Method for online elimination of roll build-up in roller hearth heat treatment furnace

Abstract

The present application belongs to the technical field of heat treatment furnace, and relates to a method for eliminating roller bed nodulation of roller bottom type heat treatment furnace online, which adopts a grinding roller steel plate to effectively eliminate the defects of the roller bed of the heat treatment furnace without fire-out and shutdown in the case that the temperature of the hearth of the heat treatment furnace is greater than 800 DEG C, according to the given furnace entry sequence and operation method and the friction between the grinding roller steel plate and the roller bed. The grinding roller steel plate comprises a herringbone groove steel plate, a narrow-thick steel plate and a wide-thick steel plate. The side of the herringbone groove steel plate in contact with the roller bed is provided with a plurality of herringbone grooves, and the other side is provided with a counterweight steel plate. The nodulation on the roller bed is polished by the herringbone grooves. The side of the narrow-thick steel plate and the wide-thick steel plate in contact with the roller bed is a plane with a sand blasting cleaning level of Sa2.5, and the roller bed is ground. The present application polishes the nodulation by the friction between the special steel plate and the roller bed, without shutdown, to realize safe and reliable and efficient removal of the nodulation of the roller bed, and to improve the surface quality of the steel plate of the heat treatment process.

Description

Technical Field

[0001] This invention belongs to the field of heat treatment furnace technology and relates to a method for online elimination of nodules on the roller conveyor of a roller hearth heat treatment furnace. Background Technology

[0002] During the production process of roller hearth heat treatment furnaces, iron oxide scale adheres to the furnace bottom rollers, forming "nodules." These nodules cause surface quality defects such as indentations and pitting on the heat-treated steel plates. Current methods for addressing this issue typically involve shutting down the furnace and allowing it to cool to room temperature before personnel re-enter to inspect and repair the nodules on the furnace rollers. This process is time-consuming, with shutdown times generally exceeding seven days, significantly impacting production efficiency. Furthermore, the confined space within the furnace poses inherent safety risks to personnel working on the furnace. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to solve the above problems and provide a method for online elimination of nodules on the roller conveyor of a roller hearth heat treatment furnace.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A method for eliminating nodules on the roller conveyor of a roller hearth heat treatment furnace is disclosed online. When the furnace temperature is >800℃, a grinding steel plate is used. The grinding operation is carried out according to a given furnace feeding sequence and operation method, utilizing the friction between the grinding steel plate and the roller conveyor. This effectively eliminates defects in the roller conveyor of the heat treatment furnace without shutting down the furnace.

[0006] Furthermore, the grinding roller steel plate includes a herringbone channel steel plate, a narrow thick steel plate, and a wide thick steel plate; the herringbone channel steel plate has multiple herringbone channels on one side that contacts the roller table, and a counterweight steel plate on the other side, which grinds the nodules on the roller table through the herringbone channels; the narrow thick steel plate and the wide thick steel plate have a surface sandblasting cleaning grade of Sa2.5 on the side that contacts the roller table, which grinds the roller table.

[0007] Furthermore, the herringbone channel steel plate is available in two sizes: 40mm×2550mm×11200mm and 45mm×2200mm×12000mm;

[0008] The counterweight steel plate is available in two sizes: 30mm×2500mm×11000mm and 35mm×2000mm×7000mm.

[0009] The narrow thick steel plate has dimensions of 60mm×2500mm×6000mm, and the wide thick steel plate has dimensions of 60mm×3500mm×6000mm.

[0010] A 30mm×2550mm×11200mm counterweight steel plate is attached to a 40mm×2500mm×11000mm herringbone channel steel plate, and a 35mm×2000mm×7000mm counterweight steel plate is attached to a 45mm×2200mm×12000mm herringbone channel steel plate.

[0011] The grinding rollers are fed into the furnace in the following order: 40mm×2550mm×11200mm herringbone channel steel plate, 45mm×2200mm×12000mm herringbone channel steel plate, narrow and thick steel plate, and wide and thick steel plate.

[0012] Furthermore, the operation method of the grinding roller is as follows: the heat treatment furnace operator sets the forward speed of the grinding roller steel plate in the furnace to 10m / min, and then loads the furnace at a speed of 10m / min; when the heat treatment furnace system's HMI main control interface detects the head of the grinding roller steel plate in the furnace, the furnace roller is adjusted to manual control mode and the speed is 5~10m / min.

[0013] Finally, the grinding roller steel plate is repeatedly ground 4 times between the roller tracks in the heating zone and the heat preservation zone of the furnace.

[0014] Furthermore, after the grinding rollers are completed, if the conditions for automatic unloading are met, the unloading is controlled normally through the HMI main control interface. If the conditions for automatic unloading are not met, the speed of the quenching machine and the speed of the roller conveyor in the furnace are manually matched for unloading.

[0015] The beneficial effects of this invention are as follows:

[0016] This invention provides an effective method for removing "nodules" from the furnace roller conveyor without shutting down the furnace. The method utilizes the friction between a specially designed steel plate and the roller conveyor to grind away the nodules. It eliminates the need for machine shutdown, achieving safe, reliable, and efficient removal of nodules from the roller conveyor, thereby improving the surface quality of the heat-treated steel plates.

[0017] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0019] Figure 1 This is a schematic diagram of the herringbone channel steel plate in this invention. Detailed Implementation

[0020] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0021] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0022] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0023] Steel plates undergoing heat treatment processes are loaded, shot blasted, turned over, heat treated, quenched, hot straightened, cooled, turned over again, sheared and sampled, sprayed (printed), surface inspected, collected and stacked, and then delivered to the warehouse after passing physical and chemical tests.

[0024] During the production process in a heat treatment furnace, iron oxide scale adheres to the furnace bottom rollers, forming "nodules." These nodules can cause surface quality defects such as indentations and pitting on the heat-treated steel plates, necessitating cleaning. The technical specifications of the roller hearth heat treatment furnace are as follows:

[0025] Heat treatment furnace type: Roller hearth heat treatment furnace with protective gas;

[0026] Applications of heat treatment furnaces: Heating of steel plates before normalizing, tempering, and quenching;

[0027] Specifications of heat-treated steel plates: thickness 6-80mm, width 1500-3800mm, length 6000-25000mm;

[0028] Maximum heat treatment temperature: 990℃; Maximum furnace temperature: 1050℃;

[0029] Fuel type: converter gas.

[0030] The technical parameters of the furnace bottom roller are as follows:

[0031] Furnace roller diameter: Φ380×30mm, roller body length: 4100mm, furnace roller spacing: 580mm, speed of furnace roller oscillation control: 0.8~3m / min, maximum oscillation distance of steel plate: 1491.5mm, roller body material: ZGCr25Ni35Nb.

[0032] A method for eliminating nodules on the roller conveyor of a roller hearth heat treatment furnace is proposed. In the case of the above-mentioned situation, when the furnace temperature is >800℃, a grinding roller steel plate is used. The grinding roller is operated according to a given furnace feeding sequence and operation method, utilizing the friction between the grinding roller steel plate and the roller conveyor. This effectively eliminates the defects in the roller conveyor of the heat treatment furnace without shutting down the furnace.

[0033] The grinding rollers are made of NM400 wear-resistant steel plates, including herringbone channel steel plates, narrow and thick steel plates, and wide and thick steel plates. The side of the narrow and thick steel plates that contacts the roller conveyor is a flat surface with a surface sandblasting cleaning grade of Sa2.5, used to grind the roller conveyor. The dimensions of the narrow and thick steel plates are 60mm × 2500mm × 6000mm, and the dimensions of the wide and thick steel plates are 60mm × 3500mm × 6000mm.

[0034] Please see Figure 1 The herringbone channel steel plate has multiple herringbone channels on one side that contacts the roller conveyor, and a counterweight steel plate is provided on the other side. The herringbone channels are used to grind off nodules on the roller conveyor. The herringbone channel steel plate is available in two sizes: 40mm×2550mm×11200mm and 45mm×2200mm×12000mm. The counterweight steel plate is available in two sizes: 30mm×2500mm×11000mm and 35mm×2000mm×7000mm.

[0035] Among them, the 40mm×2550mm×11200mm herringbone channel steel plate is equipped with a 30mm×2500mm×11000mm counterweight steel plate, and the 45mm×2200mm×12000mm herringbone channel steel plate is equipped with a 35mm×2000mm×7000mm counterweight steel plate.

[0036] The grinding rollers are fed into the furnace in the following order: 40mm×2550mm×11200mm herringbone channel steel plate, 45mm×2200mm×12000mm herringbone channel steel plate, narrow and thick steel plate, and wide and thick steel plate.

[0037] The operation method of the grinding roller is as follows: the heat treatment furnace operator sets the forward speed of the grinding roller steel plate in the furnace to 10m / min, and then loads the furnace at a speed of 10m / min; when the heat treatment furnace system's HMI main control interface detects the head of the grinding roller steel plate in the furnace, the furnace roller is adjusted to manual control mode and the speed is 5~10m / min.

[0038] Finally, the grinding roller steel plate is repeatedly ground 4 times between the roller tracks in the heating zone and the heat preservation zone of the furnace.

[0039] After the grinding rollers are completed, if the conditions for automatic unloading are met, the unloading should be controlled normally through the HMI main control interface. If the conditions for automatic unloading are not met, the quenching machine speed and the speed of the roller conveyor inside the furnace should be manually matched before unloading. When the automatic function is normal, manual unloading is strictly prohibited.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for online elimination of nodules on the roller conveyor of a roller hearth heat treatment furnace, characterized in that: When the furnace temperature in the heat treatment furnace is >800℃, grinding roller steel plates are used. The friction between the grinding roller steel plates and the roller conveyor is utilized to perform grinding operations according to a given furnace feeding sequence and operating method. The grinding roller steel plates include herringbone groove steel plates, narrow thick steel plates, and wide thick steel plates. The side of the herringbone groove steel plate that contacts the roller conveyor has multiple herringbone grooves, and the other side has a counterweight steel plate. The herringbone grooves are used to grind the nodules on the roller conveyor. The side of the narrow thick steel plate and the wide thick steel plate that contacts the roller conveyor is a flat surface with a surface sandblasting cleaning grade of Sa2.5, which grinds the roller conveyor. The herringbone channel steel plate is available in two sizes: 40mm×2550mm×11200mm and 45mm×2200mm×12000mm. The narrow thick steel plate has dimensions of 60mm×2500mm×6000mm, and the wide thick steel plate has dimensions of 60mm×3500mm×6000mm. A 30mm×2550mm×11200mm counterweight steel plate is attached to a 40mm×2500mm×11000mm herringbone channel steel plate, and a 35mm×2000mm×7000mm counterweight steel plate is attached to a 45mm×2200mm×12000mm herringbone channel steel plate. The order of feeding the grinding rollers into the furnace is as follows: 40mm×2550mm×11200mm herringbone channel steel plate, 45mm×2200mm×12000mm herringbone channel steel plate, narrow and thick steel plate, and wide and thick steel plate. The operation method of the grinding roller is as follows: the heat treatment furnace operator sets the forward speed of the grinding roller steel plate in the furnace to 10m / min, and then loads the furnace at a speed of 10m / min; when the heat treatment furnace system's HMI main control interface detects the head of the grinding roller steel plate in the furnace, the furnace roller is adjusted to manual control mode and the speed is 5~10m / min. Finally, the grinding roller steel plate is repeatedly ground 4 times between the roller tracks in the heating zone and the heat preservation zone of the furnace.

2. The method for online elimination of nodules on the roller conveyor of a roller hearth heat treatment furnace according to claim 1, characterized in that: After the grinding rollers are completed, if the conditions for automatic unloading are met, the unloading is controlled normally through the HMI main control interface. If the conditions for automatic unloading are not met, the speed of the quenching machine and the speed of the roller conveyor in the furnace are manually matched for unloading.

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