Natural gas burner for zinc impregnation furnace

Abstract

The natural gas burner for the zinc impregnation furnace comprises an outer cylinder, an inner cylinder, an air sheet, an ignition electrode and a horn mouth, the outer cylinder is sleeved on the inner cylinder, the head of the inner cylinder is connected with the air sheet, the air sheet is located at the end of the outer cylinder, the side face of the end, away from the air sheet, of the outer cylinder is connected with an air inlet pipe, and the side face of the end, away from the air sheet, of the inner cylinder is connected with a natural gas inlet pipe. The horn mouth is connected with the outer barrel at the wind blade end of the outer barrel; chutes are uniformly distributed on the circumference of the wind blade and penetrate through the top surface and the bottom surface of the wind blade, and a natural gas hole is formed in the wind blade and is used for spraying natural gas; ignition electrodes are arranged on the outer sides of the wind blades and comprise a grounding electrode and two central electrodes, the grounding electrode is located in the center of the wind blades, and the two central electrodes are symmetrically located on the two sides of the grounding electrode. By changing the structure of the natural gas burner, the flame jetted by the natural gas burner is expanded and is contacted with the furnace pipe in a large area, so that the temperature difference in the furnace pipe is small, and the zinc impregnation quality of a workpiece is uniform.

Description

Technical Field

[0001] This application relates to the technical field of industrial kiln combustion devices, specifically to a natural gas burner for a zinc diffusion furnace. Background Technology

[0002] Zinc diffusion is a chemical heat treatment process in which zinc is diffused into the surface of a workpiece. Zinc diffusion on the surface of steel parts can significantly improve their resistance to atmospheric corrosion. On railway lines, many steel workpieces, such as track pads, rail spikes, and elastic clips, need to undergo zinc diffusion treatment to resist corrosion. After zinc diffusion, these workpieces need to undergo passivation treatment of the zinc diffusion layer.

[0003] Zinc diffusion of the workpiece is carried out in a zinc diffusion furnace. The zinc diffusion furnace currently used, such as the zinc diffusion furnace disclosed in Chinese Patent Application No. CN201920659761.6, includes a furnace body, a rotating support, a furnace liner, and a furnace liner drive device. The furnace body is provided with corresponding rotating supports on the front and rear sides. A furnace liner drive device is provided on the outer side of one of the rotating supports. The furnace liner drive device has a driving gear. The furnace liner includes a regular polygonal charging cylinder and a round shaft. The round shaft is fixedly provided at the center position of the regular polygonal charging cylinder on both sides of the furnace liner. A driven gear is provided on one end of the round shaft. After the furnace liner is placed on the rotating support, the square charging cylinder is located inside the furnace body. The round shaft passes through the furnace body, and the driven gear on the round shaft meshes with the driving gear of the furnace liner drive device.

[0004] This type of zinc plating furnace is heated by burning natural gas. Conventional natural gas burners, because the air vanes are located inside the outer cylinder and are some distance from the port of the outer cylinder, produce a thin flame. This thin flame directly affects the furnace shell, resulting in a small heating area. Due to the low density of the natural gas burners in the furnace body, the temperature is high where the furnace shell is in direct contact with the flame, while the temperature is low where the burners are farther from the flame. This causes a large temperature difference inside the furnace shell, resulting in a large error in the zinc plating quality of the workpiece. Workpieces closer to the flame have a thicker zinc plating thickness, while those farther away have a thinner zinc plating thickness. This situation cannot be fundamentally improved by simply adjusting the air intake of the natural gas burners. Utility Model Content

[0005] In view of this, this application provides a natural gas burner for a zinc diffusion furnace. By changing the structure of the natural gas burner, the flame ejected by the natural gas burner expands to form a disc-shaped flame, so as to make a large-area contact with the furnace shell, resulting in a small temperature difference inside the furnace shell and uniform zinc diffusion quality of the workpiece.

[0006] According to one aspect of this application, one embodiment provides a natural gas burner for a zinc diffusion furnace, including an outer cylinder, an inner cylinder, a fan blade, an ignition electrode, and a bell mouth. The outer cylinder is sleeved on the inner cylinder, the head of the inner cylinder is connected to the fan blade, the fan blade is located at the end of the outer cylinder, the side of the outer cylinder away from the fan blade is connected to an air inlet pipe, the side of the inner cylinder away from the fan blade is connected to a natural gas inlet pipe, and the bell mouth is connected to the outer cylinder at the fan blade end.

[0007] The wind vane has evenly distributed inclined grooves on its circumference, and the inclined grooves penetrate the top and bottom surfaces of the wind vane. The air ejected from the inclined grooves can form a vortex. The wind vane is provided with natural gas holes for ejecting natural gas.

[0008] An ignition electrode is provided on the outer side of the fan blade. The ignition electrode includes a ground electrode and a center electrode. The ground electrode is located at the center of the fan blade. There are two center electrodes, symmetrically located on both sides of the ground electrode.

[0009] In some embodiments, the flared mouth is made of high-temperature resistant metal or refractory material.

[0010] In some embodiments, the outer cylinder, inner cylinder, and fan blades are made of stainless steel.

[0011] In some embodiments, the inclination angle of the inclined groove on the wind vane is 45-75°.

[0012] In some embodiments, the number of inclined slots on the air blade is 12-36.

[0013] In some embodiments, the central axis of the natural gas holes on the air vane is located on the same conical surface, the natural gas holes are arranged in an inclined cone, and the cone half angle of the conical surface is 20-45°.

[0014] In some embodiments, the number of natural gas holes on the wind vane is half the number of inclined slots minus two, with the two minus two representing the positions occupied by the two center electrodes.

[0015] In some embodiments, the end of the inner cylinder is provided with a natural gas nozzle that is opposite to the natural gas hole on the air vane and is inserted into the natural gas hole of the air vane.

[0016] In some embodiments, the ground electrode of the ignition electrode is disc-shaped, and the center electrode is shaped like a plum blossom.

[0017] In some embodiments, an ignition electrode wire is connected to the ignition electrode, and the ignition electrode wire passes through the inner cylinder and the outer cylinder respectively.

[0018] The beneficial effects of this utility model are as follows:

[0019] 1. The present invention relates to a natural gas burner for a zinc diffusion furnace. The inclined groove on the circumference of the air vane cooperates with the inclined natural gas hole to form a whirlwind-shaped flame. After the expansion of the bell mouth, a large flame is formed, which can contact the surface of the furnace lining of the zinc diffusion furnace over a large area, effectively reducing the temperature difference inside the furnace lining.

[0020] 2. The natural gas burner for a zinc diffusion furnace of this utility model has a reasonable structural design, which not only achieves a large flame, but also allows natural gas and air to be fully mixed, resulting in high combustion efficiency. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 This is a front view of the fan blade and ignition electrode of this utility model;

[0023] Figure 3 This is a schematic diagram of the structure of the fan blade and ignition electrode of this utility model.

[0024] In the diagram: 1. Outer cylinder; 2. Inner cylinder; 3. Air vane; 31. Inclined groove; 32. Natural gas inlet; 4. Ignition electrode; 41. Grounding electrode; 42. Center electrode; 43. Ignition electrode wire; 5. Trumpet mouth; 6. Air inlet pipe; 7. Natural gas inlet pipe. Detailed Implementation

[0025] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0026] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments, and the operational steps involved in each embodiment can also be rearranged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the specification and drawings are only for clearly describing a particular embodiment and do not imply that they represent the necessary components and / or order.

[0027] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0028] The temperature inside the flame of a natural gas burner is about 800℃, while the temperature at the edge can reach 1300-1700℃.

[0029] Example:

[0030] Please refer to Figure 1 , Figure 2 and Figure 3 One embodiment provides a natural gas burner for a zinc diffusion furnace, including an outer cylinder 1, an inner cylinder 2, a fan blade 3, an ignition electrode 4, and a bell mouth 5.

[0031] The outer cylinder 1, inner cylinder 2, and fan blade 3 are all made of stainless steel, such as 304 or 316 stainless steel. The bell mouth 4 is made of refractory material, such as white corundum ceramic with a refractory temperature of 1700℃, or zirconia ceramic with a refractory temperature of 2000℃. The bell mouth can also be made of metal, such as a nickel-chromium alloy Cr20Ni80 used for making heating wires with a refractory temperature of 1200℃, or a titanium alloy with a refractory temperature of up to 1600℃. The shape of the bell mouth 5 is the same as or similar to the enlarged part of the Laval nozzle, or is part of a hyperbolic shape.

[0032] The outer cylinder 1 is fitted onto the inner cylinder 2. The head of the inner cylinder 2 is connected to the air vane 3. The air vane 3 is located at the end of the outer cylinder 1. The side of the outer cylinder 1 away from the air vane 3 is connected to the air inlet pipe 6. The side of the inner cylinder 2 away from the air vane 3 is connected to the natural gas inlet pipe 7. The flared mouth 5 is connected to the outer cylinder 1 at the end of the air vane 3.

[0033] The wind vane 3 has evenly distributed inclined grooves 31 on its circumference, which penetrate the top and bottom surfaces of the wind vane 3. The inclination angle of the inclined grooves 31 is 45-75°, and there are 24 inclined grooves 31. The air ejected from the inclined grooves 31 can form a cyclone. The wind vane 3 is provided with natural gas holes 32 for ejecting natural gas. The central axis of the natural gas holes 32 on the wind vane 3 is located on the same conical surface. The natural gas holes 32 are set at an inclined cone, and the cone half angle of the conical surface is 30°. There are 10 natural gas holes 32 on the wind vane 3, which meets the requirement of half the number of inclined grooves 31 minus 2. The two subtracted slots are the positions occupied by the two central electrodes 42.

[0034] An ignition electrode 4 is provided on the outer side of the fan blade 3. The ignition electrode 4 includes a ground electrode 41 and a center electrode 42. The ground electrode 41 is disc-shaped and made of 316 stainless steel. The ground electrode 41 is located at the center of the fan blade 3. The center electrode 42 is shaped like a plum blossom and made of nickel-chromium-aluminum. There are two center electrodes 42, symmetrically located on both sides of the ground electrode 41. An ignition electrode wire 43 is connected to the ignition electrode 4. The ignition electrode wire 43 passes through a high-temperature resistant insulating ceramic tube and connects to the ground electrode 41 and the center electrode 42 respectively. It passes through the inner cylinder 2 and the outer cylinder 1 respectively. The high-temperature resistant insulating ceramic tube also passes through the fan blade 3.

[0035] The end of the inner cylinder 2 is provided with a natural gas nozzle that is opposite to the natural gas hole on the air vane 3 and is inserted into the natural gas hole 32 of the air vane 3.

[0036] This utility model discloses a natural gas burner for a zinc diffusion furnace. Natural gas is ejected from the natural gas holes 32 of the air vane 3. Since the central axis of the natural gas holes 32 of the air vane 3 is located on the same conical surface, and the conical arrangement of the natural gas holes 32 is inclined, the ejected natural gas is sprayed in all directions and mixed with the cyclone air ejected from the inclined groove 31 of the air vane 3. After being ignited by the ignition electrode 4, it passes through the bell mouth 5, making the flame very large and forming a disc-shaped flame. The contact area between the disc-shaped flame and the surface of the zinc diffusion furnace is also very large. Without changing the number of natural gas burners in the zinc diffusion furnace, the disc-shaped flame ejected by the natural gas burner acts on the surface of the furnace, and the area in direct contact with the furnace surface is much larger than before, basically ten to twenty times larger, which greatly improves the temperature difference inside the furnace.

[0037] Through practical comparison, before modifying the natural gas burner, the temperature difference inside the furnace could reach approximately 60°C. To ensure proper zinc diffusion on the workpieces, the zinc diffusion temperature needed to be controlled at 450°C, which is far above the melting point of zinc (419.4°C). This resulted in zinc-dipped workpieces with uneven zinc layer thickness, varying by more than 20 micrometers. Furthermore, the excessively high temperature caused numerous zinc nodules to form on the surface of some workpieces, severely impacting their quality. After using the natural gas burner of this invention, the temperature difference inside the furnace was reduced to less than 15°C. Controlling the zinc diffusion temperature at 395°C reduced the difference in zinc layer thickness on the produced workpieces to less than 3 micrometers. Moreover, the zinc nodules formed on the surface of the zinc-dipped workpieces due to the high temperature were eliminated, and zinc diffusion at a lower temperature was achieved.

[0038] The above-described specific examples are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art to which this invention pertains can make various simple deductions, modifications, or substitutions based on the concept of this invention.

Claims

1. A natural gas burner for a zinc plating furnace, characterized in that: It includes an outer cylinder (1), an inner cylinder (2), a fan blade (3), an ignition electrode (4), and a bell mouth (5). The outer cylinder (1) is fitted onto the inner cylinder (2). The head of the inner cylinder (2) is connected to the fan blade (3). The fan blade (3) is located at the end of the outer cylinder (1). The side of the outer cylinder (1) away from the fan blade (3) is connected to the air inlet pipe (6). The side of the inner cylinder (2) away from the fan blade (3) is connected to the natural gas inlet pipe (7). The bell mouth (5) is connected to the outer cylinder (1) at the end of the fan blade (3). The wind vane (3) has evenly distributed inclined grooves (31) on its circumference. The inclined grooves (31) penetrate the top and bottom surfaces of the wind vane. The wind vane (3) is provided with natural gas holes (32). An ignition electrode (4) is provided on the outside of the wind vane (3). The ignition electrode (4) includes a ground electrode (41) and a center electrode (42). The ground electrode (41) is located at the center of the wind vane (3). There are two center electrodes (42), which are symmetrically located on both sides of the ground electrode (41).

2. The natural gas burner for a zinc diffusion furnace according to claim 1, characterized in that: The flared mouth (5) is made of high-temperature resistant metal or refractory material.

3. The natural gas burner for a zinc diffusion furnace according to claim 1, characterized in that: The outer cylinder (1), inner cylinder (2) and wind vane (3) are made of stainless steel.

4. A natural gas burner for a zinc diffusion furnace according to claim 1, characterized in that: The inclination angle of the inclined groove (31) on the wind vane (3) is 45-75°.

5. A natural gas burner for a zinc diffusion furnace according to claim 4, characterized in that: The number of inclined grooves (31) on the wind vane (3) is 12-36.

6. A natural gas burner for a zinc diffusion furnace according to claim 1, characterized in that: The central axis of the natural gas holes (32) on the wind vane (3) is located on the same conical surface. The natural gas holes (32) are set in an inclined cone shape, and the cone half angle of the conical surface is 20-45°.

7. A natural gas burner for a zinc diffusion furnace according to claim 6, characterized in that: The number of natural gas holes (32) on the wind vane (3) is half the number of inclined slots (31) minus 2, and the two subtracted slots are the positions occupied by the two center electrodes (42).

8. A natural gas burner for a zinc diffusion furnace according to claim 1, characterized in that: The end of the inner cylinder (2) is provided with a natural gas nozzle that is opposite to the natural gas hole (32) on the air vane (3) and is inserted into the natural gas hole (32) of the air vane (3).

9. A natural gas burner for a zinc diffusion furnace according to claim 1, characterized in that: The ground electrode (41) of the ignition electrode (4) is disc-shaped, and the center electrode (42) is plum blossom-shaped.

10. A natural gas burner for a zinc diffusion furnace according to claim 1, characterized in that: Ignition electrode (4) is connected to ignition electrode wire (43), which passes through the inner cylinder (2) and the outer cylinder (1) respectively.

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