Overspray steam collection device, vacuum coating device and method based on thermal gradient roller

Abstract

The present invention discloses an overspray steam collection device based on a thermal gradient roller, a vacuum coating device and a method, wherein the vacuum coating device comprises an overspray steam collection device, the overspray steam collection device comprises an upper collection tank and a lower collection tank with openings on the same side, and an upper thermal gradient roller assembly and a lower thermal gradient roller assembly located at the openings of the upper collection tank and the lower collection tank; the upper thermal gradient roller assembly comprises a plurality of first heating round rollers arranged obliquely from bottom to top and outwardly, and the lower thermal gradient roller assembly comprises a plurality of second heating round rollers arranged obliquely from top to bottom and outwardly; the plurality of first heating round rollers and the plurality of second heating round rollers are controlled to different temperatures to form a temperature gradient. In the present invention, a space with two ends contracted is formed between the upper thermal gradient roller assembly, the lower thermal gradient roller assembly and the substrate to prevent metal vapor from diffusing; the temperature gradient prompts the metal vapor to move to the two ends of the space, which can increase the chance of the metal vapor contacting and depositing on the substrate, thereby improving the deposition rate and yield rate of the metal vapor.

Description

Technical Field

[0001] The present application belongs to the field of vacuum coating technology, and specifically relates to an overspray steam collection device based on a thermal gradient roller, a vacuum coating device and a method. Background Art

[0002] Vacuum coating technology refers to the process of heating the metal to be plated under vacuum conditions so that it is deposited on the substrate in a gaseous state to form a coating. Continuous hot-dip galvanizing of strip steel is one of the applications of vacuum coating technology. The continuous hot-dip galvanizing process of strip steel mainly includes three processes: evaporation, transportation and spray coating of zinc vapor. During the spray coating process, zinc vapor is deposited on the surface of the metal substrate, and the oversprayed zinc vapor is also easy to condense in other areas of the vacuum chamber. This phenomenon reduces the recovery rate of zinc vapor on the one hand, and makes it difficult to clean the inner wall of the vacuum chamber on the other hand.

[0003] The Chinese patent application with publication number CN115679269A discloses a steam capture device, a vacuum coating device and a method for the unstable period of vacuum coating, wherein the zinc vapor capture device includes a zinc vapor capture device, which is arranged in the vacuum chamber of the vacuum coating device and between the nozzle and the steel plate, and the collecting groove on the zinc vapor capture device corresponds to the nozzle, and the collecting groove is used to collect zinc vapor. In the Chinese patent application, the zinc vapor capture device is only used to capture zinc vapor in the unstable stage of vacuum coating, and still cannot avoid the diffusion of oversprayed zinc vapor during the coating process. The zinc vapor will still condense in the vacuum chamber and even diffuse to the vacuum lock, thereby reducing the yield rate of steel plate coating. Summary of the invention

[0004] The purpose of the present application is to provide an overspray vapor collection device, a vacuum coating device and a method based on a thermal gradient roller, wherein the overspray vapor collection device can avoid the diffusion of oversprayed metal vapor during the coating process and can also avoid the condensation of metal vapor in the vacuum chamber.

[0005] To achieve the above-mentioned purpose, the first aspect of the present application provides an overspray steam collection device based on a thermal gradient roller, comprising an upper collection trough and a lower collection trough opening on the same side, and an upper thermal gradient roller assembly and a lower thermal gradient roller assembly respectively located at the openings of the upper collection trough and the lower collection trough;

[0006] The upper thermal gradient roller assembly includes a plurality of first heating rollers arranged obliquely from bottom to top and outward, a plurality of first brush rollers respectively arranged on the inner side of each first heating roller, and a first driving unit; the roller diameters of the plurality of first heating rollers arranged from bottom to top decrease gradually and the temperatures are controlled to decrease gradually; the first brush rollers are used to brush away the sediment on the corresponding first heating rollers, and the brushed away sediment falls into the upper collecting tank;

[0007] The lower thermal gradient roller assembly includes a plurality of second heating rollers arranged obliquely from top to bottom and outward, a plurality of second brush rollers respectively arranged on the inner side of each second heating roller, and a second driving unit; the roller diameters of the plurality of second heating rollers arranged from top to bottom are gradually increased and the temperatures are controlled to be gradually decreased; the second brush rollers are used to brush away the sediment on the corresponding second heating rollers, and the brushed away sediment falls into the lower collecting tank;

[0008] The first driving unit is used to drive each first heating roller to rotate counterclockwise, and the second driving unit is used to drive each second heating roller to rotate clockwise.

[0009] In some specific embodiments, the number of first heating rollers is 3, which are recorded from bottom to top as the first near heating roller, the first transition heating roller, and the first collecting heating roller, and the roller diameters satisfy: R1=(1 / 2~2 / 3)R2, and R3=(1 / 2~2 / 3)R1; wherein R1, R2, and R3 are the roller diameters of the first transition heating roller, the first near heating roller, and the first collecting heating roller, respectively; the number of second heating rollers is 3, which are recorded from top to bottom as the second near heating roller, the second transition heating roller, and the second collecting heating roller, and the roller diameters satisfy: R4=(1 / 2~2 / 3)R5, and R5=(1 / 2~2 / 3)R6; wherein R4, R5, and R6 are the roller diameters of the second near heating roller, the second transition heating roller, and the second collecting heating roller, respectively.

[0010] In some specific embodiments, a first recovery guide plate and a first recovery chamber are provided in the upper collecting trough, one end of the first recovery guide plate is located below the upper thermal gradient roller assembly, and the sediments brushed off by the first brush roller just fall onto the first recovery guide plate and are transported to the first recovery chamber; a second recovery guide plate and a second recovery chamber are provided in the lower collecting trough, one end of the second recovery guide plate is located below the lower thermal gradient roller assembly, and the sediments brushed off by the second brush roller just fall onto the second recovery guide plate and are transported to the second recovery chamber.

[0011] As a preferred solution, the first recovery guide plate is tilted downward toward the first recovery chamber, and the angle between the first recovery guide plate and the horizontal direction is 3°-10°; the second recovery guide plate is tilted downward toward the second recovery chamber, and the angle between the second recovery guide plate and the horizontal direction is 30°-75°.

[0012] In some specific embodiments, in the upper thermal gradient roller assembly, the gap between adjacent first heated circular rollers is [0.1mm, 1mm], and the angle between the common tangent line of the outer side of the uppermost and lowermost first heated circular rollers and the horizontal direction is [45°, 90°]; in the lower thermal gradient roller assembly, the gap between adjacent second heated circular rollers is [0.1mm, 1mm], and the angle between the common tangent line of the outer side of the lowermost and uppermost second heated circular rollers and the horizontal direction is [45°, 90°].

[0013] A second aspect of the present application provides a vacuum coating device, comprising a vacuum chamber, and a steam generating unit, a steam delivery and injection unit, and an overspray steam collecting unit arranged in the vacuum chamber; the steam generating unit is used to heat metal to form metal vapor; the steam delivery and injection unit is used to deliver the metal vapor to a nozzle and inject it onto a moving substrate;

[0014] The overspray steam collection unit adopts the above-mentioned overspray steam collection device; the upper collection groove and the lower collection groove in the overspray steam collection device are respectively located above and below the steam delivery injection unit; the upper thermal gradient roller assembly and the lower thermal gradient roller assembly in the overspray steam collection device are respectively located above and below the nozzle outlet of the steam delivery injection unit.

[0015] In some specific embodiments, the distance between the uppermost first heated circular roller in the upper thermal gradient roller assembly and the substrate is [0.5mm, 3mm], and the distance between the lowermost second heated circular roller in the lower thermal gradient roller assembly and the substrate is also [0.5mm, 3mm].

[0016] A third aspect of the present application provides a vacuum coating method, which uses the above-mentioned vacuum coating device to vacuum coat a moving steel strip.

[0017] Further, the temperature gradient of the upper thermal gradient roller assembly and the lower thermal gradient roller assembly is controlled according to the moving speed of the strip. When the number of the first heating round roller in the upper thermal gradient roller assembly and the second heating round roller in the lower thermal gradient roller assembly is 3, the temperature gradient is set as follows:

[0018] When the moving speed of the strip steel is 10-50 m / min, the temperatures of the first heating round rollers arranged from bottom to top in the upper thermal gradient roller assembly are respectively controlled to be: 500°C-550°C, 400°C-500°C, 20°C-80°C; at the same time, the temperatures of the second heating round rollers arranged from top to bottom in the lower thermal gradient roller assembly are respectively controlled to be: 500°C-550°C, 400°C-500°C, 20°C-80°C;

[0019] When the moving speed of the strip steel is 51-100 m / min, the temperatures of the first heating round rollers arranged from bottom to top in the upper thermal gradient roller assembly are respectively controlled to be: 550℃-600℃, 450℃-550℃, 20℃-90℃; at the same time, the temperatures of the second heating round rollers arranged from top to bottom in the lower thermal gradient roller assembly are respectively controlled to be: 550℃-600℃, 450℃-550℃, 20℃-90℃;

[0020] When the moving speed of the strip steel is 100-200 m / min, the temperatures of the first heating round rollers arranged from bottom to top in the upper thermal gradient roller assembly are respectively controlled to be: 600℃-650℃, 550℃-600℃, 20℃-95℃; at the same time, the temperatures of the second heating round rollers arranged from top to bottom in the lower thermal gradient roller assembly are respectively controlled to be: 600℃-650℃, 550℃-600℃, 20℃-95℃;

[0021] When the strip moving speed is 200-300m / min, the temperatures of several first heating round rollers arranged from bottom to top in the upper thermal gradient roller assembly are respectively controlled to be: 650℃-700℃, 600℃-650℃, 20℃-100℃; at the same time, the temperatures of several second heating round rollers arranged from top to bottom in the lower thermal gradient roller assembly are respectively controlled to be: 650℃-700℃, 600℃-650℃, 20℃-100℃.

[0022] Compared with the prior art, this application has the following advantages and beneficial effects:

[0023] 1. An overspray steam collecting device is arranged at the nozzle of the vacuum coating device. The upper thermal gradient roller assembly and the lower thermal gradient roller assembly in the overspray steam collecting device are arranged to tilt outward to form a space with two ends contracted between the substrate. The oversprayed metal vapor is confined in the contracted space to prevent the metal vapor from diffusing everywhere. A temperature gradient is formed in the contracted space, with a higher temperature in the area close to the nozzle and a lower temperature in the area far from the nozzle, which promotes the metal vapor to move to the two ends far from the nozzle, increasing the chance of the metal vapor contacting and depositing on the metal substrate, thereby improving the deposition rate and recovery rate of the metal vapor.

[0024] 2. In the upper thermal gradient roller assembly and the lower thermal gradient roller assembly of the present application, the metal powder deposited on the surface of the heated round roller is brushed off by a brush roller and collected in the upper collecting tank and the lower collecting tank. The collected metal powder can be reused to avoid waste;

[0025] 3. It is simple to operate and requires little investment. It can be used as a set with vacuum coating technology and applied to vacuum coating of steel strips. It can improve the quality of vacuum coated steel strips and the recovery rate of metal vapor. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the specific structure of the vacuum coating device of this application;

[0027] Figure 2 It is a partial schematic diagram of a thermal gradient roller in the vacuum coating device of the present application;

[0028] Figure 3 A schematic diagram of the rotation direction of the heated round roller in the vacuum coating device of the present application;

[0029] In the figure, vacuum chamber 1, crucible 2, first heater 3, pipeline 4, nozzle 5, second heater 6, molten metal 7, metal vapor 8, substrate 9, metal coating 10, upper vacuum lock 11a, lower vacuum lock 11b, plate heater 12, upper collecting trough 13, first recovery guide 13a, first recovery chamber 13b, lower collecting trough 14, second recovery guide 14a, second recovery chamber 14b, first near heating roller 15a, first transition heating roller 15b, first collecting heating roller 15c, first brush roller 15d, second near heating roller 16a, second transition heating roller 16b, second collecting heating roller 16c, second brush roller 16d, and metal powder 17. DETAILED DESCRIPTION

[0030] The following will be combined with specific implementations and drawings to clearly and completely describe the technical solution of this application. Obviously, the specific implementation described is only a part of the implementation of this application, not all of the implementations. Based on the specific implementation of this application, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] Please refer to Figure 1 , which is a schematic diagram of the structure of a vacuum coating device in a specific embodiment. The vacuum coating device includes a vacuum chamber 1, and a steam generating unit, a steam conveying and spraying unit and an overspray steam collecting unit arranged in the vacuum chamber 1; the steam generating unit is used to heat the metal to form metal vapor; the steam conveying and spraying unit is used to convey the metal vapor to the nozzle and spray it onto the moving substrate to deposit on the surface of the substrate to form a metal coating.

[0032] In this specific embodiment, the steam generating unit includes a crucible 2 and a first heater 3 distributed outside the crucible 2; the steam conveying and spraying unit includes a pipe 4, a nozzle 5 connected to the outer end of the pipe 4, and a second heater 6 distributed outside the pipe 4 and the nozzle 5, and the inner end of the pipe 4 is connected to the crucible 2. The metal block is placed in the crucible 2 and heated to melt into a metal liquid 7. Under the action of high temperature, the metal liquid 7 further forms metal vapor 8, which is transported to the nozzle 5 through the pipe 4, and the metal vapor 8 is sprayed out through the nozzle 5 to form a metal coating 10 on the surface of the substrate 9.

[0033] Furthermore, the vacuum chamber 1 is also provided with an inlet and an outlet for the substrate 9 to enter and exit. Specifically, the inlet and the outlet are respectively provided at the top and the bottom of the vacuum chamber 1, and the inlet and the outlet are respectively provided with an upper vacuum lock 11a and a lower vacuum lock 11b, which are used to isolate the atmosphere from the vacuum chamber 1 to ensure the vacuum degree of the vacuum chamber 1. The substrate 9 enters the vacuum chamber 1 from the inlet at the top of the vacuum chamber 1, moves vertically to the spraying area, is coated in the spraying area, and the substrate 9 after coating is moved out from the outlet at the bottom of the vacuum chamber 1.

[0034] Furthermore, a plate heater 12 is provided in the vacuum chamber 1. The plate heater 12 is specifically provided on the non-coated side of the substrate 9 and is located above the spraying area, and is used to preheat the substrate 9 before the substrate 9 is moved to the spraying area.

[0035] The overspray steam collection unit in the present application is mainly used to prevent the metal vapor from spreading everywhere, increase the chance of the metal vapor contacting and depositing on the substrate, and capture and recover the oversprayed metal vapor. The overspray steam collection unit includes an upper collection tank 13 and a lower collection tank 14 respectively located above and below the pipe 4, and an upper thermal gradient roller assembly and a lower thermal gradient roller assembly respectively located above and below the nozzle 5 outlet; the upper collection tank 13 and the lower collection tank 14 are both provided with openings on the side facing the substrate 9, and the upper thermal gradient roller assembly and the lower thermal gradient roller assembly are respectively located at the openings of the upper collection tank 13 and the lower collection tank 14.

[0036] Furthermore, the upper thermal gradient roller assembly includes a plurality of first heating circular rollers arranged obliquely from bottom to top and outward, a plurality of first brush rollers 15d respectively arranged on the inner side of each first heating circular roller, and a first driving unit for driving the plurality of first heating circular rollers and the plurality of first brush rollers 15d to rotate; the roller diameters of the plurality of first heating circular rollers arranged from bottom to top decrease and the temperatures are controlled to decrease so as to form a temperature gradient; the first brush rollers 15d are used to brush off the metal powder 17 deposited on the surface of the corresponding first heating circular roller, and the brushed off metal powder 17 is collected into the upper collecting trough 13. In this specific embodiment, the number of first heating circular rollers is 3, which are recorded from bottom to top as the first near heating circular roller 15a, the first transition heating circular roller 15b, and the first collecting heating circular roller 15c; since the first near heating circular roller 15a, the first transition heating circular roller 15b, and the first collecting heating circular roller 15c are arranged to be inclined outward in sequence, the distance between the first near heating circular roller 15a, the first transition heating circular roller 15b, and the first collecting heating circular roller 15c and the substrate 9 decreases in sequence.

[0037] Furthermore, the lower thermal gradient roller assembly includes a plurality of second heating circular rollers arranged obliquely from top to bottom and outward, a plurality of second brush rollers 16d respectively arranged on the inner side of each second heating circular roller, and a second driving unit for driving the plurality of second heating circular rollers and the plurality of second brush rollers 16d to rotate; the roller diameters of the plurality of second heating circular rollers arranged from top to bottom increase gradually and the temperatures are controlled to decrease gradually to form a temperature gradient; the second brush rollers 16d are used to brush off the metal powder 17 deposited on the surface of the corresponding second heating circular roller, and the brushed off metal powder 17 is collected into the lower collecting tank 14. In this specific embodiment, the number of second heating circular rollers is 3, which are recorded from bottom to top as the second near heating circular roller 16a, the second transition heating circular roller 16b, and the second collecting heating circular roller 16c. Since the second near heating circular roller 16a, the second transition heating circular roller 16b, and the second collecting heating circular roller 16c are arranged to be inclined outward in sequence, the distance between the second near heating circular roller 16a, the second transition heating circular roller 16b, and the second collecting heating circular roller 16c and the substrate 9 decreases in sequence.

[0038] It should be noted that the heating round roller used in the present application is a prior art, and temperature control can be achieved by arranging an induction heating coil in the roller body of the heating round roller.

[0039] In the upper thermal gradient roller assembly, several first heating rollers are arranged obliquely from bottom to top and outward; in the lower thermal gradient roller assembly, several second heating rollers are arranged obliquely from top to bottom and outward; thus, a space with two ends contracted is formed between the heating rollers and the substrate 9, and the oversprayed metal vapor is constrained in the contracted space. At the same time, in the upper thermal gradient roller assembly, the temperatures of several first heating rollers arranged from bottom to top decrease successively; in the lower thermal gradient roller assembly, the temperatures of several second heating rollers arranged from top to bottom decrease successively; then a temperature gradient is formed in the contracted space, and the temperature of the area close to the nozzle 5 is higher, and the temperature of the area away from the nozzle 5 is lower. During the spray coating process, part of the metal vapor will experience reflection and / or turbulence, and thus leave the nozzle 5, and this part of the metal vapor will flow in the contracted space formed. Due to the temperature gradient, the metal vapor is prompted to move along the contracted space to the two ends away from the nozzle 5, and there are more opportunities to deposit on the substrate 9 again, thereby improving the deposition rate.

[0040] Furthermore, the temperature of the first near-heating roller 15a, the second near-heating roller 16a, the first transition heating roller 15b, and the second transition heating roller 16b located near the nozzle 5 should be controlled to be no lower than the condensation temperature of the metal vapor, so as to reduce or even avoid the condensation of the metal vapor near the nozzle 5; the temperature of the first near-heating roller 15a and the second near-heating roller 16a is controlled to be 500°C-700°C, and the temperature of the first transition heating roller 15b and the second transition heating roller 16b is controlled to be 400°C-650°C; the temperature of the first collecting heating roller 15c and the second collecting heating roller 16c located at the far end of the nozzle 5 is controlled to be no higher than 100°C, for example, 20°C-100°C, so that the metal vapor flowing here can be quickly condensed for recovery, thereby reducing or even avoiding the escape of metal vapor from the contraction space.

[0041] During the spray coating process, part of the metal vapor will condense onto the surface of the heated roller, and the metal powder on the surface will be removed by the brush roller inside the heated roller. Since the roller diameters of the heated rollers in the upper thermal gradient roller assembly and the lower thermal gradient roller assembly decrease gradually, the metal powder removed by the brush roller of the upper heated roller will fall onto the lower heated roller, and will be repeatedly removed by the brush roller of the lower heated roller, thereby achieving a better cleaning and collection effect.

[0042] In some specific embodiments, the roller diameters of the first near-heating roller 15a, the first transition heating roller 15b, and the first collecting heating roller 15c satisfy: R1=(1 / 2~2 / 3)R2, and R3=(1 / 2~2 / 3)R1; wherein R1 is the roller diameter of the first transition heating roller, R2 is the roller diameter of the first near-heating roller, and R3 is the roller diameter of the first collecting heating roller.

[0043] In some specific embodiments, the roller diameters of the second near-heating roller 16a, the second transition heating roller 16b, and the second collecting heating roller 16c satisfy: R4=(1 / 2~2 / 3)R5, and R5=(1 / 2~2 / 3)R6; wherein R4 is the roller diameter of the second near-heating roller, R5 is the roller diameter of the second transition heating roller, and R6 is the roller diameter of the second collecting heating roller.

[0044] As a preferred solution, the upper collecting tank 13 is provided with a first recovery guide plate 13a and a first recovery chamber 13b. The first recovery guide plate 13a is located behind the upper thermal gradient roller assembly. The metal powder 17 brushed off from the upper thermal gradient roller assembly falls onto the first recovery guide plate 13a and is transported to the first recovery chamber 13b. Specifically, the first near-heating round roller 15a is located above the outer end of the first recovery guide plate 13a, the first recovery chamber 13b is located at the inner end of the first recovery guide plate 13a, and the bottom end of the first recovery chamber 13b is lower than the first recovery guide plate 13a; the metal powder 17 brushed off from the first near-heating round roller 15a falls onto the first recovery guide plate 13a. In this specific embodiment, the first recovery guide plate 13a is a vibrating screen, which forms a vibration effect by reciprocating movement. Under the action of inertia, the metal powder 17 moves toward the first recovery chamber 13b and falls into the first recovery chamber 13b.

[0045] As a preferred solution, the lower collecting tank 14 is provided with a second recovery guide plate 14a and a second recovery chamber 14b. The second recovery guide plate 14a is located behind the lower thermal gradient roller assembly. The metal powder 17 brushed off from the lower thermal gradient roller assembly falls onto the second recovery guide plate 14a and is transported to the second recovery chamber 14b. Specifically, the second collecting and heating round roller 16c is located above the outer end of the second recovery guide plate 14a, the second recovery chamber 14b is located at the inner end of the second recovery guide plate 14a, and the bottom end of the second recovery chamber 14b is lower than the second recovery guide plate 14a; the metal powder 17 brushed off from the second collecting and heating round roller 16c falls onto the second recovery guide plate 14a. In this specific embodiment, the second recovery guide plate 14a is a vibrating screen, which forms a vibration effect by reciprocating movement. Under the action of inertia, the metal powder 17 moves toward the second recovery chamber 14b and falls into the second recovery chamber 14b.

[0046] As a further preferred solution, the first recovery guide plate 13a and the second recovery guide plate 14a are both arranged to be tilted downward to facilitate the metal powder 17 to fall into the recovery chamber.

[0047] See also Figure 2-3 , which is a partial schematic diagram of the upper thermal gradient roller assembly and the lower thermal gradient roller assembly in this specific embodiment. Figure 2-3 Preferred parameters for the upper thermal gradient roller assembly and the lower thermal gradient roller assembly are provided.

[0048] In the upper thermal gradient roller assembly and the lower thermal gradient roller assembly, adjacent heating rollers are close to each other but not in contact, and the gap d1 between adjacent heating rollers is: 0.1 mm≤d1≤1 mm;

[0049] The first collecting and heating circular roller 15c and the second collecting and heating circular roller 16c are close to the substrate 9 but not in contact with each other. The distance d2 between the first collecting and heating circular roller 15c and the second collecting and heating circular roller 16c and the substrate 9 is 0.5 mm ≤ d2 ≤ 3 mm.

[0050] A common tangent line is made between the outer sides of the first near heating roller 15a and the first collecting heating roller 15c, which is recorded as the first common tangent line; an external tangent line is made between the second near heating roller 16a and the second collecting heating roller 16c, which is recorded as the second common tangent line; both the first external tangent line and the second external tangent line are inclined toward the substrate 9; an angle A1 between the first external tangent line and the horizontal direction is: 45°≤A1≤90°; an angle A2 between the second external tangent line and the horizontal direction is: 45°≤A2≤90°;

[0051] The first recovery guide plate 13a is tilted downward, and its lower end is connected to the first recovery chamber 13b. The angle between the first recovery guide plate 13a and the horizontal direction is preferably 3°-10°; the second recovery guide plate 14a is tilted downward, and its lower end is connected to the second recovery chamber 14b. The angle between the second recovery guide plate 14a and the horizontal direction is preferably 30°-75°;

[0052] The heating rollers in the upper thermal gradient roller assembly and the lower thermal gradient roller assembly rotate in opposite directions. Specifically, the heating rollers in the upper thermal gradient roller assembly rotate counterclockwise, and the heating rollers in the lower thermal gradient roller assembly rotate clockwise, so as to guide the metal vapor toward the substrate 9; the rotation speed ω is: 10r / min≤ω≤60r / min; the brush roller and its corresponding heating roller rotate relative to each other, and the rotation speed is 200r / min-1000r / min;

[0053] The vibration frequency f1 of the first recovery guide plate 13a is 30-60 times / min; the vibration frequency f2 of the second recovery guide plate 14a is 20-40 times / min.

[0054] In this specific embodiment, the temperature gradient is set as follows:

[0055] When the moving speed of the substrate 9 is 10-50 m / min, the temperature ranges of the heating rollers in the upper thermal gradient roller assembly and the lower thermal gradient roller assembly in the direction away from the nozzle 5 are: 500°C-550°C, 400°C-500°C, 20°C-80°C respectively;

[0056] When the moving speed of the substrate 9 is 51-100 m / min, the temperature ranges of the heating rollers in the upper thermal gradient roller assembly and the lower thermal gradient roller assembly in the direction away from the nozzle 5 are: 550°C-600°C, 450°C-550°C, 20°C-90°C respectively;

[0057] When the moving speed of the substrate 9 is 100-200 m / min, the temperature ranges of the heating rollers in the upper thermal gradient roller assembly and the lower thermal gradient roller assembly in the direction away from the nozzle 5 are: 600°C-650°C, 550°C-600°C, 20°C-95°C respectively;

[0058] When the moving speed of the substrate 9 is 200-300 m / min, in the upper thermal gradient roller assembly and the lower thermal gradient roller assembly, the temperature ranges of the heating round rollers in the direction away from the nozzle 5 are: 650℃-700℃, 600℃-650℃, 20℃-100℃ respectively.

[0059] During the vacuum coating process, the moving speed of the substrate 9 is related to the flow rate of the injected metal vapor. The faster the moving speed, the larger the flow rate of the injected metal vapor. In this case, the temperature near the nozzle 5 needs to be increased to reduce the condensation of the metal vapor. On the contrary, the flow rate of the injected metal vapor is small, and the temperature near the nozzle 5 can be appropriately lowered.

[0060] Example 1

[0061] In this embodiment, the substrate is a steel strip, and the above device is used to evaporate zinc on the surface of the steel strip. The temperature of zinc vapor in the crucible is controlled to be 550°C, the moving speed of the steel strip is 30m / min, and the gap d1 between adjacent heating rollers is 0.2mm; the distance d2 between the first collecting heating roller, the second collecting heating roller and the steel strip is 1mm; the angle A1=50°, the angle A2=60°; the angle between the first recovery guide plate and the horizontal direction is 5°, and the angle between the second recovery guide plate and the horizontal direction is 40°; the rotation speed ω of each heating roller is 20r / min; the vibration frequency f1 of the first recovery guide plate is 40 times / min, and the vibration frequency f2 of the second recovery guide plate is 25 times / min; the temperature of the first near heating roller and the second near heating roller is controlled to be 510°C, the temperature of the first transition heating roller and the second transition heating roller is controlled to be 450°C, and the temperature of the first collecting heating roller and the second collecting heating roller is controlled to be 30°C.

[0062] Example 2

[0063] In this embodiment, the substrate is a steel strip, and the above device is used to evaporate zinc on the surface of the steel strip. The temperature of zinc vapor in the crucible is controlled to 650°C, the moving speed of the steel strip is 70m / min, and the gap d1 between adjacent heating rollers is 0.4mm; the distance d2 between the first collecting heating roller, the second collecting heating roller and the steel strip is 1.5mm; the angle A1=60°, the angle A2=65°; the angle between the first recovery guide plate and the horizontal direction is 7°, the angle between the second recovery guide plate and the horizontal direction is 50°, and the speed of each heating roller is 30r / min; the vibration frequency f1 of the first recovery guide plate is 50 times / min, and the vibration frequency f2 of the second recovery guide plate is 30 times / min; the temperature of the first near heating roller and the second near heating roller is controlled to 580°C, the temperature of the first transition heating roller and the second transition heating roller is controlled to 520°C, and the temperature of the first collecting heating roller and the second collecting heating roller is controlled to 40°C.

[0064] Example 3

[0065] In this embodiment, the substrate is a steel strip, and the above device is used to evaporate zinc on the surface of the steel strip. The temperature of zinc vapor in the crucible is controlled to 800°C, the moving speed of the steel strip is 180m / min, and the gap d1 between adjacent heating rollers is 0.5mm; the distance d2 between the first collecting heating roller, the second collecting heating roller and the steel strip is 2mm; the angle A1=60°, the angle A2=65°; the angle between the first recovery guide plate and the horizontal direction is 7°, the angle between the second recovery guide plate and the horizontal direction is 60°, and the rotation speed of each heating roller is 40r / min; the vibration frequency f1 of the first recovery guide plate is 50 times / min, and the vibration frequency f2 of the second recovery guide plate is 30 times / min; the temperature of the first near heating roller and the second near heating roller is controlled to 650°C, the temperature of the first transition heating roller and the second transition heating roller is controlled to 550°C, and the temperature of the first collecting heating roller and the second collecting heating roller is controlled to 40°C.

[0066] The device and method of the present application can be applied to vacuum coating of steel strips, can improve the quality of the vacuum coated steel strips and the recovery rate of zinc vapor, and can also realize the redeposition and collection of oversprayed zinc vapor. The present application has low investment, simple operation, and can be used in conjunction with vacuum coating technology.

[0067] Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may also include more other equivalent embodiments without departing from the concept of the present application, all of which belong to the protection scope of the present application.

Claims

1. An overspray steam collection device based on a thermal gradient roller, characterized by: It includes an upper collecting tank and a lower collecting tank with openings on the same side, and an upper thermal gradient roller assembly and a lower thermal gradient roller assembly respectively located at the openings of the upper collecting tank and the lower collecting tank; The upper thermal gradient roller assembly and the lower thermal gradient roller assembly include a near heating roller, a transition heating roller and a collecting heating roller, the distances from the substrate being successively decreased, wherein the near heating roller, the transition heating roller and the collecting heating roller in the upper thermal gradient roller assembly are arranged from bottom to top, and the near heating roller, the transition heating roller and the collecting heating roller in the lower thermal gradient roller assembly are arranged from top to bottom; the substrate is a substrate to be coated; The temperature of the near heating roller and the transition heating roller is controlled to be not lower than the condensation temperature of the metal vapor; the temperature of the collecting heating roller is controlled to be not higher than 100°C; The near heating roller, transition heating roller and collecting heating roller in the upper thermal gradient roller assembly are collectively referred to as the first heating roller, and the near heating roller, transition heating roller and collecting heating roller in the lower thermal gradient roller assembly are collectively referred to as the second heating roller; The upper thermal gradient roller assembly further includes a plurality of first brush rollers respectively arranged on the inner side of each first heating roller, and a first driving unit; the roller diameters of the plurality of first heating rollers arranged from bottom to top decrease and the temperatures are controlled to decrease; the first brush rollers are used to brush away the sediment on the corresponding first heating rollers, and the brushed away sediment falls into the upper collecting tank; The lower thermal gradient roller assembly further includes a plurality of second brush rollers respectively arranged on the inner side of each second heating roller, and a second driving unit; the roller diameters of the plurality of second heating rollers arranged from top to bottom are increased and the temperatures are controlled to decrease; the second brush rollers are used to brush away the sediment on the corresponding second heating rollers, and the brushed away sediment falls into the lower collecting tank; The first driving unit is used to drive each first heating roller to rotate counterclockwise, and the second driving unit is used to drive each second heating roller to rotate clockwise.

2. The overspray steam collecting device based on the thermal gradient roller according to claim 1, characterized in that: The number of the first heating round roller and the number of the second heating round roller are both 3.

3. The overspray steam collecting device based on the thermal gradient roller according to claim 2, characterized in that: The first heating roller in the upper thermal gradient roller assembly is sequentially recorded as the first near heating roller, the first transition heating roller, and the first collecting heating roller from bottom to top, and the roller diameter satisfies: R1=(1 / 2~2 / 3)R2, and R3=(1 / 2~2 / 3)R1; Among them, R1, R2, and R3 are the roller diameters of the first transition heating roller, the first near heating roller, and the first collecting heating roller respectively; The second heating round roller in the lower thermal gradient roller assembly is recorded as the second near heating round roller, the second transition heating round roller, and the second collecting heating round roller from top to bottom, and the roller diameters satisfy: R4=(1 / 2~2 / 3)R5, and R5=(1 / 2~2 / 3)R6; wherein R4, R5, and R6 are the roller diameters of the second near heating round roller, the second transition heating round roller, and the second collecting heating round roller, respectively.

4. The overspray steam collecting device based on the thermal gradient roller according to claim 1, characterized in that: The upper collecting tank is provided with a first recovery guide plate and a first recovery chamber, one end of the first recovery guide plate is located below the upper thermal gradient roller assembly, and the sediments brushed away by the first brush roller just fall onto the first recovery guide plate and are transported to the first recovery chamber; A second recovery guide plate and a second recovery chamber are provided in the lower collecting trough, one end of the second recovery guide plate is located below the lower thermal gradient roller assembly, and the sediments brushed off by the second brush roller just fall onto the second recovery guide plate and are transported to the second recovery chamber.

5. The overspray steam collecting device based on the thermal gradient roller according to claim 4, characterized in that: The first recovery guide is tilted downward toward the first recovery chamber, and the angle between the first recovery guide and the horizontal direction is 3°-10°; the second recovery guide is tilted downward toward the second recovery chamber, and the angle between the second recovery guide and the horizontal direction is 30°-75°.

6. The overspray steam collecting device based on the thermal gradient roller according to claim 1, characterized in that: In the upper thermal gradient roller assembly, the gap between adjacent first heating circular rollers is [0.1 mm, 1 mm], and the angle between the common tangent line of the outer side of the uppermost and lowermost first heating circular rollers and the horizontal direction is [45°, 90°]; In the lower thermal gradient roller assembly, the gap between adjacent second heating circular rollers is [0.1 mm, 1 mm], and the angle between the common tangent line of the outer side of the lowermost and uppermost second heating circular rollers and the horizontal direction is [45°, 90°].

7. A vacuum coating device, characterized in that: It comprises a vacuum chamber, and a steam generating unit, a steam conveying and spraying unit and an overspray steam collecting unit arranged in the vacuum chamber; the steam generating unit is used to heat metal to form metal vapor; the steam conveying and spraying unit is used to convey the metal vapor to a nozzle and spray it onto a moving substrate; The overspray steam collection unit is an overspray steam collection device as described in any one of claims 1 to 6; the upper collection groove and the lower collection groove in the overspray steam collection device are respectively located above and below the steam conveying injection unit; the upper thermal gradient roller assembly and the lower thermal gradient roller assembly in the overspray steam collection device are respectively located above and below the nozzle outlet of the steam conveying injection unit.

8. The vacuum coating device according to claim 7, characterized in that: The distance between the first heating circular roller at the upper end of the upper thermal gradient roller assembly and the substrate is [0.5 mm, 3 mm], and the distance between the second heating circular roller at the lower end of the lower thermal gradient roller assembly and the substrate is also [0.5 mm, 3 mm].

9. A vacuum coating method, characterized in that: The vacuum coating device according to any one of claims 7 to 8 is used to perform vacuum coating on a moving steel strip.

10. The vacuum coating method according to claim 9, wherein: Control the temperature gradient of the upper thermal gradient roller assembly and the lower thermal gradient roller assembly according to the moving speed of the strip: When the number of the first heating roller in the upper thermal gradient roller assembly and the second heating roller in the lower thermal gradient roller assembly is 3, the temperature gradient is set as follows: When the moving speed of the strip steel is 10-50 m / min, the temperatures of the first heating round rollers arranged from bottom to top in the upper thermal gradient roller assembly are respectively controlled to be: 500°C-550°C, 400°C-500°C, 20°C-80°C; at the same time, the temperatures of the second heating round rollers arranged from top to bottom in the lower thermal gradient roller assembly are respectively controlled to be: 500°C-550°C, 400°C-500°C, 20°C-80°C; When the moving speed of the strip steel is 51-100 m / min, the temperatures of the first heating round rollers arranged from bottom to top in the upper thermal gradient roller assembly are respectively controlled to be: 550℃-600℃, 450℃-550℃, 20℃-90℃; at the same time, the temperatures of the second heating round rollers arranged from top to bottom in the lower thermal gradient roller assembly are respectively controlled to be: 550℃-600℃, 450℃-550℃, 20℃-90℃; When the moving speed of the strip steel is 100-200 m / min, the temperatures of the first heating round rollers arranged from bottom to top in the upper thermal gradient roller assembly are respectively controlled to be: 600℃-650℃, 550℃-600℃, 20℃-95℃; at the same time, the temperatures of the second heating round rollers arranged from top to bottom in the lower thermal gradient roller assembly are respectively controlled to be: 600℃-650℃, 550℃-600℃, 20℃-95℃; When the strip moving speed is 200-300m / min, the temperatures of several first heating round rollers arranged from bottom to top in the upper thermal gradient roller assembly are respectively controlled to be: 650℃-700℃, 600℃-650℃, 20℃-100℃; at the same time, the temperatures of several second heating round rollers arranged from top to bottom in the lower thermal gradient roller assembly are respectively controlled to be: 650℃-700℃, 600℃-650℃, 20℃-100℃.

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