Radiant tube device and manufacturing method thereof

Abstract

The present invention relates to a radiant tube apparatus and method of manufacture thereof, which is installed in a heat treatment facility to perform heat treatment on strips. The radiant tube apparatus of the present invention includes a tube having an internal duct, and the tube has a first continuous pattern and a second continuous pattern located on its surface, extending parallel to each other at a predetermined distance apart. Each of the first continuous pattern and the second continuous pattern has a plurality of unit patterns connected in the longitudinal direction, each having a predetermined height from the surface.

Description

[Technical Field]

[0001] Cross-reference to related applications This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0169104 filed on December 17, 2019, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a radiant tube device that is arranged in a heat treatment facility to perform heat treatment on a material to be heat treated, and a method for manufacturing the same. [Background technology]

[0003] Metal materials processed by various methods such as casting, forging, rolling, and extrusion are heat treated at a specific temperature to achieve the desired strength and grain size, or they are passed through a heat treatment furnace maintained at a specific temperature for surface treatment.

[0004] Metal materials such as strips and plates can be oxidized by the oxygen present in the annealing furnace during heat treatment, so to prevent the formation of oxides, heat treatment is performed in an inert atmosphere such as nitrogen or argon, or in a vacuum. When heat treatment in an inert atmosphere or vacuum is required, an electric heating element can be used as the heat source, but the method using the heat generated by burning gas with a burner is suitable for heat treatment of large quantities of products at low cost. In this case, since a burner cannot be directly fired in an inert atmosphere without the oxygen necessary for gas combustion, a radiant tube with a burner attached is used.

[0005] Even in the case of general air atmosphere rather than an inert atmosphere, if a flame is directly injected, it may cause uneven heating and discoloration of the strip, so the flame generated from the burner circulates inside the radiant tube to heat it, and the strip is indirectly heated by the radiant heat emitted from the heated radiant tube. Radiant tubes can be manufactured by casting a tube shape using a casting method, or by forming a plate material into a tube shape and welding a bent tube and a straight tube together.

[0006] On the other hand, there have been attempts to increase the thermal efficiency of the radiant tube by forming cathode protrusions on the surface using a centrifugal casting method or by forming a pattern of multiple polygons on the surface of the radiant tube.

[0007] However, since the height of the cathode protrusion cannot exceed the surface thickness of the radiation tube, there is a limit to how much thermal efficiency can be improved. Also, since the polygons forming the patterns are arranged so that they share one side with adjacent polygons, the shapes that can be realized are limited, and since the patterns are formed intermittently, the productivity of continuous patterns that can be formed per unit time is reduced. Furthermore, when one pattern constituting a continuous pattern comes into contact with another pattern, the surface area that emits radiant heat is reduced by the contact area, which limits the increase in thermal efficiency and has been pointed out as a problem. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention provides a radiant tube device and a manufacturing method thereof, in which a plurality of continuous patterns formed in parallel at a predetermined distance from each other are printed on the surface of the radiant tube to increase the radiant heat emitting surface area. [Means for solving the problem]

[0009] According to one aspect of the present invention, a radiant tube device includes a tube having an internal duct, and a first continuous pattern and a second continuous pattern extending parallel to each other at a predetermined distance from each other are located on a surface of the tube, and each of the first continuous pattern and the second continuous pattern has a plurality of unit patterns connected in a longitudinal direction and having a predetermined height from the surface.

[0010] The tube may include a plurality of straight pipe sections extending linearly; and a curved pipe section connected to an end of the straight pipe section so that the plurality of straight pipe sections are positioned parallel to each other.

[0011] The first continuous pattern may be formed by connecting a plurality of first unit patterns, each of which is formed from one of the hypotenuse and vertical sides of a right-angled triangle, in a lengthwise direction to form a zigzag shape, and the second continuous pattern may be formed by connecting a plurality of second unit patterns, each of which is formed from a straight line, in a lengthwise direction to form a straight line.

[0012] The first continuous pattern may be formed by connecting a plurality of first unit patterns, each of which has two sides with a predetermined included angle, in the length direction to form a sawtooth shape, and the second continuous pattern may be formed by connecting a plurality of second unit patterns, each of which has a straight line, in the length direction to form a straight line.

[0013] Each of the first and second continuous patterns may be formed by connecting a plurality of unit patterns, each of which is formed from one of the hypotenuse and vertical sides of a right-angled triangle, in a lengthwise direction to form a zigzag shape, and the center of the unit pattern constituting the second continuous pattern may be shifted in parallel by a predetermined distance in the lengthwise direction from the center of the unit pattern constituting the first continuous pattern.

[0014] Each of the first continuous pattern and the second continuous pattern may be configured such that a plurality of unit patterns, each having two sides with a predetermined included angle therebetween, are connected in the longitudinal direction to form a sawtooth shape, and the center of the unit pattern constituting the second continuous pattern may be shifted in parallel by a predetermined distance in the longitudinal direction from the center of the unit pattern constituting the first continuous pattern.

[0015] The first continuous pattern may be formed by connecting a plurality of first unit patterns, each having three sides perpendicularly connected to the inside and one side perpendicularly connected to the outside, in a lengthwise direction to form a concave-convex shape, and the second continuous pattern may be formed by connecting a plurality of second unit patterns, each having a straight line, in a lengthwise direction to form a straight line.

[0016] Each of the first continuous pattern and the second continuous pattern may have a concave-convex shape formed by connecting a plurality of unit patterns in a length direction, each unit pattern having three sides perpendicularly connected to the inside and one side perpendicularly connected to the outside.

[0017] The first continuous pattern may be formed by connecting a plurality of first unit patterns in a lengthwise direction, each of which has three sides connected perpendicularly to the inside and one side connected perpendicularly to the outside, to form a concave-convex shape, and the second continuous pattern may be formed by connecting a plurality of second unit patterns in a lengthwise direction, each of which has three sides connected perpendicularly to the inside, to be positioned so as to intrude into the convexities of the first unit patterns at predetermined intervals.

[0018] The first continuous pattern may be formed by connecting a plurality of first unit patterns in a lengthwise direction, each of which has three sides perpendicularly connected to the inside and one side perpendicularly connected to the outside, to form a convex-concave shape, and the second continuous pattern may be formed by connecting a plurality of second unit patterns in a lengthwise direction, each of which has a first line and a second line perpendicularly connected to the first line, to be positioned inside the convexity of the first unit patterns at a predetermined interval.

[0019] Another feature of the present invention is a manufacturing method for a radiant tube device, which involves printing a first continuous pattern and a second continuous pattern extending parallel to each other at a predetermined distance apart on the surface of a tube having an internal channel using a three-dimensional modeling method to manufacture a radiant tube device according to any one of claims 1 to 10.

[0020] According to another feature of the present invention, a manufacturing method for a radiant tube device is to manufacture a radiant tube device according to any one of claims 1 to 10 by welding a first continuous pattern and a second continuous pattern extending parallel to each other at a predetermined distance apart on the surface of a tube having an internal duct using at least one method selected from CMT (Cold Metal Transfer), TIG (Tungsten Inert Gas) and MIG (Metal Inert Gas). [Effects of the Invention]

[0021] A radiant tube device and a manufacturing method thereof are provided that can improve the efficiency of radiant heat and increase the efficiency of heat treatment in an annealing furnace. [Brief explanation of the drawings]

[0022] [Figure 1] 1A-1C are diagrams illustrating the heat treatment of a strip passing through a heat treatment facility according to one embodiment. [Figure 2] 2 is a diagram illustrating an example in which a strip is heat-treated by radiant heat emitted from the radiant tube device of FIG. 1. FIG. [Figure 3] FIG. 2 is a diagram showing the radiation tube device of FIG. 1 in detail. [Figure 4] 2 illustrates one embodiment of a zigzag pattern located on the radiant tube surface of FIG. 1. FIG. [Figure 5] FIG. 5 is an image diagram showing the zigzag pattern of FIG. 4. [Figure 6] 2 illustrates one embodiment of a sawtooth pattern located on the radiant tube surface of FIG. 1. FIG. [Figure 7] 1. FIG. 4 illustrates another embodiment of a zigzag pattern located on the surface of the radiant tube of FIG. [Figure 8] 1. FIG. 4 illustrates another embodiment of a sawtooth pattern located on the surface of the radiant tube of FIG. [Figure 9] 2 is a diagram showing an embodiment of a concave-convex pattern located on the surface of the radiant tube of FIG. 1. FIG. [Figure 10] 1. FIG. 4 is a diagram showing another embodiment of the uneven pattern located on the surface of the radiant tube of FIG. [Figure 11] 1. FIG. 4 is a diagram showing another embodiment of the uneven pattern located on the surface of the radiant tube of FIG. [Figure 12] 1. FIG. 4 is a diagram showing another embodiment of the uneven pattern located on the surface of the radiant tube of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, the embodiments disclosed herein will be described in detail with reference to the accompanying drawings. Identical or similar components will be designated by the same or similar reference numerals, and redundant description thereof will be omitted. The suffixes "module" and / or "section" for components used in the following description are added or used interchangeably solely for the convenience of writing the specification, and do not have any distinct meanings or functions. Furthermore, in describing the embodiments disclosed herein, if it is determined that a detailed description of related prior art may obscure the gist of the embodiments disclosed herein, such a detailed description will be omitted. Furthermore, the accompanying drawings are merely intended to facilitate understanding of the embodiments disclosed herein, and the accompanying drawings should not be construed as limiting the technical ideas disclosed herein, and should be understood to include all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention.

[0024] Terms including ordinal numbers such as "first," "second," etc. may be used to describe various components, but the components are not limited by the terms. The terms are used only to distinguish one component from another.

[0025] When a component is said to be "coupled" or "connected" to another component, it should be understood that it may be directly coupled or connected to the other component, but that there may be other components in between. Conversely, when a component is said to be "directly coupled" or "directly connected" to another component, it should be understood that there are no other components in between.

[0026] In this application, the terms "comprise" or "have" and the like are intended to specify the presence of any feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood not to preclude the presence or possible addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0027] Figure 1 is a diagram explaining the heat treatment of a strip passing through a heat treatment equipment according to one embodiment, Figure 2 is a diagram explaining an example of a strip being heat treated by radiant heat emitted from the radiant tube device of Figure 1, Figure 3 is a diagram showing the radiant tube device of Figure 1 in detail, and Figures 4 to 12 are diagrams showing various examples of continuous patterns located on the surface of the radiant tube of Figure 1.

[0028] As shown in Fig. 1, a radiant tube device 100 performs heat treatment on a metal material (strip) S passing through a heat treatment furnace 1 maintained at a specific temperature for surface treatment. The radiant tube device 100 can be installed in the heat treatment furnace 1, but is not limited thereto, and can be installed in various other heat treatment facilities.

[0029] 2, a flame generated from a combustion nozzle (not shown) circulates inside the radiant tube device 100 to heat the radiant tube device 100, and the strip S is indirectly heated by radiant heat emitted from the heated radiant tube device 100. At this time, the combustion nozzle injects and burns gas, liquid, or powder fuel to heat the radiant tube device 100. For example, the combustion nozzle may include a burner, but is not limited thereto, and may include various combustion devices that can be installed in the radiant tube device 100. The strip S is a metal material processed by various methods such as casting, forging, rolling, and extrusion, and may include, for example, a steel plate.

[0030] 3, the radiant tube device 100 includes a tube 110 having an internal passage through which hot air heated by a flame passes. When the tube 110 is heated by the flame generated inside, it emits radiant heat to the outside to heat the low-temperature strip S. This prevents oxidation of the strip S.

[0031] The tube 110 may be formed in a U-shape including a plurality of straight pipe sections 111a, 111b:111 extending linearly and curved pipe sections 113 connected to the ends of the plurality of straight pipe sections 111a, 111b:111 so that the plurality of straight pipe sections 111a, 111b:111 are arranged parallel to one another. For example, the tube 110 may be formed in a U-shape or a W-shape depending on the size of the strip S and the heating temperature, but is not limited thereto.

[0032] The tube 110 includes a plurality of continuous patterns formed on its outer surface. This increases the surface area that emits radiant heat, thereby improving radiant heat efficiency. The higher the height of the continuous patterns, the greater the surface area and the higher the radiant heat efficiency. The optimum height can be set depending on the location where the radiant tube device 100 is installed and the distance to other adjacent equipment.

[0033] 4 to 12, the continuous pattern includes a first continuous pattern 300 and a second continuous pattern 400 that extend parallel to each other at a predetermined interval. Specifically, the first continuous pattern 300 and the second continuous pattern 400 are independent patterns that do not contact each other or share any sides, and extend parallel to each other at a predetermined interval.

[0034] Each of the first continuous pattern 300 and the second continuous pattern 400 may be formed by connecting a plurality of unit patterns having a predetermined height in the length direction from the outer surface of the tube 110. For example, the continuous pattern may be printed by an additive manufacturing method (hereinafter referred to as 3D printing) such as a directed energy deposition (DED) method, or an overlay welding method using cold metal transfer (CMT), tungsten inert gas (TIG), metal inert gas (MIG), or the like.

[0035] 4A is a diagram illustrating a first unit pattern 310 consisting of the hypotenuse and one of the vertical sides of a right triangle, (b) is a diagram illustrating a second unit pattern 410 consisting of a straight line, and (c) is an example diagram illustrating a first continuous pattern 300 in which a plurality of first unit patterns 310 are connected in the length direction to form a zigzag shape and a second continuous pattern 400 in which a plurality of second unit patterns 410 are connected in the length direction to form a straight line, printed in multiple numbers.

[0036] As shown in Figure 5, a plurality of first continuous patterns 300 and second continuous patterns 400 shown in Figure 4(c) can be formed on the outer surface of the tube 110. For example, when the continuous pattern shown in Figure 5 is formed on the outer surface of the tube 110 by cold metal transfer (CMT) welding, the height of the continuous pattern can be 3 mm or more and the height-to-thickness ratio of the continuous pattern can be 1.0 or more to improve radiant heat dissipation efficiency. Specifically, the diameter of the welding wire can be 0.6 mm to 1.5 mm, the welding current can be 70 A or more, the welding voltage can be 8 V to 12 V, the contact tip to work distance (CTWD) can be 10 mm to 40 mm, and the welding speed can be 0.3 m / min to 0.7 m / min. Furthermore, the first continuous pattern 300 and the second continuous pattern 400 are not limited to being formed by the CMT welding method, but may be formed by various welding methods such as TIG (Tungsten Inert Gas) or MIG (Metal Inert Gas).

[0037] For example, when 44 unit pattern pairs are printed on one radiant tube device 100 with a height of 3.34 mm to form the first continuous pattern 300 and the second continuous pattern 400 shown in Figures 4 and 5, the radiant heat emission efficiency is improved by 13.38% compared to a radiant tube device 100 with nothing printed on it. Compared to the radiant heat emission efficiency of a honeycomb pattern, which is improved by 8.6% compared to a radiant tube device 100 with nothing printed on it under the same conditions, the improvement in radiant heat of the first continuous pattern 300 and the second continuous pattern 400 is significant.

[0038] 4 and 5 may be formed in a form in which the first continuous pattern 300 and the second continuous pattern 400 are in contact with each other. That is, a point of the first continuous pattern 300 adjacent to the second continuous pattern 400 may be formed in a form in which the first continuous pattern 300 is directly connected to the second continuous pattern 400. A pattern in which the first continuous pattern 300 and the second continuous pattern 400 are partially in contact with each other improves the radiant heat emission efficiency by 12.2% compared to a radiant tube device 100 in which nothing is printed.

[0039] 6(a) is a diagram illustrating a first unit pattern 310 composed of two sides with a predetermined included angle θ°, (b) is a diagram illustrating a second unit pattern 410 composed of straight lines, and (c) is an example of a printed first continuous pattern 300 in which a plurality of first unit patterns 310 are connected in the length direction to form a sawtooth shape, and a plurality of second continuous patterns 400 in which a plurality of second unit patterns 410 are connected in the length direction to form a straight line. In this case, the predetermined included angle θ° can be any angle greater than 0° and less than 180°, and the same applies to the following description.

[0040] 7A is a diagram illustrating a first unit pattern 310 composed of the hypotenuse and one of the vertical sides of a right-angled triangle, (b) is a diagram illustrating a second unit pattern 410 composed of the hypotenuse and one of the vertical sides of a right-angled triangle and whose center is shifted a predetermined distance d in the longitudinal direction from the center of the first unit pattern 310, and (c) is an example diagram of a plurality of printed first continuous patterns 300 in which a plurality of first unit patterns 310 are connected in the longitudinal direction to form a zigzag shape, and a plurality of printed second continuous patterns 400 in which a plurality of second unit patterns 410 are connected in the longitudinal direction to form a zigzag shape. For example, the predetermined distance d can be set shorter than the horizontal spacing between the first unit patterns 310 and the second unit patterns 410, and the same applies in the following description.

[0041] 8A is a diagram illustrating a first unit pattern 310 consisting of two sides with a predetermined included angle θ°, (b) is a diagram illustrating a second unit pattern 410 consisting of two sides with a predetermined included angle θ° and whose center is shifted a predetermined distance d in parallel in the length direction from the center of the first unit pattern 310, and (c) is an illustrative diagram illustrating a first continuous pattern 300 in which a plurality of first unit patterns 310 are connected in the length direction to form a sawtooth shape, and a second continuous pattern 400 in which a plurality of second unit patterns 410 are connected in the length direction to form a sawtooth shape, printed in multiple numbers.

[0042] 9A is a diagram illustrating a first unit pattern 310 consisting of three sides connected vertically to the inside and one side connected vertically to the outside, (b) is a diagram illustrating a second unit pattern 410 consisting of straight lines, and (c) is an example diagram illustrating a first continuous pattern 300 in which a plurality of first unit patterns 310 are connected in the length direction to form an uneven shape, and a second continuous pattern 400 in which a plurality of second unit patterns 410 are connected in the length direction to form a straight line, printed in multiple numbers.

[0043] 10A and 10B are diagrams illustrating a first unit pattern 310 and a second unit pattern 410 configured such that one of the four sides constituting a quadrangle is extended perpendicularly to the outside of the adjacent other side, and FIG. 10C is an example diagram illustrating a first continuous pattern 300 in which a plurality of first unit patterns 310 are connected in the length direction to form a concave-convex shape, and a second continuous pattern 400 in which a plurality of second unit patterns 410 are connected in the length direction to form a concave-convex shape, printed in multiple numbers.

[0044] 11A is a diagram illustrating a first unit pattern 310 having three sides connected perpendicularly to the inside and one side connected perpendicularly to the outside, (b) is a diagram illustrating a second unit pattern 410 having three sides connected perpendicularly to the inside, and (c) is an example of a printed first continuous pattern 300 having a concave-convex shape formed by connecting a plurality of first unit patterns 310 in the length direction, and a second continuous pattern 400 having a plurality of second unit patterns 410 arranged discontinuously in the length direction so as to intrude into the convexities of the first continuous pattern 300 at predetermined intervals. In this case, the second unit patterns 410 can be arranged so as to intrude into the convexities of the first continuous pattern 300 at predetermined intervals within a range that does not contact the convexities of the first continuous pattern 300.

[0045] 12(a) is a diagram illustrating a first unit pattern 310 composed of three sides connected perpendicularly to the inside and one side connected perpendicularly to the outside, (b) is a diagram illustrating a second unit pattern 410 composed of a first line 411 and a second line 413 connected perpendicularly to an arbitrary position of the first line 411, and (c) is an example diagram of a first continuous pattern 300 in which a plurality of first unit patterns 310 are connected in the length direction to form a concave-convex shape, and a plurality of second continuous patterns 400 formed by connecting a plurality of first unit patterns 310 in the length direction with the second lines 413 positioned so as to intrude at predetermined intervals inside the convexities of the first continuous pattern 300. In this case, the second lines 413 of the second unit pattern 410 can be positioned so as to intrude at predetermined intervals inside the convexities of the first continuous pattern 300 without contacting them.

[0046] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited to these, and various modifications and improvements made by those skilled in the art to which the present invention pertains also fall within the scope of the present invention.

Claims

1. a tube having an internal conduit; a first continuous pattern and a second continuous pattern extending parallel to a length of the tube are positioned on a surface of the tube; the first continuous pattern includes a plurality of first unit patterns having a predetermined first height from the surface, the plurality of first unit patterns having a sawtooth shape with two sides having a predetermined included angle, and the first continuous pattern has a zigzag shape by being connected to each other in the length direction; the second continuous pattern includes a plurality of second unit patterns having a predetermined second height from the surface, the plurality of second unit patterns being linear and connected to each other in the length direction, so that the second continuous pattern forms a straight line; A radiant tube device, wherein the height of each of the first unit patterns and each of the second unit patterns is 3 mm or more, and the height / thickness ratio of the first unit patterns and the second unit patterns is 1.0 or more.

2. The tube a plurality of straight pipe sections extending in a straight line; and The radiant tube device according to claim 1 , further comprising a curved tube section connected to an end of the straight tube section so that the straight tube sections are positioned in parallel.

3. A manufacturing method for manufacturing the radiant tube device according to claim 1 or 2, by printing a first continuous pattern and a second continuous pattern extending parallel to each other at a predetermined distance apart on a surface of a tube having an internal channel using a three-dimensional modeling method.

4. 3. A method for manufacturing the radiant tube device according to claim 1 or 2, by welding a first continuous pattern and a second continuous pattern extending parallel to each other at a predetermined distance on the surface of a tube having an internal duct by at least one method selected from the group consisting of CMT (Cold Metal Transfer), TIG (Tungsten Inert Gas) and MIG (Metal Inert Gas).

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