Electric infrared heating furnace for steel reinforcement

Abstract

This invention relates to an electric infrared heating furnace for heating reinforcing bars, belonging to the technical field of infrared heating furnaces. An electric infrared heating furnace for heating reinforcing bars includes a frame, a tunnel-type oven mounted on the frame, a roller conveyor mounted on the frame and disposed within the oven, and electric infrared heating lamps disposed within the oven. The electric infrared heating lamps include an upper heating lamp disposed above the roller conveyor and a lower heating lamp disposed below the conveyor surface of the roller conveyor; furthermore, the upper and lower heating lamps are not symmetrically arranged vertically. This invention's electric infrared heating furnace solves the problem of low-magnetic metal materials being unable to be heated using medium-frequency induction heating; by employing a through-type roller conveyor, the length of the heated workpiece can be relatively long, effectively increasing production output.

Description

Technical Field

[0001] This invention relates to an electric infrared heating furnace, and more particularly to an electric infrared heating furnace for heating steel bars, belonging to the field of infrared heating furnace technology. Background Technology

[0002] In modern construction engineering and metal processing industries, steel reinforcement is a crucial basic building material, and its processing and usage efficiency directly impacts the progress and quality of the entire project. Traditional steel reinforcement heating methods often utilize fossil fuels such as coal and natural gas, which not only cause severe environmental pollution but also suffer from low heating efficiency and high energy consumption. Some commonly used heating methods, such as medium-frequency induction heating, offer the advantage of high heating efficiency. However, not all steel grades are suitable for medium-frequency induction heating. Some special steel grades have low magnetic permeability, making magnetic induction heating difficult and requiring alternative methods.

[0003] Electro-infrared heating technology has attracted attention due to its unique advantages. It utilizes electrical energy converted into infrared radiation energy to directly heat objects, perfectly solving the problem of low-magnetic materials being unable to be heated by medium frequency. It features rapid heating, high efficiency, ease of control, and environmental friendliness. However, existing electro-infrared heating equipment still has certain limitations in the application of steel reinforcement heating, such as insufficient heating uniformity, high energy consumption, and complex operation. These problems restrict the widespread application of electro-infrared heating technology in the field of steel reinforcement heating. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned problems by providing an electric infrared heating furnace for heating reinforcing bars. This electric infrared heating furnace solves the problem that low-magnetic metal materials cannot be heated using medium-frequency induction heating; it employs a through-type roller conveyor, allowing for relatively long heated workpieces and effectively increasing production output.

[0005] The technical solution of the present invention to solve the above problems is as follows:

[0006] An electric infrared heating furnace for heating steel bars includes a frame, a tunnel-type oven mounted on the frame, a roller conveyor mounted on the frame and disposed within the oven, and electric infrared heating lamps disposed within the oven. The electric infrared heating lamps include an upper heating lamp disposed above the roller conveyor and a lower heating lamp disposed below the conveyor surface of the roller conveyor. Furthermore, the upper heating lamp and the lower heating lamp are not symmetrically arranged vertically.

[0007] In existing technologies, rebar heating is generally performed before or after the spraying process. For some frames constructed by bending rebar, the rebar is bent first and then heated, often using large suspended heating spraying lines. This results in long heating cycles and relatively small production quantities per batch. Compared to large suspended lines, this invention has the advantages of requiring less floor space, having no restrictions on rebar length, and enabling continuous batch production.

[0008] As a preferred embodiment of the above technical solution, the upper heating lamp is suspended and installed on the upper wall of the oven via a lifting assembly.

[0009] As a preferred embodiment of the above technical solution, the lifting assembly includes a vertical rod penetrating the upper wall of the oven and an upper horizontal frame fixed based on the lower extension section of the vertical rod; the upper extension section of the vertical rod is a threaded section, and the lifting assembly further includes a height adjusting nut disposed on the threaded section; the upper heating lamp is disposed on the upper horizontal frame.

[0010] As a preferred embodiment of the above technical solution, the lower heating lamp is installed at the bottom of the oven via a fixing assembly.

[0011] As a preferred embodiment of the above technical solution, the fixing component includes a lower horizontal frame disposed at the bottom of the oven; the lower heating lamp is disposed on the lower horizontal frame.

[0012] As a preferred embodiment of the above technical solution, the electric infrared heating furnace further includes a jetting assembly, which includes a quick-connect air nozzle connector, a compressed air cooling section connected to the quick-connect air nozzle connector, and an air jet outlet disposed on the compressed air cooling section.

[0013] As a preferred embodiment of the above technical solution, the upper / lower cross frame is a hollow tubular structure, and the compressed air cooling section is composed of the upper / lower cross frame.

[0014] As a preferred embodiment of the above technical solution, the jet nozzle is located at the part of the upper / lower crossbeam that contacts the upper / lower heating lamp.

[0015] As a preferred embodiment of the above technical solution, the density of the electric infrared heating lamps gradually decreases according to the workpiece conveying direction.

[0016] Preferably, the oven is divided into five temperature sections. The first and second sections are arranged with 7 on top and 8 on the bottom, totaling 15 light panels; the third and fourth sections are arranged with 6 on top and 6 on the bottom, totaling 12 light panels; and the fifth section is arranged with 3 on top and 3 on the bottom, totaling 6 light panels.

[0017] During the heating of reinforcing bars, the layout of the infrared lamp array directly affects the uniformity of temperature distribution. An unreasonable configuration of the lamp spacing parameters can worsen the uniformity of temperature distribution on the heated surface. This device establishes a digital model to solve for the lamp spacing parameters that minimize temperature non-uniformity within the constraints, thereby optimizing the lamp array layout and improving the uniformity of temperature distribution.

[0018] As a preferred embodiment of the above technical solution, the oven is composed of multiple chamber units connected in series.

[0019] Preferably, each temperature range corresponds to one enclosure unit.

[0020] As a preferred embodiment of the above technical solution, the oven is provided with a lid, and the joint between the lid and the oven body is stepped.

[0021] As a preferred embodiment of the above technical solution, the joint includes at least two steps, and a sealing layer is provided on each step.

[0022] As a preferred embodiment of the above technical solution, the cover is provided with a pull ring.

[0023] As a preferred embodiment of the above technical solution, the roller conveyor is equipped with a drive motor for every two adjacent rollers, and each drive motor is connected to the roller via a chain drive.

[0024] In summary, the present invention has the following beneficial effects:

[0025] This invention is mainly used for heating straight steel bars. It adopts a process of heating first, then spraying, and then bending. The whole structure adopts a roller conveyor type. The workpiece is heated from the moment it enters the furnace. The conveying speed is 0.8 to 3 meters per minute. When the workpiece comes out of the tail of the furnace, it has reached the required temperature.

[0026] The furnace body features a hollow structure with grooved roller conveyors inside. High-temperature bearings are installed on both sides of the roller conveyors, using chain drive to prevent direct heat transfer to the motor. The grooved roller conveyors are made of 2304 stainless steel, which has low thermal conductivity, resulting in a slower heating rate and high-temperature resistance, reducing the impact of bearing tension caused by thermal expansion and contraction. The outer shell of the furnace is welded from 1.5T stainless steel plates, while the interior four sides are made of mirror-finished stainless steel, effectively reflecting infrared radiation onto the workpiece. The inner cavity formed by the stainless steel plates is evenly filled with insulation cotton, up to 150mm thick. The furnace body adopts a segmented design, with observation windows on both sides of each segment. The top cover is designed to open, and it also has a small processing window, both for easy observation and maintenance.

[0027] The infrared lamp panels inside the furnace are arranged in a staggered pattern, denser at the front and sparser at the back. This forms the front section of the furnace body for heating and the rear section for insulation. The infrared lamp panels are divided into upper and lower layers, each assembled by bending components pressed onto two 40x40x1mm stainless steel square tube frames. Compressed air flows through these tubes, and the compressed air cools the lamp strip wiring harness at the contact point between the lamp panel and the tube, preventing damage from overheating. The upper lamp panel assembly also features height adjustment. It is welded to the stainless steel square tube frame by four screws. Through the insulation layer, the height of the upper infrared lamp assembly can be controlled by adjusting the nuts on the four screws and comparing them with a scale on the side. This allows for better reflection of radiant heat onto workpieces of different diameters. The control logic divides the lamp panel assembly into 10 zones. From the moment a workpiece enters the furnace, the lamp panels activate like a flowing light, turning on in advance when the workpiece reaches a specific zone to achieve the appropriate output power. After a workpiece passes a certain area, the lamp assembly will delay and reduce its power until the next workpiece arrives. By activating the lamp assembly at specific locations, the steel bars can be precisely heated while reducing energy consumption, thus achieving the goal of energy conservation and emission reduction. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention;

[0029] Figure 2 yes Figure 1 Sectional view along axis AA;

[0030] In the diagram, 1-frame, 2-tunnel oven, 3-roller conveyor, 8-cover, 9-pull ring;

[0031] 41-Upper heating lamp, 42-Lower heating lamp, 51-Vertical rod, 52-Upper crossbar, 53-Height adjustment nut, 61-Lower crossbar, 71-Quick-connect air nozzle connector, 81-Sealing layer, 82-Scale.

[0032] like Figures 1-2 As shown, an electric infrared heating furnace for heating steel bars includes a frame 1, a tunnel-type oven 2 mounted on the frame 1, a roller conveyor 3 mounted on the frame 1 and disposed within the oven, and electric infrared heating lamps disposed within the oven 2. The electric infrared heating lamps 4 include an upper heating lamp 41 disposed above the roller conveyor 3 and a lower heating lamp 42 disposed below the conveyor surface of the roller conveyor; furthermore, the upper heating lamp 41 and the lower heating lamp 42 are not symmetrically arranged vertically.

[0033] The oven 2 consists of five chamber units connected in series. The oven is divided into five temperature sections, each corresponding to one chamber unit. The density of the infrared heating lamps gradually decreases according to the workpiece conveying direction. Specifically, the first and second temperature sections have 15 lamps arranged in a 7-8 configuration (7 on top, 8 on the bottom); the third and fourth temperature sections have 12 lamps arranged in a 6-6 configuration (6 on top, 6 on the bottom); and the fifth temperature section has 6 lamps arranged in a 3-3 configuration (3 on top, 3 on the bottom).

[0034] Figure 1 The diagram shows the structural schematics of the third and fourth housings corresponding to the third and fourth temperature sections; the diagram clearly shows that the third and fourth temperature sections are respectively arranged with six lamp panels on top and six on the bottom, totaling twelve lamp panels.

[0035] like Figure 2 As shown, the upper heating lamp 41 is suspended on the upper wall of the oven via a lifting assembly. The lifting assembly includes a vertical rod 51 penetrating the upper wall of the oven and an upper horizontal frame 52 fixed based on the lower extension of the vertical rod. The upper extension of the vertical rod 51 is a threaded section, and the lifting assembly also includes a height adjusting nut 53 disposed on the threaded section. The upper heating lamp 41 is disposed on the upper horizontal frame 52. The lower heating lamp 42 is installed at the bottom of the oven via a fixing assembly. The fixing assembly includes a lower horizontal frame 61 disposed at the bottom of the oven. The lower heating lamp 42 is disposed on the lower horizontal frame 61. The electric infrared heating furnace also includes a jetting assembly, which includes a quick-connect air nozzle connector 71, a compressed air cooling section communicating with the quick-connect air nozzle connector 71, and an air jet outlet disposed on the compressed air cooling section. The upper horizontal frame 52 / lower horizontal frame 61 is a hollow tubular structure, and the compressed air cooling section is composed of the upper horizontal frame 52 / lower horizontal frame 61. The air jet is located at the point where the upper crossbeam 52 / lower crossbeam 61 contacts the upper heating lamp 41 / lower heating lamp 42. The oven 2 is equipped with a cover 8, and the joint between the cover and the oven body is stepped. The joint includes two steps, each step having a sealing layer 81. The cover 9 is equipped with a pull ring 9.

[0036] The roller conveyor 3 is equipped with a drive motor for every two rollers, and each drive motor is connected to the rollers via a chain drive.

[0037] This invention is mainly used for heating straight steel bars. It adopts a process of heating first, then spraying, and then bending. The whole structure adopts a roller conveyor type structure. The workpiece is heated from the moment it enters the furnace body. The conveying speed is 0.8 to 3 meters per minute. When the workpiece comes out of the tail of the furnace body, it has reached the required temperature.

[0038] The furnace body has a hollow structure with a grooved roller conveyor 3 installed inside. High-temperature bearings are installed on both sides of the roller conveyor 3, and chain drive is used to avoid direct heat conduction to the motor. The grooved roller conveyor 3 is made of 2304 stainless steel with low thermal conductivity, resulting in a slower heating rate and high temperature resistance, which can reduce the impact of bearing tension caused by thermal expansion and contraction. The outer shell of the furnace body is welded from 1.5T stainless steel plates, and the four internal surfaces are made of mirror-finished stainless steel, which can effectively reflect infrared radiation onto the workpiece. The inner cavity formed by the stainless steel plates is uniformly filled with insulation cotton with a thickness of up to 150mm. The furnace body adopts a segmented design, with observation windows on both sides of each segment. The top cover is designed to be openable, and the cover also has a small processing window, both for easy observation and maintenance.

[0039] The infrared lamp panels inside the furnace are arranged in a staggered pattern, denser at the front and sparser at the back. This forms the front section of the furnace body for heating and the rear section for insulation. The infrared lamp panels are divided into upper and lower layers, each mounted on two 40x40x1mm stainless steel square tube frames using bent components. Compressed air flows through these tubes, and the compressed air cools the lamp strip wiring harness at the contact point between the lamp panel and the tube, preventing damage from overheating. The upper lamp panel assembly is height-adjustable, welded to the stainless steel square tube frame by four screws. Through the insulation layer, the height of the upper infrared lamp assembly can be controlled by adjusting the nuts on the four screws and comparing them with the scale 82 on the side. This allows for better reflection of radiant heat onto workpieces of different diameters. The control logic divides the lamp panel assembly into 10 zones. From the moment a workpiece enters the furnace, the lamp panels activate like a flowing light, turning on in advance when the workpiece reaches a specific zone to achieve the appropriate output power. After a workpiece passes a certain area, the lamp assembly will delay and reduce its power until the next group of workpieces arrives. By activating the lamp assembly at specific locations, the steel bars can be heated precisely while reducing energy consumption, thus achieving the goal of energy conservation and emission reduction.

Claims

1. An electric infrared heating furnace for heating steel bars, comprising a frame (1), a tunnel-type oven (2) mounted on the frame (1), a roller conveyor (3) mounted on the frame (1) and disposed within the oven, and electric infrared heating lamps disposed within the oven; characterized in that: The electric infrared heating lamp (4) includes an upper heating lamp (41) disposed above the roller conveyor (3) and a lower heating lamp (42) disposed below the conveyor surface of the roller conveyor; and the upper heating lamp (41) and the lower heating lamp (42) are not symmetrically arranged. The upper heating lamp (41) is suspended and installed on the upper wall of the oven (2) by a lifting assembly; The lifting assembly includes a vertical rod (51) that penetrates the upper wall of the oven (2) and an upper crossbar (52) fixed based on the lower extension of the vertical rod; the upper extension of the vertical rod (51) is a threaded section, and the lifting assembly also includes a height adjusting nut (53) set on the threaded section; the upper heating lamp (41) is set on the upper crossbar (52). The electric infrared heating furnace also includes a jetting assembly, which includes a quick-connect air nozzle connector (71), a compressed air cooling section connected to the quick-connect air nozzle connector (71), and a jet nozzle disposed on the compressed air cooling section. The upper crossbeam (52) / lower crossbeam (61) is a hollow tubular structure, and the compressed air cooling section is composed of the upper crossbeam (52) / lower crossbeam (61); The jet nozzle is located on the part of the upper crossbeam (52) that contacts the upper heating lamp (41); or, the jet nozzle is located on the part of the lower crossbeam (61) that contacts the lower heating lamp (42).

2. An electric infrared heating furnace for heating reinforcing bars according to claim 1, characterized in that: The lower heating lamp (42) is mounted on the bottom of the oven by a fixing assembly.

3. An electric infrared heating furnace for heating reinforcing bars according to claim 2, characterized in that: The fixing assembly includes a lower crossbeam (61) based on the bottom of the oven; the lower heating lamp (42) is mounted on the lower crossbeam (61).

4. An electric infrared heating furnace for heating reinforcing steel according to claim 1, characterized in that: The density of the electric infrared heating lamps gradually decreases according to the workpiece conveying direction.

5. An electric infrared heating furnace for heating reinforcing steel according to claim 1, characterized in that: The oven (2) is composed of multiple box units connected in series.

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