Popular Science Monthly/Volume 73/October 1908/The Industries of Niagara Falls
|THE INDUSTRIES OF NIAGARA FALLS|
ROCHESTER, N. Y.
NOTWITHSTANDING the fact that the Niagara Falls region is chiefly celebrated by reason of its natural wonders, intelligent people are gradually coming to understand that here are to be found engineering works in the form of electrical-power development plants which are unrivaled anywhere in the world, and electrochemical industries which are likely to grow of greater importance with increasing knowledge of the electrochemical art.
When ground was broken in 1890 for the installation of the first great power plant at Niagara Falls, the engineers in charge of the project regarded the development of even fifteen thousand horse-power of electrical current with grave concern because at that time economical transmission of electricity over long distances was deemed hardly practicable and because the possibilities in the field of electro-chemistry had been to only a slight extent foreseen. Except in the minds of a few, therefore, the utilization of any large amount of water from the Niagara River for the generation of power was held to be an undertaking of doubtful wisdom at best.
However, within a comparatively short time after the determination
of engineers to install a large generator plant at Niagara Falls, discoveries were announced in the field of electrochemistry which if extensively developed would require the use of thousands of horse-power of electrical energy, and these discoveries encouraged the promoters of the great power project to believe that capital invested in the proposed plant would not be spent in vain. Moreover, the perfecting of an economical system of transmitting the electric current over considerable distances made it evident to engineers that very large quantities of Niagara power could be utilized commercially beyond the immediate vicinity of the power plants.
Two of the great power houses have been erected on the American side of the Niagara River somewhat over a mile from the crest of the cataract. In order to take advantage of the potential energy of the water and to afford an outlet for the water after its pressure has been used, two wheelpits were excavated out of solid limestone and shale about 177 feet deep, 18 feet wide and 450 feet long. Over each of these wheelpits was constructed a massive power house to contain the generators, switchboards, oil switches and other necessary apparatus. Extending vertically down the wheelpits to the depth of about 140 feet are hollow shafts to connect the generators on the power house floor with the turbines or water wheels below. Running parallel with each of the ten or eleven shafts in each power house is an immense pipe, or penstock as it is technically termed, of seven and one half feet in diameter through which water, after proper screening to remove ice and other obstructions, is conveyed from the intake canal to each turbine. After the large volume of water conveyed to each turbine, under an effective head of about 140 feet, dashes against the turbine blades, the water is disgorged into a subterranean tunnel about 21 feet in height and over a mile in length, through which the discharged water is conducted to the lower Niagara River, just below the abutment of the upper steel arch bridge.
The turbines, by means of the shaft connection, cause the generators on the power-house floor to revolve at the rate of 250 revolutions a minute and to develop a two-phase alternating current of 5,000 horse-power.
Each generator with its connected turbine is entirely distinct from the other generators and turbines, and can be stopped by shutting off the water from the supplying penstock and by applying electrically operated brakes.
Practically, the whole tremendous weight of each generator, shaft and turbine is sustained by the hydrostatic upward pressure of water conveyed in separate pipes from the level of the intake canal to a compartment of the turbine wheel-case where the water presses against the lower surface of a disc secured to the shaft.
To generate an electric current by dynamos a coil of wire must cut the lines of magnetic force emanating from a magnetic field. It is immaterial whether the coils of wire (or armature) revolve around the magnetic field or the magnetic field revolves around the armature. For mechanical reasons, however, all the great generators at Niagara Falls are constructed so that their magnetic fields shall revolve about the coils of wire (the armature).After the generators have developed the electrical energy the current controlled by appropriate switching devices is transmitted to the power tenants in the immediate vicinity and to the more distant tenants in Buffalo, Lockport and elsewhere. Where power is delivered to tenants within a short radius of the power plants, the current is transmitted at the generator voltage, but where power tenants are situated at such distances from the generators that electric current could be transmitted only at considerable loss at the generator voltage, it becomes necessary for economical transmission to increase or "step up" the voltage of the current by passing the electrical flow through transformers. A transformer by means of primary and secondary coils of wire of different diameters wound around a laminated iron core and with windings in a fixed ratio to each other may increase or diminish the voltage of a current according as an increase or a diminution of voltage may be necessary. The voltage of the current delivered in Buffalo is about 22,000, but as it would be obviously impossible to utilize so great a current pressure the electricity in Buffalo again passes through transformers where the voltage of the current is reduced to that required in the electric light and electric car service and for other power purposes.
On the Canadian side of the Niagara River are three great power plants which are now generating about 160,000 horse-power, but which will ultimately develop nearly 400,000 horse-power. The Canadian generators are of much greater capacity than those on the American side and develop from' 10,000 to 12,500 horse-power each. Two of these plants are built over wheelpits like those described on the American side and one of the companies in order to release the water used in its turbines has constructed under the Niagara River a tail race tunnel, the portal of which discharges directly beneath the Horse Shoe Falls.
The Ontario Power Company by erecting a power-house at the level of the lower river and near the foot of the Horse Shoe Falls and by
conveying water through an eighteen-foot conduit from an intake canal above the falls has obviated the necessity and the great expense of building a wheelpit for the utilization of the water pressure and has acquired for its turbines practically the full head of water between the upper and lower rivers, a difference in level of approximately 175 feet.Directly above the Ontario Company's power-house the great eighteen-foot conduit is tapped by penstocks nine feet in diameter which convey the rushing water to the blades of the turbines. The generator attached to each turbine is thereby caused to revolve at the rate of 1871⁄2 revolutions a minute. Each generator weighs 231 tons and develops an alternating current of 10,000 to 12,000 horse-power at 12,000 volts, much of which is transformed to a voltage of 60,000 and transmitted with comparatively small loss over aluminum cables to Rochester, Auburn and Syracuse, a maximum distance of 160 miles.
The uses to which electrical power is put in the city of Niagara Falls are most interesting. In 1886 Charles M. Hall, at the age of twenty-two and fresh from Oberlin College, devised a process for the inexpensive production of aluminum. Prior to Mr. Hall's discovery aluminum though the most abundant of all metals was united to other elements in such a way that a separation of the metal from its compounds was very difficult and correspondingly expensive.
Mr. Hall's process for obtaining aluminum from its ore is a reduction or deoxidation process by electrolysis. Into a carbon lined vat or "reducing pot" extend carbon cylinders. The vat is partly filled with powdered cryolite, a beautiful white mineral mined in southern Greenland. When the electric current passes, the resistance
to the passage of the current offered by the cryolite transforms into heat sufficient electrical energy to fuse the cryolite. Into the fused cryolite is poured calcined and purified bauxite in powdered form. The oxygen of the purified bauxite combines with the carbon of the anodes or positive poles of the electrolytic cell to form carbon monoxide and carbon dioxide gases and the aluminum is withdrawn in an almost chemically pure state. Since the cryolite serves merely as a solvent for the bauxite from which the aluminum is obtained and is unaffected by the electric current, the reduction of bauxite is continued indefinitely by pouring into the reducing pot enough bauxite to supply the place of that reduced.Another electrolytic process in use at Niagara Falls is the production of caustic soda. The demand for caustic soda in many industries such as soap-making and paper-making is so great that an inexpensive way of producing this important alkali is imperative. The process is
comparatively simple. Into an electrolytic cell is poured common salt in solution. When the electric current passes through the brine the salt is separated into its constituent elements, chlorine gas and the metal sodium. The chlorine gas is evolved at the anodes of the cell and being led off combines with slacked lime to form chloride of lime or bleaching powder. The sodium unites or reacts with water to form sodium hydroxide or caustic soda.
When Moissan, the great French chemist, perfected the electric furnace he gave to scientists an easy way of producing a temperature which far exceeds that of ordinary fuel and even that of the oxyhydrogen flame, and which made possible new and useful combinations and dissociations of matter obtainable in no other way than by the use of intense heat. The electric furnace is used at Niagara Falls in the manufacture of several new and important products.Among the many recent discoveries in the field of electrochemistry
that of carborundum in 1891 by Mr. Edward G. Acheson is of great practical value. This new product is made by chemically combining in the intense heat of an electric furnace of the resistance type common sand and ground coke. After the charge has remained in the furnace for about thirty-six hours in a temperature of over 7,000° Fahrenheit, the resulting combination is found in a beautiful crystalline form. Carborundum ranks next to the diamond in hardness and is therefore used as an abrasive. In its so-called amorphous form it is used as a substance of great refractory power.
Metallic silicon, which is largely used in the steel industry to absorb the gases of the molten steel, is made at Niagara Falls by a deoxidation or reduction process. Ordinary sand and ground coke are intimately mixed and subjected to the heat of an electric furnace. The carbon combining with the oxygen of the sand is evolved as carbon monoxide gas; the residue is the element silicon in almost chemically pure condition.Another of Mr. Acheson's useful discoveries is the production of graphite by artificial means. Graphite is carbon, but not the only form of carbon. Carbon exists in the amorphous form as in coal,
charcoal and lampblack; in the crystallized form as diamond, and in the graphitic form as graphite. Until the discovery of a process for making graphite out of amorphous carbon the only source of supply
|Interior Power House No 1, Niagara Falls Power Company (American side).||Generator and Governor (oil pressure operation). Niagara Power Company (American side).|
|Interior of Power House No. 2, Niagara Falls Power Company (American side).||Interior Power House, Ontario Power Company, Niagara Falls, Ontario, showing ten and twelve thousand horse power generators and double turbines.|
lay in graphite mines such as those in the United States, England and Ceylon.
Artificial graphite is now made from any amorphous carbon which contains an admixture of some carbide forming substance and though other carbonaceous substances are used anthracite coal has been found to be the most satisfactory and economical carbonaceous material from which to make graphite.
Graphite is made by heating anthracite coal to a very high temperature, approximating 7,500° Fahrenheit. Into a long fire brick furnace is placed anthracite coal and through it a carbon rod passes. The heat generated by the resisted passage of the electric current through the charge is so great that practically all the impurities of the coal are volatilized, leaving its carbon content in the graphitic form.
Mr. Acheson has lately perfected a process whereby artificial graphite can be treated with gallotannic acid in such a way as to produce graphite so fine that it is well nigh molecular.
In the year 1892 it was accidentally discovered that if ordinary quicklime and coke were fused together, the resulting chemical combination would, by the addition of water, produce an illuminating gas of great brilliancy. The gas formed in this peculiar way is acetylene gas and the material from which it is generated is calcium carbide.
Calcium carbide is made at Niagara Falls by placing an intimate mixture of about three parts of powdered quicklime to two parts of powdered coke into an electric furnace of the so-called arc type. The current of electricity generates an intense heat which chemically combines the calcium of the quicklime with the carbon of the coke, the oxygen of the quicklime uniting with some of the carbon to form carbon monoxide gas which escapes.
It is interesting to know that the discovery of calcium carbide was almost simultaneously announced by two independent workers in electrochemistry, Moissan, the great French chemist, and Thomas L.
Willson, an American. Willson's discovery of calcium carbide, however, antedated Moissan's announcement by about six months.
At Niagara Falls are also to be found an immense paper mill which produces annually thousands of tons of newspaper made from
|Carborundum Furnace with Charge ready for heating.||Carborundum Furnace while Charge is being Heated, showing carbon monoxide gas issuing from side of furnace.|
spruce logs reduced to the proper consistency by the mechanical and the chemical or sulphite process, a plant where lead is economically separated from its ore by electrolysis, a laboratory where vanilla and other natural extracts are successfully prepared by synthetic chemistry, and furnaces where bauxite is crystallized into an extremely hard substance for abrasive purposes.
From the foregoing survey of some of the industrial enterprises at
|Carborundum Furnace with Walls removed after Heating, showing blocks of crystalline carborundum.||Electric Furnaces of the Resistance Type in which Artificial Graphite is made.|
Niagara Falls it is evident that that region is a very important electric and electrochemical center and that it is destined to increase in importance with every new discovery in the electrochemical art.