Device and method for condensing metal for continuous casting

Abstract

The invention relates to a device for condensing metal for continuous casting, the device is simple in overall structure and easy to manufacture, a pulse oscillator does not need to be in direct contact with the surface of a casting blank, so that the device can be better applied to the continuous casting process, and in the condensation and crystallization process of the metal casting blank, composition segregation can be reduced, the grain size can be refined, and the production efficiency is improved. And the finished product performance of the metal casting blank is remarkably improved, the use experience of a user is enhanced, and popularization and application of the metal condensing device for continuous casting in the market are facilitated. According to the method for condensing the metal for continuous casting, the device for condensing the metal for continuous casting is applied, the pulse frequency can be automatically controlled to be kept consistent with the inherent frequency of a casting blank, and meanwhile energy generated by detonation of combustible mixed gas (natural gas, oxygen and air) serves as an energy source; and the material and energy cost can be reduced while the production efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the field of metallurgical casting technology, in particular to a device and method for condensing metal for continuous casting, which can be used for the production of high-quality metal ingots / products in the metallurgical industry and the machinery manufacturing industry. Background Art

[0002] Continuous casting is a common technology for producing metals in the field of metallurgy. The technology involves pulling the ingot out of the crystallizer and cooling it with water in the secondary cooling zone. The general continuous casting process affects the metal structure of the ingot by ensuring optimal cooling conditions. In addition, methods of influencing its metal structure through magnetic and electromagnetic fields are also widely used.

[0003] Prior art ① discloses a metal treatment method and equipment for vibration crystallization [USSR: 2087251, TPC: B22D27 / 08, 1997.05.20]. Specifically, the invention relates to a technology and device for treating metal ingots by mechanical vibration, which can be used for the refinement of metals of different types and properties. The purpose of the invention is to improve the performance and quality of cast metals. For metals or alloys of different types and properties, multi-angle vibration treatment is applied in the horizontal, vertical and inclined (45° angle) directions during the crystallization of the ingot. According to the different combinations of vibration modes and the changes in vibration angles, the performance of the metal ingot is affected. The device of the method includes a casting mold, a workbench, a frame (cast iron), an elastic element and a vibration base. Through the action of the pneumatic exciter on the vibration base, non-metallic inclusions in the metal or alloy can be better removed, while the grains can be refined and the performance can be improved. However, in this method, since the pneumatic exciter must have mechanical contact with the metal, and is affected by the billet drawing speed under the action of the high temperature of the metal, it is difficult to apply it to the continuous casting process. In addition, the pneumatic ball vibrator used in this method is also difficult to induce high-amplitude elastic vibrations.

[0004] Prior art ② discloses a vibration pulse processing method for molten metal [Russian patent: 965058, TPC: B22D27 / 02, C22B9 / 20, 2000.01.10]. This method generates a pulse shock in the electro-hydraulic device through the pulse discharge of the pulse power supply, and introduces it into the metal molten pool connected in series with the electro-hydraulic device, thereby effectively affecting the refining and crystallization process of the metal, thereby improving the quality and performance of the metal. Like patent ①, this method also requires mechanical contact, so it is difficult to apply to the continuous casting process. And this method needs to operate at a higher voltage, which poses a higher safety risk.

[0005] Both the above-mentioned prior art ① and the above-mentioned prior art ② improve the performance of the cast metal by introducing elastic vibration, and neither involves the introduction of sound waves or long-wave phonons.

[0006] Prior art ③ discloses a method for producing ingots [USSR: 2132252, TPC: B22D27 / 00, 1999.06.10]. The method is a method and device for treating metal billets in a resonant state by using acoustic vibration. The method uses a resonator to amplify the billet's own energy as the energy source of the oscillator. By applying an oscillation frequency close to or equal to the natural frequency of the metal billet, the sound wave generated by the acoustic vibration affects the crystallization process of the metal billet, thereby optimizing the performance of the metal billet. In this method, due to the harsh use environment, the sound guide tube used not only needs high fire resistance, but also needs to have high elasticity at high temperatures to ensure effective sound conduction, which has certain manufacturing difficulties. Since it is necessary to use the billet's own acoustic vibration, the vibrator used is complex to manufacture and expensive. At the same time, the sound radiation generated by other facilities in the continuous casting device will also be amplified by the vibrator. The inconsistency between these facilities and the billet's natural frequency will affect its processing efficiency. In addition, the billet's own natural frequency will change according to factors such as temperature, size, and gap with the vibrator, which requires the oscillation frequency of the resonator to be variable. Even if the corresponding device can be completed, high-quality metal castings cannot be obtained by sonication alone.

[0007] Prior art ④ discloses a combined processing method and equipment for ingots in metal casting [USSR: 2025212, TPC: B22D27 / 08, 1994.12.30]. This invention is a method for applying a vibration combination to a metal ingot in a casting mold. When the molten metal fills the mold, continuous ultrasonic treatment is performed. The introduction of ultrasonic waves can be directly introduced through the solidified metal surface or indirectly through the side wall of the mold. Direct and indirect ultrasonic treatment methods improve their processing efficiency, thereby improving the quality of the ingot. This method also has the defect that it is difficult to apply in the continuous casting process due to mechanical contact.

[0008] Prior art ⑤ discloses an acoustic wave treatment device for crystallizing molten metal [USSR: 1052561, TPC: C22F3 / 02, 1983.11.07]. The invented device is a container for cooling and crystallizing molten metal, which has a tray, an acoustic wave transducer and a cooling system. The acoustic wave transducer is combined with the cooling system, and during the cooling process of the cooling system through the sprayer, the transmission of the acoustic wave is completed to complete the influence on the molten metal. Similarly, it is difficult to apply to continuous casting because of the need for mechanical contact.

[0009] At present, in the continuous casting process of metallurgy, the effect of influencing the metal crystallization process by mechanical vibration, electromagnetic stirring and other methods is limited, and it is difficult to produce high energy density even at high power. However, there is almost no loss when introducing sound waves and elastic waves into metals. In the known inventions, very few use sound waves to treat ingots, and even fewer use sound waves and elastic waves in combination. Similar methods of using sound waves to treat metal crystallization are difficult to apply in the continuous casting process; even if they can be applied to the continuous casting process, their methods and devices have problems such as high requirements for parts, control of resonance frequency, and insufficient effect of single sound waves. Summary of the invention

[0010] In order to overcome the defects in the above-mentioned prior art, the first invention object of the present invention is to provide a device for condensing metal for continuous casting, which has a simple overall structure and is easy to manufacture, wherein the pulse oscillator does not need to be in direct contact with the surface of the ingot, so it can be well applied in the continuous casting process, and in the condensation and crystallization process of the metal ingot, it can reduce component segregation, refine the grain size, significantly improve the finished product performance of the metal ingot, enhance the user experience, and facilitate the promotion and application of the above-mentioned device for condensing metal for continuous casting in the market. The second invention object of the present invention is to provide a method for condensing metal for continuous casting, which uses the above-mentioned device for condensing metal for continuous casting, which can automatically control the pulse frequency to be consistent with the natural frequency of the ingot itself, and use the energy generated by the detonation of the combustible mixed gas (natural gas, oxygen and air) as the energy source, which can greatly improve production efficiency while reducing material and energy costs.

[0011] The above-mentioned device for condensing metal for continuous casting and the method for condensing metal for continuous casting are technically related to each other and belong to the same inventive concept.

[0012] In order to achieve the above-mentioned first invention object, the present invention adopts the following technical scheme: a device for condensing metal for continuous casting, comprising a built-in elastic wave and sound wave generator, a control panel for supplying combustible mixed gas, and an analog control system for controlling the ignition frequency by a signal sent by a vibration sensor, a crystallizer is located at the outlet of a tundish, liquid metal is poured from the tundish into the crystallizer to form a cast billet, the cast billet has a liquid metal portion and a billet shell, a lead-out mechanism is provided at the bottom of the crystallizer, and the cast billet can be pulled out of the crystallizer and enter the secondary cooling zone through the lead-out mechanism, The secondary cooling zone includes a pulse oscillator and a secondary cooling water pipeline, and the nozzle of the pulse oscillator is merged with the nozzle of the secondary cooling water pipeline; the pulse oscillator includes a high-frequency detonation device with a spark plug; a plurality of water pipes are arranged around the ingot, and the water pipes are equipped with a plurality of nozzles capable of spray cooling the ingot, and pulse oscillations are introduced into the gap around the nozzle of the pulse oscillator filled with water, and the pulse oscillations are transmitted to the cooling water in the water pipes and the nozzles, and while the cooling water cools the ingot, a thermal elastic effect is produced on the ingot shell with pulse vibrations of a resonant frequency.

[0013] As a preferred solution of the present invention, the lead-out mechanism includes a dummy rod and support rollers, the dummy rod is located at the bottom outlet of the crystallizer, and there are multiple support rollers, which are arranged on both sides of the ingot.

[0014] As a preferred solution of the present invention, the nozzle of the pulse oscillator is combined with the nozzle of the secondary cooling water pipeline and fixed together in the fixed pipeline.

[0015] As a preferred solution of the present invention, the pulse oscillator further comprises a connector for connecting the nozzle of the pulse oscillator.

[0016] As a preferred solution of the present invention, there are at least two pulse oscillators.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: a device for condensing metal for continuous casting in the present invention has a simple and ingenious structure and is easy to operate. In the condensation and crystallization process of the metal ingot, it can reduce component segregation, refine the grain size, and significantly improve the finished product performance of the metal ingot. At the same time, high-intensity sound waves, elastic vibrations and thermoelastic vibrations at resonance frequencies are introduced to ensure sufficient influence on the crystallization process of the metal ingot; the device of the present invention can automatically control the pulse frequency to be consistent with the inherent frequency of the ingot itself, and at the same time use the energy generated by the detonation of the combustible mixed gas (natural gas, oxygen and air) as the energy source to reduce the material and energy costs. The overall structure of the device of the present invention is simple and easy to manufacture, wherein the pulse oscillator does not need to be in direct contact with the surface of the ingot, so it can be better used in the continuous casting process.

[0018] In order to achieve the above-mentioned second invention purpose, the present invention adopts the following technical scheme: a method for condensing metal for continuous casting, using the above-mentioned device for condensing metal for continuous casting, including the following steps: pouring liquid metal into a crystallizer, then pulling out the ingot, and cooling it in a secondary cooling zone; in the process of pulling it out from the crystallizer and then into the secondary cooling zone, performing multi-form combined resonance treatment on the ingot by a pulse oscillator fixed in the secondary cooling zone; using the energy generated by the explosion of the combustible mixed gas provided by the operating console as the energy source of the pulse oscillator, and adjusting the vibration frequency through the vibration sensor fixed on the support roller and the analog control system to complete the resonance treatment of the ingot crystallization process.

[0019] As a preferred embodiment of the present invention, the multiple forms of combined resonance treatment on the ingot include but are not limited to acoustic, elastic and thermoelastic vibration pulses on the ingot.

[0020] As a preferred solution of the present invention, the effects of high-intensity sound waves, elastic vibrations and thermoelastic vibrations on the surface of the ingot are processed at a frequency close to or equal to the natural frequency of the ingot, and the operating frequency of the pulse oscillator is automatically adjusted through a vibration sensor fixed on the support roller.

[0021] As a preferred embodiment of the present invention, the resonance treatment of the surface of the ingot by high-intensity sound waves, elastic vibrations and thermoelastic vibrations is carried out between the zero-segment rollers in the secondary cooling zone along the heat dissipation direction.

[0022] As a preferred embodiment of the present invention, the vibration pulses of high-intensity sound waves, elastic vibrations and thermoelastic vibrations act in a direction perpendicular to both sides of the billet shell and pass through the billet shell, wherein the billet shell does not exceed 20% of the entire billet cross-section.

[0023] Compared with the prior art, the beneficial effects of the present invention are: a method for condensing metal for continuous casting in the present invention, by applying the above-mentioned low-energy consumption and easy-to-operate device for condensing metal for continuous casting, can automatically control the pulse frequency to be consistent with the inherent frequency of the ingot itself, and at the same time use the energy generated by the detonation of the combustible mixed gas (natural gas, oxygen and air) as the energy source, which can greatly improve production efficiency while reducing material and energy costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 1 is a schematic structural diagram of a device for condensing metal for continuous casting according to an embodiment of the present invention; Figure 2 It is a schematic structural diagram of a secondary cooling zone in a device for condensing metal for continuous casting according to an embodiment of the present invention; Figure 3 yes Figure 2 Structural cross-section view at AA in the middle; Figure 4 yes Figure 2 Structural cross-section view at the middle BB; Figure 5 It is a schematic diagram of the macroscopic structure of the aluminum alloy system (Al-6%Cu-0.8%Zr) after condensation and crystallization without being treated by a pulse oscillator; Figure 6 This is a schematic diagram of the macroscopic structure of the aluminum alloy (Al-6%Cu-0.8%Zr) after condensation and crystallization and being treated by a pulse oscillator.

[0025] Figure numerals: 1. generator; 2. operating console; 3. analog control system; 4. vibration sensor; 5. liquid metal part; 6. billet shell; 7. support roller; 8. ingot guide rod; 9. crystallizer; 10. tundish; 12. pulse oscillator; 12-1. high-frequency detonation device; 12-2. joint; 13. secondary cooling water pipeline; 14. fixed pipeline; 15. water pipe; 16. nozzle; 17. gap. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0027] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0028] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] The invention is based on the following physical principle: In a wide temperature range of metals, the interaction between conductive electrons and phonons is the main mechanism for establishing equilibrium. Only at very low temperatures do electron collisions produce thermal conductivity, so in the typical temperature range of cooling a cast ingot, electron-phonon collisions have a decisive influence on thermal conductivity.

[0030] By introducing acoustic phonons and elastic vibrations, additional phonons are excited, thereby strengthening their influence on thermal conductivity. In this case, the efficiency of the electron-phonon interaction is evaluated by the lattice constant, the effective mass of the electron, and the atomic mass. When long-wave phonons are absorbed, an additional factor is introduced into the calculation: the frequency and amplitude of the phonons are taken into account. When the frequency of the pulse oscillator coincides with the natural frequency of the ingot, an additional coefficient is introduced, which has a value greater than 1.

[0031] Acoustic long-wave phonons are reflected when colliding with atoms and molecules of dense media (metal alloys), forming a coherent wave system. During their interference, heterogeneities are formed in the melt, which form unstable, rapidly decaying acoustic nuclei with subcritical size. The high density of the number of acoustic nuclei compensates for their instability.

[0032] Applying different types of vibrations (acoustic, elastic, thermoelastic vibrations) to the same volume of metal (cast billet) at the same time, they have the same frequency vibration (close to or equal to the natural frequency of the cast billet), the introduction of multiple vibrations can change the physical properties of the metal alloy. In this case, the crystallization, electrical conductivity and thermal conductivity of the alloy can be described by nonlinear wave equations.

[0033] The metal crystallization is enhanced by using a combination of multiple types of vibrations (acoustic, elastic, thermoelastic) with a natural frequency (close to or equal to the natural frequency of the ingot), which generates electronic disturbances in a resonance phenomenon. Due to the factors of phonon-electron interaction, interference defects in the form of eddy currents, pressure antinodes (pressure pools) and atomic displacements are formed. The additional disturbance in the liquid metal increases the number of crystallization nuclei, ensures a fine-grained homogeneous structure of the metal ingot, reduces the possibility of chemical inhomogeneities (segregation), and reduces the crystallization time.

[0034] If the physical principle of the resonant frequency and acoustic frequency action on liquid metal is considered as a set of vibration units related to the state density p(n) (restricted by the framework ra - Rc), the interaction energy (Ei - ion-ion, Еe - electron-electron, Еe.i - ion-electron) is equal to the sum of the atomic vibrations SЕj, and the atomic vibrations can be considered to exist independently and do not interact with each other. Since each vibration unit is independent of other vibrations around it, it reflects the additivity of its pseudopotential. In this case, the natural vibration frequency of each vibration unit is consistent with the frequency of the excited oscillation when the phonon is introduced. Therefore, there may be two resonance phenomena in liquid metal: at the macroscopic level, the natural frequency of the metal billet resonates with the exciting force in the form of elastic waves; at the microscopic level, the atomic vibration unit resonates with the vibration of acoustic phonons.

[0035] In terms of energy, the value of hv / kT is mainly considered, where hv is the exchange energy transferred between atoms and kT is related to the thermal vibrations of atoms, whose temporary positions must be "frozen" (fixed) by cooling. Therefore, the supercooling of liquid metal is related to the "dumping (release)" of energy from clusters to statistically ordered microregions. As the temperature drops, the external heat source cannot maintain the required level of thermal energy kTpl, so only the statistically ordered microregions can be used as a source of increased energy. Their fluctuation energy is 3 / 2kTpl, supported by the "release" of the energy of the growing clusters. Therefore, the maximum supercooling depth in kT should correspond to the statistically ordered fraction, which is 0.35 parts.

[0036] The introduction of resonant oscillations excites atomic vibration units, destroys boundary concentrations, and increases the probability of large clusters releasing energy and forming smaller, lower-energy clusters. The "freezing" of small clusters contributes to the uniform distribution of alloying elements and the formation of fine-grained structures in metal alloys.

[0037] The pulsed cooling jet forms thermoelastic oscillations, which accelerate the segregation and release of non-metallic and gaseous inclusions from the metal. Compared with mechanical vibrations, the combined resonance effect on the liquid metal provides more crystallization nuclei at a lower energy consumption.

[0038] The shock waves acting on the surface of the metal strand are an additional factor in processing the metal surface layer. When the vibration movement direction of the liquid metal pool in the crystallizer changes, the vibration of the surface can be used to determine the flow state of the crystallized metal.

[0039] To test the method, a pulse oscillator 12 was designed and manufactured, which had a system for introducing a combustible mixture and a spark plug. The pulse detonation in the pulse oscillator 12 was started by adjusting the signal frequency output from the analog control system 3 to the spark plug by the vibration sensor 4. The analog control system 3 provides a signal output of a resonant frequency to ensure that the operating frequency is consistent with the natural vibration frequency of the metal casting.

[0040] The pulse oscillator 12 is installed directly below the crystallizer 9 as in the secondary cooling zone. The gas distributor and ignition control system are installed behind the wall of the secondary cooling zone of the ingot.

[0041] The effectiveness of crystallization by elastic and acoustic waves was tested on an alloy (Al-6%Cu-0.8%Zr). The crucible containing the liquid alloy was placed in an elastic and acoustic wave generator, and the crystallization results of the alloy were: the grain size was reduced by 90%-95%, the alloy elements were evenly distributed, and the tensile strength (ultimate strength) of the alloy was increased by 12-15%.

[0042] like Figures 1 to 4As shown, a device for condensing metal for continuous casting includes a built-in elastic wave and sound wave generator 1, a control panel 2 for supplying flammable gas and oxidant, and an analog control system 3 for controlling the ignition frequency by a signal sent by a vibration sensor 4. The above-mentioned crystallizer 9 is located at the outlet of the tundish 10. Liquid metal is poured from the above-mentioned tundish 10 into the above-mentioned crystallizer 9 to form a cast billet. The above-mentioned cast billet has a liquid metal part 5 and a billet shell 6. The bottom of the above-mentioned crystallizer 9 is provided with a lead-out mechanism, through which the above-mentioned lead-out mechanism can be pulled out of the above-mentioned crystallizer 9 and enter into a secondary cooling zone. The secondary cooling zone includes a pulse oscillator 12 and a second The secondary cooling water pipeline 13, the nozzle of the pulse oscillator 12 is combined with the nozzle of the secondary cooling water pipeline 13; the pulse oscillator 12 includes a high-frequency detonation device 12-1 with a spark plug; multiple water pipes 15 are arranged around the above-mentioned ingot, and the water pipes 15 are equipped with multiple nozzles 16 capable of spray cooling the above-mentioned ingot, and pulse oscillation is introduced in the gap 17 around the nozzle of the pulse oscillator 12 filled with water, and the pulse oscillation is transmitted to the cooling water in the water pipe 15 and the nozzle 16, and the cooling water cools the ingot while generating a thermoelastic effect on the ingot shell 6 with a pulse vibration of a resonant frequency. Specifically, the metal is poured into the crystallizer 9 of the continuous casting machine, and then the slab is pulled out and cooled in the secondary cooling zone. In the process of pulling out from the crystallizer 9 and then to the secondary cooling zone, the ingot is subjected to resonance treatment in various forms (high-intensity sound waves, elastic vibrations and thermoelastic vibrations) through the pulse oscillator 12 fixed in the secondary cooling zone. The energy generated by the explosion of the combustible mixed gas is used as the energy source of the pulse oscillator 12, and the vibration frequency is adjusted through the vibration sensor 4 and the analog control system 3 to complete the resonance treatment of the ingot crystallization process. The ingot treated by the above process can achieve automatic frequency modulation while improving the metal crystallization effect. It is simple to operate and can effectively reduce segregation, refine grains, and improve the finished product performance of the metal ingot.

[0043] The pulse action of high-intensity sound waves, elastic vibrations and thermoelastic vibrations on the surface of the ingot is processed at a frequency close to or equal to the natural frequency of the ingot, and the working frequency of the pulse oscillator 12 is automatically adjusted by the vibration sensor 4, thereby ensuring the quality of the ingot. In order to improve the cooling efficiency and quality of the ingot, the pulse resonance action of high-intensity sound waves, elastic vibrations and thermoelastic vibrations on the surface of the ingot is carried out along the heat dissipation direction between the zero-section rollers in the secondary cooling zone. In the production process, by performing the pulse resonance action along the heat dissipation direction, the cooling process of the ingot can be better controlled, more precise process control can be achieved, and then the production efficiency and product quality can be improved.

[0044] The vibration pulses of high-intensity sound waves, elastic vibrations and thermoelastic vibrations act in a direction perpendicular to both sides of the billet shell 6 and pass through the billet shell 6, wherein the billet shell 6 does not exceed 20% of the entire billet cross section. Too thick a billet shell 6 may cause cracks in the billet during cooling because stress is generated by different cooling rates inside and outside. Limiting the thickness of the billet shell 6 can reduce this stress difference and reduce the risk of cracks and fractures. Keeping the thickness of the billet shell 6 within a certain range helps to achieve uniform cooling of the billet and avoid internal defects caused by uneven cooling.

[0045] The above-mentioned lead-out mechanism in the present invention includes a dummy rod 8 and a support roller 7. The dummy rod 8 is located at the bottom exit of the above-mentioned crystallizer 9. The cast billet can be pulled downward from the crystallizer 9 by the dummy rod 8. In order to reduce the probability of deformation of the cast billet during the position movement, a support roller 7 arranged along the pulling direction is also arranged in the lead-out mechanism. The above-mentioned support roller 7 is multiple, and the multiple support rollers 7 are arranged on both sides of the above-mentioned cast billet and are arranged at intervals. The above-mentioned vibration sensor 4 can be fixed on the support roller 7, so as to detect the vibration frequency of the cast billet by detecting the vibration frequency of the support roller 7.

[0046] The nozzle of the pulse oscillator 12 is combined with the nozzle of the secondary cooling water pipe 13 and fixed together in the fixed pipe 14, that is, the outlet nozzle of the pulse oscillator 12 is combined with the secondary cooling pipe 13, and the vibration pulse passes through the metal wall of the nozzle to the cooling water, so that the cooling water is ejected in a pulse with a resonant frequency. The cooling water ejected by the pulse can contact the surface of the ingot more effectively, increase the heat exchange area between the cooling water and the ingot, and thus increase the cooling rate. The cooling water ejected by the pulse can also better cover the surface of the ingot, reduce the unevenness during the cooling process, and help the ingot to form a uniform microstructure. Pulse cooling can reduce oxidation and crusting on the surface of the ingot, thereby reducing the generation of surface cracks and other defects.

[0047] The outlet nozzle of the pulse oscillator 12 is made in the form of a thin-walled tube, which is built into the secondary cooling pipe 13 and has an annular gap. The design of the thin-walled tube and the annular gap can increase the heat exchange area between the cooling water and the ingot and improve the heat exchange efficiency. The annular gap can also prevent the cooling water from being blocked in the pipe and ensure the continuous flow of the cooling water.

[0048] In order to facilitate connection and reduce the difficulty of operation, the pulse oscillator 12 also includes a connector 12 - 2 for connecting the nozzle of the pulse oscillator 12 .

[0049] Two or more pulse oscillators 12 are installed in the secondary cooling zone. By installing the pulse oscillators 12 at different positions, the distribution of cooling water and the cooling intensity can be more effectively controlled to enhance the cooling effect. Multiple pulse oscillators 12 can cover a larger area, which helps to achieve uniform cooling of the surface of the ingot and avoid local overcooling or insufficient cooling. By adjusting the operating frequency and intensity of different pulse oscillators 12, the cooling process can be accurately controlled to adapt to ingots of different materials and sizes. Multiple pulse oscillators 12 can also be independently controlled according to production needs, providing higher production flexibility and adaptability. The pulse oscillator 12 includes an automatic control system for detonation frequency, which adjusts the ignition frequency of the spark plug through the vibration sensor 4 and the analog control system 3 until the pulse frequency is close to or the same as the natural frequency of the ingot.

[0050] A method for condensing metal for continuous casting, using the above-mentioned device for condensing metal for continuous casting, includes the following steps: pouring liquid metal into a crystallizer 9, then pulling out the billet, and cooling it in a secondary cooling zone; in the process of pulling out from the crystallizer 9 and then to the secondary cooling zone, the billet is subjected to a multi-form combined resonance treatment by a pulse oscillator 12 fixed in the secondary cooling zone; the energy generated by the explosion of the combustible mixed gas provided by the operating console 2 is used as the energy source of the pulse oscillator 12, and the vibration frequency is adjusted by the vibration sensor 4 fixed on the support roller 7 and the analog control system 3 to complete the resonance treatment of the billet crystallization process. The multi-form combined resonance treatment of the billet includes but is not limited to the sound, elastic and thermoelastic vibration pulses of the billet. The high-intensity sound wave, elastic vibration and thermoelastic vibration act on the billet surface to be close to or equal to the natural frequency of the billet, and the working frequency of the pulse oscillator 12 is automatically adjusted by the vibration sensor 4 fixed on the support roller 7. The resonance treatment of the billet surface by high-intensity sound waves, elastic vibrations and thermoelastic vibrations is carried out between the zero-segment rollers in the secondary cooling zone along the heat dissipation direction.

[0051] The pulse oscillator 12 outlet nozzle is integrated into the cooling system to transmit the pulse pressure generated by the shock wave to the cooling system. The processing mode of the billet and the oscillation input position are adjusted. The distance from the edge of the pulse oscillator 12 outlet nozzle to the billet surface is set to 50mm. The number of devices used at the same time is 1-2, and the action point is located below the crystallizer 9 300mm away from the billet swing device. The device uses a combustion chamber with a volume of 25×10-6m 3 The detonation device is started by a spark plug through an electronic system and a standard signal generator. The volume of the combustible mixture and the distance from the generator nozzle to the slab surface will affect the elastic pressure and acoustic pressure density on the surface of the casting.

[0052] This method takes the casting of 125×125mm 25G2С billet as an example, and the billet drawing speed is 2.9 m / min. According to the requirements of this patent, the pulse energy passing through the billet shell thickness shall not exceed 20% of the billet cross section, so the processing point is set at the billet shell thickness of 10mm. Generator 1 is installed 500mm below the crystallizer 9, and generator 1 starts working when the billet passes. According to the working principle of the detonation frequency, the simulation control system 3 controls the change of the detonation frequency until resonance is achieved in the billet, and maintains the working frequency with the natural frequency of the billet.

[0053] The properties of the treated ingots were analyzed and tested, and the organizational structure of the ingot samples in cross section and longitudinal section were analyzed respectively. It was found that the macroscopic organization was uniform, the grain size was reduced by 90%-95%, the alloy elements were evenly distributed without segregation, and the tensile strength of the metal alloy was increased by 12-15%.

[0054] Example 1: The relationship between the working frequency of the device of the present invention and the natural frequency of the billet was determined. According to the technical requirements of the present invention, the detonation generator 1 is started at different frequencies (smoothly changing from 1 to 40 Hz). As the detonation frequency changes, the vibration of the billet can be monitored by the vibration sensor 4 fixed on the support roller 7 of the continuous casting machine. When the detonation frequency (impact frequency) is consistent with the natural frequency of the billet, the signal amplitude of the vibration sensor 4 will increase sharply. The experimental results show that the natural frequency of the 125×125 mm billet in the continuous casting machine is in the frequency range of 18-21 Hz. If it is necessary to ensure that the resonant frequency changes periodically within this range, the control of the automatic control system is required, otherwise it is difficult to ensure the consistency of the working frequency with the natural frequency of the billet.

[0055] Example 2: The effect of a pulse detonation generator on the secondary cooling zone of the ingot was determined. The outlet nozzle of the generator 1 was built into the pipe of the water cooling system so that there was an annular gap of 10-15 mm between the nozzle wall and the pipe. The water cooling nozzle was supplied with water through the annular gap, and the supply pulsation of the nozzle was recorded visually, and it was observed that its frequency was equal to the operating frequency of the generator. The surface of the ingot was pulse-cooled at the resonant frequency, resulting in corresponding thermoelastic vibrations in the ingot.

[0056] Example 3: The effects of two different generator operating frequencies and detonation modes on the production of billets were determined.

[0057] A) The frequency automatic control system is turned off and the operating frequency is set to 5Hz, 10Hz, 15Hz, 20Hz, 25Hz, and 30Hz.

[0058] B) The frequency automatic control system is turned on and the operating frequency is within the resonant frequency range.

[0059] Analysis of the properties of the ingots obtained by the two different treatments shows that the properties of the metal alloy can be improved under the action of the working frequency of 15-23Hz. The automatic control system for adjusting the working frequency ensures grain refinement and reduces component segregation.

[0060] Example 4: The influence of the number of generators during the production of cast billets was determined.

[0061] A) Install two generators, with the spacing of the cooling nozzles as the interval, and place them along the casting direction.

[0062] B) Install 4 generators, and place them in the same way as A).

[0063] C) Install 1 generator, and place it in the same way as A).

[0064] The test shows that two generators can achieve the best effect.

[0065] Example 5 The influence of the installation position on a generator during the production of cast billets was determined.

[0066] A) The generator is installed 500mm from the end of the crystallizer and fixed to the front of the slab. The thickness of the slab shell is 20mm here.

[0067] B) The generator is installed 1000mm from the end of the crystallizer and fixed to the front of the slab. The thickness of the slab shell is 30mm here.

[0068] C) The generator is installed 1500mm from the end of the crystallizer and fixed to the front of the slab. The thickness of the slab shell is 40mm here.

[0069] D) The generator is installed 2000mm from the end of the crystallizer and fixed to the front of the slab. The thickness of the slab shell is 50mm here.

[0070] Tests have shown that the best effect can be obtained at installation position A. As the thickness of the slab shell increases, the processing efficiency becomes lower and the effect becomes worse.

[0071] Example 6 The influence of the nozzle installation position on a generator during the production of ingots was determined.

[0072] A) The generator detonation nozzle is installed separately from the secondary cooling area of ​​the continuous casting machine.

[0073] B) The generator detonation nozzle is built into the secondary cooling zone of the continuous casting machine.

[0074] Tests show that the cooling system of the embedded structure improves the efficiency of handling elastic vibrations.

[0075] Example 7 According to the above example test, the oscillator was installed in the optimal installation method and then tested. The test results are shown in Table 1. The optimal operating frequency of the casting is 17-21 Hz.

[0076] Table 1 Example test results like Figure 5 The figure shows the schematic diagram of the macroscopic structure of the aluminum alloy system (Al-6%Cu-0.8%Zr) after condensation and crystallization without being treated by a pulse oscillator; Figure 6 It is a schematic diagram of the macroscopic structure of aluminum alloy (Al-6%Cu-0.8%Zr) after condensation and crystallization being processed by a pulse oscillator. Compared with the normal production process of ingot casting, the use of the present invention reduces energy consumption, and the device has a simple structure and low cost. When the working frequency of the vibration sensor 4 is close to or suppressed from the natural frequency of the ingot casting, the ingot casting has the best effect, which can not only affect the crystallization process of the metal, but also affect the efficiency of water cooling the surface of the ingot casting.

[0077] The method for condensing metal in the continuous casting process of the present invention can realize the combined effect of acoustic, elastic and thermoelastic vibration pulses on the ingot. The combined effect is caused by the pulse jet when the water-combustible mixed gas cools the ingot in the secondary cooling zone below the crystallizer 9. The pulse jet contains sound waves and impact jets with a speed of up to 3000m / s, a frequency of 1-40Hz and a sound pressure exceeding 140dB. The sound vibration frequency in each impact wave is in the range of 20-20000Hz, thereby also providing the input of long-wave phonons.

[0078] The device for condensing metal for continuous casting of the present invention uses the energy generated by the detonation of the combustible mixed gas as an energy source. The high-frequency detonation device of its combustion in a compression detonation mode or a concentrated energy explosion mode is different from the device of fixed detonation combustion. The shock wave velocity of the high-frequency detonation device is about 1.4 times that of the latter, so the energy density generated by the high-frequency detonation device is also 2-3 times higher. The outstanding performance reduces the cost of materials and energy.

[0079] The device for condensing metal for continuous casting of the present invention can realize automatic adjustment of the pulse frequency during the action of the pulse oscillator 12. Through the vibration sensor 4 fixed on the continuous casting machine support roller 7 and the analog control system 3, the tangential jet of the combustible mixed gas is supplied to the combustion chamber, and the spark plug at the front of the compression of the combustible mixed gas is controlled to detonate, so as to achieve the effect that the working frequency of the pulse oscillator is close to or equal to the natural frequency of the metal casting billet. The controllable range of the resonant frequency improves the efficiency of the combined action and provides conditions for the reliable operation of the pulse oscillator.

[0080] The device for condensing metal for continuous casting of the present invention has no moving parts or easily worn parts, which enables it to operate reliably during the continuous casting process. At the same time, the combination of the pulse oscillator 12 and the secondary cooling device ensures the input of acoustic vibration and thermoelastic vibration in the ingot, enhances the interaction between phonons and electrons, and interferes with the formation of defects in the ingot. At the same time, due to the strong interaction between phonons and electrons, the thermal conductivity of the ingot is increased, thereby improving the crystallization rate.

[0081] Metal crystallization theory shows that the combination of long-wave phonons, elastic and thermoelastic vibrations close to or equal to the natural frequency of the ingot at the microscopic level can effectively increase the thermal conductivity of the metal ingot by at least 20%, affect the growth space of columnar dendrites and form many pseudocrystalline nuclei. At the same time, because high-amplitude sound waves and elastic vibrations can pass through the ingot with minimal loss, this method does not require high energy supply.

[0082] The method and device for producing ingots from crystalline metals proposed by the present invention will improve the quality of finished metal ingots with minimal energy consumption and simple operation.

[0083] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention; therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0084] Although the following terms are used more frequently in this article: 1. generator; 2. console; 3. analog control system; 4. vibration sensor; 5. liquid metal part; 6. billet shell; 7. support roller; 8. dummy rod; 9. crystallizer; 10. tundish; 12. pulse oscillator; 12-1. high-frequency detonation device; 12-2. joint; 13. secondary cooling water pipeline; 14. fixed pipeline; 15. water pipe; 16. nozzle; 17. gap, etc., the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A device for condensing metal for continuous casting, characterized in that: The invention comprises a generator (1) with built-in elastic waves and sound waves, a control panel (2) for supplying a combustible mixed gas, and an analog control system (3) for controlling the ignition frequency by a signal sent by a vibration sensor (4). The crystallizer (9) is located at the outlet of a tundish (10). Liquid metal is poured from the tundish (10) into the crystallizer (9) to form a cast billet. The cast billet has a liquid metal portion (5) and a billet shell (6). A lead-out mechanism is provided at the bottom of the crystallizer (9). The lead-out mechanism can be used to pull the cast billet out of the crystallizer (9) and into a secondary cooling zone. A pulse oscillator (12) and a secondary cooling water pipeline (13) are provided in the secondary cooling zone. ), the nozzle of the pulse oscillator (12) is combined with the nozzle of the secondary cooling water pipeline (13); the pulse oscillator (12) includes a high-frequency detonation device (12-1) with a spark plug; a plurality of water pipes (15) are arranged around the ingot, the water pipes (15) are equipped with a plurality of nozzles (16) capable of spray cooling the ingot, pulse oscillation is introduced into the gap (17) around the nozzle of the pulse oscillator (12) filled with water, and the pulse oscillation is transmitted to the cooling water in the water pipes (15) and the nozzles (16), and the cooling water cools the ingot while generating a thermoelastic effect on the ingot shell (6) with pulse vibrations of a resonant frequency.

2. The device for condensing metal for continuous casting according to claim 1, characterized in that: The lead-out mechanism comprises a dummy rod (8) and a support roller (7), the dummy rod (8) being located at the bottom outlet of the crystallizer (9), and a plurality of support rollers (7), which are arranged on both sides of the ingot.

3. The device for condensing metal for continuous casting according to claim 1, characterized in that: The nozzle of the pulse oscillator (12) is combined with the nozzle of the secondary cooling water pipe (13) and fixed together in the fixed pipe (14).

4. The device for condensing metal for continuous casting according to claim 1, characterized in that: The pulse oscillator (12) further comprises a connector (12-2) for connecting a nozzle of the pulse oscillator (12).

5. The device for condensing metal for continuous casting according to claim 4, characterized in that: There are at least two pulse oscillators (12).

6. A method for continuous casting of condensed metal, using a device for continuous casting of condensed metal as claimed in any one of claims 1 to 5, characterized in that: The method comprises the following steps: pouring liquid metal into a crystallizer (9), then pulling out the ingot and cooling it in a secondary cooling zone; in the process of pulling out the ingot from the crystallizer (9) and then into the secondary cooling zone, performing a multi-form combined resonance treatment on the ingot by a pulse oscillator (12) fixed in the secondary cooling zone; using the energy generated by the explosion of the combustible mixed gas provided by the operating console (2) as the energy source of the pulse oscillator (12), and adjusting the vibration frequency by a vibration sensor (4) fixed on the support roller (7) and an analog control system (3) to complete the resonance treatment of the crystallization process of the ingot.

7. A method for continuous casting of condensed metal according to claim 6, characterized in that: The multiple forms of combined resonance treatment on the ingot include but are not limited to acoustic, elastic and thermoelastic vibration pulses on the ingot.

8. A method for continuous casting of condensed metal according to claim 6, characterized in that: The effects of high-intensity sound waves, elastic vibrations and thermoelastic vibrations on the surface of the ingot are processed at a frequency close to or equal to the natural frequency of the ingot, and the working frequency of the pulse oscillator (12) is automatically adjusted through a vibration sensor (4) fixed on the support roller (7).

9. A method for continuous casting of condensed metal according to claim 6, characterized in that: The resonance treatment of the surface of the ingot by high-intensity sound waves, elastic vibrations and thermoelastic vibrations is carried out between the zero-segment rollers in the secondary cooling zone along the heat dissipation direction.

10. A method for continuous casting of condensed metal according to claim 6, characterized in that: The vibration pulses of high-intensity sound waves, elastic vibrations and thermoelastic vibrations act in a direction perpendicular to both sides of the billet shell (6) and penetrate the billet shell (6), wherein the billet shell (6) does not exceed 20% of the entire billet cross-section.

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