend
ent on hand fired furnaces, as GER
tain types of mechanical stokers can
be installed under a guarantee of
high economy. with reduction of labor
for the fireman.
None of the problems of combus-
ton has received more experimental
treatment than the burning of coal in
furnaces. Hundreds of de-
vices for smokeless combustion have
been patented but almost without ex-
ception they have proved failures
This record may be explained by the
fact that many of the patentees have
been unfamiliar with all the difficult
ties to be overcome, or have begun
at the wrong end. Numerous patents
cover such processes as causing the
waste gases to re-enter the furnace,
and schemes for collecting and burn
ing the SCOT are legion. So many
who have been looking
for some cheap addition to a poorly
furnace to make it smoke
less have experienced inevitable fail
ure that the work of educating the
public to rid cities of the smoke nui-
sance has been hard, long and only
partly successful.