El Paso herald. (El Paso, Tex.) 1901-1931, 1911-03-11
CAL.OR||nETER
TESTS HEAT
Of COAL
Southwestern Cement Com
pany Instals New Instru-
ment in Laboratory.
RESEMBLES COMMON
ICE CREAM FREEZER

The Southwestern Cement Co., OF Ell
Paso, has recently installed & new ca
lorimeter in its laboratory for the pur-
pose of Judging the quality of the coal
purchased and the heating power of
the charges used in the kilns. made
by blending several different varieties.
The tests, which in times past have
numbered more than 500 year, are
made personally by the head chemist,
S. K. Simon, who has been with the
company for two years. coming from
the Northwestern States Cement Co.,
Cowhem system. OF Mason City, Ia.
Resembles ice Cream Freezer.
rhe construction of the calorimeter
used by the company is not unlike
that of an ordinary ice cream freezer.
The outside vessel is made of brown
paper fiber, double cased with dead
air space between to decrease the in
fluence of the outside temperature, and
is about a foot high and nine inches
in diameter. 1t has a top of the same
material. which carries a thermome-
ter, small pulley wheel. and switch
connecting with wires carrying an cleo
trio current. Inside is steel can,
open at the top, containing two HterS
of water (about two quarts) in which
the end of the thermometer dips, and
having in the center an upright axis
rotated by the pulley wheel and carry
ing a cylindrical bomb of copper, nickel
plated to contain the powdered coal
and having small wings on the out
side to mix the water. The bomb is
about four inches long and one inch in
diameter, inside. 1t can be taken from
the axis and is closed Theoretically by
a steel screw cap.
How the Test is Made.
The sample of powdered coal, which
has been very carefully taken so as
to be an accurate representation of the
whole carload or lot, is weighed on
delicate balance, about half gram
being taken, and placed in the dried
and cleaned bomb with certain
weight OF sodium peroxide and potas-
sium chlorate, chemicals which supA
ply oxygen to the burning coal After
a thorough mixture the cap of the
bomb is screwed on and it is put in its
place on the axis and immersed in wa
ter. The cover is then put on, the pull
ley connected with a small motor and
the bomb revolved for about five min
utes to get a fixed temperature, when
e reading is taken and recorded Then
the electric current is turned on for an
instant, igniting the coal Immediate
ly the temperature of the water rises,
being heated by the bomb containing
the burning coal.
When the temperature has risen to
the highest point and ceases TO rise
further another reading is taken The
rotation is then stopped and the bomb
taken out for cleaning. From the diff
ference in the two readings on the
thermometer, making allowance for
certain rises due TO other causes than
the burning Of coal, the heat given on
by the fuel is determined and the heat
ing value calculated.
The heat given off is measured by a
unit called the British Thermal unit.
a quantity Of heat sufficient to raise
one pound of water one degree Fair
enheit, and abbreviated B. T. Z. The
result is expressed in B. T. US peg
pound Anthracite Goals run the high
est, CT course, with semi-bituminous
and bituminous following. An extra
good coal of the first variety may go
more than $4,000 B. T. U.
A chemical test is also made on each
coal in the laboratory, the moisture,
volatile matter, fixed carbon. and ash
being determined, sometimes the sui
phur and phosphorus. But the main
reliance is placed on the calorimeter
determination. The company has been
making such tests for five years and
is well pleased with the results cb-
tanned.
The Ordinary Tests.
When the average householder wishes
to Judge the quality of the coal he is
using, he inspects the ash, considers
the heat given of, the relative ease Of
burning, and the freedom from form
ing clinkers.
A more accurate test, one commonly
employed for coal used to stoke fur
naces under boilers, is to burn GER
tain weight of coal and measure the
amount of water eyaporated by its
Another method is to take sample
of the coal to a chemist and have 1t
analyzed. From the table Of constitu-
ents as determined by the analyst.
rough approximation of the actual fuel
value. may be calculated
BY far the most accurate and scien-
tific method. however, is to determine
the heating value IN a calorimeter,
which measures precisely the amount
OF heat given off by a certain weight
of the coal or other fuel burned in it.