RU2058482C1 - Process of formation of pulse high-speed jets of poorly conductive fluids and device for its implementation - Google Patents

Abstract

FIELD: magneto hydrodynamic equipment. SUBSTANCE: process of formation of pulse high-speed jets of poorly conductive fluids consists in injection of poorly conductive fluid by portions with formation of gas space on side opposite to direction of movement of pulse high-speed jets of poorly conductive fluid. Plasma column is formed for each portion of fluid through which discharge current is passed simultaneously with passing of electric current through poorly conductive fluid. Acceleration of portion of poorly conductive fluid takes place as result of interaction of discharge current with external magnetic field. Device for realization of proposed process has barrel with extended accelerating electrodes forming oblong channel for portion of poorly conductive fluid which has compartment for creation of plasma column where igniting electrode is placed between accelerating electrodes and is connected to meter feeding portion of poorly conductive fluid into barrel. EFFECT: enhanced operational reliability and efficiency of device. 10 cl, 2 dwg

Description

 The invention relates to magnetohydrodynamic technology and can be used for punching holes in solid materials, as well as for mechanical impact on solids: for cutting, cleaning, etc.

 Widely known methods for creating high-pressure jets of liquids and devices for their implementation. Most of these devices include a fluid chamber, a high pressure source, and a nozzle. The fluid velocity is limited by the pressure value, which, in turn, is limited by the strength of the chamber.

 For technological applications, it is most convenient, as a rule, to use electricity as an energy source. In this case, high pressure in the discharge chamber is usually obtained due to the electro-hydraulic effect of the electric discharge in the liquid. However, this results in very high impulse pressures, which leads to the need to use special materials in the design.

 In addition, due to the loss of discharge energy due to compression of the liquid at high pressures and radiation due to high temperatures in the discharge channel, the pressure in the discharge chamber rapidly decreases with time, which reduces the efficiency of liquid acceleration.

 In some methods and devices for their implementation, the acceleration of the liquid is carried out by the combined action of high pressure from the electro-hydraulic effect and the forces of electromagnetic rock.

 So, there is a known method of creating pulsed high-speed liquids, which consists in the interaction of the flow of electric current passing through a fluid placed in an elongated channel with an external magnetic field applied normally to the direction of flow in the fluid (Povkh I.L. Technical hydrodynamics, L. Mechanical Engineering, 1969, p. 472).

 A device for creating pulsed high-speed jets of liquids is known that implements the above method and contains a barrel having elongated accelerating electrodes forming an elongated channel for holding liquid and connected to a power source, and a magnetic system that creates an external magnetic field normal to accelerating electrodes (see ibid.) .

 The specified method and device for its implementation are mainly intended for pumping well-conducting liquids (molten metals). When electrolytes are dispersed in this way, the liquid is quickly heated by the current passing through it until it boils, after which an electric breakdown of the liquid column occurs and its destruction. Calculations show that the acceleration of an electrolyte such as sea water is limited due to the indicated effect to velocities of 150-200 m / s.

 There is a method of creating pulsed high-speed jets of liquids, which consists in the interaction of the flow of electric current passing through a fluid placed in an annular channel with an external traveling magnetic field (Branover G.G. Zinober A.B. Magnetic hydrodynamics of incompressible media, M. Nauka, 1970, pp. 330-332).

 In this method, a traveling magnetic field acts on solids floating in a liquid having high electrical conductivity and special ferromagnetic inserts.

 A device for creating pulsed high-speed jets of liquids is known that implements the above method and contains an annular channel for accommodating liquids and solids having high electrical conductivity, ferromagnetic inserts and a traveling magnetic field inductor (see ibid.).

 The specified method and device for its implementation when used to accelerate portions of liquid require a continuous supply of bodies of intermediaries, since they fly out of the device along with portions of liquid.

 A known method of creating pulsed high-speed jets of liquids, including weakly conductive, and a device for its implementation, in which the restriction associated with low conductivity of the liquid is removed (Mechanics of liquid and gas, N 5, 1988, p. 39-44).

 The indicated method for creating pulsed high-speed jets of weakly conducting liquids consists in interacting with the flow of electric current passing through a weakly conducting liquid placed in an elongated channel with an external magnetic field applied normally to the direction of the flow of electric current generated in a weakly conducting liquid (see ibid. )

 In this method, a stream of weakly conducting liquid is introduced continuously into the elongated channel, and the electric discharge is carried out directly in the liquid.

 A device is known for creating pulsed high-speed jets of weakly conducting liquids, implementing the above method and comprising a barrel having elongated accelerating electrodes forming an elongated channel for accommodating a weakly conducting liquid and connected to a power source, and a magnetic system that creates an external magnetic field normal to accelerating electrodes (see there same).

 In the specified device, the accelerating electrodes are located coaxially. One of the ends of the barrel is hermetically sealed with a dielectric bottom. The annular volume between the electrodes is filled with liquid. Near the bottom, the electrodes are interconnected by a thin wire jumper. A voltage of several kilovolts is applied to the electrodes. In this case, the wire jumper is explosively destroyed and the fluid is accelerated due to the electro-hydraulic effect. Under the influence of the current flowing through the coaxial electrodes, an annular magnetic field is formed in the gap between them. The interaction of the current in the discharge gap with the magnetic field leads to the appearance of an additional accelerating force acting on the liquid.

 In the specified device for implementing the above method, it is difficult to provide a high repetition rate of the duty cycle due to the need to install a wire jumper. In addition, it is necessary to make high demands on the strength of the materials of the device, which is associated with high pressures during the explosive destruction of the bridge.

 The large power consumption of the power source required to create and maintain a high magnetic field during the entire acceleration of the liquid, leads to large dimensions and weight of the power source, and therefore the entire device.

 Due to the low conductivity of the liquid in the specified method and device for its implementation, it is impossible to pass current directly through the liquid, otherwise the latter boils without reaching the desired speed.

 The basis of the invention is the development of a method for creating pulsed high-speed jets of weakly conducting liquids, through which a weakly conducting liquid is introduced into an elongated channel and creating such conditions for its acceleration that maximizes the speed and frequency of ejection of jets, as well as creating a simple device for creating pulsed high-speed jets weakly conducting liquids, which is so structurally designed that allows the implementation of the above method.

 This is achieved by the fact that by the method of creating pulsed high-speed jets of weakly conductive liquids, which consists in the interaction of the flow of electric current passing through a weakly conductive fluid placed in an elongated channel with an external magnetic field applied normally to the direction of the flow of electric current generated in weakly conductive liquid, according to the invention, a weakly conductive liquid is introduced portionwise into the oblong channel with the creation of a gas gap from the side, opposite to the direction of movement of the pulsed high-speed jets of a weakly conducting liquid, and for each portion of a weakly conducting liquid in this gas gap a plasma column is created through which a discharge current is passed simultaneously with the passage of an electric current through a weakly conducting liquid, as a result of which, when the discharge current interacts with an external magnetic field, acceleration portions of slightly conductive fluid.

 A portion of a slightly conductive liquid can be divided into separate parts, separated from one another by plasma gaps.

 It is desirable that the creation of the gas gap was carried out by selecting a predetermined portion of the introduction of a portion of a weakly conducting liquid into the elongated channel from the side of its side wall.

 It is advisable that the creation of the gas gap was carried out by introducing a portion of a weakly conductive fluid into the elongated channel from the side of its end and tearing off a portion of the weakly conductive fluid from this end.

 It is reasonable that a portion of the weakly conductive fluid is separated from the end of the oblong channel by shutting off the flow of weakly conductive fluid supplied by excess pressure greater than the static pressure in the end of the oblong channel.

 It is reasonable that the portion of the weakly conducting liquid be separated from the end of the elongated channel by supplying gas for a period of time between adjacent portions of the weakly conducting liquid.

 This is also achieved by the fact that in the device for creating pulsed high-speed jets of weakly conducting liquids, implementing the above method and comprising a barrel having elongated accelerating electrodes forming an elongated channel for accommodating a weakly conducting liquid and electrically connected to a power source, and a magnetic system that creates an external magnetic field normal to the accelerating electrodes, according to the invention, the barrel has a compartment for creating a plasma column and an ignition electrode is provided, placed in the compartment between the acceleration electrodes, and a dispenser for supplying a weakly conducting fluid portions into an elongated bore.

 The dispenser can be connected to the elongated bore of the barrel behind the barrel compartment in the direction of movement of high-speed jets of weakly conducting liquid or to the end of the elongated bore of the barrel from the compartment side.

 The advantages of the proposed method and device for its implementation are that simple means provide the maximum increase in the speed and frequency of the ejection of jets of a slightly conductive liquid.

 In FIG. 1 shows a General diagram of the proposed device for creating pulsed high-speed jets of weakly conducting liquids, implementing the inventive method (before accelerating a weakly conducting liquid); in FIG. 2 is a general diagram of an embodiment of the proposed device implementing the inventive method.

 The proposed method for creating pulsed high-speed jets of weakly conducting liquids is that they interact with the flow of electric current passing through a weakly conducting liquid placed in an elongated channel with an external magnetic field applied normally to the direction of the flow of electric current generated in a weakly conducting liquid. A weakly conducting liquid is introduced into the oblong channel portionwise with the creation of a gas gap on the side opposite to the direction of movement of the pulsed high-speed jets of a weakly conducting liquid, and for each portion of a weakly conducting liquid in this gas gap a plasma column is created through which a discharge current is passed simultaneously with the passage of an electric current through the weakly conducting liquid as a result of which, when the discharge current interacts with an external magnetic field, a portion accelerates with aboprovodyaschey liquid.

 The creation of a gas gap in the first embodiment of the proposed method is carried out by introducing a portion of a weakly conducting liquid into the elongated channel from the side of its side wall.

 Thus, the discharge current passes through a well-conducting plasma column, which mechanically presses on the accelerated portion of the liquid. The weakly conducting liquid and the plasma column are connected in parallel. Since the plasma conductivity in the discharge is several orders of magnitude higher than the liquid conductivity, the heating of the liquid by electric current is negligible and boiling does not occur. To facilitate the formation of a plasma column and to eliminate the occurrence of high pressures during the breakdown of a liquid, a plasma column is created not in the liquid, but in the gas behind the portion of the liquid. To do this, a portion of the liquid before acceleration is positioned by choosing the place of entry into the barrel so that there is a gas gap on both sides of it. This gap on the right side of the liquid column is ionized by a high voltage pulse (igniting pulse). Simultaneously with the high voltage pulse, an accelerating voltage is supplied. If the accelerating voltage is supplied later than the igniting pulse, then the ionized gas may already lose conductivity and the discharge will not occur, but if earlier, the liquid column will be connected to a high voltage and boiling and electrical breakdown may occur. Breakdown in the volume of liquid leads to spraying of the liquid.

 The creation of a gas gap in the second embodiment of the proposed method is carried out by introducing a portion of a weakly conductive fluid into the oblong channel from the side of its end face and tearing off a portion of the weakly conductive fluid from this end face. In this embodiment, a portion of the weakly conducting liquid is separated from the end of the oblong channel by blocking the flow of the weakly conducting liquid supplied under an excess pressure greater than the static pressure in the end of the oblong channel, and the portion of the weakly conducting liquid is divided into separate parts separated by plasma gaps. The remaining methods are performed in the same way as described above in the first embodiment of the method.

 The third embodiment of the proposed method is carried out similarly to the second embodiment of the method. The difference lies in the fact that the separation of a portion of a weakly conducting fluid from the end of the elongated channel is carried out by supplying gas for a time between adjacent portions of a weakly conducting fluid.

 When implementing the proposed method, it should be borne in mind that a portion of a slightly conductive liquid can be divided into parts in the first embodiment. In addition, it should be borne in mind that the proposed method can accelerate any weakly conducting liquids, including water.

 The proposed device comprises a barrel 1 (Fig. 1) having elongated accelerating electrodes 2 and 3, forming, together with dielectric spacers 4 and 5 located on the elongated surfaces of the electrodes 2 and 3, an elongated channel 6 to accommodate a portion of a slightly conductive liquid 7. Electrodes 2 and 3 are electrically connected to a power source 8. The device also contains a magnetic system 9, which creates an external magnetic field normal to the accelerating electrodes 2 and 3, and a dispenser 10 for supplying a portion of a weakly conducting liquid 7 into the elongated channel 6 of the barrel 1. The barrel 1 has a compartment 11 for creating a plasma column in which between the accelerating electrodes 2 and 3, an ignition electrode 12 is located. Magnetic system 9 contains solenoids 13 and 14 spanning the barrel 1. One of the ends of the conductors of the solenoids 13 and 14 is connected to the electrodes 2 and 3, respectively. The other end of the conductor of the solenoid 13 is connected through a key 15 to a power source 8 and through resistance 16 to the primary winding 17 of the pulse transformer 18 connected to the other end of the conductor of the solenoid 14. The secondary winding 19 of the transformer 18 is connected at one end through a resistance 20 to the ignition electrode 12, and the other end with the electrode 3 and one of the ends of the conductor of the solenoid 14. Parallel to the power supply 8 is connected a diode 21 and a capacitor bank 22 connected to the key 15 and to the primary winding 17 of the transformer 18 and the end p ovodnika solenoid 14.

 In the described embodiment of the device that implements the proposed method, the dispenser 10 is connected to the elongated channel 6 of the barrel 1 behind the screening 11 of the barrel 1 in the direction of movement of high-speed jets of weakly conducting liquid (arrow A). The dispenser 10 is connected to the reservoir 23.

 The device shown in FIG. 2 is made similarly to the device in FIG. 1. The difference lies in the fact that it implements the second and third embodiments of the proposed method, in which a portion of a weakly conductive liquid 7 is divided into separate parts 24, separated from one another by plasma gaps, so the dispenser 10 is connected to the end face 25 of the channel 6 of the barrel 1 from the side compartment 11 and there is a transformer control unit 26. The arrows B indicate the direction of the magnetic field.

 The principle of operation of the proposed device for creating a pulsed weakly conducting liquids carrying out the inventive method is as follows.

 The acceleration of a portion of a slightly conductive liquid 7 (Fig. 1) begins when the key 15 is closed. Transformer 18 gives a high voltage pulse supplied to the electrode 12. Air near the electrode 12 is ionized and pierced by the voltage applied to the accelerating electrodes 2 and 3. The current flowing through the plasma the pillar in compartment 11 also passes through the winding of the solenoids 13 and 14, which create a magnetic field between the accelerating electrodes 2 and 3. The interaction of the discharge current with the magnetic field leads to the acceleration of a portion of the liquid 7.

 After the departure of a portion of the liquid 7 from the barrel 1 and the consumption of energy distributed in the battery 22, and the inductance of the solenoids 13 and 14, the discharge stops and the preparation of the next accelerator cycle begins. To do this, the capacitor bank 22 is charged from the power source 8, the dispenser 10 injects the next portion of the liquid 7 into the channel 6 of the barrel 1. Then the process is repeated.

 Prior to acceleration, a portion of the liquid 7 is held in place by capillary and inertial forces, since at a cycle repetition rate of the order of 100 Hz, the portion of the liquid 7 does not have time to substantially shift due to gravity and other forces.

 The principle of operation of the device of figure 2 is similar to the principle of operation of the device of figure 1. The difference is that the acceleration of the next portion of the liquid 7 begins before the departure of the previous portion of the barrel 1. This allows you to increase the frequency of the ejection of portions of the liquid.

 When implementing the second variant of the method in the device of figure 2, the dispenser 10 performs the function of a damper that blocks the flow of liquid supplied under pressure along the line. With a sharp shutdown of the flow, a portion of the liquid 7 is torn off by inertia from the end face 25 of the barrel 1. After a portion of the liquid 7 passes through the inertia, the ignition electrode 12, the control unit 26 sends a high-voltage pulse ionizing the liquid vapor to the ignition electrode 12 through the pulse transformer 18 filling the compartment 11 between the end face 25 of the barrel 1 and a portion of the liquid 7. Ionization of the vapor leads to a breakdown of the discharge gap between the accelerating electrodes (not shown in FIG. 2) and the beginning of a new acceleration cycle. Since in the second variant of the method several plasma columns passing the current (behind each portion of liquid) are simultaneously located in the barrel 1, measures are necessary to eliminate the shunting effect of the plasma columns on one another, for example, by dividing the accelerating electrodes into separate sections along the length of the barrel 1.

 When implementing the third variant of the method in the device of FIG. 2, the dispenser 10, after supplying the next portion of the liquid 7 to the barrel 1, supplies a portion of the gas sufficient to move the portion of the liquid 7 outside the ignition electrode 12. In this embodiment, the liquid can be supplied to the barrel 1 at a lower pressure than when implementing the second variant of the method. The rest of the second and third variants of the method do not differ from each other.

 The proposed method and device for its implementation are simple to implement. Since the current flows through the plasma, and not through the liquid, in this device it is possible to accelerate weakly conducting liquids, including water. Acceleration by electromagnetic forces avoids the limitation on the maximum jet velocity associated with the relatively low velocity of the shock wave in the gas. Providing approximately constant discharge current, it is easy to obtain an acceleration mode close to uniformly accelerated. In this case, the maximum fluid pressure on the walls of the device has a minimum value, ceteris paribus. This allows you to make the device from available materials. The device is structurally simple. There are no high requirements for the strength of materials.

Claims (9)

 1. The method of creating pulsed high-speed jets of weakly conducting liquids, which consists in the fact that they interact with the flow of electric current passing through a weakly conducting liquid placed in an elongated channel with an external magnetic field applied normally to the direction of the flow of electric current generated in a weakly conducting liquid, characterized the fact that a weakly conducting liquid is introduced portionwise into the elongated channel with the creation of a gas gap from the side opposite to the direction ne repulsive high-speed jets of a weakly conducting liquid, and for each portion of a weakly conducting liquid in this gas gap a plasma column is created through which a discharge current is passed simultaneously with an electric current passing through a weakly conducting liquid, as a result of which, when a discharge current interacts with an external magnetic field, an acceleration of a portion of a weakly conducting liquids.  2. The method according to claim 1, characterized in that the portion of the weakly conductive liquid is divided into separate parts separated from one another by plasma gaps.  3. The method according to p. 1 or 2, characterized in that the creation of a gas gap is carried out by selecting a predetermined portion of the input portion of a weakly conductive liquid into the elongated channel from the side of its side wall.  4. The method according to p. 1 or 2, characterized in that the creation of a gas gap is carried out by introducing a portion of a weakly conducting liquid into the elongated channel from the side of its end and tearing off a portion of a weakly conducting liquid from this end.  5. The method according to p. 4, characterized in that the separation of a portion of a weakly conductive fluid from the end of the oblong channel is carried out by blocking the flow of weakly conductive fluid supplied under excess pressure, greater than the static pressure at the end of the oblong channel.  6. The method according to p. 4, characterized in that the separation of a portion of a weakly conductive fluid from the end of the elongated channel is carried out by supplying gas for a time between adjacent portions of a weakly conductive fluid.  7. A device for creating pulsed high-speed jets of weakly conducting liquids, containing a barrel having elongated accelerating electrodes forming an elongated channel for placing a weakly conducting liquid and electrically connected to a power source, and a magnetic system that creates an external magnetic field normal to accelerating electrodes, characterized in that in it, the barrel has a compartment for creating a plasma column, and an ignition electrode located in this compartment between the accelerating electrodes is provided, and OP for feeding portions of a slightly conductive fluid into the elongated bore of the barrel.  8. The device according to claim 7, characterized in that the dispenser is connected to an elongated bore of the barrel behind the barrel compartment in the direction of movement of high-speed jets of weakly conducting liquid.  9. The device according to claim 7, characterized in that the dispenser is connected to the end of the elongated barrel channel from the compartment side.

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