Transactions of the American Society of Civil Engineers Part 11

The testing of other portions of the same s.h.i.+pment 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 c.o.king 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 subst.i.tute 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 diminis.h.i.+ng the loss of values up the smokestack and the amount of smoke produced;

Investigations and tests into the possibilities of c.o.king coals which have hitherto been cla.s.sed as non-c.o.king, 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 was.h.i.+ng 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 c.o.ke 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 a.n.a.lyses; 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 a.n.a.lyzed, 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 a.n.a.lysis 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 a.n.a.lyzing 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 s.h.i.+pment of the samples in hermetically sealed cans or jars to the chemical laboratory at Was.h.i.+ngton, 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 c.o.king 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 Was.h.i.+ngton, coal purchased for Government use on a guaranteed-a.n.a.lysis 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 Was.h.i.+ngton to look after the deliveries of coal to the many public buildings, and to collect and prepare samples taken from these deliveries for a.n.a.lysis, as well as to prepare samples received from public works and buildings in other parts of the country.

[Ill.u.s.tration: Fig. 10.

COAL-SAMPLING ROOM, GEOLOGICAL SURVEY, WAs.h.i.+NGTON, D.C.]

The preparation of these samples is carried on in a room in the bas.e.m.e.nt of the building, where special machinery has been installed for this work. Fig. 10 shows a plan of this room and the arrangement of the sampling and crus.h.i.+ng machinery.

The crus.h.i.+ng of the coal produces great quant.i.ties of objectionable dust, and to prevent this dust from giving trouble outside the sampling room, the wooden part.i.tions on three sides of the room (the fourth side being a masonry wall) are completely covered on the outside with galvanized sheet iron. The only openings to the room are two doors, which are likewise covered with sheet iron, and provided with broad f.l.a.n.g.es of the same material, in order to seal effectually the openings when the doors are shut. Fresh air is drawn into the room by a fan, through a pipe leading to the outer air. A dust-collecting system which carries the coal dust and spent air from the room, consists of an arrangement of 8-in. and 12-in. pipes leading from hoods, placed over the crus.h.i.+ng machines, to the main furnace stack of the building. The draft in this stack draws all the dust from the crushers directly through the hoods to the main pipe, where most of it is deposited.

The equipment of the sampling room consists of one motor-driven, baby hammer crusher, which has a capacity of about 1 ton per hour and crushes to a fineness of -in. mesh; one adjustable chipmunk jaw crusher, for 5- and 10-lb. samples; one set of 4 by 7-in. rolls, crus.h.i.+ng to 60 mesh, for small samples; one large bucking board, and several different sizes of riffle samplers for reducing samples to small quant.i.ties. The small crushers are belted to a shaft driven by a separate motor from that driving the baby crusher.

In conducting the inspection of departmental purchases of coal in Was.h.i.+ngton, the office is notified whenever a delivery of coal is to be made at one of the buildings, and an inspector is sent, who remains during the unloading of the coal. He is provided with galvanized-iron buckets having lids and locks; each bucket holds about 60 lb. of coal.

In these buckets he puts small quant.i.ties of the coal taken from every portion of the delivery, and when the delivery has been completed, he locks the buckets and notifies the office to send a wagon for them. The buckets are numbered consecutively, and the inspector makes a record of these numbers, the date, point of delivery, quality of coal delivered, etc. The buckets are also tagged to prevent error. He then reports to the office in person, or by telephone, for a.s.signment to another point in the city. All the samples are delivered to the crus.h.i.+ng room in the bas.e.m.e.nt of the Survey Building, to be prepared for a.n.a.lysis.[11]

Samples taken from coal delivered to points outside of Was.h.i.+ngton are taken by representatives of the department for which the coal is being purchased, according to instructions furnished them, and, from time to time, the regular inspectors are sent to see that these instructions are being complied with. These samples are crushed by hand, reduced to about 2 lb. at the point where they are taken, and sent to Was.h.i.+ngton, in proper air-tight containers, by mail or express, accompanied by appropriate descriptions.

Each sample is entered in the sample record book when received, and is given a serial number. For each contract a card is provided giving information relative to the contract. On this card is also entered the serial number of each sample of coal delivered under that contract.

After the samples are recorded, they are sent to the crus.h.i.+ng room, where they are reduced to the proper bulk and fineness for a.n.a.lysis.

They are then sent, in rubber-stoppered bottles, accompanied by blank a.n.a.lysis report cards and card receipts, one for each sample, showing the serial numbers, to the fuel laboratory for a.n.a.lysis. The receipt card for each sample is signed and returned to the inspection office, and when the a.n.a.lysis has been made, the a.n.a.lysis report card showing the result is returned. This result is entered at once on the contract card, and when all a.n.a.lyses have been received, covering the entire delivery of coal, the average quality is calculated, and the results are reported to the proper department.

The matter of supplying the Pittsburg plant with fuel for test purposes is also carried on from the Was.h.i.+ngton office. Preliminary to a series of investigations, the kinds and amounts of coal required are decided on, and the localities from which these coals are to be obtained are determined. Negotiations are then opened with the mine owners, who, in most cases, generously donate the coal. When the preliminaries have been arranged, an inspector is sent to the mine to supervise the loading and s.h.i.+pment of the coal. This inspector enters the mine and takes, for chemical a.n.a.lysis, small mine samples which are sent to the laboratory at Pittsburg in metal cans by mail, accompanied by proper identification cards. The results of the a.n.a.lysis are furnished to the experts in charge at the testing plant, for their information and guidance in the investigations for which the coal was s.h.i.+pped.

All samples for testing purposes are designated consecutively in the order of s.h.i.+pment, "Pittsburg No. 1," "Pittsburg No. 2," etc. A complete record of all s.h.i.+pments is kept on card forms at the Pittsburg plant, and a duplicate set of these is on file in the inspection office at Was.h.i.+ngton.

_a.n.a.lysis of Fuels._--The routine a.n.a.lyses of fuel used in the combustion tests at Pittsburg, and of the gases resulting from combustion or from explosions in the testing galleries, or sampled in the mines, are made in Building No. 21.[12] A small laboratory is also maintained on the second floor of the south end of Building No. 13, for a.n.a.lyses of gases resulting from combustion in the producer-gas plant, and from explosions in Galleries Nos. 1 and 2, etc. From four to six chemists are continually employed in this laboratory (in 8-hour s.h.i.+fts), during prolonged gas-producer tests, and three chemists are also employed in a.n.a.lyzing gases relating to mine explosions.

In addition to these gas a.n.a.lyses, there are also made in the main laboratory, a.n.a.lyses and calorific tests of all coal samples collected by the Geological Survey in connection with its land-cla.s.sification work on the coal lands of the Western States. Routine a.n.a.lyses of mine, car, and furnace samples of fuels for testing, before and after was.h.i.+ng and briquetting, before c.o.king and the resultant c.o.ke, and extraction a.n.a.lyses of binders for briquettes, etc., are also made in this laboratory.

The fuel-testing laboratory at Was.h.i.+ngton is equipped with three Mahler bomb calorimeters and the necessary balances and chemical equipment required in the proximate a.n.a.lysis of coal. More than 650 deliveries of coal are sampled each month for tests, representing 50,000 tons purchased per month, besides daily deliveries, on s.h.i.+p-board, of 550,000 tons of coal for the Panama Railroad. The data obtained by these tests furnish the basis for payment. The tests cover deliveries of coal to the forty odd bureaus, and to the District Munic.i.p.al buildings in Was.h.i.+ngton; to the a.r.s.enals at Watertown, Ma.s.s., Frankford, Pa., and Rock Island, Ill.; and to a number of navy yards, through the Bureau of Yards and Docks; to military posts in various parts of the country; for the Quartermaster-General's Department; to the Reclamation Service; to Indian Agencies and Soldiers' Homes; to several lighthouse districts; and to the superintendents of the various public buildings throughout the United States, through the Treasury Department; etc. During 1909, the average rate of reporting fuel samples was 540 per month, requiring, on an average, six determinations per sample, or about 3,240 determinations per month.

_Fuel-Research Laboratories._--Smaller laboratories, occupying, on the average, three rooms each, are located in Building No. 21. One is used for chemical investigations and calorific tests of petroleum collected from the various oil fields of the United States; another is used for investigations relative to the extraction of coal and the rapidity of oxidization of coals by standard solutions of oxidizing agents; and another is occupied with investigations into the destructive distillation of coal. The researches under way show the wide variation in chemical composition and calorific value of the various crude oils, indicate the possibility of the extraction of coal const.i.tuents by solvents, and point to important results relative to the equilibrium of gases at high temperatures in furnaces and gas producers. The investigations also bear directly on the c.o.king processes, especially the by-product process, as showing the varying proportion of each of the volatile products derivable from types of coals occurring in the various coal fields of the United States, the time and temperature at which these distillates are given off, the variation in quality and quant.i.ty of the products, according to the conditions of temperature, and, in addition, explain the deterioration of coals in storage, etc.

[Ill.u.s.tration: Fig. 11.

PLAN OF CONSTRUCTION DETAILS OF METAL HOOD]

At the Was.h.i.+ngton office, microscopic investigations into the life history of coal, lignite, and peat are being conducted. These investigations have already progressed far enough to admit of the identification of some of the botanical const.i.tuents of the older peats and the younger lignites, and it is believed that the origin of the older lignites, and even of some of the more recent bituminous coals, may be developed through this examination.

In the chemical laboratories, in Building No. 21, the hoods (Figs. 11 and 12) are of iron, with a brick pan underneath. They are supported on iron pipes, as are most of the other fixtures in the laboratories in this building. The hood proper is of j.a.panned, pressed-iron plate, No.

22 gauge, the same material being used for the boxes, slides, and bottom surrounding the hood. The sash is hung on red copper pulleys, and the corners of the hood are reinforced with pressed, j.a.panned, riveted plate to which the ventilating pipe is riveted.

[Ill.u.s.tration: Fig. 12.

ELEVATION OF CONSTRUCTION DETAILS OF METAL HOOD]

There is some variety in the cupboards and tables provided in the various laboratories, but, in general, they follow the design shown in Fig. 13. The table tops, 12 ft. long, are of clear maple in full-length pieces, ? in. thick and 2? in. wide, laid on edge and drilled at 18-in. intervals for bolts. These pieces are glued and drawn together by the bolts, the heads of which are countersunk. The tops, planed off, sanded, and rounded, are supported on pipe legs and frames of 1 by 1-in. galvanized-iron pipe with screw f.l.a.n.g.es fitting to the floor and top. Under the tops are drawers and above them re-agent shelves. Halfway between the table top and the floor is a wire shelf of a frame-work of No. 2 wire interlaced with No. 12 weave of ?-in. square mesh.

Certain of the tables used in the laboratory are fitted with cupboards beneath and with drawers, and, in place of re-agent stands, porcelain-lined sinks are sunk into them. These tables follow, in general style and construction, the re-agent tables. The tables used in connection with calorimeter determinations are ill.u.s.trated in Fig. 14.

The sinks provided throughout these laboratories are of standard porcelain enamel, rolled rim, 18 by 13 in., with enameled back, over a sink and drain board, 24 in. long on the left side, though there are variations from this type in some instances.

The plumbing includes separate lines of pipe to each hood and table; one each for cold water, steam at from 5 to 10 lb. pressure, compressed air, natural gas, and, in some cases, live steam at a pressure of 60 lb.

On each table is an exposed drainage system of 2-in. galvanized-iron pipe, in the upper surface of which holes have been bored, through which the various apparatus drain by means of flexible connections of gla.s.s or rubber. These pipes and the sinks, etc., discharge into main drains, hung to the ceiling of the floor beneath. These drains are of wood, asphaltum coated, with an inside diameter ranging from 3 to 6 in., and at the proper grades to secure free discharge. These wooden drain-pipes are made in short lengths, strengthened by a spiral wrapping of metal bands, and are tested to a pressure of 40 lb. per sq. in. Angles are turned and branches connected in 4- and 6-in. square headers.

[Ill.u.s.tration: Fig. 13.

PLAN OF CONSTRUCTION DETAILS OF REAGENT TABLES BUILDING 21.]

[Ill.u.s.tration: Fig. 14.

CONSTRUCTION DETAILS OF CALORIMETER TABLES]