El Paso herald. (El Paso, Tex.) 1901-1931, 1912-11-18

black smoke issuing from the chimneys
OF the public buildings. Uncle sam.
after having passed a law abating
smoke, found himself hailed before
the bar Of justice for having violated
his own law. Buc today things are
somewhat different. Investigate
begun by the geological survey and
continued in an exhaustive manner
I by the bureau of mines have demon
strated fully how smoke may be over
come, and Uncle Sans buildings no
/ longer help TO cover their own white
| marble surfaces with CRIME by con-
tributing to the smoke nuisance.
The investigation by the bureau of
mines covered all conditions and cir
J cumstances relating to the smOkeless
I combustion Of coal in boiler furna ces.
1t demonstrated that with proper
[ equipment efficient labor. and fntelIi-
1 grades of bitUminous coal can be Gscd
/ without smoke in both small and large
plants The investigation covered be-
| tween 400 and 900 plants located N
I Is large cities in nine states. Goals
from large number of states were
! covered by the Investigation.
Prevention Is Profitable.
The conclusions feached were that
/ smoke prevention is at once possible
! and profitable, that good apparatus
] set under boilers where the PRINCIPLES
I OF combustion have not been recOg-
! nized are less useful than poor appa-
J ratus installed with properly built
! boilers. 1t was found that the tenn
/ perature at the fire surface Is around
{ $500 degrees Fahrenheit and that at
/ the boiler surface around $50 degrees,
{ and that combustion necessarily is hin
! fire and the boiler is great
/ enough that the gases are
J completely consumed before reach
I ing the boiler . surface. The
/ length of time it requires for the gas
/ to pass from the coal to the boiler
/ surface in an ordinary furnace is one
/ second. The Investigations further
! revealed the fact that the elimination
I of the human element by the substi-
tuition of some mechanical method or
I throwing the coal on the fire is always
productive Of the best results
When the lnTeStl CATION was being
made the experts, on entering
city. obtained a list of the plants where
ordinary hand-firing had been dis
stituted- Smoke observations OF their
/ chimneys We're made without the
knowledge Of anyone connected with
the plant. the observations covering
periods OF from one 10 ten hours each.
These were checked up with the smoke
inspectors records. Plants with chain
crates, front feed, and side feed ste
kers were examined plants with
underfeed mechanical stOkerss and all
sorts of hand-fired plants
Chain Crate a FnTOrife.
The chain CRATE stOker is a favOrite in
many factories 1t consists OF an end
less belt made of iron crates. This
chain Of CRATES revOlves aronud two
sets OF wheels, one set inside the fur
mace and the other outside They are
driven by a small engine set TO run at
a constant speed The coal is fed on
the crate through a large hopper
which distributes il evenly over the
surface There is a fire brick arch
into which the crate passes, and the
CRATES movement is so timed that the
coal is entirely burned by the time II
reaches the rear set OF Wheels- AS
the CRATE chain passes down over
these wheels IL dumps the ashes into
the ashpit and moves on around 10
bring in a new load Of coal
The front feedstOker consists Of a hop
per and a reciprOcaing pusher, which
pushes the coal into the outlying
precincts of the furnace, where il
comes upon the CRATES, which are
built with a considerable incline and
placed so as to be mechanically
moved for passing the coal down over
them and the residue on TO the asnplt,
it being completely converted into
ashes by the time the pit IS reached
Mechanical StOkers.
The underfed mechanical stOker
sends the coal in beneath the burning
material that has preceded it. In one
underfed furnace this is accomplished
by a cone-shaped screw, driven by a
small steam engine, which forces the
coal in under the bed of fire. In
another it is forced in heavy charges
instead of in d continuous supply.
This forces the live Goals I'D and out
ward. and they are caught in a large
chamber where thorough combustion
is completed.
There are innumerabIe devices on the
market to promote efficient and non
smoking hand-firing. One of the
earliest of these is the cOking furnace, /
in which the coal is first deposited at
the front end of the furnace and
gradually pushed back into the hotter
portions as it reaches the proper heat.
The front end of the furnace has no
CRATES in it, but has dead plate in
stead.
The steam jet is a favorite appara-
tus by which many hand-fired fur
naces are rendered smOkeless. AS a
furnace is fired a Jet of steam is al I
thoroughly mix the air and the gases Z
in the furnace. Some have asserted /
that the steam jet is economical, but !
the geological survey found IN It's eN- 7
Deriments that it is expensive unless /
properly applied, and that even then I
it has to take some of the heat that {
the boilers. The only value of the 7.
steam jet is to prevent smoke Tt I
adds nothing to the thermal value of Z
the coal, according to the survey re- !
Doyvndraft Furnaces.
Downdraft furnaces are resorted to I
in many. plants to avoid the emission 4
of smoke. Such furnace has an J
upper crate. sometimes consisting of /
water tubes through which the water 4
going into the boiler circulates. The I
IreSn coal Is thrown upon Lueses ]
whence. after partial burning, It falls 1
through this crate to = regulation I
crate below. where the process of !
combustion is completed
The investigation by the bureau OF 4
mines reveals a surprising number of /
central heating plants 1t showed a /
such plants in Illinois, IL in Indiana.
10 in New York. "a in Ohio. and % in 1
Pennsylvania, with 80 others scattered /
through the states. Some of these /
heating plants have been in commits /
sion for a quarter Of a century but /
most of them have been placed in I
operation in the past decade. They
range in size from 500 to 10000 horse I
power, and the price Of the coal used ;
ranges from $500 per short ton i'm .
Montana, to 80 cents per short ton in 4
Illinois. They have successfully and [
economically furnished heat and steam
within a radius of a mile, which. in
a city would represent some four
hundred ordinary blocks for each plant. /
1t has been suggested that the best
way to run a central heating plant
would be in connection with some
other business where heat has to be
made for other purposes. For instance. !
big factory, needing a great deal
of power for its own operation. might
install a central heating plant and sell 7
heat as a by-prOduct. The best prdc-
ffea that naaH hr ]