Coating application device for glass tube

Abstract

At least one embodiment of the present disclosure provides a coating application apparatus for a glass tube, comprising: a coating cover defining a coating application space into which a glass tube is configured to be fed; a coating application assembly; and at least one outer circulation loop disposed outside the coating cover. Each external circulation loop comprises a loop inlet port and a loop outlet port which are respectively communicated with the coating application space; a blower for conveying fluid from the circuit inlet port to the circuit outlet port; an inlet duct separate from the coating cover and connecting the loop inlet port and the blower; and an outlet duct separate from the coating cover and connecting the loop outlet port and the blower. In order to ensure the uniformity of coating application, the coating cover of the coating application device for the glass tube is small in size. As the outer circulation loop is arranged outside the coating cover, the size of the coating cover cannot be increased, and the size of the coating cover can be reduced.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a coating application device for glass tubes. Background Art

[0002] Coatings such as hot-end coatings and cold-end coatings can be applied to glass articles to improve the performance of the glass articles. For example, coatings can be applied to glass articles to protect the glass articles from being scratched and reduce the likelihood of breakage during subsequent processes, thereby increasing the life cycle of the glass articles.

[0003] A device for applying a coating to a glass bottle includes a coating hood and a conveyor belt for conveying glass bottles one by one to the coating hood. The coating compound is usually supplied to the coating hood in a liquid form and then evaporated inside the coating hood. The surface temperature of the glass bottle exceeds 400 °C, so that when the coating compound is applied thereto, the coating compound immediately reacts and is converted into a metal oxide coating or the like.

[0004] Glass tubes can be prepared by a continuous pull-up process. For glass tubes, the coating hood of the coating application device for glass bottles has a large space, which will result in a large amount of heat loss during the coating process and uneven coatings on the surface of the glass tubes. Simply reducing the size of the coating hood cannot meet the layout size requirements of other components and still makes it difficult to achieve the uniformity of glass tube coating. Therefore, a coating application device is needed to uniformly apply a coating to a glass tube. Summary of the Utility Model

[0005] At least one embodiment of the present disclosure provides a coating application device, which includes: a coating hood that defines a coating application space having a hood inlet and a hood outlet, the coating application space having a longitudinal axis and being configured such that an object to be coated is advanced along the longitudinal axis from the hood inlet to the hood outlet; a coating application assembly for supplying a coating compound or its precursor to the coating application space, which includes a first supply port communicating with the coating application space; and at least one outer circulation loop provided outside the coating hood and closer to the hood outlet than the first supply port. Each outer circulation loop includes: a loop inlet port and a loop outlet port, which are respectively communicated with the coating application space; a blower for transporting a fluid from the loop inlet port to the loop outlet port; an inlet pipe separated from the coating hood and connecting the loop inlet port and the blower; and an outlet pipe separated from the coating hood and connecting the loop outlet port and the blower.

[0006] For example, in some embodiments, the object to be coated is a pipe fitting, and the coating application device is configured such that the pipe fitting extends along the longitudinal axis in the coating application space.

[0007] Preferably, in some embodiments, the object to be coated is a glass tube, and the coating application device is configured such that the glass tube extends along a longitudinal axis in the coating application space.

[0008] For example, in some embodiments, the coating application assembly further includes a second supply port that communicates with an inlet pipe or an outlet pipe of at least one of the outer circulation loops.

[0009] For example, in some embodiments, the coating application assembly includes a heater and a supply pipe. The heater heats the supply pipe to heat the coating compound or its precursor supplied through the supply pipe. In one embodiment, the coating application assembly further includes a controller configured to control the power supplied to the heater to maintain the heater at a predetermined temperature.

[0010] For example, in some embodiments, the heater is a metal heater that includes a body formed of metal, a channel formed in the body and in which a heating element is disposed, a hole formed in the body and in which a temperature sensor is disposed, and a groove disposed on the surface of the body or within the body and in which at least a portion of the supply pipe is fitted.

[0011] For example, in some embodiments, the coating application assembly is disposed outside the coating hood.

[0012] For example, in some embodiments, the coating application space can be divided into one or more segments of equal length along the longitudinal axis direction, and each segment includes an outer circulation loop.

[0013] For example, in some embodiments, the loop inlet port and the loop outlet port of each outer circulation loop have a length along the longitudinal axial direction that is 1 / 4 to 3 / 4, preferably 1 / 3 to 2 / 3, of the length of the segment along the longitudinal axis direction.

[0014] For example, in some embodiments, the coating application device includes one or more outer circulation loops. The loop inlet port of the outer circulation loop closest to the hood inlet is disposed at a position that is 1 / 6 to 1 / 2, such as 1 / 6, 1 / 5, 1 / 4, 1 / 3, 1 / 2, of the length of the coating application space from the hood inlet along the longitudinal axis direction. The loop outlet port of the outer circulation loop closest to the hood outlet is disposed at a position that is 1 / 6 to 1 / 2, such as 1 / 6, 1 / 5, 1 / 4, 1 / 3, 1 / 2, of the length of the coating application space from the hood outlet along the longitudinal axis direction.

[0015] For example, in some embodiments, the coating application device includes a plurality of outer circulation loops. In the direction of the longitudinal axis, the loop outlet port of the outer circulation loop closer to the hood inlet among two adjacent outer circulation loops is closer to the hood inlet or flush with the loop inlet port than the loop inlet port of the outer circulation loop closer to the hood outlet.

[0016] For example, in some embodiments, the coating application device includes a plurality of outer circulation loops, and the distance between the loop inlet port and the loop outlet port of each outer circulation loop is equal.

[0017] For example, in some embodiments, the coating hood includes a plurality of hood ports that communicate with the coating application space. The loop inlet port of the outer circulation loop is detachably connected to any one of the plurality of hood ports, and the loop outlet port of the outer circulation loop is detachably connected to any other one of the plurality of hood ports.

[0018] It can be understood that the number of hood ports is greater than or equal to the total number of loop inlet ports and loop outlet ports connected to the coating hood.

[0019] For example, in some embodiments, the number of hood ports is greater than the total number of loop inlet ports and loop outlet ports connected to the coating hood.

[0020] For example, in some embodiments, the coating application device further includes a waste discharge assembly, which includes: a discharge inlet that communicates with the coating application space and is arranged closer to the hood outlet than at least one outer circulation loop; a waste discharge blower; and a discharge pipe that connects the discharge inlet and the waste discharge blower.

[0021] For example, in some embodiments, in a cross-section of the coating hood perpendicular to the longitudinal axis, the maximum distance between any two points is not greater than 1.2 meters, preferably not greater than 0.8 meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present disclosure, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 Shows a schematic diagram of a coating application device according to an embodiment of the present disclosure;

[0024] Figure 2 Shows a schematic diagram of a coating application device according to another embodiment of the present disclosure;

[0025] Figure 3 Shows a schematic diagram of a coating application device according to still another embodiment of the present disclosure; and

[0026] Figure 4A and Figure 4B Show a side view and a top view of a heater in a coating application assembly according to an embodiment of the present disclosure, respectively. Detailed implementation manners

[0027] Next, a coating application device according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. To make the objectives, technical solutions, and advantages of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, of the embodiments of the present disclosure.

[0028] Therefore, the following detailed description of the embodiments of the present disclosure provided in conjunction with the accompanying drawings is not intended to limit the scope of the claimed present disclosure, but merely represents selected embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0029] Unless otherwise defined in the context, the singular forms include the plural forms. Throughout the specification, terms such as "including", "having", etc. are used herein to specify the presence of the described features, numbers, steps, operations, elements, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.

[0030] In addition, even though ordinal terms such as "first", "second", etc. are used to describe various components, these components are not limited by these terms, and these terms are only used to distinguish one element from other elements.

[0031] Figure 1 A schematic diagram of a coating application device according to an embodiment of the present disclosure is shown.

[0032] As Figure 1As shown, the coating application device includes a coating hood 110, a coating application assembly 120, an external circulation loop 130, and a waste discharge assembly 140. The coating hood 110 can be, for example, a thin-walled housing made of a material such as stainless steel. The coating hood 110 defines a coating application space 111 that extends in the longitudinal axis direction and has a hood inlet 112 and a hood outlet 113 that are opposite to each other in the longitudinal axis direction. The glass tube T produced in the continuous pulling process continuously extends and is continuously fed from the hood inlet 112 towards the hood outlet 113 into the coating application space 111, such that the extension direction of the glass tube T is substantially along the direction of the longitudinal axis of the coating application space 111. Thus, the glass tube T can be continuously and uniformly coated in the coating application space 111, which helps to cooperate with other steps of the continuous pulling process without causing interruption to other steps of the continuous pulling process. Hereinafter, "upstream" and "downstream" are defined with respect to the feeding direction of the glass tube T. Additionally, the coating application device may optionally further include a plurality of supports (not shown) for supporting the glass tube T in the coating application space 111, and a driver (not shown) for pushing the glass tube T to advance along the longitudinal axis.

[0033] The coating application assembly 120 is used to supply a coating compound or its precursor to the coating application space 111 and includes a first supply port 121 that communicates with the coating application space 111, and the first supply port 121 is provided near the hood inlet 112. In one example, the coating application assembly 120 may include a supply pipe 123, and the coating compound or its precursor to be applied, which is usually in liquid form, is transported into the coating application space 111 via the supply pipe 123. Since a high temperature is maintained in the coating application space 111, the applied coating compound or its precursor can be evaporated after being applied into the coating application space 111 to deposit on the surface of the glass tube T. In another example, the coating application assembly 120 may further include a heater 122, and the coating compound or its precursor to be applied is heated to a preset temperature range before entering the coating application space 111, which helps to improve the uniformity of the coating. The coating compound includes, but is not limited to, tin compounds, etc.

[0034] Figure 4A and Figure 4B respectively show a side view and a top view of the heater in the coating application assembly according to an embodiment of the present disclosure. As Figure 4A and 4BAs shown, in one embodiment, the heater 120 is a metal heater, including a body 1221 formed of metal, a channel 1222 formed within the body 1221 and into which a heating element (not shown) is inserted, a groove 1223 formed within one surface of the body 1221 and into which at least a portion of the supply pipe 123 is fitted, and a hole 1224 formed within the body 1221 and into which a temperature sensor (not shown) is inserted. The channel 1222 may penetrate the body, however, the present disclosure is not limited thereto. Heat from the heating element is propagated through the body 1221 to the supply pipe 123 to heat the coating compound or its precursor passing through the supply pipe 123. Additionally, the temperature of the heater is detected by the temperature sensor, and the temperature sensor sends a signal representing the detected temperature of the heating element to a controller (not shown). The controller controls the power supplied to the heater based on the detected temperature to maintain the heater at a predetermined temperature.

[0035] The outer circulation loop 130 is used to circulate the atmosphere in the coating application space 111. The outer circulation loop 130 is arranged outside the coating hood 110 and downstream of the first supply port 121, that is, closer to the hood outlet 113 than the first supply port 121. Different from coating application devices for applying coatings to articles such as glass bottles, the volume of the glass tube T is small. To ensure the uniformity of coating application, the volume of the coating hood 110 should match the diameter of the glass tube T and thus have a small volume. For example, in a cross-section of the coating hood perpendicular to its longitudinal axis, the maximum distance between any two points is not greater than 1.2 meters, for example, within the range of 0.1 - 1.2 meters, for example, not greater than 0.3, 0.4, 0.5, 0.6, 0.8, 0.9, 1.0, and 1.1 meters. The term "the maximum distance between any two points" should have the meaning commonly known in the art. For example, when the cross-section of the coating hood is semi-circular or circular, the maximum distance between any two points is the diameter of the semi-circle or circle. For example, when the cross-section of the coating hood is rectangular or square, the maximum distance between any two points is the length of the diagonal. However, simply reducing the volume of the coating hood 110 will result in no space for arranging a circulation loop or the like for circulating the gas inside the coating hood 110. In this embodiment, since the outer circulation loop 130 is arranged outside the coating hood 110, it will not increase the volume of the coating hood 110, which helps to reduce the volume of the coating hood 110 without affecting the number and position of the arranged circulation loops. The coating hood 110 may have a plurality of hood ports (not shown). Each outer circulation loop 130 includes a loop inlet port 131 and a loop outlet port 132 that are respectively connected to the coating application space 111 by detachably connecting to a hood port, a blower 133 for transporting the fluid from the loop inlet port 131 to the loop outlet port 132 for discharge, an inlet pipe 134 connecting the loop inlet port 131 and the blower 133, and an outlet pipe 135 connecting the loop outlet port 132 and the blower 133. In this example, the loop outlet port 132 is downstream of the loop inlet port 131, that is, closer to the hood outlet 113. Since the inlet pipe 134 and the outlet pipe 135 that are separated from the coating hood 110 respectively connect the coating application space 111 to the blower 133, rather than directly connecting the blower 133 to the coating application space 111 or arranging pipelines in the wall of the coating hood 110. Therefore, even if the volume of the coating hood 110 is small, a blower 133 with a large volume and the required pipes can be conveniently and flexibly arranged without causing an increase in the volume of the coating hood 110. Here, the inlet pipe 134 or the outlet pipe 135 being separated from the coating hood 110 means that the corresponding pipe is not arranged in the housing or the cavity of the housing of the coating hood 110, but extends outside the coating hood 110. In addition, the coating application assembly 120 is also arranged outside the coating hood 110 to further reduce the volume of the coating hood 110.

[0036] The waste discharge assembly 140 is used to discharge the evaporated coating compound into the exhaust gas treatment system to avoid pollution of the environment where the coating application device is located. The waste discharge assembly 140 includes a discharge inlet 141, a waste discharge blower 142, and a discharge pipe 143 connecting the discharge inlet 141 and the waste discharge blower 142. The discharge inlet 141 communicates with the coating application space 111 and is arranged downstream of the outer circulation loop 130, that is, closer to the hood outlet 113 than the outer circulation loop 130. In addition, the waste discharge assembly 140 sucks the gas in the coating application space 111, which helps to promote the flow of the gas in the coating application space 111, and thus helps to make the atmosphere in the coating application space 111 more uniform.

[0037] When the coating application device is operating, the coating compound or its precursor is continuously supplied to the coating application space 111 by the coating application assembly 120 via the first supply port 121. Figure 1 The dashed arrows in schematically show the flow path of the evaporated coating compound or its precursor. However, it should be understood that the coating compound or its precursor will be more evenly diffused into the coating application space 111. As Figure 1 shown by the solid arrows in, the glass tube T is continuously fed from the hood inlet 112 into the coating application space 111, and the evaporated coating compound or its precursor will contact the surface of the glass tube T, so as to deposit and decompose into a protective coating on the surface of the glass tube T. The outer circulation loop 130 transfers the atmosphere in the coating application space 111 from the upstream loop inlet port 131 to the downstream loop outlet port 132, so that the coating compound or its precursor in the atmosphere is more evenly distributed in the coating application space 111. Therefore, the coating formed on the glass tube T is more uniform. The glass tube T that has completed the coating process leaves the coating application space 111 of the coating hood 110 via the hood outlet 113. At the hood outlet 113, the remaining coating compound is discharged into the exhaust gas treatment system by the waste discharge assembly 140 to avoid pollution.

[0038] The number of the outer circulation loops 130 and the positions of the loop inlet port 131 and the loop outlet port 132 of the outer circulation loop 130, etc. can be adjusted according to the required parameter conditions.

[0039] In Figure 1 the illustrated embodiment, the coating application device includes only one outer circulation loop 130. The loop inlet port 131 is set at 1 / 6 to 1 / 2 of the entire length of the coating hood 110 from the hood outlet 113, and the loop outlet port 132 is set at 1 / 6 to 1 / 2 of the entire length of the coating hood 110 from the hood inlet 112. The distance from the loop inlet port 131 to the loop outlet port 132 is 1 / 3 to 2 / 3 of the entire length of the coating hood 110. This is conducive to forming a more uniform atmosphere in the coating application space 111. However, the present disclosure is not limited thereto.

[0040] In some embodiments, the coating application device may have a plurality of outer circulation loops 130, for example, two, three or more. For example, the coating application space 111 may be equally divided into a plurality of segments along the longitudinal axis direction, and one outer circulation loop 130 is provided in each segment. For example, the length of the loop inlet port 131 and the loop outlet port 132 of each outer circulation loop along the longitudinal axis direction is 1 / 4 to 3 / 4 of the length of the segment along the longitudinal axis direction, preferably 1 / 3 to 2 / 3. For example, the coating application space 11 may be equally divided into 2 segments along the longitudinal axis direction, and one outer circulation loop is provided in each segment, for a total of 2 outer circulation loops. The length of the loop inlet port and the loop outlet port of each outer circulation loop along the longitudinal axis direction is 1 / 8 to 3 / 8 of the length of the coating application space 111 along the longitudinal axis direction (i.e., 1 / 4 to 3 / 4 of the length of each 1 / 2 segment). Therefore, the uniform arrangement of the outer circulation loops 130 and the proper arrangement of the loop inlet port 131 and the loop outlet port 132 can help to achieve a uniform atmosphere in each segment of the coating application space 111.

[0041] In some embodiments, when the coating application device includes a plurality of outer circulation loops 130, in the direction of the longitudinal axis, the loop outlet port 132 of the outer circulation loop 130 that is closer to the hood inlet 112 among two adjacent outer circulation loops 130 is closer to the hood inlet 112 than the loop inlet port 131 of the outer circulation loop 130 that is closer to the hood outlet 113 or is flush with the loop inlet port 131 of the outer circulation loop 130 that is closer to the hood outlet 113. That is to say, the loop outlet port 132 of the outer circulation loop 130 that is closer to the hood inlet 112 among two adjacent outer circulation loops 130 is not closer to the hood outlet 113 than the loop inlet port 131 of the outer circulation loop 130 that is closer to the hood outlet 113. Such a configuration is beneficial to the uniformity of the atmosphere in the coating application space and is beneficial to the circulation efficiency of the outer circulation loop 130.

[0042] In some embodiments, the loop inlet port 131 of the outer circulation loop 130 that is closest to the hood inlet 112 of the coating application device is provided at a position that is 1 / 6 to 1 / 2 of the length of the coating application space along the longitudinal axis direction from the hood inlet 112, and the loop outlet port 132 of the outer circulation loop 130 that is closest to the hood outlet 113 is provided at a position that is 1 / 6 to 1 / 2 of the length of the coating application space along the longitudinal axis direction from the hood outlet 113.

[0043] In some embodiments, when the coating application device includes a plurality of outer circulation loops 130, the distance between the loop inlet port 131 and the loop outlet port 132 of each outer circulation loop 130 is equal.

[0044] In some embodiments, the coating hood 110 may be provided with redundant hood ports. The loop inlet port 131 and the loop outlet port 132 may be selectively and detachably connected to any one of the hood ports of the coating hood 110, respectively. For example, when there are multiple hood ports for the loop outlet port 132 to connect to, the loop outlet port 132 may be selectively connected to any one of these hood ports. Therefore, when parameters such as the moving speed of the glass tube, the size of the glass tube, and the inlet concentration of the coating compound or its precursor change, the positions of the loop inlet port 131 and the loop outlet port 132 of each outer circulation loop 130 relative to the coating hood 110 can be flexibly changed, and even the number of the outer circulation loops 130 can be flexibly adjusted to meet the uniformity requirements. The hood outlet 113 not connected to the loop inlet port 131 and the loop outlet port 132 may be detachably closed.

[0045] Figure 2 A schematic diagram of a coating application device according to another embodiment of the present disclosure is shown. For the sake of brevity, configurations that are the same as or similar to the Figure 1 coating application device shown will not be described in detail. Without contradiction, the descriptions of the coating application device and its components with reference to Figure 1 can be applied to the Figure 2 coating application device shown. As Figure 2 shown, the coating application device includes a coating hood 110, a coating application assembly 120, outer circulation loops 150, 160, and a waste discharge assembly 140. The coating hood 110 defines a coating application space 111 into which the glass tube T to be coated is fed. Different from the Figure 1 coating application device shown, Figure 2 the coating application device shown includes two circulation loops, namely a first outer circulation loop 150 and a second outer circulation loop 160, both of which are provided outside the coating hood 110. The two outer circulation loops 150, 160 are connected to Figure 1The outer circulation loop 130 shown is similarly arranged. The first outer circulation loop 150 includes a first loop inlet port 151, a first loop outlet port 152 downstream of the first loop inlet port 151, a first blower 153, a first inlet pipe 154 connecting the first loop inlet port 151 and the blower 153, and a first outlet pipe 155 connecting the first loop outlet port 152 and the blower 153. The second outer circulation loop 160 is integrally arranged downstream of the first outer circulation loop 160. The second outer circulation loop 160 includes a second loop inlet port 161, a second loop outlet port 162 downstream of the second loop inlet port 161, a second blower 163, a second inlet pipe 164 connecting the second loop inlet port 161 and the blower 163, and a second outlet pipe 165 connecting the second loop outlet port 162 and the blower 163. The first outer loop inlet port 151 is arranged at a position from 1 / 6 to 1 / 2 of the length of the coating application space 111 along the longitudinal axis direction from the hood inlet 112, and the second loop outlet port 162 is arranged at a position from 1 / 6 to 1 / 2 of the length of the coating application space 111 from the hood outlet 113.

[0046] For the two adjacent outer circulation loops 150, 160, the loop outlet port 152 of the outer circulation loop 150 closer to the hood inlet 112 is closer to the hood inlet 112 than the loop inlet port 161 of the outer circulation loop 160 closer to the hood outlet 113 or is flush with the loop inlet port 161 of the outer circulation loop 160 closer to the hood outlet 113.

[0047] The lengths of the loop inlet port 151 and the loop outlet port 152 of the outer circulation loop 150 along the longitudinal axial direction are 1 / 4 to 3 / 4 of the length of this section along the longitudinal axis direction, that is, 1 / 8 to 3 / 8 of the entire coating application space 111 along the longitudinal axis direction.

[0048] Wherein the lengths of the loop inlet port 161 and the loop outlet port 162 of the outer circulation loop 160 along the longitudinal axial direction are 1 / 4 to 3 / 4 of the length of this section along the longitudinal axis direction, that is, 1 / 8 to 3 / 8 of the entire coating application space 111 along the longitudinal axis direction.

[0049] The distance between the loop inlet port 151 and the loop outlet port 152 of the outer circulation loop 150 is equal to the distance between the loop inlet port 161 and the loop outlet port 162 of the outer circulation loop 160.

[0050] When the coating application device is operating, as Figure 2As shown by the dashed arrows in the figure, the first outer circulation loop 150 transfers the atmosphere in the coating application space 111 from the first loop inlet port 151 at the upstream to the first loop outlet port 152 in the middle. The second outer circulation loop 160 transfers the atmosphere in the coating application space 111 from the second loop inlet port 161 in the middle to the second loop outlet port 162 at the downstream. Therefore, the coating compound or its precursor in the atmosphere is more evenly distributed in the coating application space 111, and the coating formed on the glass tube T is more uniform.

[0051] Figure 3 FIG. shows a schematic diagram of a coating application device according to another embodiment of the present disclosure. For the sake of brevity, configurations that are the same as or similar to the Figure 1 coating application device shown will not be described in detail. Without contradiction, the description of the coating application device and its components can be applied to the Figure 1 coating application device shown. As Figure 3 shown, the coating application device includes a coating hood 110, a coating application assembly 170, an outer circulation loop 130, and a waste discharge assembly 140. The coating hood 110 defines a coating application space 111 into which the glass tube T to be coated is fed. The coating application assembly 170 includes a first supply port 171 connected to the coating application space 111, a supply pipe 173, and a heater 172. Different from the Figure 3 coating application device shown, the coating application assembly 170 further includes a second supply port 174 that is connected to the inlet pipe 134 of the outer circulation loop 130. Therefore, the chemical concentration of the coating compound in the atmosphere circulated through the outer circulation loop 130 can be increased. And when the first supply port 171 is blocked, the coating compound can be supplied using the second supply port 174. In addition, in this embodiment, the coating application device may further include a coating application blower 175 to increase the flow momentum of the chemicals. For example, the coating application blower 175 is connected between the heater 172 and the first supply port 171 on the supply pipe 173. As Figure 1 shown, the coating application device includes only one outer circulation loop 130. In a coating application device including multiple outer circulation loops 130, additional second supply ports 174 can be provided for connection to more outer circulation loops 130. Figure 3

[0052] The scope of the present disclosure is not limited by the embodiments described above, but is defined by the appended claims and their equivalent scope.​

Claims

1. A coating application device, characterized in that: include: a coating hood defining a coating application space having a hood inlet, a hood outlet, the coating application space having a longitudinal axis and the coating application device being configured such that an object to be coated is propelled along the longitudinal axis from the hood inlet to the hood outlet; a coating application assembly for supplying a coating compound or a precursor thereof to the coating application space, comprising a first supply port connected to the coating application space; as well as At least one external circulation loop, which is arranged outside the coating hood and closer to the hood outlet than the first supply port, each of the external circulation loops comprising: a loop inlet port and a loop outlet port, which are respectively connected to the coating application space; a blower for transferring fluid from the circuit inlet port to the circuit outlet port; an inlet duct separate from the coating hood and connecting the circuit inlet port and the blower; and An outlet duct is separated from the coating hood and connects the circuit outlet port and the blower.

2. The coating application device according to claim 1, characterized in that The object to be coated is a glass tube, and the coating application device is configured such that the glass tube extends along the longitudinal axis in the coating application space.

3. The coating application device according to claim 1, characterized in that The coating application assembly further includes a second supply port connected to the inlet pipe or the outlet pipe of at least one of the external circulation loops.

4. The coating application device according to claim 1, characterized in that The coating application assembly includes a heater and a supply conduit, the heater heating the supply conduit to heat the coating compound or a precursor thereof supplied through the supply conduit.

5. The coating application device according to claim 4, characterized in that The coating application assembly also includes a controller configured to control power supplied to the heater to maintain the heater at a predetermined temperature.

6. The coating application device according to claim 4, characterized in that The heater is a metal heater, which includes a body formed of metal, a channel formed in the body and in which a heating element is arranged, a hole formed in the body and in which a temperature sensor is arranged, and a groove arranged on the surface of the body or in the body and in which at least a portion of the supply pipe is fitted.

7. The coating application device according to claim 1, characterized in that The coating application assembly is disposed outside of the coating mask.

8. The coating application device according to claim 1, characterized in that The coating application space can be divided into one or more sections of equal length along the longitudinal axis direction, wherein each section includes an outer circulation loop, And wherein the length of the loop inlet port and the loop outlet port of each of the external circulation loops along the longitudinal axis direction is 1 / 4 to 3 / 4 of the length of the segment along the longitudinal axis direction.

9. The coating application device according to claim 8, characterized in that The length of the circuit inlet port and the circuit outlet port of each of the external circulation circuits along the longitudinal axis direction is 1 / 3 to 2 / 3 of the length of the section along the longitudinal axis direction.

10. The coating application device according to claim 1, characterized in that The coating application device includes one or more external circulation loops, the loop inlet port of the external circulation loop closest to the cover inlet is set at 1 / 6 to 1 / 2 of the length of the coating application space along the longitudinal axis direction from the cover inlet, and the loop outlet port of the external circulation loop closest to the cover outlet is set at 1 / 6 to 1 / 2 of the length of the coating application space along the longitudinal axis direction from the cover outlet.

11. The coating application device according to claim 1, characterized in that The coating application device includes multiple external circulation loops. In the direction of the longitudinal axis, the loop outlet port of the external circulation loop close to the hood inlet in two adjacent external circulation loops is closer to the hood inlet than the loop inlet port of the external circulation loop close to the hood outlet or is flush with the loop inlet port.

12. The coating application device according to claim 1, characterized in that The coating application device comprises a plurality of external circulation loops, and the distance between the loop inlet port and the loop outlet port of each external circulation loop is equal.

13. The coating application device according to claim 1, characterized in that The coating mask includes a plurality of mask ports connected to the coating application space, The circuit inlet port of the external circulation circuit is detachably connected to any one of the plurality of hood ports, and the circuit outlet port of the external circulation circuit is detachably connected to any other one of the plurality of hood ports.

14. The coating application device according to claim 13, characterized in that The number of the mask ports is greater than the total number of the circuit inlet ports and the circuit outlet ports connected to the coating mask.

15. The coating application device according to claim 1, characterized in that The coating application apparatus also includes a waste discharge assembly comprising: a discharge inlet connected to the coating application space and arranged closer to the hood outlet than the at least one external circulation loop; Waste discharge blowers; and A discharge duct connects the discharge inlet and the waste discharge blower.

16. The coating application device according to any one of claims 1 to 15, characterized in that In a cross section of the coating mask perpendicular to the longitudinal axis, the maximum distance between any two points is no greater than 1.2 meters.

17. The coating application device according to any one of claims 1 to 15, characterized in that In a cross section of the coating mask perpendicular to the longitudinal axis, the maximum distance between any two points is no greater than 0.8 meters.

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