HISTORY OF CABLE: FROM AN ANCHOR ROPE TO THE STRUCTURED CABLE SYSTEMS
The border of ХVІІІ – ХІХ century marked by itself the cardinal changes public life. Fast development of the systems for remote-control and sending information on distance, growth of industrial and city population, professional differentiation promoted, in particular, facilities of sending information by electric signals. In this connection a topic about electric cables development is very interesting and deserves the special respect and understanding. Interestingly, that history of determination a «cable» appearance backtraces after a chart: “cable” – wire – rope – cable. This concept determines the function of connection and distance, which yet and today has priority in communication systems planning.
Telegraphy, as known, belongs to the first electrical discovery. In the 40th 19 century first telegraph lines were air and made from ferrous wires. The unisolated wires in the ground laid in wooden chamfers; isolated with silk – in metallic or clay pipes. . In 1842 in Russia Moric Herman Jacobi laid a telegraph cable from a copper wire, wrapped in paper with coverage in a few resin, beeswax and fat layers. A cable was placed into a glass tube. Because the glass collapsed quickly, these lines did not find the practical use.
A requirement in cables arises up almost at once. First telephones invented by Soemmering, Shilling, Morse, that gave visual information, and by Hughes, Whitson, Bodo, Simens - type printer. This devices were need for multi wire connection between the stations of transmission and electric signal receiving. For long time known term a “cable” wich identified a rope, anchor rope - was carried in terminology of the electrical engineering.
“Kabeln tr” meant to telegraph by cable. A cable wirepriduction becomes similar to technology of making and construction of rope, anchor rope.
The study of electrical engineering products become more effective due to an acquaintance with history of electric cable origin.
Long before our era people made a wire from metal, flattening on letters, with a subsequent scission on thin filaments. The standards of wire, made by such method in VIII centuries B.C., are saved in Kensington museums, London.
Dragging of wire was applied later.
Wires was not twist up in a rope for a long time, thus were bound by pinches.
The ropes of double wring were named ropes, triple – a cable.
Transference of electrical engineering products technologies from weak (telegraph, telephone) to strong currents (illumination, transmission of electric energy), was an incitement to application of new materials for an electric isolation, protective coverage of cable construction.
In 80th ХІХ century basic technological achievements in production of cable electrical engineering products were: isolation of submarine cables by the layers of gutta-percha or rubber, protection an armour from wires or ferrous ribbons, or impregnated with yarn; the use of the fibred impregnated with isolation for underground cables (at first from the cocoons of the Indian plant - jute, later – from the paper) and leaden containment shell; vacuum drying of cable insulation.
One of the considerable inventions was the Simens press for cable nonsuture gutta-percha insulation (1847); press for continuous imposition of leaden shells (swiss engineer Borelli, 1879). (Gutta-percha – is from plant louseberry widely widespread in Ukraine and in Beloruss, sometimes it is named as prick-tree. It is wonderful as gutta-percha. In a bark his root containes 10-12 % of gutta).
The first implementation of cable products as the necessities of power engineering and electrification associated with the construction of central power-station (New York, 1882) and with the name of Thomas Alva Edison. A low-voltage underground network had basic elements of modern cable busses, connecting box, etc. Installation of such network was inflexible.
A power cable showed by itself a ferrous pipe, in which two or three copper barbells was laid , isolated between themselves and from a pipe by bituminous mass.
Underground cables with a jute isolation and leaden shell were flexible and reliable enough, but had voltage not higher as 2kV. Only usage of the impregnated paper by Italian Ferranti Sebastian Ciani de Ferranti (1890), enabled the English firm Kollenders (1890) to lay between London and Deptford the first cable with working voltage of 10 kV.
As well as in a rope, in a cable separate elements take place around cable strand, that symbolizes inflexibility, hardness, reliability. All together clamps a wide ribbon - a bandage. Each, from the considered systems, in one or another way assisted in fast development of electric cable networks for the reliable and trouble-free passing of electric energy for the users.
In 1890 in Kyiv by the project of prominent power engineering specialist, professor of polytechnic institute M.A. Artemiev in the district of National opera the first city power plant by power 150 hp (110,3 kW) on constant current started and was laid the first low-voltage underground cable network by voltage of 110 V for illumination of Khreschatik str. It supplied 14 electric arc torches.
Totaly new construction of oil-filled cable was developed by Italian Emmanuel L. In 1923 the Italian firm Pirelli executed the experimental network 130 kV with monophase cable of this construction. In 1927 in New York and Chicago were laid two industrial lines 132 kV with oil-filled cables.
In Kyiv in 1959 operated the first in the former USSR cable network 35 kV, and in 1977 – cable network 110 kV.
Presently modern industry produces more than 500 brands of conductor cables of different voltage, to 500 kV inclusive, which are widely used in industry, particularly in power engineering. Kievan cable networks have 8979,9 km of cable busses 0,4 – 110 kV, 1360,3 km of air-tracks electro-transmission 0,4 – 110 kV, 59 substations 35 – 110 kV, 165 distributive points 10 kV, 3045 transformer substations 10/0,4 kV, that incorporated in the unique network.
FROM BLACKSMITH TO “ELEKTROHEPHAESTUS”
The development of welding technologies begin from the period of a Stone Age. From the nuggets of gold, silver, copper forged plates, fine edges, scrapers a stone. Connected a few details such technological reception from a metal. And it was already one metals welding types in the cold state. Effective application is perfected and finds the method of the cold welding in our time for connection of copper and aluminium wires, shells of electric cables, cables of connection and others like that. In those distant times this method was more frequent all used for work with gold, that has good plasticity and has thin oxidizing tape. On the nuggets of gold made together it was succeeded shots to get them strong connection.
Later people started up to warm metal to make it plastic, which facilitated connection forging. It named blacksmith's welding.
Metallography wares researches of Cucuteni tribes which lived on territory of South-west Ukraine and Bessarabia in ІV-III thousand B.C. indicated that awl, chisel, amulets and sewn brooches making applied blacksmith's welding of copper. When made copper beads on round mandrel staff connected the ends of arcuated overlapping and welded blacksmith's method. In the epoch of late Stone Age Cucuteni tribes had application of blacksmith's welding because local masters did not yet know the technique of melting and founding of metals.
In the epoch of late Stone Age bronze became basic material for making the most responsible tools and weapon. Wares from a bronze testify that in V – ІІІ thousand B.C. a few sorts of bronze ware made, which differed by composition on the tenth particle of percent. There were known technologies, which made durability of instruments from bronze to durability of modern steel instruments, technologies with electric power alloys of aluminium. But as it is known, clear aluminiumis is possibleto get only by electrolysis.
How to interpret the things of everyday, with unattainable exactness of surface treatment, chemical composition, and image to the unread inscriptions on the plates since the age of about 12 thousand years, located in the historical and archaeological museum-reserve "stone tomb in Melitopol Zaporozhye area?
This problem, equal to another, which belongs to the epoch of late Stone Age and study of previous hitech societies, their world views, expect the researcher.
At the beginning of blacksmiths age a weapon and objects were made out of iron. In those remote times people began to weld separate parts of iron for connection of details and for repairing of the broken ferrous facilities for labour, and weapon by heating and smithery
Handicraft of blacksmiths was in honour all over the world. Such imagination of people was caused that blacksmith could change the form of the strongest material and owned the secrets of his treatment.
Found on the places of the blasted Roman fortresses and lifted from the flooded ships, plenty of ferrous swords is saved in the different museums of the world. Surprisings by the construction swords, made in I-III century. The blades of swords are heterogeneous by the thickness they are done from plenty of thin ribbons. Technicians understood properties of steel and knew that every ribbon had certain characteristics. Such work needed capture from blacksmith all characteristics welding, large experience and intuition.
Far greater value for development of of of black metals treatment technique was made by welding of iron with different maintenance of carbon with the purpose of blade quality improvement for cutting weapon. In all of these cases welding is executed at high level, so as the welded guy-sutures can be seen only on microsection. Using such method of welding the best connection of one detai to another was made with the help of specially cutted end, wich was called "swallow tail".
In different localities in old times were developed many methods of connection of metal, brick, stone and wooden details for building habitation and fortresses. People use nowaday some technologies and materials which was used in old times. And some methods of connection thoroughly changed or in general disappeared from everyday life.
Interestingly, that the inventor, which opened the new method of metals welding at the end of 19 century was from Ukraine. In May 1881 Nickolay Benardos, being in Paris, in the laboratory of the Russian physicist Nickolay Kabata, first carried out the electric arc welding of metal, at first lead, and then iron.
Benardos was born in the Kherson province in Benardosivka village on the 8th July of 1842, which brought fame the Benardos family. His interest to metals treatment passed from a great-grandfather – famous blacksmith Nikita Demidov. He called the method of welding “ELEKTROHEPHAESTUS” in honour of ancient greek god of blacksmith - Hephaestus.
And in our time technical service, repair, technical rearmament, reconstruction and development of power network of Ukraine, on providing of reliable and trouble-free energy supply for users would be impossible without the responsible profession of electric welder.
THE STUDY BY SCIENTISTS OF ELECTROMAGNETIC INTERACTION NATURAL FORCES
EXPLODE TO INTENSIVE DEVELOPMENT OF ROTATORY ELECTRIC MACHINES
As known, for perfect understanding in regularity of any field of knowledges, it is necessary to know history of its development. Study of natural forces of electromagnetic interaction, which was considered by contemporaries as abstract, are extraordinarily instructive and deserve the special attention and understanding.
Consequently, shortly. Electric and magnetic properties of bodies were known long time ago. The first advanced study about electricity was a treatise “About a magnet, magnetic bodies and large magnet – Earth”, written by the known English scientist W.Gilbert in 1600 W.Gilbert named “electric” bodies which are able to be electrified and determined the term “electricity”. By W.Gilbert determination “electricity” is the aggregate of the phenomena in which exist and are in motion and interaction charged particles. The term of “electricity” changed the determination for ages, but even nowadays for educated persoon with higher education, electricity is not fully clear and studied, - especially its influence on living beings, especially its medical properties, and influence on the environment, plants etc.
O.Gerike in 1660 described the first electric friction machine, which consisted sulphur sphere, that at rotation was rubbed by the hands. At the beginning of ХVІІІ century F.Gauksbi replaced a sulphur sphere an empty glass sphere.
In 1743 a sliding contact was added which took off electric charges and machine began constantly reproduce electric charges. In Kyiv such electric machine was first set in 1783 in a cabinet of the Kievan Mohylyan academy library with І. I. Falkovsky assistance .
At the end of ХVІІІ century capacitive electric machine was created, the rotor of which was executed as the disk with diameter 2м. This machine created a spark 2м long.
In ХІХ and ХХ centuries development of capacity machines of friction, or influence machines continued, but, as power electromechanics transformers were used only inductive machines – and capacity electric machines were almost forgotten.
It is accepted to consider that history of electric machines began since, when in 1821 M. Faraday (1791 – 1867) created an electric engine, which consisted of permanent magnet, around which was revolved electrical conductor with a direct current, composed above a magnet. A sliding contact was provided via mercury, poured in a glass bowl.
In the engine of M. Faraday with a direct current and permanent magnetic field, created by permanent magnet, there was converting of electric energy into mechanical.
Exceptionally important part of M. Faraday's work was dedicated to the electric field.
M. Faraday first enters a concept about the magnetic force lines. On the first stage of the electrical engineering development, the construction of electric machines, considerably successes influence of steam engines creation in which recurrently forward motion of piston grew into rotary-type motion of billow. The algorithm of electric motor creation on principle of recurrently forward motion was carried in the phenomena of electromagnetic interaction and appeared a vicious way, took much time and efforts for the inventors of electric engines and did not give positive result.
In 1831 the American physicist Joseph Henry offered the engine of recurrently forward motion, in which a mobile electromagnet was attracted to the permanent magnets and pushed off from them, connected and disconnected the contacts of battery of galvanic elements. The engine by Henry carried out 75 rpm and had power of 0,04 W. There were other attempts of electric motors creation of recurrently forward motion, but the future was after electric machines in which the phenomena of electromagnetic interaction were used and transform into rotary-type motion of electric machine rotor by interaction of electromagnetic rotary-type field, created in stator winding.
In 1832 Pixis brothers, on the basis of works of M. Faraday, created generator with rotary-type permanent electromagnets. In immobile spools with the coiles of isolated wires, during the rotation of permanent magnets. It was one of the first alternators. However an alternating current did not find the great use in those times, and for converting of current into permanent, mechanical switchboards were used.
In 1834 by academician Boris Jakobi created and described an electric motor which worked due to approaching and pushing away of 4th horseshoe electromagnets. Without going into detail of construction of this engine here is an example his use.
In 1838 Boris Jacobi united 40 electric motors which worked on two boat shafting (with 20 engines). The electric motors power supply element consisted of 320 galvanic elements. Boat with 12 passengers floated on Neva a few hours, at high wind and against current. This was the first practical use of electric machines! Only in 100 years electric engines were used as a drive mechanism of screw. Then electric engines began to use on steamships, and engines, offered by Boris Jacobi, did not find the use.
In 1838 E. Lenc experimentally showed possibility of work of direct-current machine in the mode of electric motor and mode of generator.
In 1873 F. Hefner-Alteneck and W. Simens created the direct-current generator with a drum anchor, which had all basic elements of modern direct-current generator.
In Kyiv in 1890 direct-current power-station was built in the district of National opera and the city electric system was laid.
At the end of 80th ХІХ century M. Tesla and G. Ferrari, as a result of the researches, showed that two spools with the coil of isolated wire, placed at right angles to each other and connected to the sources of alternating sinewave current, create the vector of total magnetic induction in an intersection to the axes of these spools, which gets even rotary-type motion, not changing on an absolute value.So it was proved, that by two, or more alternating sinewave currents, it is possible to get the constantly rotary-type magnetic field.
In 1889 prominent electrical engineer Mihail Dolivo-Dobrovolskiy offered the three-phase system of alternating sinewave current and in the same year created the first three-phase generator, asynchronous engine, the rotor of which is revolved as a result of cross effect with the constantly rotary-type magnetic field, created due to alternating current in the three-phase electric system. Dolivo-Dobrovolskiy at first intuitively proved that in the three-phase system of alternating current is created the most effective transmission of electric energy on every distances and subsequent increase of phases number is unreasonable, so as it will result in the considerable increase of charges for copper on wires. At the same time the symmetric rotary-type electromagnetic field which is revolved proportionally to the frequency of alternating current is created in the three-phase system of alternating current. His genius idea was confirmed later by mathematical way and construction of different vectograms. On this principle of electromagnetic interaction all electric motors of alternating current work in different industries of humen activity in the whole World.
The three-phase system of alternating current from the beginning of 90th ХІХ century was implemented in energy. People began to use powerful natural forces of electromagnetic interaction in industry, and in all of spheres of human activity in general.
THEY WERE THE FIRST CREATORS OF STEAM-TURBINES
The Italian engineer Giovanni Branca in 1629 year constructed a steam wheel for the occasion of slowly operating shock mill, which became almost in 260 years by the prototype of active steam-turbines. Impossibility of the complete use of potential energy of steams in even it kinetic energy at the efflux of steamt through cylinder attachment for a long time detained development of steam-turbines.
The row of attempts of creation of steam-turbines began yet in 1791 (Sadler) and proceeded to 1837 year (Jakme). The steam-out experiments of Saint-Venant and Vintcel showed, that a problem had consisted in high-rate of steam. In the issue of Delonshan, published in 1853 was written, that „...steam, what low its pressure was not, has extraordinarily high speed on leaving from a volume, which it is in. For the receipt of good output-input ratio, speed on the rim of steam-driven wheel, must not be less half of steamspeed, and these circumstances blocked at present time usage of reactive wheel. In reality, aquatic steam at 5 атм. initial pressure, goes out in air at a speed of a 500 mps. A wheel which this steam is operated has speed on a rim near a 300 mps. From here, if the diameter of wheel is equal 0,95 м., it is revolved at a speed of 6000 rpm and the axes of wheel at any diameter will be revolved with such speed at which would survive no bearings, so as they would be smelted through the insignificant interval of time”.
Thus, two ways appeared before the inventors of steam-turbines: searches of methods of decline of number of turns of steam-turbines, - without the decline of efficiency and development of constructions, able to work on large turns (a few thousand rpm).
The first way was offered Lerua as early as 1840. He foresaw the use of a few pressure difference in a turbine. More thoroughly principle of pressure difference was exposed in the message of Turner, which was considered in 1853 on meeting in the Paris academy of sciences: „... can compelling to avoid these difficulties gas, or steam, to lose the pressure or slowly, or by separate parts and to operate a few times on the shoulder-blades of steam-turbines, located properly..”. Except for Turner, a few pressure difference was offered by inventors (Zhirar,1855, Perrigo and Farko,1864, Edvards, in 1871 and a lot oАf other).
By creation of steam-turbines the inventors of different countries worked during long time.
From 1880 to on 1890 in England 52 patents were given out on steam-turbines. And from 1890 to on 1900 already 186. But the successful most technical decision was given by Swede Charles Gustav Patrik de Laval and Englishman Charlz Parsons.
And only after the use of the gradually extended supersonic nozzle the Swedish engineer K. Laval in 1889 year succeeded to decide this problem. Karl Gustav Patrik de Laval (1845-1921) was the Swedish engineer and inventor. Graduated a technological institute in Stockholm and university in Upsal (1872) with the rank of Ph.D. Workings at the chemical plant, in 1878 year a centrifugal separator constructed for milk.In 1883 year K. Laval offered as drive for centrifugal separator use the simple turbine as Heron's Eolipyl, that worked on reactive principle, demonstrated in Egypt near I century C.E. by Heron from Alexandria. Trying to promote efficiency turbines, K. Laval in 1889 constructed a nozzle, that had a little gradual expansion. Snuffled Laval enables to reduce pressure of steam below critical, giving him here supersonic speed and possibility to promote initial pressure of steam and economy of steam-turbine (in a critical point the warmth of vaporization equals a zero, in this point the liquid and steam phases of water do not differ). By an excellent feature, gradually extended nozzle there is that pressure of steam on an exit from a nozzle, can be well-proven to pressure of environment which a steam is included in. The nozzle of Laval enable to use the pressure difference. Steam goes out from a nozzle with supersonic speed and with the even distributing on a volume, energy of which can be used for the turns of turbine. The turbine of Laval consisted of mobile temporary disk of small diameter with one row of workings shoulder-blades, turbine casing, on the circle of which the gradually extended immobile nozzles a steam was given in which from a caldron were set. In nozzles there was converting of kinetic energy of steam into mechanical work on the shoulder-blades of mobile temporary disk of turbine. Had power, the considerable charges of steam (8-9 kg/kW) in the active turbines of K. Lavalya limited their use in industry (for comparison: in the modern steam-turbines of expense of steam of 3-4 kg/kW). They were used mainly for the occasion of low-powered aggregates. The turbine Charles Gustav Patrik where Laval patented in 1883 In 1889 K. Laval' created new, more difficult with one overfall of pressure active turbine.
With one overfall of pressure highly circulating active turbines for connection with electric generator required the dear gearing.
Reactive turbines were offered by Charles Aldzhernon Parsons (1854-1931), English engineer and businessman, member of London royal society. He borned in London, Сент-Джон Kembridzhskogo made off a college to the university in 1876 year. From 1877 worked in the factory of Amstronga an engineer in industry of engineer. In 1884 -1889 became the partner of company Amstronga. In 1889 founded an enterprise from building of steam-turbines of the system in Tunic.
Reactive turbines, offered Ч. Parsonsom, made with the pressure difference and showed by itself the row of immobile and mobile workings shoulder-blades. Expansion of steam took a place not only in nozzles, to the receipt of him on workings shoulder-blades, as in an active turbine, but also in a period passing of steam between workings shoulder-blades.
For diminishing of circuitous speed of workings shoulder-blades of reactive turbine and diminishing of number of turns Charles Parsons offered initial pressure of steam to utillize not in one overfall of pressure, but to divide into a few overfalls of pressure. In 1884 he got a patent on a reactive turbine with many pressure difference by power 8 kW at speed in 1000 rpm Connecting a turbine with the billow of electric generator of Ch. Parsons got the first turbogenerator for power-station.
The reactive turbines of Ch. Parsonsa began to be widely used from 1900 year, when in Germany on El'bertfel'dskiy of power-station were set and tested two turbines by power 1000 kW at 1500 rpm. Turbines worked at middle pressure of steam of 1,05 Mpa and temperature 200 degrees celsius and had charges of steam of 8-9 kg/kW at complete loaded (for comparison: maximal middle pressure is used in modern steam-turbines, in the cylinders of high-pressure of 25,5 Mpa, at a maximal middle temperature 555°C. overall consumption of steams in three cylinders of turbine of 3-4 kg/KW).
For diminishing of circular speed of workings shoulder-blades of turbines the American engineer Charles Kertis in 1896 year entered the overfalls of speed in practice of турбінобудування. Principle of overfalls of speed consists in because kinetic energy of steam grows into mechanical on the workings shoulder-blades of one not row, but 2-3 rows between which immobile shoulder-blades stand for the change of direction of motion of steam. In active turbines with the overfalls of speed circular speed diminishes effectively, but they have low efficiency, what goes down with the increase of number of overfalls. And that is why the disk of Kertisa was saved in modern turbines only as the first disk of turbine.
For active turbines the pressure difference were first offered in practice French professor Ogyust Ratto, which in 1900 year built at the French plant of Sotte-garle the first active turbine with the pressure difference by power 1000 ph It is possible to decrease speed of turns of rotor the increases of number of pressure difference to the necessary size at the maintainance of high efficiency turbines.
A Swiss engineer Henry Celli perfected the turbine of O. Ratto, used in 1903 attachments (snuffled) with a slanting cut. Due to it it was succeeded to rev up steam on an exit from a nozzle and to decrease the number of pressure difference to 5-8. Changes were borne and in the construction of temporary disks which was increased in a diameter in dependence with the decline of pressure of steam (for comparison: in modern steam-turbines used on the average to 27 pressure difference, in three cylinders of steam-turbines).
In spite of enormous fossil fuel and presence of most water energy sources, tsar's Russia ranked the last places in the world in the production of electric power. In 1913 Russia made in 2,5 times less energy, than Germany and in 15 times less than in the USA. A small quantity of engineering industry and electric factories, which were in Russia, belonged essentially to foreign companies and worked as frame-clamping, utillizing the imported details. At the end of 1920 in the former USSR demand on this equipment due to creative designer and technical and project staff which used to world practical experience in building of steam-turbines, it was succeeded fully to satisfy. The Leningrad metallic factory and factory is „Electro-force” captured the issue of large for that time steam-turbines power 50 MW on 3000 rpm In 1937 year projects were developed for the issue of turbine by power to 100 MW. And on July, 26 in 1938 at the Kharkov turbogenerator plant was made a steam-turbine by power 100 MW on 3000 rpm and generator to it. A large role in development of energy and engineering industry was played by factories and enterprises of Ukraine, and in particular the Kharkov factories of Turboatom, Elektrovazhmash, Electromechanics factory (KHEMZ). On the Kharkov engineering industry factories the turbogenerators of wide nomenclature of powers are presently produced to 500 MW.
For today complex study of development of engineering industry in Ukraine not conducted, the creative search of cohort of talented engineers, designers of builders of steam-turbines widely did not have lighted up in public editions, and even in general was inaccessible for illumination of some concrete stages of this development. Implementation of researches is with the ground of renewal in the individual order of term of exploitation of turbines in the rotors of which found out cracks or with most probability it is possible to expect the accumulation of most values of damage in compared to other turbines of it to the type option. Creation of the automated system of diagnostics of cylinders of, which provides continual control of change of radial gaps in running part at the start-stop and transitional operations of work of turbines yet ahead.
The originals of articles prepared by V.Cyganenko
|