A jet impact type rapid cooling device based on ultrasonic atomization

Abstract

The application discloses a kind of based on ultrasonic atomization's jet impact type rapid cooling device, including ultrasonic atomization and jet impact composite nozzle unit, cooling speed accurate closed-loop control system and anti-blocking and water quality processing integrated supply system;It is integrated ultrasonic transducer, liquid flow channel and gas flow channel in nozzle body, so that cooling water is broken into superfine mist drop when flowing through transducer working surface by high-frequency vibration, fundamentally solve the problem of poor traditional gas mist cooling effect;By the multivariable coordinated control of cooling speed accurate closed-loop control system, the phase change process of strip steel is accurately controlled, and the desired organization and performance are obtained;By setting anti-blocking and water quality processing integrated supply system to process cooling water quality, and each composite nozzle is equipped with regular compressed air backflushing pipeline, remove possible residual moisture and impurities at nozzle internal and injection port when nozzle injection is intermittent or shutdown, avoid blocking, guarantee long-term reliable operation of device.

Description

Technical Field

[0001] This application relates to the field of metal heat treatment technology, and in particular to a cooling device for the cooling section of a heat treatment furnace, specifically a rapid cooling device based on ultrasonic atomization jet impact for the cooling section of a roller hearth heat treatment furnace. Background Technology

[0002] High-strength and ultra-high-strength steels are widely used in the automotive, machinery, and aerospace industries due to their excellent strength-toughness ratio. The properties of these steels are highly dependent on the microstructure obtained during their heat treatment, and the cooling process (i.e., the controlled phase transformation process) is the key factor determining the final metallographic structure and mechanical properties. To obtain target microstructures such as martensite and bainite, the steel must have a sufficiently high cooling rate within a specific temperature range, and the cooling path must be precisely controlled to avoid soft phase transformation regions such as pearlite.

[0003] Currently, the cooling section of heat treatment production lines (such as roller hearth furnaces) often uses air mist cooling, which involves mixing compressed air and cooling water to form a two-phase flow to cool the strip steel. However, traditional air mist cooling has the following inherent drawbacks:

[0004] (1) Limited and uneven cooling capacity: poor atomization effect, large droplet size and uneven distribution, resulting in uneven coverage of cooling medium impacting the strip surface, easily generating cooling "dead zone" and "soft spot", causing poor microstructure and plate shape.

[0005] (2) Vapor film effect: When large droplets impact the surface of a high-temperature steel plate, they will quickly vaporize to form a stable vapor insulation film. This film severely hinders the direct contact heat exchange between subsequent droplets and the plate surface, greatly reducing the critical heat flux and cooling efficiency.

[0006] (3) Low control precision: Traditional systems have a slow response to the control of water-air ratio and flow rate, making it difficult to achieve millisecond-level precise control that matches the strip speed and temperature in real time. This results in large fluctuations in the cooling curves of the same coil or different batches of steel, leading to poor product performance consistency.

[0007] Therefore, it is necessary to propose a new technical solution to address the problems existing in the current technology. Summary of the Invention

[0008] This application provides a jet impact rapid cooling device based on ultrasonic atomization to solve the problems of low cooling efficiency and poor cooling effect of existing heat treatment furnace cooling section cooling devices.

[0009] To achieve the above objectives, this application provides the following technical solution:

[0010] This application provides a jet-impact rapid cooling device based on ultrasonic atomization, comprising:

[0011] An ultrasonic atomization and jet impact composite nozzle unit includes multiple composite nozzles. Each composite nozzle includes: a nozzle body, an ultrasonic transducer disposed inside the nozzle body, a liquid flow channel disposed inside the nozzle body and in fluid communication with the working surface of the ultrasonic transducer, and a gas flow channel disposed inside the nozzle body and surrounding the liquid flow channel. The spray port on the nozzle body faces the cooling station.

[0012] A precise closed-loop control system for cooling speed includes: an online temperature measuring instrument installed on the cooling station for detecting the temperature of the workpiece to be cooled, a controller electrically connected to the online temperature measuring instrument, and a drive unit electrically connected to the controller; the drive unit is electrically connected to the ultrasonic transducer, a liquid supply device for supplying liquid to the liquid channel, and a gas supply device for supplying gas to the gas channel.

[0013] An integrated anti-clogging and water treatment supply system includes: a liquid supply pipeline connected to the liquid flow channel, an air supply pipeline connected to the gas flow channel, and a backflush pipeline connected in parallel with the air supply pipeline; the liquid supply pipeline is equipped with a multi-stage filter and a water softening device; one end of the backflush pipeline is connected to an air source, and the other end is connected to the liquid flow channel.

[0014] Furthermore, in the above technical solution, the ultrasonic transducer is located at the center of the nozzle body; the nozzle body forms a nested structure consisting of a transducer mounting cavity, an annular liquid flow channel, and an annular gas flow channel arranged coaxially from the inside out; the working surface of the ultrasonic transducer is exposed in the annular liquid flow channel, which is used to efficiently break and atomize the liquid flowing over its surface into ultrafine droplets with a particle size ≤10μm; the inner ring wall of the annular gas flow channel is provided with a jet annular slit, and the airflow ejected from the jet annular slit can capture, carry, and accelerate the ultrafine droplets before ejecting them from the jet nozzle, forming one or more impact jets that vertically impact the workpiece to be cooled.

[0015] Furthermore, the nozzle body includes a tubular body and a conical nozzle connected to one end of the tubular body. The conical nozzle has an injection port at the end opposite to the tubular body. The injection port has a fan-shaped or circular geometry and is used to shape the mixed gas-liquid two-phase flow into a fan-shaped or circular impact jet field with controllable coverage.

[0016] Furthermore, the thickness of the liquid film formed when the working surface of the ultrasonic transducer comes into contact with the liquid is adjusted by the liquid supply pressure, so that the droplet particle size formed by ultrasonic vibration is ≤10μm.

[0017] Furthermore, the ultrasonic transducer operates in the frequency range of 1.0MHz to 2.4MHz, and the interface between the ultrasonic transducer and the liquid flow channel is made of a corrosion-resistant and highly thermally conductive material.

[0018] Furthermore, the nozzle body is made of corrosion-resistant and high-temperature-resistant material.

[0019] Furthermore, the drive unit includes: a first frequency converter electrically connected to the ultrasonic transducer, a second frequency converter electrically connected to the liquid supply device, and a third frequency converter electrically connected to the gas supply device; the controller is equipped with a PID control algorithm or a feedforward-feedback composite control algorithm, and stores the target cooling curve of the workpiece to be cooled. The controller is configured to: based on the target cooling curve, the real-time speed of the workpiece to be cooled, and the deviation between the actual temperature of the workpiece to be cooled and the target temperature, output an adjustment signal to the drive unit through the PID control algorithm or the feedforward-feedback composite control algorithm to dynamically adjust the power of the ultrasonic transducer, the water supply pressure and flow rate of the liquid supply device, and the gas supply pressure and flow rate of the gas supply device, thereby achieving precise control of the cooling intensity and ensuring that the actual cooling curve of the workpiece to be cooled matches the target cooling curve.

[0020] Furthermore, the liquid supply device is a water pump, the air supply device is a fan or an air compressor; the online temperature measuring instrument is a non-contact infrared thermometer or a hot metal detector, and multiple online temperature measuring instruments are arranged at equal intervals along the width direction of the cooling station.

[0021] Furthermore, the multi-stage filter includes at least a coarse filter and a fine filter.

[0022] Furthermore, the water softening device employs ion exchange resin or membrane treatment.

[0023] Furthermore, a switching valve is provided on the backflush pipeline, and the switching valve is electrically connected to the controller; the controller is configured to: when it receives a signal that the composite nozzle has stopped spraying, control the switching valve to open so as to use the purging airflow to purge the liquid flow channel and the spray nozzle.

[0024] Furthermore, the jet-impact rapid cooling device is installed in the cooling section of the heat treatment furnace, and the workpiece to be cooled is a strip steel on the cooling station of the cooling section. At least one row of the composite nozzles is symmetrically arranged above and below the strip steel.

[0025] Compared with the prior art, this application has at least the following beneficial effects:

[0026] 1. This application provides a jet impact rapid cooling device based on ultrasonic atomization, including an ultrasonic atomization and jet impact composite nozzle unit, a precise closed-loop control system for cooling speed, and an integrated supply system for anti-clogging and water treatment. By integrating an ultrasonic transducer, a liquid flow channel, and a gas flow channel surrounding the liquid flow channel within the nozzle body, the cooling water is directly broken into ultrafine droplets by high-frequency vibration as it flows through the transducer's working surface, fundamentally solving the problem of poor atomization effect in traditional aerosol cooling. Because the droplets are immediately entrained, mixed, and accelerated by the surrounding high-speed airflow after generation, a uniformly distributed high-speed impact jet is formed. This process avoids droplet aggregation and uneven settling during spraying, ensuring uniform coverage of the cooling medium impacting the strip surface and eliminating cooling "dead zones" and "soft spots." Simultaneously, the ultrafine droplets have a large specific surface area, allowing them to vaporize instantly upon impacting the high-temperature steel plate surface without forming a continuous vapor insulation film, significantly improving the heat transfer coefficient. Furthermore, the impact of the high-speed airflow further disrupts any existing local vapor film and rapidly carries away vaporization products, ensuring continuous contact between the fresh cooling medium and the plate surface. This results in heat transfer efficiency (ultra-fast cooling) far exceeding that of traditional aerosol cooling and extremely high cooling uniformity.

[0027] 2. This application installs an online temperature measuring instrument at the cooling station to monitor the temperature of the workpiece (strip steel) to be cooled in real time. The controller compares the measured temperature with the pre-stored cooling curve (critical section of the CCT curve) for the target steel grade. Based on the deviation, it dynamically and collaboratively adjusts three key actuators through a control algorithm (such as PID or feedforward-feedback composite): the ultrasonic transducer (power, controlling the atomization amount and droplet fineness), the liquid supply device (frequency / valve, controlling water pressure and flow rate), and the air supply device (controlling air pressure and flow rate). This multi-variable coordinated control enables the system to match changing working conditions (such as strip steel speed and inlet temperature fluctuations) in real time, achieving millisecond-level fine adjustment of the cooling intensity, thereby accurately controlling the phase transformation process of the strip steel and obtaining the desired microstructure and properties.

[0028] 3. Since the flow channels and micropores of the ultrasonic atomizing nozzle are extremely sensitive to water quality, impurities and excessive hardness in the water can lead to scaling or clogging. Therefore, this application sets up an integrated anti-clogging and water treatment supply system to ensure the long-term stable and reliable operation of the cooling device. The integrated anti-clogging and water treatment supply system includes a multi-stage precision filter (final accuracy 1μm) and a water softening device installed on the liquid supply pipeline, as well as a periodic compressed air backflush pipeline equipped for each composite nozzle. The backflush pipeline is linked to the working status of the composite nozzle. When the nozzle sprays intermittently or stops, a high-pressure gas is automatically injected to remove any residual moisture and impurities that may remain inside the nozzle and at the spray port, fundamentally preventing clogging problems caused by water evaporation and crystallization.

[0029] 4. This application achieves a leapfrog improvement in cooling capacity, uniformity, and cooling temperature control accuracy through the synergistic effect of ultrasonic atomization and jet impact composite nozzle unit, precise closed-loop control system for cooling speed, and integrated supply system for anti-clogging and water treatment. It is particularly suitable for the heat treatment production of high-strength steel and ultra-high-strength steel with extremely demanding cooling process requirements. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing this application. For example, based on the technical concepts disclosed in this application and the exemplary drawings, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, and size ratios of certain units (components).

[0031] Figure 1 This is a schematic diagram of the arrangement of the cooling device provided in this application in the cooling section of a roller hearth heat treatment furnace in one embodiment.

[0032] Figure 2 This is a schematic diagram of the principle of the precise closed-loop control system for cooling rate in this application in one embodiment;

[0033] Figure 3 This is a schematic diagram of the internal structure of the composite nozzle in one embodiment of the present application, mainly showing the structural arrangement relationship of the transducer mounting cavity, liquid flow channel and gas flow channel from the inside to the outside.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Strip steel; 2. Roller conveyor; 3. Composite nozzle; 31. Transducer mounting cavity; 32. Liquid flow channel; 33. Gas flow channel; 34. Injection port. Detailed Implementation

[0036] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] In the description of this application: unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," etc., in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "including," "comprising," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).

[0038] In the heat treatment of high-strength steel and ultra-high-strength steel, the uniformity and control precision of the cooling rate are extremely important. Traditional air mist cooling methods have inherent defects such as insufficient cooling capacity, poor uniformity, and easy formation of vapor film insulation, which lead to substandard metallographic structure and large fluctuations in mechanical properties of the product.

[0039] To improve atomization effects, the industry has been exploring the application of ultrasonic atomization technology in the cooling field. For example, Chinese invention patent CN120347583A discloses an ultrasonic atomizing pulsed cold gas jet cooling lubrication device and its operating process. This device amplifies the high-frequency mechanical vibration amplitude of the ultrasonic transducer through a stepped amplitude transformer, and utilizes cavitation and capillary wave effects to efficiently atomize the cutting fluid into micron-sized droplets. These droplets are then mixed with pulsedly released low-temperature gas to form a uniform gas-liquid two-phase jet, which is applied in the cutting machining field.

[0040] While the aforementioned technical solutions improve atomization fineness and controllability, they are primarily designed for machining scenarios, and their structure and control logic are difficult to directly transplant to continuous strip cooling production lines in metallurgical heat treatment. Specifically, the following technical differences and shortcomings exist: First, in the nozzle structure of this solution, the liquid flow channel is located inside the amplitude transformer, and the gas flow channel surrounds the sealing cover. This does not form a tightly nested gas-liquid flow channel structure optimized for large-area, continuous heat treatment cooling scenarios, making it difficult to achieve jet stability over a large coverage area while ensuring atomization effect. Second, the control objective of this solution is to match the pulse frequency and cooling gas temperature to the cutting rhythm, which cannot respond to the stringent requirements for cooling speed in metallurgical processes—that is, it cannot perform millisecond-level coordinated adjustment of atomization quantity and spray speed based on the deviation between the actual temperature of the strip and the target continuous cooling transition curve (CCT curve), making it difficult to accurately control the phase transformation process of the strip. Third, this solution lacks anti-clogging design to address the problems of scaling in industrial circulating water and nozzle clogging. If directly used in heat treatment production lines operating continuously for long periods, it will face the problem of frequent downtime for maintenance. Therefore, it is necessary to propose a cooling device specifically designed for continuous cooling production lines of heat treatment, which can achieve uniform coverage of ultrafine droplets, precisely control the cooling rate to match the CCT curve, and has the ability to prevent clogging in industrial-grade continuous operation.

[0041] Therefore, the problems of low cooling efficiency and poor cooling effect in the cooling section of traditional heat treatment furnaces still exist. To solve the problems of existing technologies, this application proposes a jet impact rapid cooling device based on ultrasonic atomization for the cooling section of a heat treatment furnace by combining ultrasonic atomization technology with the jet impact principle. This device can efficiently break down cooling water into micron-sized ultrafine droplets and impact the surface of the strip steel at high speed vertically, completely destroying the steam insulation film and achieving extremely high heat transfer coefficient and cooling uniformity. In addition, this device can precisely control the cooling path through a closed-loop control model, thereby stably obtaining the target microstructure and properties.

[0042] The ultrasonic atomization-based jet impact rapid cooling device provided in this application mainly includes: an ultrasonic atomization and jet impact composite nozzle unit, a precise closed-loop control system for cooling speed, and an integrated supply system for anti-clogging and water treatment.

[0043] I. Ultrasonic Atomization and Jet Impact Composite Nozzle Unit

[0044] The ultrasonic atomization and jet impact composite nozzle unit integrates ultrasonic high-frequency vibration atomization technology with gas ejection acceleration technology. It generates micron-sized droplets through ultrasonic atomization and combines them with high-speed airflow to form an impact jet, achieving ultra-fast and highly uniform cooling of the strip steel.

[0045] The ultrasonic atomization and jet impact composite nozzle unit includes multiple composite nozzles 3. Each composite nozzle 3 has an ultrasonic transducer installed at its center inside the nozzle body. A liquid flow channel 32 is arranged around the ultrasonic transducer on the side wall of the nozzle body, and a gas flow channel 33 surrounds the liquid flow channel 32. Figure 3 The nozzle body's spray port faces the cooling station. The working surface of the ultrasonic transducer is exposed in the annular liquid flow channel. Cooling water, under water pressure, evenly flows over the working surface of the ultrasonic transducer and is broken into micron-sized droplets by high-frequency vibration. At the same time, jet slits are opened on the inner ring wall of the annular gas flow channel. The high-pressure airflow ejected from the jet slits can instantly engulf and accelerate the newly generated ultrafine droplets before ejecting them from the contracting circular or fan-shaped spray port, forming one or more nearly vertical impact jets that impact the steel strip.

[0046] like Figure 3 The nozzle body includes a tubular main body and a conical nozzle connected to one end of the tubular main body. The tubular main body contains a nested structure consisting of a transducer mounting cavity 31, an annular liquid flow channel 32, and an annular gas flow channel 33, arranged coaxially from the inside out. An injection port 34 is opened at the end of the conical nozzle opposite to the tubular main body. The injection port has a fan-shaped or circular geometry, used to shape the mixed gas-liquid two-phase flow into a fan-shaped or circular impact jet field with controllable coverage.

[0047] The ultrasonic transducer is electrically connected to the first frequency converter. The liquid flow channel is connected to an external water source through a liquid supply pipeline, on which a water pump is installed, and the water pump is equipped with a second frequency converter. The gas flow channel is connected to a gas supply device through a gas supply pipeline, and the gas supply device is equipped with a third frequency converter.

[0048] The ultrasonic transducer receives high-frequency electrical signals from an ultrasonic generator and, utilizing the piezoelectric effect of piezoelectric ceramics, converts these signals into mechanical vibrations. These vibrations act on the water film flowing across its vibrating surface, causing it to overcome surface tension and be "torn" into micron-sized ultrafine droplets (the thickness of the liquid film formed when the working surface of the ultrasonic transducer contacts the liquid is adjusted by the supply pressure, ensuring that the droplet size formed by ultrasonic vibration is ≤10μm). These extremely small droplets with a huge specific surface area are then captured, carried, and accelerated by a high-speed airflow (compressed air or nitrogen) ejected from the gas chamber. After passing through the nozzle's ejection outlet, they form one or more stable, dense impact jets that impact the upper and lower surfaces of the strip steel at a near-vertical angle at high speed. When these micron-sized droplets impact the high-temperature plate surface, they vaporize instantly without forming a continuous vapor insulation film, significantly improving the heat transfer coefficient. Meanwhile, the impact of the high-speed airflow further disrupts any existing local vapor film and rapidly carries away the vaporization products, allowing the fresh cooling medium to remain in continuous contact with the plate surface. This results in heat exchange efficiency (ultra-fast cooling) far exceeding that of traditional air mist cooling and extremely high cooling uniformity.

[0049] In practical applications, the shape and size of the nozzle's jet outlet can be designed independently to form a stable, uniform, and controllable impact jet field.

[0050] In a preferred embodiment of this application, the ultrasonic transducer operates in the frequency range of 1.0MHz to 2.4MHz, and its contact interface with the water cavity is made of a corrosion-resistant, high thermal conductivity material (such as 316L stainless steel) to ensure efficient vibration energy transfer and heat dissipation. In a specific embodiment, the ultrasonic transducer operates at a frequency of 1.7MHz.

[0051] In one specific embodiment, within the cooling section of the roller hearth heat treatment furnace, multiple rows of composite nozzles 3 are symmetrically arranged above and below the running path of the strip 1, with multiple composite nozzles evenly spaced in each row. The strip 1, conveyed by the roller conveyor 2, passes uniformly through the intense cooling zone formed by the upper and lower composite nozzle groups, such as... Figure 1 .

[0052] II. Precise Closed-Loop Control System for Cooling Rate

[0053] The hardware foundation of the precise closed-loop control system for cooling speed includes: an online temperature sensor located at the outlet of the cooling section, a controller (PLC), and a drive unit electrically connected to the controller. The drive unit includes three frequency converters connected to the ultrasonic transducer, the liquid supply device, and the gas supply device, respectively.

[0054] Online temperature measuring instruments are used to monitor the temperature of strip steel in real time.

[0055] The controller compares the measured strip temperature with the pre-stored cooling curve (continuous cooling transition curve, or CCT curve) of the target steel grade. Based on the comparison results, it dynamically and collaboratively adjusts three control actuators using advanced control algorithms (such as PID or feedforward-feedback composite): the ultrasonic transducer (power, controlling atomization amount and droplet fineness), the liquid supply device (frequency / valve, controlling water pressure and flow rate), and the air supply device (fan / pressure regulating valve, controlling air pressure and flow rate). The specific control method is as follows:

[0056] 1. The controller has pre-stored target cooling path curves corresponding to different steel grades;

[0057] 2. An online temperature measuring instrument installed at the outlet of the cooling section collects the strip steel exit temperature in real time and feeds it back to the controller;

[0058] 3. Based on the target cooling curve, real-time strip speed, and the deviation between the measured temperature and the target temperature, the controller dynamically adjusts the power of the ultrasonic transducer, the water supply pressure and flow rate of the water pump, and the air supply pressure and flow rate of the fan through a PID control algorithm or a feedforward-feedback composite control algorithm. This achieves millisecond-level precise control of the cooling intensity, ensuring that the actual cooling curve of the strip matches the target CCT curve.

[0059] like Figure 2 This demonstrates the workflow of a precise closed-loop control system for cooling speed. The controller (PLC) has a pre-set target cooling curve for a specific grade of high-strength steel. When the strip enters the cooling section, an infrared thermometer array at the outlet monitors its temperature in real time and feeds it back to the controller. Based on the current strip speed, the deviation between the measured temperature and the target curve, the controller uses a built-in PID algorithm to calculate and output control signals in real time to the ultrasonic generator, variable frequency water pump, and variable frequency fan (or electric regulating valve), dynamically adjusting the atomization intensity, water flow rate, and air flow rate to ensure that the actual cooling path of the strip is precisely controlled within the target range.

[0060] This multivariate coordinated control enables the system to match changing operating conditions (such as strip speed and temperature fluctuations) in real time, achieving millisecond-level fine adjustment of cooling intensity, thereby precisely controlling the phase transformation process of the strip and obtaining the desired microstructure and properties.

[0061] In a preferred embodiment of this application, the online temperature measuring instrument is a non-contact infrared thermometer or a hot metal detector, and multiple measuring points are arranged along the width direction in the cooling section of the heat treatment furnace to monitor and ensure the uniformity of transverse cooling of the strip steel.

[0062] III. Integrated Water Supply System for Anti-clogging and Water Treatment

[0063] The anti-clogging and water treatment integrated supply system includes: a multi-stage precision filter (with a final filtration accuracy of not less than 1μm) and a water softening device (to reduce the hardness of cooling water) arranged in series along the liquid supply pipeline, as well as a backflush pipeline for periodic compressed air backflushing connected in parallel with the air path of each composite nozzle.

[0064] In this application, the control program of the backflushing pipeline is linked to the start and stop signal of the composite nozzle. When the composite nozzle stops spraying (i.e. during the spraying interval of the composite nozzle or when the machine stops), high-pressure gas is automatically turned on to briefly and forcefully purge the liquid flow channel and spray port inside the nozzle to prevent residual water evaporation from causing solute crystallization and blockage.

[0065] The aforementioned multi-stage precision filter includes at least one coarse filter and one fine filter.

[0066] The water softening devices mentioned above use ion exchange resins or membrane treatment devices.

[0067] An integrated anti-clogging and water treatment supply system is crucial for ensuring the long-term stable and reliable operation of the device. Because the flow channels and micropores of the ultrasonic atomizing nozzles are extremely sensitive to water quality, impurities and excessive hardness in the water can lead to scaling or clogging. Therefore, this device is equipped with a multi-stage precision filtration system (final accuracy 1μm) and a water softening treatment device at the water supply end. More importantly, each nozzle is equipped with a periodic compressed air backflush circuit. This circuit is linked to the nozzle's operating status; during nozzle spray intervals or when the system stops, a burst of high-pressure air is automatically injected to remove any residual moisture and impurities inside the nozzle and at the outlet, fundamentally preventing clogging problems caused by water evaporation and crystallization.

[0068] Therefore, this application achieves a leapfrog improvement in cooling capacity, uniformity, and cooling temperature control accuracy through the synergistic effect of ultrasonic atomization and jet impact composite nozzle unit, precise closed-loop control system for cooling speed, and integrated supply system for anti-clogging and water treatment. It is particularly suitable for the heat treatment production of high-strength steel and ultra-high-strength steel with extremely demanding cooling process requirements.

[0069] The technical features of the above embodiments can be combined in any way (as long as there is no contradiction in the combination of these technical features). For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; these embodiments not explicitly written should also be considered to be within the scope of this specification.

[0070] The present application has been described in a relatively specific and detailed manner above through general descriptions and specific embodiments. It should be understood that, based on the technical concept of the present application, several conventional adjustments or further innovations can be made to these specific embodiments; however, as long as they do not depart from the technical concept of the present application, the technical solutions obtained by these conventional adjustments or further innovations also fall within the protection scope of the claims of the present application.

Claims

1. A jet-impact rapid cooling device based on ultrasonic atomization, characterized in that, include: An ultrasonic atomization and jet impact composite nozzle unit includes multiple composite nozzles. Each composite nozzle includes: a nozzle body, an ultrasonic transducer disposed inside the nozzle body, a liquid flow channel disposed inside the nozzle body and in fluid communication with the working surface of the ultrasonic transducer, and a gas flow channel disposed inside the nozzle body and surrounding the liquid flow channel. The spray port on the nozzle body faces the cooling station. A precise closed-loop control system for cooling speed includes: an online temperature measuring instrument installed on the cooling station for detecting the temperature of the workpiece to be cooled, a controller electrically connected to the online temperature measuring instrument, and a drive unit electrically connected to the controller; the drive unit is electrically connected to the ultrasonic transducer, a liquid supply device for supplying liquid to the liquid channel, and a gas supply device for supplying gas to the gas channel. An integrated anti-clogging and water treatment supply system includes: a liquid supply pipeline connected to the liquid flow channel, an air supply pipeline connected to the gas flow channel, and a backflush pipeline connected in parallel with the air supply pipeline; the liquid supply pipeline is equipped with a multi-stage filter and a water softening device; one end of the backflush pipeline is connected to an air source, and the other end is connected to the liquid flow channel.

2. The rapid cooling device based on ultrasonic atomization jet impact as described in claim 1, characterized in that, The ultrasonic transducer is located at the center of the nozzle body; the nozzle body forms a nested structure consisting of a transducer mounting cavity, an annular liquid flow channel, and an annular gas flow channel arranged coaxially from the inside out; the working surface of the ultrasonic transducer is exposed in the annular liquid flow channel, which is used to efficiently break and atomize the liquid flowing over its surface into ultrafine droplets with a particle size ≤10μm; the inner ring wall of the annular gas flow channel is provided with an air jet annular slit, and the airflow ejected from the air jet annular slit can capture, carry, and accelerate the ultrafine droplets before ejecting them from the jet nozzle, forming one or more impact jets that vertically impact the workpiece to be cooled.

3. The rapid cooling device based on ultrasonic atomization jet impact as described in claim 2, characterized in that, The nozzle body includes a tubular body and a conical nozzle connected to one end of the tubular body. The conical nozzle has an injection port at the end opposite to the tubular body. The injection port has a fan-shaped or circular geometry and is used to shape the mixed gas-liquid two-phase flow into a fan-shaped or circular impact jet field with controllable coverage.

4. The jet-impact rapid cooling device based on ultrasonic atomization according to claim 2, characterized in that, The thickness of the liquid film formed when the working surface of the ultrasonic transducer comes into contact with the liquid is adjusted by the liquid supply pressure, so that the droplet particle size formed by ultrasonic vibration is ≤10μm.

5. The jet-impact rapid cooling device based on ultrasonic atomization according to claim 1, characterized in that, The ultrasonic transducer operates in the frequency range of 1.0MHz to 2.4MHz, and the interface between the ultrasonic transducer and the liquid flow channel is made of a corrosion-resistant and highly thermally conductive material. The nozzle body is made of corrosion-resistant and high-temperature-resistant materials.

6. The jet-impact rapid cooling device based on ultrasonic atomization according to claim 1, characterized in that, The drive unit includes: a first frequency converter electrically connected to the ultrasonic transducer, a second frequency converter electrically connected to the liquid supply device, and a third frequency converter electrically connected to the gas supply device. The controller is equipped with a PID control algorithm or a feedforward-feedback composite control algorithm. The controller stores the target cooling curve of the workpiece to be cooled. The controller is configured to: based on the target cooling curve, the real-time speed of the workpiece to be cooled, and the deviation between the actual temperature of the workpiece to be cooled and the target temperature, output an adjustment signal to the drive unit through the PID control algorithm or the feedforward-feedback composite control algorithm, so as to dynamically adjust the power of the ultrasonic transducer, the water supply pressure and flow rate of the liquid supply device, and the air supply pressure and flow rate of the air supply device, so as to achieve precise control of the cooling intensity and ensure that the actual cooling curve of the workpiece to be cooled matches the target cooling curve.

7. The jet-impact rapid cooling device based on ultrasonic atomization according to claim 6, characterized in that, The liquid supply device is a water pump, and the gas supply device is a fan or an air compressor; The online temperature measuring instrument is a non-contact infrared thermometer or a hot metal detector, and multiple online temperature measuring instruments are arranged at equal intervals along the width direction of the cooling station.

8. The jet-impact rapid cooling device based on ultrasonic atomization according to claim 1, characterized in that, The multi-stage filter includes at least a coarse filter and a fine filter; The water softening device uses ion exchange resin or membrane treatment device.

9. The jet-impact rapid cooling device based on ultrasonic atomization according to claim 1, characterized in that, A switching valve is installed on the backflush pipeline, and the switching valve is electrically connected to the controller. The controller is configured to: when it receives a signal that the composite nozzle has stopped spraying, control the switching valve to open so as to use the purging airflow to purge the liquid flow channel and the spray nozzle.

10. The jet-impact rapid cooling device based on ultrasonic atomization according to claim 1, characterized in that, The jet impact rapid cooling device is installed in the cooling section of the heat treatment furnace. The workpiece to be cooled is a strip steel on the cooling station of the cooling section. At least one row of the composite nozzles is symmetrically arranged above and below the strip steel.

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