The scope of the fuel investigations has been planned to conform to the
provisions of the Act of Congress which provides for analyzing and
testing coals, lignites, and other mineral fuel substances belonging to
the United States, or for the use of the United States Government, and
examinations for the purpose of increasing the general efficiency or
available supply of the fuel resources in the United States.
In conformity with this plan, the investigations inaugurated at St.
Louis had for their initial object the analyzing and testing of the
coals of the United States, using in this work samples of from 1 to 3
carloads, collected with great care from typical localities in the more
important coal fields of the country, with a view to determining the
relative values of those different fuels. In the work at Norfolk, during
1907, this purpose was modified to the extent of keeping in view
relative fuel efficiencies for naval purposes. The tests at Denver have
been on coal from Government land or from land contiguous thereto, and
are conducted solely with a view to perfecting methods of coking this
coal by prior washing and by manipulation in the process of coking.
Three general lines of inquiry are embodied in the plan of investigation
undertaken and contemplated by the Technologic Branch, after conference
and with the advice and approval of the Advisory Board: 1. The
ascertainment of the best mode of utilizing any fuel deposit owned or to
be used by the Government, or the fuel of any extensive deposit as a
whole, by conducting a more thorough investigation into its combustion
under steam boilers, conversion into producer gas, or into coke,
briquettes, etc. 2. The prevention of waste, through the study of the
possibility of improvement in the methods of mining, shipping,
utilizing, etc. 3. The inspection and analysis of coal and lignite
purchased under specification for the use of the Government, to
ascertain its heating value, ash, contained moisture, etc.
The first general line of work concerns the investigation and testing of
the fuel resources of the United States, and especially those belonging
to the Federal Government, to determine a more efficient and more
economical method of utilizing the same. This work has developed along
the following lines:
The collection of representative samples for chemical analysis, and
calorimeter tests by a corps of skilled mine samplers, from the mines
selected as typical of extensive deposits of coal in a given field or
from a given bed of coal; and the collection from the same mines of
larger samples of from 1 to 3 carloads, shipped to the testing station
for tests in boiler furnaces, gas producers, etc., as a check on the
analysis and calorimeter tests;
The testing of each coal received to determine the most efficient and
least wasteful method of use in different furnaces suitable for public
buildings or power plants or ships of the Government;
The testing of other portions of the same shipment of coal in the gas
producer, for continuous runs during periods of a few days up to several
weeks, in order to determine the availability of this fuel for use in
such producers, and the best method of handling it, to determine the
conditions requisite to produce the largest amount of high-grade gas
available for power purposes;
The testing of another portion of the same coal in a briquette machine
at different pressures and with different percentages and kinds of
binder, in order to determine the feasibility of briquetting the slack
or fine coal. Combustion tests are then made of these briquettes, to
determine the conditions under which they may be burned advantageously;
Demonstrations, on a commercial scale, of the possibility of producing
briquettes from American lignites, and the relative value of these for
purposes of combustion as compared with the run-of-mine coal from which
the briquettes are made;
The finding of cheaper binders for use in briquetting friable coals not
suited for coking purposes;
Investigations into the distribution, chemical composition, and
calorific value of the peat deposits available in those portions of the
United States where coal is not found, and the preparation of such peat
for combustion, by drying or briquetting, to render it useful as a local
substitute for coal;
Investigations into the character of the various petroleums found
throughout the United States, with a view to determining their calorific
value, chemical composition, and the various methods whereby they may be
made most economically available for more efficient use as power
producers, through the various methods of combustion;
Investigations and tests into the relative efficiency, as power
producers in internal-combustion engines, of the heavier distillates of
petroleum, as well as of kerosene and gasoline, in order to ascertain
the commercial value and relative efficiency of each product in the
various types of engines;
Investigations into the most efficient methods of utilizing the various
coals available throughout the United States for heating small public
buildings, army posts, etc., in order that these coals may be used more
economically than at present;
Investigative studies into the processes of combustion within boiler
furnaces and gas producers to ascertain the temperatures at which the
most complete combustion of the gases takes place, and the means whereby
such temperatures may be produced and maintained, thus diminishing the
loss of values up the smokestack and the amount of smoke produced;
Investigations and tests into the possibilities of coking coals which
have hitherto been classed as non-coking, and the making of comparative
tests of all coals found in the United States, especially those from the
public lands of the West;
Investigations, by means of washing in suitable machines, to determine
the possibility of improving the quality of American coals for various
methods of combustion, and with a view to making them more available for
the production of coke of high-grade metallurgical value, as free as
possible from sulphur and other injurious substances.
At each stage of the process of testing, samples of the coal have been
forwarded to the chemical laboratory for analyses; combustion
temperatures have been measured; and samples of gas collected from
various parts of the combustion chambers of the gas producers and boiler
furnaces have been analyzed, in order that a study of these data may
throw such light on the processes of combustion and indicate such
necessary changes in the apparatus, as might result in larger economies
in the use of coal.
The second line of investigation concerns the methods of mining and
preparing coal for the market, and the collection of mine samples of
coal, oil, etc., for analysis and testing. It is well known that, under
present methods of mining, from 10 to 75% of any given deposit of coal
is left underground as props and supports, or as low-grade material, or
in overlying beds broken up through mining the lower bed first. An
average of 50% of the coal is thus wasted or rendered valueless, as it
cannot be removed subsequently because of the caving or falling in of
the roofs of abandoned galleries and the breaking up of the adjoining
overlying beds, including coal, floor, and roof.
The investigations into waste in mining and the testing of the waste,
bone, and slack coal in gas producers, as briquettes, etc., have, for
their purpose, the prevention of this form of waste by demonstrating
that these materials, now wasted, may be used profitably, by means of
gas producers and engines, for power purposes.
The third general line of investigation concerns the inspection and
sampling of fuel delivered to the Government under purchase contracts,
and the analyzing and testing of the samples collected, to determine
their heating value and the extent to which they may or may not comply
with the specifications under which they are purchased. The coal
delivered at the public buildings in the District of Columbia is sampled
by special representatives of the Technologic Branch of the Survey. The
taking of similar samples at public buildings and posts throughout the
United States, and the shipment of the samples in hermetically sealed
cans or jars to the chemical laboratory at Washington, is for the most
part looked after by special officers or employees at each place. These
purchases are made, to an increasing extent, under specifications which
provide premiums for coal delivered in excess of standards, and
penalties for deliveries below standards fixed in the specifications.
The standard for bituminous coals is based mainly on the heat units,
ash, and sulphur, while that for anthracite coal is based mainly on the
percentage of ash and the heat units.
In connection with all these lines of fuel testing, certain research
work, both chemical and physical, is carried on to determine the true
composition and properties of the different varieties of coal, the
changes in the transformation from peat to lignite, from lignite to
bituminous coal, and from bituminous to anthracite coal, and the
chemical and physical processes in combustion. Experiments are conducted
concerning the destructive distillation of fuels; the by-products of
coking processes; the spontaneous combustion of coal; the storage of
coal, and the loss in value in various methods of storing; and kindred
questions, such as the weathering of coal. These experiments may yield
valuable results through careful chemical research work supplemented by
equally careful observations in the field.
_Inspection and Mine Sampling._--In the Geological Survey Building, at
Washington, coal purchased for Government use on a guaranteed-analysis
or heat-value basis, is inspected and sampled.
Some of the employees on this work are constantly at the mines taking
samples, or at public works inspecting coal for Government use, while
others are stationed at Washington to look after the deliveries of coal
to the many public buildings, and to collect and prepare samples taken
from these deliveries for analysis, as well as to prepare samples
received from public works and buildings in other parts of the country.
[Illustration: Fig. 10.