A waste heat recovery device for a roller hearth furnace

Abstract

This utility model relates to the field of roller hearth furnace technology and discloses a waste heat recovery device for roller hearth furnaces. The device includes a set of furnace rollers and a heat exchanger. Side insulation components are installed at both ends of the heat exchanger. A bottom insulation component is not located directly below the heat exchanger at the bottom of the furnace rollers. A preheating chamber is formed between the heat exchanger, the two side insulation components, and the bottom insulation component. This waste heat recovery device for roller hearth furnaces utilizes waste heat from exhaust gases to preheat the material before it enters the high-temperature furnace chamber. This significantly reduces the effective heat required to heat the material from room temperature to the target temperature within the furnace chamber. Furthermore, the preheating process is conducted in a relatively sealed space, reducing airflow and heat dissipation, which facilitates better, faster, and higher temperature preheating. The time required for the preheated material to reach the target process temperature after entering the furnace chamber is shortened, thus improving the overall heating efficiency and production efficiency of the roller hearth furnace.

Description

Technical Field

[0001] This utility model relates to the field of roller hearth furnace technology, and in particular to a waste heat recovery device for roller hearth furnaces. Background Technology

[0002] In the metal heat treatment industry, roller hearth furnaces, as a continuous heating device, are widely used in the heat treatment of workpieces such as plates and strips. Traditional gas-fired furnaces directly heat the materials inside the furnace by burning gas to generate high-temperature flue gas, but there is significant room for improvement in their energy utilization efficiency.

[0003] In the prior art, although some gas-fired heating furnaces are equipped with waste heat recovery devices, these devices are usually only used to preheat combustion air or heat boiler water, and have not yet formed a preheating scheme for the feed material itself.

[0004] The recovered waste heat is mainly used to preheat the combustion air, rather than directly using this high-grade waste heat to preheat the cold material itself. When the material enters the high-temperature furnace, it is usually at ambient temperature, requiring a large amount of effective heat in the furnace to heat it to the target temperature. Existing waste heat recovery schemes fail to address this huge energy demand, resulting in a large amount of medium- and high-grade waste heat being directly discharged or used only for preheating air at lower temperatures. This fails to achieve the more direct and effective energy-saving approach of preheating the cold material entering the furnace. Utility Model Content

[0005] Given that the existing waste heat is usually only used to preheat combustion air or heat boiler water, and no preheating scheme for the feedstock itself has been developed, this utility model is proposed.

[0006] Therefore, the purpose of this utility model is to provide a waste heat recovery device for a roller hearth furnace, the purpose of which is to preheat the material to be fed into the furnace using the high-temperature waste gas generated after combustion in the gas furnace.

[0007] To solve the above technical problems, the present invention provides the following technical solution: a waste heat recovery device for a roller hearth furnace, comprising a set of furnace rollers and a heat exchanger, wherein side insulation components are installed at both ends of the heat exchanger, and a bottom insulation component is not provided at the bottom of the furnace rollers directly below the heat exchanger, and a preheating cavity is formed between the heat exchanger, the two side insulation components and the bottom insulation component.

[0008] The heat exchanger includes a hollow frame, a cover plate is installed on the top of the hollow frame, and ventilation openings are provided on both sides and in the middle of the top of the cover plate. A heat exchange plate is installed below the interior of the furnace roller, and a heat exchange cavity is formed between the hollow frame, the cover plate and the heat exchange plate.

[0009] As an improved technical solution, an exhaust gas inlet pipe is fixed at the top of the cover plate, directly opposite the two side ventilation openings, and an exhaust gas outlet pipe is fixed at the top of the cover plate, directly opposite the central ventilation opening.

[0010] As an improved technical solution, a set of partition plates is fixed on both sides inside the heat exchange cavity. The two adjacent partition plates in the same set are staggered, and a guide channel is formed between the staggered partition plates in the same set.

[0011] As an improved technical solution, the side insulation component includes two rod seats installed on the top of the heat exchanger. A second electric push rod is installed on the top of the rod seats. A linkage block is fixedly connected to the drive end of the second electric push rod. An insulation baffle is installed between the two linkage blocks on the same side.

[0012] As an improved technical solution, the bottom of the heat-insulating baffle is provided with a roller groove adapted to the furnace roller, and the bottom of the heat-insulating baffle is integrally formed with a protrusion between two adjacent roller grooves.

[0013] As an improved technical solution, the bottom insulation component includes a first electric push rod, the movable end of which is fixedly connected to a lifting plate, and U-shaped frames are installed on both sides of the top of the lifting plate in a symmetrical and opposite state.

[0014] After adopting the above technical solution, the beneficial effects of this utility model are:

[0015] 1. In this utility model, the material sheet is located directly below the heat exchange plate, achieving a preheating effect on the material sheet. This allows the waste heat in the high-temperature exhaust gas to preheat the material sheet for a certain period of time, ensuring that the material sheet has a certain temperature before entering the furnace body. This reduces the heat required for subsequent furnace heating, saving energy and thus improving energy efficiency. Furthermore, the guiding channel formed by the partition plates in the same group extends the residence time of the high-temperature exhaust gas inside the heat exchange chamber, allowing for more effective and full utilization of the heat in the exhaust gas.

[0016] 2. In this utility model, the top of the lifting plate is attached to the outer wall of the furnace roller, and the U-shaped frame passes through the cavity between two adjacent furnace rollers and abuts against the bottom of the heat exchanger. The space between the two U-shaped frames on the same side is sealed with a heat-insulating baffle. At this time, the material is positioned in a relatively closed cavity, which reduces heat dissipation and helps to increase the temperature of the material in the preheating chamber. This further helps to reduce the heat required for subsequent heating of the material, thus improving the energy-saving effect. In addition, the roller groove and the protrusion are used to seal the cavity between the furnace roller and two adjacent furnace rollers, improve the airtightness of the preheating chamber, and reduce the heat dissipation inside.

[0017] 3. This utility model utilizes waste heat from exhaust gas to preheat the material sheets before they enter the high-temperature furnace, giving them a certain initial temperature. This significantly reduces the effective heat required to heat the material sheets from room temperature to the target temperature in the furnace, thereby directly reducing gas consumption and achieving significant energy savings. Furthermore, the preheating process is conducted in a relatively sealed space, reducing airflow and heat dissipation, which facilitates better, faster, and higher-temperature preheating. Additionally, the time required for the preheated material sheets to reach the target process temperature after entering the furnace is shortened, contributing to improved overall heating and production efficiency of the roller hearth furnace. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0019] Figure 1 This is a schematic diagram of the overall structure of a waste heat recovery device for a roller hearth furnace according to the present invention.

[0020] Figure 2 This is a schematic diagram showing the heat exchanger, side insulation component, and bottom insulation component of a waste heat recovery device for a roller hearth furnace in their separated states according to this utility model.

[0021] Figure 3 This is an exploded structural diagram of a heat exchanger for a waste heat recovery device for a roller hearth furnace according to the present invention.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1. Furnace roller; 2. Heat exchanger; 21. Hollow frame; 22. Cover plate; 23. Exhaust gas inlet pipe; 24. Exhaust gas outlet pipe; 25. Heat exchange plate; 26. Partition plate; 27. Guide channel; 3. Side insulation component; 31. Rod seat; 32. Second electric push rod; 33. Linkage block; 34. Insulation baffle; 35. Roller groove; 36. Protrusion; 4. Bottom insulation component; 41. First electric push rod; 42. Lifting plate; 43. U-shaped frame. Detailed Implementation

[0024] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Example 1

[0025] Reference Figures 1-3This is the first embodiment of the present invention, which provides a waste heat recovery device for a roller hearth furnace. This waste heat recovery device for a roller hearth furnace includes a set of furnace rollers 1 and a heat exchanger 2. The heat exchanger 2 is located above the furnace rollers 1. Side insulation components 3 are installed at both ends of the heat exchanger 2. A bottom insulation component 4 is provided at the bottom of the furnace rollers 1 and directly below the heat exchanger 2. A preheating cavity is formed between the heat exchanger 2, the two side insulation components 3 and the bottom insulation component 4.

[0026] The heat exchanger 2 includes a hollow frame 21, a cover plate 22 is installed on the top of the hollow frame 21, and ventilation openings are provided on both sides and in the middle of the top of the cover plate 22. A heat exchange plate 25 is installed in the lower part of the furnace roller 1. A heat exchange cavity is formed between the hollow frame 21, the cover plate 22 and the heat exchange plate 25.

[0027] When high-temperature exhaust gas enters the heat exchange chamber through exhaust gas inlet pipe 23, heat exchange plate 25 absorbs the heat from the waste heat. The material sheet is located directly below the heat exchange plate 25, achieving a preheating effect on the material sheet. This allows the waste heat in the high-temperature exhaust gas to preheat the material sheet for a certain period of time, so that the material sheet has a certain temperature before entering the furnace body, reducing the heat required for subsequent furnace heating, saving energy, and thus achieving the goal of improving energy efficiency.

[0028] An exhaust gas inlet pipe 23 is fixed at the top of the cover plate 22, directly opposite the two side ventilation openings, and an exhaust gas outlet pipe 24 is fixed at the top of the cover plate 22, directly opposite the central ventilation opening.

[0029] A set of partition plates 26 are fixed on both sides inside the heat exchange chamber. The two adjacent partition plates 26 in the same group are staggered. A guide channel 27 is formed between the staggered partition plates 26 in the same group. The guide channel 27 formed by the partition plates 26 in the same group will prolong the residence time of the high temperature exhaust gas inside the heat exchange chamber, and make more effective and full use of the heat in the exhaust gas. Example 2

[0030] Reference Figure 2 This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the side insulation component 3 includes two rod seats 31 installed on the top of the heat exchanger 2. A second electric push rod 32 is installed on the top of the rod seat 31, and the movable end of the second electric push rod 32 is located below the rod seat 31. A linkage block 33 is fixedly connected to the driving end of the second electric push rod 32. An insulation baffle 34 is installed between the two linkage blocks 33 on the same side.

[0031] The bottom of the heat insulation baffle 34 is provided with a roller groove 35 that is compatible with the furnace roller 1. The bottom of the heat insulation baffle 34 is integrally formed with a protrusion 36 between two adjacent roller grooves 35, and the protrusion 36 is located between two adjacent furnace rollers 1. The roller groove 35 and the protrusion 36 are used to seal the cavity between the furnace roller 1 and two adjacent furnace rollers 1, improve the airtightness of the preheating cavity, and reduce the heat loss inside.

[0032] The bottom insulation component 4 includes a first electric push rod 41, the movable end of which is fixedly connected to a lifting plate 42, and U-shaped frames 43 are installed on both sides of the top of the lifting plate 42 in a symmetrical and opposite state.

[0033] Positioning the material sheet within a relatively enclosed cavity reduces heat dissipation, which helps increase the temperature at which the preheating chamber heats the material sheet. This further reduces the heat required for subsequent heating of the material sheet, thus improving energy efficiency.

[0034] During operation, the waste heat from the exhaust gas is utilized to preheat the sheet material before it enters the high-temperature furnace, giving it a certain initial temperature. This significantly reduces the effective heat required to heat the sheet material from room temperature to the target temperature in the furnace, thereby directly reducing gas consumption and resulting in significant energy savings. At the same time, the sheet material is in a relatively sealed space during preheating, reducing air flow and heat dissipation, which facilitates better, faster, and higher temperature preheating. Furthermore, the time required for the preheated sheet material to reach the target process temperature after entering the furnace is shortened, which helps to improve the overall heating efficiency and production efficiency of the roller hearth furnace.

[0035] During use, when the material is preheated, the rod seat 31 extends and drives the lifting plate 42 toward the bottom of the furnace roller 1, and the top of the lifting plate 42 is in contact with the outer wall of the furnace roller 1. At this time, the U-shaped frame 43 passes through the cavity between two adjacent furnace rollers 1 and abuts against the bottom of the heat exchanger 2.

[0036] At the same time, the extension of the second electric push rod 32 drives the heat insulation baffle 34 to move downward, and the heat insulation baffle 34 blocks the space between the two U-shaped frames 43 on the same side. At this time, the material sheet is placed in a relatively closed cavity, reducing the heat dissipation.

[0037] Before feeding, the U-shaped frame 43 and the heat insulation baffle 34 are reset, and then the material is driven to move and enter the furnace body by the drive furnace roller 1.

[0038] The remaining structure is the same as that in Example 1.

[0039] Based on embodiments 1-2, the working principle of this utility model is as follows: The high-temperature exhaust gas generated by the combustion of the gas furnace is connected to the exhaust gas inlet pipe 23 through a pipeline. The material pieces are placed on the surface of the furnace roller 1. When the previous batch of material pieces enters the inside of the roller hearth furnace, the material pieces that have not entered will temporarily stay on the furnace roller 1. When the furnace body heats the material pieces inside, the material pieces located on the furnace roller 1 will enter the interior of the residual heat chamber to preheat the material pieces that have not entered the furnace body and are located on the furnace roller 1. When the furnace body accurately feeds the material, the material pieces have been heated to a certain temperature and directly enter the furnace body for further heating.

[0040] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model 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 solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A waste heat recovery device for a roller hearth furnace, comprising a set of furnace rollers (1), characterized in that: It also includes a heat exchanger (2), both ends of which are equipped with side insulation components (3). The bottom of the furnace roller (1) is not directly below the heat exchanger (2) and a bottom insulation component (4) is provided. A preheating cavity is formed between the heat exchanger (2), the two side insulation components (3) and the bottom insulation component (4). The heat exchanger (2) includes a hollow frame (21), a cover plate (22) is installed on the top of the hollow frame (21), and ventilation openings are provided on both sides and in the middle of the top of the cover plate (22). A heat exchange plate (25) is installed in the lower part of the furnace roller (1), and a heat exchange cavity is formed between the hollow frame (21), the cover plate (22) and the heat exchange plate (25).

2. The waste heat recovery device for a roller hearth furnace according to claim 1, characterized in that: The top of the cover plate (22) and the position directly opposite the two side ventilation openings are fixed with exhaust gas inlet pipes (23), and the top of the cover plate (22) and the position directly opposite the middle ventilation opening are fixed with exhaust gas outlet pipes (24).

3. A waste heat recovery device for a roller hearth furnace according to claim 2, characterized in that: A set of partition plates (26) are fixed on both sides inside the heat exchange chamber. The two adjacent partition plates (26) in the same set are staggered, and a guide channel (27) is formed between the staggered partition plates (26) in the same set.

4. A waste heat recovery device for a roller hearth furnace according to claim 3, characterized in that: The side insulation component (3) includes two rod seats (31) installed on the top of the heat exchanger (2). A second electric push rod (32) is installed on the top of the rod seat (31). A linkage block (33) is fixedly connected to the drive end of the second electric push rod (32). An insulation baffle (34) is installed between the two linkage blocks (33) on the same side.

5. A waste heat recovery device for a roller hearth furnace according to claim 4, characterized in that: The bottom of the heat insulation baffle (34) is provided with a roller groove (35) that is compatible with the furnace roller (1), and the bottom of the heat insulation baffle (34) is integrally formed with a protrusion (36) between two adjacent roller grooves (35).

6. A waste heat recovery device for a roller hearth furnace according to claim 5, characterized in that: The bottom insulation component (4) includes a first electric push rod (41), the movable end of the first electric push rod (41) is fixedly connected to a lifting plate (42), and the two sides of the top of the lifting plate (42) are symmetrically and oppositely equipped with U-shaped frames (43).

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