Online low-heat electromagnetic drying device for aluminum strip

Abstract

The present application aims at providing an online low-heat electromagnetic drying device for aluminum strip, solving the problems of large volume of traditional aluminum strip online drying equipment, increased production line limitation by drying equipment, and traditional electromagnetic heating cannot be used for online thin plate aluminum strip heating. The scheme firstly adopts low-heat electromagnetic induction heating, greatly simplifies the main structure, compared with the traditional tunnel drying type equipment with open flame, can meet the installation of multiple production lines in smaller space, and greatly reduces the volume; on the other hand, the scheme adopts planar electromagnetic heating actuator, which breaks through the structure of traditional ring or ring-like electromagnetic heating coil, realizes clean, low-heat and high-efficiency effect in the heating process, greatly improves the line of traditional thin plate aluminum strip online drying equipment, and has great application and promotion prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of thin aluminum strip heating and drying, in particular to an online low-heat electromagnetic drying device for aluminum strip. BACKGROUND

[0002] Nowadays, most of the metal motor vehicle license plates are made of aluminum, and the base material is a thin plate structure with a thickness of 0.5-1.5 mm. The production process of the license plate includes aluminum roll feeding, cleaning, drying, spraying, and stamping. Industrial cleaning agents are used in the cleaning process, and thorough drying must be performed after cleaning to ensure the subsequent spraying effect. At present, an aluminum roll feeding machine or a roll-off machine is used to realize slow feeding of the aluminum roll, and an aluminum strip cleaning device is used to realize the cleaning process by setting a cleaning tank or a cleaning nozzle. The more commonly used drying equipment is a tunnel-type drying equipment. Although the traditional tunnel-type drying equipment has good drying effect, it needs to be provided with a separate heat source, such as an oil-fired, coal-fired, or gas-fired type, etc. Moreover, the drying tunnel of the tunnel-type drying equipment corresponds to the discharge end of the cleaning machine. Due to the continuous discharge, the tunnel-type drying equipment can only correspond to one cleaning machine. For a small production line, the utilization rate of the tunnel-type drying equipment is not high, and the tunnel-type drying equipment occupies a large area.

[0003] In fact, electromagnetic drying as a means of metal drying also exists in other fields, but the traditional electromagnetic drying equipment cannot be directly used for drying the product. Moreover, aluminum strip is a weak magnetic induction material. When using electromagnetic induction principle to dry the thin aluminum strip, it is inevitable that the temperature of each part of the aluminum strip will be different due to uneven distribution of electromagnetic induction, which will easily cause warping and deformation due to uneven distribution of internal thermal stress, resulting in material damage or affecting the subsequent process. On the other hand, one of the advantages of electromagnetic drying is that the temperature rises rapidly. The traditional electromagnetic drying is easy to cause local temperature to be too high, resulting in local oxidation discoloration, which makes the subsequent material unable to be used. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide an online low-heat electromagnetic drying device for aluminum strip, which solves the problems of large volume of traditional aluminum strip online drying equipment, large production line limited by drying equipment, and the problem that traditional electromagnetic heating cannot be used for online thin plate aluminum strip heating.

[0005] The technical scheme is as follows: a heating unit and a temperature control unit are provided, the heating unit generates heat for drying water stains on the surface of the aluminum strip, the temperature control unit is used to control the heating unit to maintain a suitable drying temperature, and a feeding channel for the aluminum strip to pass through is further provided. The heating unit includes an electromagnetic drying actuator, the electromagnetic drying actuator includes a magnetic field generating component for generating an alternating frequency electromagnetic field, the magnetic field generating component includes a copper bar arranged in a meandering or serpentine shape, the copper bar is electrically connected to an alternating frequency current input terminal, and the copper bar is arranged in a meandering or serpentine shape to form a structure for generating an alternating frequency electromagnetic field.

[0006] The temperature control unit comprises a circulating channel located at the position of the magnetic field generating component, the copper bar is a hollow tubular structure, the copper bar is connected to the container and the circulating pump through the external pipeline, forming a structure in which the temperature control medium can circulate through the copper bar, the external pipeline, the container and the circulating pump; the temperature control unit further comprises a temperature acquisition unit for acquiring the surface temperature of the copper bar and the surface temperature of the aluminum strip, and a temperature controller, the temperature controller sets and stores the standard values of the surface temperature of the copper bar and the surface temperature of the aluminum strip, the temperature information acquired by each temperature acquisition unit is compared with the standard values of the surface temperature of the copper bar and the surface temperature of the aluminum strip, when the acquired temperature is lower or higher than the standard value, the power of the circulating pump is increased to increase the flow of the temperature control medium, when the acquired temperature is lower than the standard value, the power of the circulating pump is reduced or maintained to reduce or maintain the flow of the temperature control medium, and the output power of the electromagnetic field of the magnetic field generating component is increased at the same time.

[0007] In the above or some embodiments, the feeding channel comprises a plurality of floating rollers arranged in the feeding direction from top to bottom, and a horizontal supporting plate arranged below the floating rollers, the supporting plate and the floating rollers form a space for the aluminum strip to pass through; the floating rollers are movably installed on the rack, forming a structure for applying pressure to the passing aluminum strip, and the supporting plate is fixed to the rack.

[0008] In the above or some embodiments, the temperature control unit further comprises a heat preservation unit located above the copper bar and a heat equalization unit located below the heat preservation unit; the heat preservation unit is composed of the floating rollers, and the heat equalization unit is composed of the supporting plate, and the floating rollers and the supporting plate are made of non-metallic insulating materials; each floating roller comprises a cylindrical shell made of ceramic material, and a core column located inside the shell, the core column and the inner wall of the shell form a space for placing a heating pipe spirally wound on the outer surface of the core column, the inlet and outlet of the heating pipe are connected to the external temperature control medium, forming a circulating inlet and outlet structure driven by a circulating power; the inlets and outlets of the plurality of floating rollers are connected to a multi-pipeline distributor through flexible pipelines; the supporting plate is an aluminum oxide ceramic plate, and the supporting plate is in close contact with the copper bar.

[0009] In the above or some embodiments, the rack comprises a vertical mounting plate for mounting the floating rollers, the mounting plate is located on both sides of the copper bar, the mounting plate is provided with a "∪" groove matched with the diameters of the two ends of the floating roller, and the "∪" groove is rotatably connected with the floating roller, forming a structure in which each floating roller rolls and presses the passing aluminum strip.

[0010] In the above or some embodiments, the alternating current is generated by an inverter circuit, the inverter circuit comprises IGBT, resonance capacitor, transformer, three-phase 380V 50HZ alternating current is rectified by thyristor, the rectified alternating current is filtered by reactor and filter capacitor, and then is converted into 530V smooth and stable direct current, then the 530V direct current is inverted into high-frequency alternating current required by the load by IGBT module, resonance capacitor and transformer.

[0011] In the above or some embodiments, the rack comprises a frame type cubic structure, the frame type cubic structure is divided into an upper space and a lower space by a middle beam, the upper space and the lower space are divided by the middle beam and a partition plate, the copper bar is located in the upper space, the copper bar is fixed to the upper surface of the partition plate through an insulation truss, the transformer is fixedly installed on the upper surface of a bottom plate in the lower space, and a resonance capacitor is located above the transformer; a mounting back plate is further arranged in the middle of the lower space, and the mounting back plate is used for mounting a main control board, a reactor, a filter capacitor and a thyristor module.

[0012] The scheme firstly adopts low-heat electromagnetic induction heating, the main structure is greatly simplified, compared with a traditional tunnel type drying equipment with open fire, the scheme can meet the installation of multiple production lines in a smaller space, and the volume is greatly reduced; on the other hand, the scheme adopts a planar electromagnetic heating actuator, which breaks through the structure of a traditional annular or annular electromagnetic heating coil, the heating process realizes clean, low-heat and high-efficiency effects, and greatly improves the linear thin plate type aluminum strip online drying equipment of the traditional thin plate type aluminum strip online drying equipment, and has great application and promotion prospects. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a perspective structural schematic view of an embodiment of the present application.

[0014] Figure 2 is a front view of the embodiment shown. Figure 1

[0015] Figure 3 is a schematic view of a copper bar structure in an embodiment of the present application.

[0016] Figure 4 is a structural schematic view of a floating roller in an embodiment of the present application.

[0017] Figure 5 is a circuit schematic diagram of an embodiment of the present application. DETAILED DESCRIPTION

[0018] ​Embodiments of the present application are described below in the detailed description and illustrated in the accompanying drawings by using examples, which are intended to explain the present application, and should not be understood as limiting the present application.

[0019] In the description of the present application, the meaning of "a plurality of" is two or more, unless explicitly and specifically limited.

[0020] The present application adopts the self-heating mode of the aluminum strip to dry the surface of the aluminum strip. The principle is that high-frequency alternating current generates a high-frequency magnetic field through the magnetic field generating component 100. When the aluminum strip is in a high-frequency alternating magnetic field, an induced electromotive force will be generated in the aluminum strip according to Faraday's law of electromagnetic induction. Since the resistance of the conductor is very small, a strong induced current is generated. According to the Joule-Lenz law, the alternating magnetic field will make the current in the conductor tend to flow on the surface of the conductor, causing skin effect. The density of the instantaneous current is proportional to the frequency, the higher the frequency, the more serious the skin effect, the effective conductive area decreases, and the resistance increases, thereby rapidly heating the conductor. The aluminum strip will face many problems during the electromagnetic heating process, such as the aluminum strip used for the signboard is a thin plate structure with a thickness of 0.5-1.5mm. Generally, the traditional electromagnetic heating adopts a ring coil structure, and the required heating part is placed in the ring coil. The heating speed of the electromagnetic coil is very fast. Since the spatial distribution of the ring electromagnetic coil magnetic field is not uniform, the temperature difference of the aluminum strip heating part will be enlarged in a period of time. The temperature difference is easy to cause warping and deformation due to uneven internal thermal stress distribution, causing material damage or affecting the subsequent process. On the other hand, one of the advantages of electromagnetic drying is that the electromagnetic drying is rapid. The traditional electromagnetic drying is easy to cause local temperature to be too high, causing local oxidation discoloration, so that the subsequent material cannot be used. If the power is reduced to control the temperature, the drying is not enough due to the large surface area of the aluminum strip and the heat dissipation block, and the problem of water stains remaining in some areas.

[0021] In the present scheme, a cabinet type structure rack 400 is adopted, which includes a frame type cubic structure made of aluminum alloy profiles or shaped steel. The middle part of the frame type cubic structure is divided into an upper space 401 and a lower space 402 by a middle beam 403. The upper and lower spaces 402 are separated by the middle beam 403 and a partition plate 405. The copper bar 101 is located in the upper space 401, and a mounting back plate 407 is further provided in the middle part of the lower space 402. The upper space forms a space through which the aluminum strip passes.

[0022] The alternating current in the scheme is generated by an inverter circuit, which includes a three-phase full-bridge inverter circuit composed of IGBT, resonance capacitor 500 and transformer 600. Three-phase 380V 50HZ alternating current is rectified by thyristor, reactor, filter capacitor, converted into 530V smooth and stable direct current and used as the input circuit of the three-phase full-bridge inverter circuit. Then the 530V direct current is converted into high-frequency alternating current required by the load through IGBT module, resonance capacitor 500 and transformer 600. The high-frequency alternating current is induced by the secondary coil of the transformer 600 and transmitted to the copper bar 101. In order to control and set parameters, the scheme also includes an operation panel 700 installed on one side of the rack through a stand.

[0023] In the above or some embodiments, the copper bar 101 is fixed to the upper surface of the partition plate 405 through the insulating truss 404, which can be made of insulating engineering plastic. The copper bar 101 can be fixed to the insulating truss 404 through a clamp. The transformer 600 is fixedly installed on the upper surface of the bottom plate 406 of the lower space 402 and includes a resonance capacitor 500 above the transformer 600. The mounting back plate 407 is used to install the main control board, reactor, filter capacitor and thyristor module.

[0024] Unlike traditional electromagnetic induction heating, the magnetic field generating part 100 of the heating unit in the scheme includes a copper bar 101 arranged in a meandering or serpentine shape. The copper bar 101 is arranged in a plane, and its electromagnetic field distribution is in the form of a ring-shaped envelope along the arrangement direction of the copper bar 101. When the aluminum strip is heated, the aluminum strip as a plate structure passes through N electromagnetic fields at the same time. Its structure can be roughly in the form of a long strip region passing through an electromagnetic field along the arrangement direction of the copper bar 101, forming a structure similar to a strip region. The wrapped strip region generates an alternating electric field, and the disordered movement of electrons in the aluminum strip generates heat, forming a heating process. Since the copper bar 101 in the scheme is arranged in a meandering or serpentine shape, in fact, the alternating electromagnetic field formed by it can cover most of the area in the cross-sectional direction of the aluminum strip. Due to the fact that this structure cannot achieve full coverage, its heating speed is slower than that of the traditional ring-shaped electromagnetic induction heating coil.

[0025] In order to better realize the heating of the aluminum strip, and the control of the temperature during the heating process, including the temperature rising speed, the temperature rising amplitude control, also including the feeding channel for the aluminum strip to pass through, the temperature control unit includes a circulating channel at the position of the magnetic field generating component 100, the copper bar 101 is a hollow tubular structure, the copper bar 101 is connected to the container, the circulating pump through the external pipeline, forming a structure that the temperature control medium can circulate through the copper bar 101, the external pipeline, the container, the circulating pump, in order to realize the insulation between the copper bar 101 and the temperature control medium, the inner surface of the copper bar 101 is coated with an insulation layer 102, which can be in the form of a thermoplastic rubber liquid flowing through the pipeline to cover. The temperature control medium in the scheme can use water and other cooling liquids, the external pipeline and the copper bar can be connected through the connecting head to realize the communication, the container can use a water tank, which can be fixedly installed in the internal rack. It also includes a temperature acquisition unit for collecting the surface temperature of the copper bar 101 and the surface temperature of the aluminum strip passed through, and a temperature controller, the temperature controller sets and stores the standard value of the surface temperature of the copper bar 101 and the surface temperature of the aluminum strip, each temperature acquisition unit compares the temperature information with the standard value of the surface temperature of the copper bar 101 and the surface temperature of the aluminum strip, when the collected temperature is lower than or higher than the temperature standard value, the circulating pump power is increased to increase the flow of the temperature control medium, when the collected temperature is lower than the temperature standard value, the circulating pump power is reduced or maintained to reduce or maintain the flow of the temperature control medium, while the output power of the magnetic field generating component 100 is increased. The temperature acquisition unit includes a temperature sensor, which is arranged between the copper bar and the insulation truss, and also arranged in the area passed through by the aluminum strip, the temperature sensor can use a non-contact infrared temperature sensor, such as an OTP-638D2 infrared non-contact temperature sensor with a measurement range of-50-700.

[0026] The equipment of the scheme is used online, in order to keep the stability of feeding, and better fit the aluminum strip in the feeding process, the feeding channel includes a plurality of floating rollers 200 arranged along the feeding direction above, and also includes a horizontal arranged supporting plate below the floating rollers 200, the supporting plate floating rollers 200 form a space for the aluminum strip to pass between, in use, the aluminum strip passes between the floating rollers 200 and the supporting plate, the floating rollers 200 apply pressure to the aluminum strip, so that it completely fits the supporting plate, the supporting plate completely fits the copper bar 101, on the one hand, controls the cooperation of the alternating electric field generated by the aluminum strip and the copper bar 101, on the other hand, the copper bar 101 also generates auxiliary heat in the process of generating alternating electric field, the heat conduction performance of the supporting plate can be used to contact the copper bar 101 to realize uniform distribution of temperature, and the aluminum strip can further obtain uniform low temperature heating; when installed, the floating rollers 200 are movably installed at the rack 400, forming a structure for applying pressure to the passing aluminum strip, and the supporting plate is a structure fixed to the rack 400. In the above or some embodiments, the rack 400 includes a vertically placed mounting plate for mounting the floating rollers 200, the mounting plate is located on both sides of the copper bar 101, the mounting plate is provided with a "∪" groove matched with the shaft diameter of both ends of the floating roller 200, of course, the "∪" groove is rotatably connected with the floating roller 200, forming a structure of each floating roller 200 rolling the passing aluminum strip.

[0027] In order to further realize the uniform control of the temperature field in the aluminum strip drying process, and to more efficiently utilize the heat, in the above or some embodiments, the temperature control unit further includes a heat preservation unit above the copper bar 101 and a heat equalizing unit below the heat preservation unit; the heat preservation unit is composed of each floating roller 200, and the heat equalizing unit is composed of a supporting plate, and each of the floating roller 200 and the supporting plate is made of a non-metallic insulating material; each of the floating rollers 200 includes a cylindrical shell 201 made of ceramic material, and also includes a core column 202 inside the shell 201, the core column 202 and the inner wall of the shell 201 form a heating pipe 203 wound on the outer surface of the core column 202, the inlet and outlet of the heating pipe 203 are connected with the outside temperature control medium, forming a circulating inlet and outlet structure driven by a circulating power, each heating pipe can be connected in series with the water outlet of the copper bar, forming a structure that the water heated by the copper bar is used for auxiliary heating by the heating pipe, so that the self-heating of the copper bar is fully utilized; the inlets and outlets of the plurality of floating rollers 200 are connected to a multi-pipe distributor through flexible pipelines; the supporting plate is an aluminum oxide ceramic plate, and the supporting plate is tightly connected with the copper bar 101.

[0028] In the above or some embodiments, the shell 201 and the core column 202 are an integral ceramic structure, further comprising an end cover 204 sealing one end of the shell 201, the end cover 204 can be threadedly connected with the end of the shell 201, the support plate is made of alumina ceramic, the heating pipe 203 spirally wound on the outer periphery of the core column 202 is an integral structure, the end cover 204 is provided with a central hole for the water inlet end 205 and the water outlet end 206 of the heating pipe to pass through, the water inlet end 205 and the water outlet end 206 pass through a sleeve, the sleeve and the central hole are rotatably connected through a bearing, the water inlet end 205 and the water outlet end 206 extend to the outside and are connected with the water inlet and outlet ends 206 of the liquid distributor through joints, during use, the shell and the core column can be rotated to realize rolling and pressing of the aluminum strip; the support plate is fixedly installed on the insulating truss 404 through bolts.

[0029] The scheme firstly adopts low-heat electromagnetic induction heating, the main structure is greatly simplified, compared with the traditional tunnel type drying equipment with open flame, it can meet the installation of multiple production lines in smaller space, and the volume is greatly reduced; on the other hand, the planar electromagnetic heating executive mechanism breaks through the structure of the traditional annular or annular electromagnetic heating coil, the heating process realizes the effect of cleanliness, low heat and high efficiency, greatly improves the linear of the traditional thin plate type aluminum strip online drying equipment, and has great application and promotion prospect.

Claims

1. An online low-heat electromagnetic drying device for aluminum strip, comprising a heating unit and a temperature control unit, the heating unit generates heat for drying water stains on the surface of the aluminum strip, and the temperature control unit is used to control the heating unit to maintain a suitable drying temperature, and further comprising a feeding channel for the aluminum strip to pass through, characterized in that: the heating unit comprises an electromagnetic drying actuator, and the electromagnetic drying actuator comprises a magnetic field generating component (100) for generating an alternating frequency electromagnetic field, wherein the magnetic field generating component (100) comprises a copper bar (101) arranged in a meandering or serpentine shape, and the copper bar (101) is electrically connected to an alternating frequency current input terminal to form a structure in which the copper bar (101) arranged in a meandering or serpentine shape generates an alternating frequency electromagnetic field; the temperature control unit comprises a circulation channel located at the position of the magnetic field generating component (100), the copper bar (101) is in a hollow tubular structure, and the copper bar (101) is connected to an external pipeline and a container through a circulating pump to form a structure in which a temperature control medium can circulate through the copper bar (101), the external pipeline, the container, and the circulating pump; further comprising a temperature acquisition unit for acquiring the surface temperature of the copper bar (101) and the surface temperature of the aluminum strip passing through, and further comprising a temperature controller, which sets and stores standard values of the surface temperature of the copper bar (101) and the surface temperature of the aluminum strip, and each temperature acquisition unit compares the acquired temperature information with the standard values of the surface temperature of the copper bar (101) and the surface temperature of the aluminum strip; the feeding channel comprises a plurality of floating rollers (200) arranged in a feeding direction above, and further comprises a horizontal supporting plate arranged below the floating rollers (200), and a space for the aluminum strip to pass through is formed between the supporting plate and the floating rollers (200); the floating rollers (200) are movably mounted at a rack (400) to form a structure for applying pressure to the passing aluminum strip, and the supporting plate is fixed to the rack (400); the temperature control unit further comprises a heat preservation unit located above the copper bar (101) and a heat equalization unit located below the heat preservation unit; the heat preservation unit is composed of the floating rollers (200), and the heat equalization unit is composed of the supporting plate, and the floating rollers (200) and the supporting plate are made of non-metallic insulating materials; each floating roller (200) comprises a cylindrical shell (201) made of ceramic material, and further comprises a core column (202) located inside the shell (201), and a heating pipe (203) is spirally wound on the outer surface of the core column (202) between the core column (202) and the inner wall of the shell (201), the inlet and outlet of the heating pipe (203) are connected to an external temperature control medium to form a circulating inlet and outlet structure driven by a circulating power; the inlets and outlets of the plurality of floating rollers (200) are connected to a multi-pipeline distributor through flexible pipelines; the supporting plate is an aluminum oxide ceramic plate, and the supporting plate is in close contact with the copper bar (101). ​ ​ The rack (400) includes vertically placed mounting plates for mounting the floating roller (200), which are located on both sides of the copper bar (101), and the mounting plates are provided with "∪" grooves matched with the shaft diameters of both ends of the floating roller (200), which are rotationally connected with the floating roller (200) to form a structure for rolling the aluminum strip.

2. The online low heat electromagnetic drying device for aluminum strip according to claim 1, characterized in that, When the collection temperature is higher than the temperature standard value, the circulating pump power is increased to increase the flow of the temperature control medium, and when the collection temperature is lower than the temperature standard value, the circulating pump power is reduced or maintained to reduce or maintain the flow of the temperature control medium, while the output power of the alternating frequency electromagnetic field of the magnetic field generating part (100) is increased.

3. The online low heat electromagnetic drying device for aluminum strip according to claim 2, characterized in that, The alternating frequency current is generated by an inverter circuit, which includes IGBT, resonance capacitor (500), transformer (600), three-phase 380V 50HZ alternating current is rectified by thyristor, reactor, filter capacitor, converted into 530V smooth and stable direct current, and then the 530V direct current is inverted into high-frequency alternating current required by the load by IGBT module, resonance capacitor (500), transformer (600).

4. The online low heat electromagnetic drying device for aluminum strip according to claim 3, characterized in that, The rack (400) includes a frame type cubic structure, the middle part of which is separated by a middle beam (403) to form an upper space (401) and a lower space (402), the upper space (401) and the lower space (402) are separated by the middle beam (403) and a partition (405), the copper bar (101) is located in the upper space (401), the copper bar (101) is fixed to the upper surface of the partition (405) through an insulating truss (404), the transformer (600) is fixedly installed on the upper surface of the bottom plate (406) of the lower space (402), and the resonance capacitor (500) is located above the transformer (600); the middle part of the lower space (402) is further provided with a mounting back plate (407), and the mounting back plate (407) is used for mounting a main control board, a reactor, a filter capacitor and a thyristor module.

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