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ABSTRACT: Decreased electrode erosion is important to maintain an arc and reduce costs. Normally, a vacuum or rare gases such as argon and helium are used to prevent electrode erosion. However, associated equipment and its arrangement are expensive. If the anode attachment of the arc is moving, electrode erosion can be decreased even in an air atmosphere. This paper specifically addresses arc movement, especially the restrike phenomenon, in a rail-gun. The arc length was measured using a plasma image processing on pictures taken with a high-speed video camera. Thereby, the lengths and positions of the arc are determined over time. The average velocity of the anode is as fast as that of the cathode, even in restrike mode.
IEEE Transactions on Plasma Science 05/2005; · 1.17 Impact Factor
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ABSTRACT: This paper presents a new calculation method for wheeling prices for power markets. This novel method of wheeling prices includes adding to the ordinary capacity cost, newly congestion cost and loss cost of transmission lines. Finally, case study results show that the proposed method of wheeling prices is very useful for giving an economic signal to transmission users and suppressing transmission line congestion.
Power System Technology, 2004. PowerCon 2004. 2004 International Conference on; 12/2004
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ABSTRACT: According to experimental results, the temperature on a horizontally curved conductor proved to be higher than that on a straight conductor. The temperature deviation increased with the current ratio I/I<sub>cr</sub> increasing or the curved angle α and curved radius R<sub>0</sub> decreasing, where I<sub>cr</sub> is the critical melting current. In a previous paper, the critical melting current I<sub>cr</sub> of horizontal, straight copper conductors in the air can be expressed by the following equation: I<sub>cr</sub> = 2.21 × 10<sup>3</sup> D<sup>1.505</sup> (A) (1) (70 A ≤ I<sub>cr</sub> ≤ 2500 A, 0.1 cm ≤ D ≤ 1 cm, D-diameter). Therefore, if the maximum surface temperature is settled for conductors of the same diameter and manufactured of the same material, the current conducted by a curved conductor was smaller than that conducted by a straight one. When the curved angle α was ∠45° and current ratio I/I<sub>cr</sub> was 38.5%, the current decrease deviation was approximately 10%.
IEEE Transactions on Power Delivery 11/2002; · 1.35 Impact Factor
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ABSTRACT: When a reduction of the waste and dissolution of the iron are carried out by using a high temperature medium, the radiant power emitted from it should be suppressed. On the contrary, it is useful for lightning and treatment of hazardous waste because it has a highly intense radiation. In this paper, we tried to calculate the mass density and radiant power density emitted from atmospheric air contaminated with tungsten vapor to apply the radiant power to treatment of hazardous wastes. The contaminated mol ratio of W/N<sub>2</sub>/O<sub>2</sub> is considered as 5%/76%/19%, because it is assumed that the high temperature air contaminated with tungsten is generated by free arc discharge of 1,700 W. The W is dominant in the mass density and radiant power density from 6,000 to 10,000 K. And then, the radiant power densities with absorption are calculated. The W is still dominant in the radiant power density even if with absorption. On the other hand, the N and O decrease if the absorption is considered. At the end, the application of the radiant 'power emitted from high temperature atmospheric air with tungsten vapor is proposed.
Plasma Science, 2002. ICOPS 2002. IEEE Conference Record - Abstracts. The 29th IEEE International Conference on; 02/2002
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ABSTRACT: Deals with thermal equilibrium between the particles in argon plasma arcs. The current limit for LTE is experimentally defined as a function of the pressures. Plasma parameters were spectroscopically determined. In particular, the electron temperature and heavy particle temperature were measured. The electron temperature was determined from an absolute continuum strength. Two temperatures were obtained for the heavy particles, one of which was determined from the Doppler component of the Halpha line when argon gas seeded with hydrogen was used. The second was obtained through a kinetic formula using the measured density and temperature of the electron. The results show that the electrons did not equilibrate with the heavy particles at low currents and pressures. The limit value of the current for LTE increased with decreasing gas pressure. It is shown, furthermore, that the measured field strength of the arc was remarkably lower than those calculated at currents less than the above limits.
Journal of Physics D Applied Physics 11/2000; 13(5):805. · 2.54 Impact Factor
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ABSTRACT: The problem of the disposal of hazardous wastes has become very
important in recent years. Plasma treatment is being developed and
tested for incinerator ash, low level radioactive wastes, industrial and
biomedical wastes, etc. by industrial companies and municipalities world
wide. In this paper, the principles are discussed and examples of waste
treatment such as fly ash, asbestos, aluminum, municipal wastes, low
level nuclear wastes, etc. by using DC arc discharge plasma are shown
IEEE Transactions on Dielectrics and Electrical Insulation 11/2000; · 1.09 Impact Factor
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ABSTRACT: The torch plasma generated by the plasma torch has the characteristics of high temperature and highly intense radiation. We focused on the radiation that has been ignored as a loss to treat the materials, especially hazardous wastes. The radiation power was 1540 W when the input power was 7000 W and the appearance plasma length was 2 cm at 1 atm. And then, the temperature of the radiation spot concentrated from torch plasma by a lens was measured. The increasing temperature of the radiation spot was 8.2 K. If all the radiation can be focused on the spot, this would lead to thousands of degrees in the temperature rise
Industry Applications Conference, 2000. Conference Record of the 2000 IEEE; 11/2000
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ABSTRACT: We measured the radiation power emitted from a plasma torch as a function of the electric input power. The radiation power was measured to be 700~1500 W for the input power of 4400~7000 W and increased in proportion to the 1.83th power of the current or to near 1.55th power of the input power. Therefore, the radiation power increases steeply with the input power. The radiation efficiency for a wall-stabilized arc model was 41% in a condition of 2 cm in the appearance plasma length, 150 A in current and 7000 W in input power
Power Engineering Society Summer Meeting, 2000. IEEE; 02/2000
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ABSTRACT: To destroy dioxin's, the toxic polynuclear molecular compounds, a
DC argon plasma of 0.02 MPa to 0.1 MPa in pressure was applied. Because
of the terrible toxicity of Dioxin's, biphenyl, which is of the same
polynuclear molecular structure like dioxin's but nontoxic, was wed as
the test chemical. The test current was 50 A, 100 A and 150 A,
respectively. The plasma temperature was measured to be higher than 8000
K. The temperature characteristics of the low pressure plasma was
discussed. By analyses of the heat transfer from the plasma to the
biphenyl corpuscles, the necessary time for disposal of biphenyl
corpuscles in Ar, N<sub>2</sub>, He and H<sub>2</sub> plasma was
calculated
Discharges and Electrical Insulation in Vacuum, 2000. Proceedings. ISDEIV. XIXth International Symposium on; 02/2000
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ABSTRACT: When reduction of waste and dissolution of iron are carried out by using arc plasma, one needs to reduce the arc radiation power, because there are some cases where radiation can damage the furnace wall. On the other hand, one can use it as a clean source for heating materials. The authors measured the radiation power from plasma torches. The radiation power increased in proportion to the 1.8-2.0 th power of the current. The radiation power in a unit length increases with the apparent plasma length. The radiation efficiency is 41% for an apparent plasma length of 3 cm and 31% for the whole plasma length of 3 cm due to a wall-stabilized arc model at 100 A
Power Engineering Society Summer Meeting, 1999. IEEE; 08/1999
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ABSTRACT: The distribution properties of magnetic force and surface
temperature on a curved conductor have been investigated. The results
reveal that those distributions are nonuniform along the conductor. The
maximum value is located at the vertex of the curved part and is
influenced by the curved radius and the curved angle
IEEE Power Engineering Review 08/1999;
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ABSTRACT: When reduction of waste and dissolution of iron are carried out by using arc plasma, we need to reduce the arc radiation power, because there are some cases of damaging the furnace wall due to the radiation. On the other hand, we can use it as a clean source for heating materials. In this case, it's expected that radiation becomes greater. In both cases the radiation power from plasmas has to be precisely controlled. So, we measured the radiation power from torches with a plasma length from 1 to 3 cm. The radiation power decreased in proportion to the 1.8~1.9th power of the current. The radiation power in a unit length decreases with the appearance plasma length. The radiation efficiency was 41% for the appearance plasma, 32% for the wall-stabilized arc model, and 20% for the plasma torch at 100 A and length of 3 cm
Industry Applications Conference, 1999. Thirty-Fourth IAS Annual Meeting. Conference Record of the 1999 IEEE; 02/1999
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ABSTRACT: The research on decomposing hazardous polynuclear compounds such as Dioxin was carried out. A hollow cathode plasma instrument was applied to the process. With the aid of a commercial software, the temperature and velocity distributions in the hollow cathode argon plasma were analyzed. The highest temperature was calculated to be about 15,000 K, which coincided with the experimental result roughly. The maximum velocity was 53 m/s and the average velocity of the fluid field was about 5 m/s. The time for the particles to pass through the high-temperature region was about 40 ms. Referring to the sublimating time of the particles of diameters from 0.1 to 0.4 mm in Ar, N2, He and H2 plasma, under temperatures up to 25,000 K, the disposal effect was discussed. The biphenyl particles should be 0.2 mm or smaller in diameter to be perfectly evaporated and discomposed.
Vacuum.
