Equipment and method for improving uniform distribution of bar temperature

Abstract

The invention relates to equipment and a method for improving uniform distribution of bar temperature, belongs to the technical field of induction heat treatment quenching equipment, and solves the problem that an existing device is poor in bar soaking effect. The equipment comprises a transmission system, an induction heating assembly, a soaking assembly and a cooling system, the induction heating assembly, the soaking assembly and the cooling system are sequentially arranged, and a bar is conveyed by the transmission system and sequentially passes through the induction heating assembly, the soaking assembly and the cooling system; the soaking assembly comprises a soaking main body provided with an inner cavity, and the two ends of the soaking main body are open; the soaking assembly further comprises blocking pieces to seal the openings in the two ends of the soaking body, and a bar penetrates through the blocking pieces and then enters the inner cavity of the soaking body.

Description

Technical Field

[0001] The invention relates to the technical field of induction heat treatment quenching equipment, and in particular to an equipment and method for improving the uniform distribution of the temperature of a bar. Background Art

[0002] Induction heating technology is a technology that uses the principle of electromagnetic induction to achieve heating. It generates eddy currents in metals or other conductive materials to make the materials themselves heat up. Induction heating technology originated from the electromagnetic induction phenomenon discovered by Faraday, that is, alternating currents will generate induced currents in conductors, causing the conductors to heat up. Since Swedish technicians invented the first induction melting furnace in 1890, induction heating technology has gradually entered the practical stage, and with the rapid development of power electronic devices and technologies in the 20th century, induction heating technology has been greatly promoted.

[0003] Induction heaters use the principle of electromagnetic induction for heating. Since eddy currents are mainly concentrated near the surface of the conductor, they can achieve fast and uniform heating effects. Induction heating has many advantages. For example, compared with traditional heating methods, induction heaters can save energy and improve production efficiency; induction heaters can control the heating power by adjusting the frequency and amplitude of high-frequency current, thereby achieving precise control of the heating process; induction heaters do not directly contact the heating medium, reducing the safety risks brought by operators contacting high-temperature objects; induction heaters do not require fuel, do not produce harmful substances such as exhaust gas, wastewater and waste residue, and have good environmental protection; induction heating equipment can reach the required temperature of the workpiece in a very short time, and can even be completed within 1 second. The surface oxidation and decarburization of the workpiece are low, and most of them do not require gas protection; the equipment has a high degree of automation and is simple to operate. It can be started or stopped at any time, and no preheating is required, which effectively reduces transportation and saves manpower and financial resources.

[0004] Induction heating technology has been widely used in industrial production due to its advantages such as high efficiency, energy saving and environmental protection. However, it also has some limitations. For example, induction heaters are mainly suitable for materials with good conductivity. For non-conductive materials, the induction heating effect is poor. Compared with traditional heating equipment, induction heaters are more expensive and require special design and manufacturing. They may not be economical and practical in some application scenarios. Induction heating requires a high cost at the beginning, and the interchangeability and adaptability of induction coils are relatively poor. Especially when encountering workpieces with particularly complex shapes, induction heating is not as good as conventional heating. In addition, there is a skin effect in induction heating. When there is alternating current or an alternating electromagnetic field in the conductor, the current inside the conductor is unevenly distributed, and the current is concentrated in the "skin" part of the conductor, that is, the current is concentrated in a thin layer on the surface of the conductor. The closer to the surface of the conductor, the greater the current density, and the current inside the conductor is actually smaller. As a result, the resistance of the conductor increases, and its power loss also increases, which means that when the thickness or width of the workpiece is large, the temperature distribution of the workpiece will become significantly uneven. When the temperature of the core of the steel bar reaches 870°C, the surface temperature may exceed 1000°C, making the surface structure of the steel bar coarse and the core structure fine, and the workpiece structure and performance are uneven, which seriously restricts the application of induction heating equipment in the field of medium and thick plates (20-30mm thick).

[0005] The patent with publication number CN 104775012 A solves the above problem by placing the induction coil in an atmosphere furnace. However, placing the induction coil in the atmosphere furnace will cause the induction coil to be heated, affecting the magnetic field of the coil and greatly reducing the heating efficiency of the coil. If the induction coil is placed outside the atmosphere furnace, the plate cannot be heated to the required temperature.

[0006] Moreover, the patent with publication number CN 104775012 A is for plates with a thickness of only about 5 mm, and the above device has poor heat distribution effect for bars with a thickness of 20 to 30 mm. Therefore, there is an urgent need for a device to improve the uniform distribution of induction heating temperature of steel bars. Summary of the invention

[0007] In view of the above analysis, the present invention aims to provide a device and method for improving the uniform distribution of the temperature of the rod, so as to solve the problem that the existing device has a poor uniform heat distribution effect on the rod.

[0008] The purpose of the present invention is mainly achieved through the following technical solutions:

[0009] In a first aspect, the present invention provides an apparatus for improving uniform temperature distribution of a bar, comprising a transmission system, an induction heating component, a heat-saturating component and a cooling system;

[0010] The induction heating component, the soaking component and the cooling system are arranged in sequence, and the rod is transmitted by the transmission system and passes through the induction heating component, the soaking component and the cooling system in sequence;

[0011] The heat-spreading assembly comprises a heat-spreading body with an internal cavity, and both ends of the heat-spreading body are open;

[0012] The heat-spreading assembly further includes a blocking piece to seal the openings at both ends of the heat-spreading body, and the rod penetrates through the blocking piece and enters the internal cavity of the heat-spreading body.

[0013] Optionally, the induction heating component is longitudinal magnetic heating, including a transformer, an inductor and an induction coil connected in sequence.

[0014] Optionally, the transmission system includes a roller frame, a roller system, and a plurality of inlet and outlet roller lines arranged along the traveling direction of the rod;

[0015] Optionally, the rolling system is used to realize the rolling of the inlet roller line and the outlet roller line.

[0016] Optionally, according to the traveling direction of the rod, a gap is provided between the last inlet roller line and the first outlet roller line, and the induction coil and the heat equalizing assembly are arranged in the gap.

[0017] Optionally, the transmission system further comprises a position guide, which is fixed on the roller frame and is used for positioning the rod when it moves on the feed roller line.

[0018] Optionally, the position guide comprises a first vertical plate and a second vertical plate connected to each other, and a third vertical plate and a fourth vertical plate connected to each other;

[0019] The third vertical plate and the first vertical plate are arranged opposite to each other to form a trumpet-shaped passage; the fourth vertical plate and the second vertical plate are arranged opposite to each other and in parallel.

[0020] Optionally, the trumpet-shaped channel is arranged at one end close to the first feed roller line.

[0021] Optionally, the distance between the fourth vertical plate and the second vertical plate is 2-3 mm larger than the diameter of the rod.

[0022] Optionally, the angle between the first vertical plate and the second vertical plate is 30°-60°.

[0023] In a second aspect, the present invention provides a method for improving the uniform distribution of the induction heating temperature of a bar, which is performed using the above-mentioned device and comprises the following steps:

[0024] Step 1: Check whether the water circuit is working properly;

[0025] Step 2: Check whether the transmission system works normally;

[0026] Step 3: Place the rod on the transmission system, start the induction heating component, and the test rod passes through the transmission system, induction heating component, heat soaking component and cooling system in sequence to complete the test.

[0027] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0028] (1) After the rod is treated by the equipment of the present invention, the temperature difference between the center and the edge of the rod is very small, only 14-77°C (see Table 1).

[0029] (2) The heat soaking assembly of the present invention has a simple structure and good heat preservation effect, and can meet the use requirements of steel bars with a diameter of 20-50 mm and a length of 1000-1300 mm. In addition, the induction coil of the present invention is arranged outside the heat soaking body of the heat soaking assembly to prevent the induction coil from being heated in the furnace, and can ensure that the coil has a high heating efficiency.

[0030] (2) The present invention provides a clamping roller with a certain pressure to enable the rod to obtain forward momentum, thereby ensuring that the rod can pass through the soaking furnace and the induction coil smoothly.

[0031] (3) Compared with the prior art which uses a special furnace door to seal the inlet and outlet, the present invention uses asbestos to seal the inlet and outlet. On the one hand, it is more conducive to heat preservation. On the other hand, the structure is simpler, there is no need to make a furnace door, and the cost is lower.

[0032] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can be obvious from the description or understood by practicing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0034] Figure 1 It is a schematic diagram of the structure of the device of the present invention;

[0035] Figure 2 It is a schematic diagram of the matching structure of the feed roller line and the feed clamp roller of the present invention;

[0036] Figure 3 This is a schematic diagram of the coordination structure between the position guide and the feed roller line of the present invention;

[0037] Figure 4 Heating temperature distribution diagram for those without using a heat soaking assembly;

[0038] Figure 5 Temperature distribution diagram for heating using a heat soaking assembly;

[0039] Figure 6 This is a diagram showing the position relationship between the air knife and the rod.

[0040] Reference numerals:

[0041] 1-roller frame; 2-roller feed line; 3-nip roller feed; 4-chain; 5-induction coil; 6-sensor; 7-transformer; 8-heat equalization body; 9-water retaining box; 10-sprinkler; 11-nozzle; 12-cooling system; 13-roller system; 14-roller outlet line; 15-nip roller outlet; 16-air knife; 17-position guide; 18-first vertical plate; 19-second vertical plate; 20-third vertical plate; 21-first vertical plate; 23-rod; α-angle between the air knife and the rod. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0043] In a first aspect, the present invention provides a device for improving the uniform distribution of temperature of a rod, comprising a transmission system, an induction heating component, a heat equalizing component, and a cooling system.

[0044] The transmission system is used for conveying the rods, the induction heating assembly is used for heating the rods, the heat-saturating assembly is used for improving the temperature uniformity of the rods after being heated by the induction heating assembly, and the cooling system is used for cooling the rods.

[0045] The induction heating component, the soaking component and the cooling system are arranged in sequence, and the rod is transported by the transmission system and passes through the induction heating component, the soaking component and the cooling system in sequence.

[0046] The induction heating assembly is longitudinal magnetic heating, and includes a transformer 7, an inductor 6, and an induction coil 5 connected in sequence. The transformer 7 is used to provide a stable voltage and current to the inductor 6, and the induction coil 5 is used to provide a magnetic field to heat the pipe. The inductor 6 is used to provide a current of a specific frequency to the induction coil 5, thereby generating a magnetic field of a specific frequency.

[0047] The induction heating assembly further includes a cooler (not shown in the figure), which is used to cool the induction coil 5, the inductor 6 and the transformer 7. Specifically, the cooling medium in the cooler first flows through the inductor 6, and then flows from the inductor 6 through the transformer 7 and the induction coil 5 respectively.

[0048] In a preferred embodiment, the induction coil 5 is protected by a high-temperature insulating sleeve to prevent short circuit caused by contact with the rod 23 .

[0049] In addition, the size of the induction coil 5 is larger than that of the test bar, and the heating efficiency is improved as much as possible under the premise of ensuring safe testing. For example, the length, width and height of the induction coil 5 are respectively 10 mm larger than the length, width and height of the test bar.

[0050] Specifically, the power of the transformer is 140-170 kW, for example, 140 kW, 145 kW, 150 kW, 155 kW, 160 kW, 165 kW, 170 kW. The inductor is a medium frequency inductor.

[0051] The heat-saturating assembly includes a heat-saturating body 8 having an internal cavity, and the heat-saturating body 8 has two openings at both ends, which are an inlet and an outlet, respectively. A heating resistance wire is provided in the cavity of the heat-saturating body 8 to increase the temperature of the cavity inside the heat-saturating body 8. Exemplarily, the temperature in the cavity of the heat-saturating body 8 is 800-1000°C.

[0052] Exemplarily, the heat-saturating body has a length of 400 mm, a width of 300 mm, and a height of 40 mm.

[0053] The heat spreader assembly also includes a plugging member (not shown in the figure) for sealing the openings at both ends of the heat spreader body to play a role in heat preservation and reduce the heat dissipation of the heat spreader assembly. Exemplarily, the plugging member is asbestos. The rod penetrates the plugging member and enters the internal cavity of the heat spreader body.

[0054] The test rod will penetrate the asbestos when passing through the inlet and outlet of the heat-saturating body. After the test is completed, the asbestos is used as a consumable and will be replaced with new asbestos during the next test.

[0055] The prior art uses a special furnace door to block the inlet and outlet, but a large amount of heat will be lost during the process of opening and closing the door. The present invention uses asbestos to block the inlet and outlet, which is more conducive to heat preservation on the one hand, and has a simpler structure, does not need to make a furnace door, and has lower costs.

[0056] like Figure 1 As shown, the transmission system includes a roller frame 1, a rolling system 13, and a plurality of inlet roller lines 2 and outlet roller lines 14 arranged along the traveling direction of the bar 23. The two ends of the inlet roller line 2 and the outlet roller line 14 are respectively placed on the roller frame 1, and the rolling system 13 is used to realize the rolling of the inlet roller line 2 and the outlet roller line 14.

[0057] Specifically, the lengths of the inlet roller line and the outlet roller line are both 1 meter.

[0058] According to the traveling direction of the rod, a certain gap is provided between the last inlet roller line and the first outlet roller line, and the induction coil 5 and the heat-averaging component are arranged in the gap.

[0059] like Figure 2As shown, in a preferred embodiment, the transmission system also includes an inlet clamping roller 3 and an outlet clamping roller 15 with a certain pressure. The inlet clamping roller 3 is arranged above the last inlet roller line 2, and a gap is left between the inlet clamping roller 3 and the last inlet roller line 2. The rod 23 obtains the power to move forward after passing through the gap.

[0060] The exit clamping roller 15 is arranged above the first exit roller line 14, and a gap is left between the exit clamping roller 15 and the first exit roller line 14. The rod 23 obtains the driving force to move forward after passing through the gap.

[0061] The present invention provides an inlet clamping roller and an outlet clamping roller with a certain pressure, so that the rod obtains the driving force to move forward, and can ensure that the rod passes through the soaking furnace and the induction coil smoothly.

[0062] The transmission system also includes a chain 4, and the plurality of inlet roller lines and the plurality of outlet roller lines are connected by a multi-section chain, so as to ensure that the line speeds of the inlet roller lines and the outlet roller lines are consistent. Specifically, the multi-section chain connects one end of the plurality of inlet roller lines and the plurality of outlet roller lines.

[0063] In a preferred embodiment, the transmission system further includes a position guide 17, such as Figure 3 As shown, the guide 17 is fixed on the roller frame 1 and is used to position the rod 23 when it moves on the feed roller line 2, ensuring that the steel rod, the induction coil 5 and the heat-averaging body 8 are in the same straight line to prevent the rod from deviating from the normal path during the test.

[0064] Specifically, the position guide includes a first vertical plate and a second vertical plate connected to each other, and a third vertical plate and a fourth vertical plate connected to each other, and the angle between the first vertical plate and the second vertical plate is 30°-60°. The angle between the third vertical plate and the fourth vertical plate is 30°-60°.

[0065] The third vertical plate and the first vertical plate are arranged opposite to each other to form a trumpet-shaped channel. The fourth vertical plate and the second vertical plate are arranged opposite to each other and in parallel. The distance between the fourth vertical plate and the second vertical plate is 2-3 mm larger than the diameter of the rod.

[0066] Specifically, the trumpet-shaped channel is arranged at one end close to the first feed roller line.

[0067] In a preferred embodiment, the upper ends of the first upright plate, the second upright plate, the third upright plate and the fourth upright plate are flush with the upper ends of the rods, or are 5-50 mm higher than the upper ends of the rods.

[0068] The cooling system comprises a sprayer 10 and a water retaining box 9. The water retaining box 9 is arranged at the periphery of the sprayer 10 to prevent the water of the sprayer 10 from splashing out of the spraying area and causing damage to peripheral components.

[0069] In addition, the device of the present invention also includes a protective member for preventing water from flowing on the rod beyond the position of the water retaining box 9 when the rod is cooled, and splashing onto the induction coil 5 to cause a short circuit.

[0070] Specifically, the protective member is an air knife 16, which is arranged between the heat-saturating component and the cooling system. For example, the air knife is generated by a high-pressure air pump, such as Figure 6 As shown, the angle α between the direction of the wind knife and the rod is 15°-60°. The present invention can ensure that the cooling water will not splash outside by setting the wind knife and controlling the angle α between the direction of the wind knife and the rod to 15°-60°. If the angle exceeds this, the cooling water will splash out, which will cause a test hazard.

[0071] The existing induction heating line adopts a sloped design, that is, the inlet is high and the outlet is low. Although it can prevent the cooling water from flowing into the induction coil, it will still cause the water on the steel rod to flow around. Moreover, the induction line adopts a sloped design, and it is extremely complicated to adjust the height of the test line for each test. The present invention adopts an air knife to block the water flow, and there is no need to use a sloped design. The entire induction heating line can be kept horizontal, and it is very simple to adjust the height of the test line, which greatly shortens the adjustment time.

[0072] The sprayer adopts laminar cooling, spraying water evenly from top to bottom, and the lower water spray pressure reaches 1.1 times the upper water spray pressure, ensuring that the cooling speed of the lower surface of the side of the test bar tends to be consistent.

[0073] The positions that may contact the cooling water, such as the roller frame 1, the sprayer 10, the inlet roller line 2, the outlet roller line 14, the inlet clamping roller 3, the outlet clamping roller 15, etc., are all made of stainless steel to prevent the parts from rusting.

[0074] After the rod is treated by the equipment of the present invention, the temperature difference between the center and the edge of the rod is very small, only 14-77° C. (see Table 1).

[0075] The heat soaking assembly of the present invention has a simple structure and good heat preservation effect, and can meet the use requirements of steel bars with a diameter of 20-50 mm and a length of 1000-1300 mm. In addition, the induction coil of the present invention is arranged outside the heat soaking body of the heat soaking assembly to prevent the induction coil from being heated in the furnace, and can ensure that the coil has a high heating efficiency.

[0076] The present invention provides an inlet clamping roller and an outlet clamping roller with a certain pressure, so that the rod obtains the driving force to move forward, and can ensure that the rod passes through the soaking furnace and the induction coil smoothly.

[0077] The present invention can ensure that the steel rod, the induction coil and the heat-saturating body are in the same straight line by arranging the position guide, so as to prevent the rod from deviating from the normal path during the test.

[0078] The existing induction heating line adopts a sloped design, that is, the inlet is high and the outlet is low. Although it can prevent the cooling water from flowing into the induction coil, it will still cause the water on the steel rod to flow around. Moreover, the induction line adopts a sloped design, and it is extremely complicated to adjust the height of the test line for each test. The present invention adopts an air knife to block the water flow, and there is no need to use a sloped design. The entire induction heating line can be kept horizontal, and it is very simple to adjust the height of the test line, which greatly shortens the adjustment time.

[0079] Compared with the prior art which uses a special furnace door to seal the inlet and outlet, the present invention uses asbestos to seal the inlet and outlet. On the one hand, it is more conducive to heat preservation. On the other hand, it has a simpler structure, does not need to make a furnace door, and has lower costs.

[0080] In a second aspect, the present invention also provides a method for improving the uniform distribution of the induction heating temperature of a bar, comprising the following steps:

[0081] Step 1: Check whether the water circuit works normally, including starting the cooling machine to check the water circuit, including the induction coil 5 and the sensor 6; after checking that everything is correct, start the cooling system 12 to check the water circuit, check the water blocking condition of the nozzle 11, the operating status of the sprinkler 10, and the sealing status of the water retaining box 9, and close the cooling system after confirming that there is no abnormality;

[0082] Step 2: Check whether the transmission system works normally, including starting the rolling system 13, confirming that the inlet roller line 2 and the outlet roller line 14 run smoothly, and the test bar passes through the inlet roller line 2, the guide 17, the inlet clamping roller 3, the induction coil 5, the heat-averaging body 8, the outlet clamping roller 15, and the sprayer 10 in sequence. After confirming that the test bar does not collide with the induction coil 5, the heat-averaging body 8 and the sprayer 10, the rolling system 13 is closed;

[0083] Step 3: Place the test bar on the feed roller line 2, start the sensor transformer 7, start the sensor 6, and start the roller system 13 after confirming that there is no short circuit in the circuit system, turn on the air knife 16, and the test bar passes through the feed roller line 2, the inlet clamping roller 3, the induction coil 5, the heat equalizing body 8, the outlet clamping roller 15, the sprayer 10, and the outlet roller line 14 in sequence.

[0084] Among them, the material of the rod is steel rod, for example, Q235, Q345, Q195, Q215.

[0085] The method for induction heating using the device of the present invention is described in detail below in conjunction with specific embodiments.

[0086] Embodiment 1: The present invention provides a method for improving the uniform distribution of temperature of a steel bar by induction heating, which is used for a steel bar (Q235) with a length of 1000 mm and a diameter of 30 mm, comprising the following steps:

[0087] 1) Start the chiller to check the water circuit, including the induction coil and sensor, and control the water temperature at 10-25℃; after checking everything, start the cooling system to check the water circuit, check the nozzle water blockage, the sprinkler operation status, the water retaining box sealing status, and shut down the cooling system after confirming that there is no abnormality;

[0088] 2) Start the roller system, confirm that the inlet and outlet rollers are running smoothly, and the test steel bar passes through the inlet roller line, guide, inlet roller, induction coil (5 turns), heat-saturating body, outlet roller, and sprayer in turn. After confirming that the test steel bar does not collide with the induction coil, heat-saturating body, and sprayer, close the roller system. If there is any collision, adjust the height of the roller frame, induction coil, and heat-saturating body to ensure that the test steel bar does not collide with all devices.

[0089] 3) Drill two Φ2mm holes on the side of the test steel bar. The two holes are 15mm deep and located in the core of the steel bar. Insert the multi-point contact thermocouple into them and seal them with sand and high-temperature glue to ensure that the end points of the thermocouple touch the core of the steel bar; two thermocouples are glued to the surface with high-temperature glue to measure the surface temperature. Place the test steel bar on the infeed roller line, turn on the cooling system, enable the wind knife, the transformer power supply (medium frequency) of the sensor, start the sensor (160kW), and start the roller system after confirming that there is no short circuit in the circuit system. Set the steel bar linear speed to 4mm / s. The test steel bar passes through the infeed roller line, the infeed roller, the induction coil, the heat-saturating body, the outfeed roller, the sprayer, and the outfeed roller line in turn. The specific data are shown in Table 1.

[0090] Embodiment 2: The present invention provides a method for improving the uniform distribution of temperature of a steel bar by induction heating, which is used for a steel bar (Q235) with a length of 1300 mm and a diameter of 20 mm, comprising the following steps:

[0091] 1) Start the chiller and check the water circuit, including the induction coil and sensor, and control the water temperature at 10-25°C; after checking that everything is correct, start the cooling system and check the water circuit, check the nozzle blockage, the sprinkler operation status, the water retaining box sealing status, and shut down the cooling system after confirming that there is no abnormality.

[0092] 2) Start the roller system, confirm that the inlet and outlet rollers are running smoothly, and the test steel bar passes through the inlet roller line, guide, inlet roller, induction coil (5 turns), heat-saturating body, outlet roller, and sprayer in turn. After confirming that the test steel bar does not collide with the induction coil, heat-saturating body, and sprayer, close the roller system. If there is any collision, adjust the height of the roller frame, induction coil, and heat-saturating body to ensure that the test steel bar does not collide with all devices.

[0093] 3) Drill two Φ2mm holes on the side of the test steel bar. The two holes are 10mm deep and located in the core of the steel bar. Insert the multi-point contact thermocouple into them and seal them with sand and high-temperature glue to ensure that the end points of the thermocouple touch the core of the steel bar; two thermocouples are glued to the surface with high-temperature glue to measure the surface temperature. Place the test steel bar on the infeed roller line, turn on the cooling system, enable the wind knife, the transformer power supply (medium frequency) of the sensor, start the sensor (160kW), and start the roller system after confirming that there is no short circuit in the circuit system. Set the steel bar linear speed to 4mm / s. The test steel bar passes through the infeed roller line, the infeed roller, the induction coil, the heat equalization body, the outfeed roller, the sprayer, and the outfeed roller line in turn. The specific data are shown in Table 1.

[0094] Embodiment 3: The present invention provides a method for improving the uniform distribution of temperature of a steel bar by induction heating, which is used for a steel bar (Q235) with a length of 1200 mm and a diameter of 50 mm, comprising the following steps:

[0095] 1) Start the chiller and check the water circuit, including the induction coil and sensor, and control the water temperature at 10-25°C; after checking that everything is correct, start the cooling system and check the water circuit, check the nozzle blockage, the sprinkler operation status, the water retaining box sealing status, and shut down the cooling system after confirming that there is no abnormality.

[0096] 2) Start the roller system, confirm that the inlet and outlet rollers are running smoothly, and the test steel bar passes through the inlet roller line, guide, inlet roller, induction coil (5 turns), heat-saturating body, outlet roller, and sprayer in turn. After confirming that the test steel bar does not collide with the induction coil, heat-saturating body, and sprayer, close the roller system. If there is any collision, adjust the height of the roller frame, induction coil, and heat-saturating body to ensure that the test steel bar does not collide with all devices.

[0097] 3) Drill two Φ2mm holes on the side of the test steel bar. The two holes are 25mm deep and located in the core of the steel bar. Insert the multi-point contact thermocouple into them and seal them with sand and high-temperature glue to ensure that the end points of the thermocouple touch the core of the steel bar; two thermocouples are glued to the surface with high-temperature glue to measure the surface temperature. Place the test steel bar on the infeed roller line, turn on the cooling system, enable the wind knife, the transformer power supply (medium frequency) of the sensor, start the sensor (160kW), and start the roller system after confirming that there is no short circuit in the circuit system. Set the steel bar linear speed to 4mm / s. The test steel bar passes through the infeed roller line, infeed roller, induction coil, heat-saturating body, outfeed roller, sprayer, and outfeed roller line in turn. The specific data are shown in Table 1.

[0098] Embodiment 4: The present invention provides a method for improving the uniform distribution of temperature of a steel bar by induction heating, which is used for a steel bar (Q235) with a length of 1300 mm and a diameter of 30 mm, comprising the following steps:

[0099] 1) Start the chiller and check the water circuit, including the induction coil and sensor, and control the water temperature at 10-25°C; after checking that everything is correct, start the cooling system and check the water circuit, check the nozzle blockage, the sprinkler operation status, the water retaining box sealing status, and shut down the cooling system after confirming that there is no abnormality.

[0100] 2) Start the roller system, confirm that the inlet and outlet rollers are running smoothly, and the test steel bar passes through the inlet roller line, guide, inlet roller, induction coil (5 turns), heat-saturating body, outlet roller, and sprayer in turn. After confirming that the test steel bar does not collide with the induction coil, heat-saturating body, and sprayer, close the roller system. If there is any collision, adjust the height of the roller frame, induction coil, and heat-saturating body to ensure that the test steel bar does not collide with all devices.

[0101] 3) Drill two Φ2mm holes on the side of the test steel bar. The two holes are 15mm deep and located in the core of the steel bar. Insert the multi-point contact thermocouple into them and seal them with sand and high-temperature glue to ensure that the end points of the thermocouple touch the core of the steel bar; two thermocouples are glued to the surface with high-temperature glue to measure the surface temperature. Place the test steel bar on the infeed roller line, turn on the cooling system, enable the wind knife, the transformer power supply (medium frequency) of the sensor, start the sensor (160kW), confirm that there is no short circuit in the circuit system, and then start the roller system. Set the steel bar linear speed to 12mm / s. The test steel bar passes through the infeed roller line, the infeed roller, the induction coil, the heat-saturating body, the outfeed roller, the sprayer, and the outfeed roller line in turn. The specific data are shown in Table 1.

[0102] Embodiment 5: The present invention provides a method for improving the uniform distribution of temperature of a steel bar by induction heating, which is used for a steel bar (Q235) with a length of 1300 mm and a diameter of 30 mm, comprising the following steps:

[0103] 1) Start the chiller and check the water circuit, including the induction coil and sensor, and control the water temperature at 10-25°C; after checking that everything is correct, start the cooling system and check the water circuit, check the nozzle blockage, the sprinkler operation status, the water retaining box sealing status, and shut down the cooling system after confirming that there is no abnormality.

[0104] 2) Start the roller system, confirm that the inlet and outlet rollers are running smoothly, and the test steel bar passes through the inlet roller line, guide, inlet roller, induction coil (5 turns), heat-saturating body, outlet roller, and sprayer in turn. After confirming that the test steel bar does not collide with the induction coil, heat-saturating body, and sprayer, close the roller system. If there is any collision, adjust the height of the roller frame, induction coil, and heat-saturating body to ensure that the test steel bar does not collide with all devices.

[0105] 3) Drill two Φ2mm holes on the side of the test steel bar. The two holes are 15mm deep and located in the core of the steel bar. Insert the multi-point contact thermocouple into them and seal them with sand and high-temperature glue to ensure that the end points of the thermocouple touch the core of the steel bar; two thermocouples are glued to the surface with high-temperature glue to measure the surface temperature. Place the test steel bar on the infeed roller line, turn on the cooling system, enable the wind knife, the transformer power supply (medium frequency) of the sensor, start the sensor (160kW), and start the roller system after confirming that there is no short circuit in the circuit system. Set the steel bar linear speed to 3mm / s. The test steel bar passes through the infeed roller line, the infeed roller, the induction coil, the heat-saturating body, the outfeed roller, the sprayer, and the outfeed roller line in turn. The specific data are shown in Table 1.

[0106] Comparative Example 1 (Comparative Example does not contain a heat soaking assembly): The present invention provides a comparative example for a steel bar (Q235) with a length of 1300 mm and a diameter of 30 mm, comprising the following steps:

[0107] 1) Start the chiller and check the water circuit, including the induction coil and sensor, and control the water temperature at 10-25°C; after checking that everything is correct, start the cooling system and check the water circuit, check the nozzle blockage, the sprinkler operation status, the water retaining box sealing status, and shut down the cooling system after confirming that there is no abnormality.

[0108] 2) Start the roller system, confirm that the inlet and outlet rollers are running smoothly, and the test steel bar passes through the inlet roller line, guide, inlet clamping roller, induction coil, outlet clamping roller, and sprayer in turn. After confirming that the test steel bar does not collide with the induction coil and sprayer, close the roller system. If there is any collision, adjust the height of the roller frame and induction coil to ensure that the test steel bar does not collide with all devices.

[0109] 3) Drill two Φ2mm holes on the side of the test steel bar. The two holes are 15mm deep and located in the core of the steel bar. Insert the multi-point contact thermocouple into them and seal them with sand and high-temperature glue to ensure that the end points of the thermocouple touch the core of the steel bar; two thermocouples are glued to the surface with high-temperature glue to measure the surface temperature. Place the test steel bar on the infeed roller line, turn on the cooling system, enable the wind knife, the transformer power supply (medium frequency) of the sensor, start the sensor (160kW), and start the roller system after confirming that there is no short circuit in the circuit system. Set the steel bar linear speed to 4mm / s. The test steel bar passes through the infeed roller line, infeed roller, induction coil, outfeed roller, sprayer, and outfeed roller line in turn. The specific data are shown in Table 1.

[0110] Table 1 Specific data list of examples and comparative examples

[0111]

[0112] It can be seen from the data of Comparative Example 1 and Example 1 in Table 1 that when the heat equalization component (Comparative Example 1) is not used, the temperature equalization time is longer (47 seconds).

[0113] It can be seen from the data of Examples 1-3 that the smaller the diameter of the steel rod, the higher the uniform temperature and the shorter the uniform temperature time.

[0114] From the data of Examples 1, 4 and 5, it can be seen that, when comparing different line speeds, the lower the line speed, the higher the uniform temperature and the shorter the temperature equalization time.

[0115] It can also be seen from Table 1 that when a heat-saturating assembly is used, the temperature difference between the center and edge of the steel rod is only 14-77°C (Examples 1-5), while when a heat-saturating assembly is not used, the temperature difference between the center and edge of the steel rod is as high as 170°C (Comparative Example 1).

[0116] The equipment of the present invention can meet the test requirements of uniform temperature of 500-1000°C for steel rods with a diameter of 20-50mm and a linear speed of 3-12mm / s, and the uniform temperature time is 10-70s.

[0117] In addition, the temperature curves of the core and edge of the steel bar of Comparative Example 1 and Example 1 are plotted, which are Figure 4 and Figure 5 .Depend on Figure 4 It can be seen that when the heat-saturating assembly is not used, the temperature difference between the center and the edge of the steel bar is as high as 170°C. Figure 5 It can be seen that after the heat soaking treatment is performed using the heat soaking assembly of the present invention, the temperature difference between the core and the edge of the steel rod is very small.

[0118] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A device for improving the uniform distribution of bar temperature, characterized in that: Including transmission system, induction heating component, heat soaking component and cooling system; The induction heating component, the soaking component and the cooling system are arranged in sequence, and the rod is transmitted by the transmission system and passes through the induction heating component, the soaking component and the cooling system in sequence; The heat-spreading assembly comprises a heat-spreading body provided with an internal cavity, and both ends of the heat-spreading body are open; The heat-spreading assembly further includes a blocking piece to seal the openings at both ends of the heat-spreading body, and the rod penetrates through the blocking piece and enters the internal cavity of the heat-spreading body.

2. The device according to claim 1, characterized in that The induction heating assembly is longitudinal magnetic heating, and includes a transformer, an inductor and an induction coil connected in sequence.

3. The device according to claim 2, characterized in that The transmission system includes a roller frame, a roller motion system, and a plurality of inlet and outlet roller lines arranged along the traveling direction of the bar; The two ends of the inlet roller line and the outlet roller line are respectively placed on the roller frame, and the rolling system is used to realize the rolling of the inlet roller line and the outlet roller line.

4. The device according to claim 3, characterized in that According to the traveling direction of the rod, a gap is arranged between the last inlet roller line and the first outlet roller line, and the induction coil and the heat equalizing component are arranged in the gap.

5. The device according to claim 3, characterized in that The transmission system also includes a position guide, which is fixed on the roller frame and is used to position the bar when it moves on the feed roller line.

6. The device according to claim 5, characterized in that The position guide comprises a first vertical plate and a second vertical plate connected to each other, and a third vertical plate and a fourth vertical plate connected to each other; The third vertical plate and the first vertical plate are arranged opposite to each other to form a trumpet-shaped channel; The fourth vertical plate and the second vertical plate are arranged opposite to and in parallel.

7. The device according to claim 6, characterized in that The trumpet-shaped passage is arranged at one end close to the first feed roller line.

8. The device according to claim 6, characterized in that The distance between the fourth vertical plate and the second vertical plate is 2-3 mm larger than the diameter of the rod.

9. The device according to claim 6, characterized in that The included angle between the first vertical plate and the second vertical plate is 30°-60°.

10. A method for improving the uniform distribution of temperature of a bar during induction heating, characterized in that: The method is carried out using the device according to any one of claims 1 to 9, comprising the following steps: Step 1: Check whether the water circuit is working properly; Step 2: Check whether the transmission system works normally; Step 3: Place the rod on the transmission system, start the induction heating component, and the test rod passes through the transmission system, induction heating component, heat soaking component and cooling system in sequence to complete the test.

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