A medium frequency furnace waste heat recovery device for cast iron pan production

Abstract

This utility model relates to the field of waste heat recovery technology for medium-frequency furnaces, specifically a waste heat recovery device for a medium-frequency furnace used in cast iron pot production. It includes a medium-frequency furnace body, a waste heat collection hood mounted on the top of the furnace body with screws, a fixing ring fixed to the outlet of the furnace body, a groove at the bottom of the waste heat collection hood, and the groove of the waste heat collection hood being inserted into the fixing ring. A protective mechanism is installed on the inner ring of the waste heat collection hood. The beneficial effects are: when the furnace body and the waste heat collection hood are connected, the groove at the bottom of the waste heat collection hood aligns with the fixing ring and engages, achieving precise positioning. The inner ring's pressure ring presses against the guide hood. Due to the toughness of the connecting base, the guide hood tilts, narrowing the opening at the top, causing the smoke from the furnace to concentrate upwards. Simultaneously, an insulating skirt is added to insulate heat, preventing the connection between the furnace body and the waste heat collection hood from becoming too hot and shortening its lifespan. The guide hood's inward movement initially isolates the high-temperature flame.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology of medium frequency furnaces, specifically a waste heat recovery device for medium frequency furnaces used in cast iron pot production. Background Technology

[0002] In the smelting process of cast iron pots, medium-frequency furnaces are usually used as heating equipment. During operation, a large amount of high-temperature flue gas is generated. If it is directly discharged, it will not only waste heat energy, but also cause the ambient temperature of the workshop to rise and thermal damage to the equipment connection parts. The high-temperature gas generated by the medium-frequency furnace is collected by the waste heat collection hood and then sent to the heat exchanger through the waste heat pipe. The fins of the heat exchanger greatly increase the heat exchange area, so that the sensible heat and part of the latent heat in the flue gas can be efficiently transferred to the cold water flowing in the pipe. The cold water enters the heat exchanger from the bottom, is heated and discharged from the top and enters the hot water supply tank for storage. The hot water in the hot water supply tank is then used.

[0003] In the prior art, such as a medium-frequency electric furnace waste heat recovery device, with application number CN202421822711.2, a waste heat recovery box is set up to ensure a tight fit between the waste heat recovery box and the aluminum silicate fiber sleeve. When using the device, the setting of the waste heat recovery box and the aluminum silicate fiber sleeve helps to reduce waste heat loss, facilitates temperature preservation, and increases the usability of the device.

[0004] However, during use, the intermediate frequency furnace and its top waste heat collection cover are prone to misalignment during installation, which leads to flue gas dispersion and heat concentration damaging the connection parts. At the same time, the lack of preliminary isolation measures for high-temperature flames makes the connection between the fixing ring and the cover body prone to overheating, reducing the service life of the equipment. Utility Model Content

[0005] The purpose of this invention is to provide a waste heat recovery device for a medium-frequency furnace used in the production of cast iron pots, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: it includes a medium-frequency furnace body, a waste heat collection cover installed on the top of the medium-frequency furnace body by screws, a fixing ring fixed to the outlet of the medium-frequency furnace body, a groove opened at the bottom end of the waste heat collection cover, the groove of the waste heat collection cover being inserted into the fixing ring, and a protective mechanism installed on the inner ring of the waste heat collection cover.

[0007] Preferably, the bottom end of the waste heat collection hood is fixed with a fixing seat. There are four sets of fixing seats, all located on the side of the waste heat collection hood. The fixing seats are fixed to the upper surface of the medium frequency furnace body by screws.

[0008] Preferably, the bottom end of the waste heat collection hood has an inverted frustum-shaped structure, and the inlet at the bottom end of the waste heat collection hood has an annular structure.

[0009] Preferably, the top of the medium-frequency furnace body is provided with an annular groove, which is located in the inner ring of the fixed ring.

[0010] Preferably, the groove is an annular groove, and the fixing ring has an annular cross-section.

[0011] Preferably, the outer ring of the waste heat collection cover has a vacuum cavity on its inner wall, and the vacuum cavity is located outside the groove.

[0012] Preferably, the protective mechanism includes a connecting base, a flow guide, a heat insulation skirt, and a pressure ring. The connecting base is fixed to the inner ring of the outlet of the medium-frequency furnace body and has a ring-shaped cross-section. The flow guide is fixed to the upper surface of the inner ring of the connecting base and is inclined, with a ring-shaped cross-section. The heat insulation skirt is fixed to the inner ring of the inlet of the waste heat collection hood and has an "L"-shaped cross-section and a ring-shaped structure. The bottom plate of the heat insulation skirt is located in the annular groove. The pressure ring is fixed to the inner ring of the heat insulation skirt and has an arc-shaped cross-section and a ring-shaped structure. When the medium-frequency furnace body and the waste heat collection hood are connected, the pressure ring is tangent to the outer ring of the flow guide.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] The waste heat recovery device for medium-frequency furnaces used in cast iron pot production proposed in this utility model allows for precise positioning when the main body of the medium-frequency furnace and the waste heat collection hood are connected. The groove at the bottom of the waste heat collection hood is aligned with the fixing ring and snapped in. The inner ring pressure ring presses down on the guide hood. Due to the toughness of the connecting base, the guide hood becomes tilted, narrowing the opening at the top, causing the smoke from the medium-frequency furnace to concentrate upwards. At the same time, the addition of a heat-insulating skirt isolates the heat, preventing the connection between the main body of the medium-frequency furnace and the waste heat collection hood from becoming too hot and shortening its lifespan. The guide hood moves towards the inner ring, initially isolating the high-temperature flame, thus achieving long-term use. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the structure of the medium-frequency furnace body and the waste heat collection hood after separation.

[0017] Figure 3 This utility model Figure 2 A top-view structural diagram;

[0018] Figure 4 This utility model Figure 3 A schematic diagram of the AA-direction cross-section structure;

[0019] Figure 5 This utility model Figure 4 A magnified structural diagram at point A;

[0020] Figure 6 This is a schematic diagram of the structure of the medium-frequency furnace body and the waste heat collection cover after they are connected.

[0021] Figure 7 This utility model Figure 6 A top-view structural diagram;

[0022] Figure 8 This utility model Figure 7 Schematic diagram of the BB-direction cross-section structure;

[0023] Figure 9 This utility model Figure 8 A magnified structural diagram at point B.

[0024] In the diagram: 1. Medium frequency furnace body; 2. Waste heat collection cover; 3. Waste heat pipe; 4. Heat exchanger; 5. Hot water supply tank; 6. Fixing base; 7. Fixing ring; 8. Groove; 9. Ring groove; 10. Connecting base; 11. Flow guide cover; 12. Pressure ring; 13. Insulation skirt. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clear and complete, the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of this utility model, and are merely used to explain the embodiments of this utility model. They are not intended to limit the embodiments of this utility model. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] Example 1

[0027] Please see Figures 1 to 9 This utility model provides a technical solution: a waste heat recovery device for an intermediate frequency furnace used in the production of cast iron pots, including an intermediate frequency furnace body 1, a waste heat collection cover 2 installed on the top of the intermediate frequency furnace body 1 by screws, a fixing seat 6 fixed at the bottom of the waste heat collection cover 2, four sets of fixing seats 6 are provided, all located on the side of the waste heat collection cover 2, the fixing seat 6 is fixed to the upper surface of the intermediate frequency furnace body 1 by screws, the bottom of the waste heat collection cover 2 has an inverted frustum structure, and the inlet at the bottom of the waste heat collection cover 2 has a circular structure, the outlet of the waste heat collection cover 2 is connected to a waste heat pipe 3, the other end of the waste heat pipe 3 is connected to a heat exchanger 4, and the outlet of the heat exchanger 4 is connected to a hot water tank 5;

[0028] Specifically, the waste heat recovery device consists of a waste heat collection hood 2, waste heat pipes 3, a heat exchanger 4, and a hot water tank 5. The medium-frequency furnace body 1 consists of a furnace shell, furnace lining, induction coil, furnace chamber, and furnace top smoke cap. The heat exchanger 4 consists of an inner circular tube and outer wound fins. The raw material pig iron for the cast iron pot needs to be melted in the medium-frequency furnace body 1, using medium-frequency electromagnetic induction heating. The temperature inside the furnace chamber can reach over 1500℃. High-temperature flue gas will be continuously discharged from the furnace top. The inlet of the waste heat collection hood 2 above the furnace top is connected to the furnace top outlet. The high-temperature flue gas rises and enters the waste heat collection hood 2 for collection. The high-temperature flue gas is introduced into the heat exchanger 4 through the waste heat pipe 3. The heat exchanger consists of a base tube and multiple layers of fins. The fins greatly increase the heat exchange area, so that the sensible heat and part of the latent heat in the flue gas can be efficiently transferred to the cold water flowing in the tube. The cold water enters the heat exchanger from the bottom, is heated and discharged from the top and enters the hot water tank 5 for storage. It is used for molding sand drying, workshop heating or domestic hot water supply in the cast iron pot production process, thereby realizing the comprehensive utilization of waste heat. At the same time, the cooled flue gas is drawn away by the fan through the heat exchanger outlet and discharged to the chimney (not shown in the figure), maintaining the negative pressure at the furnace mouth and preventing the flue gas from leaking out.

[0029] To reiterate, the main body 1 of the medium-frequency furnace adopts the same model as Wanfeng's 1.5-ton medium-frequency furnace for pig iron melting, and the waste heat collection hood 2 adopts a steam finned tube heat exchanger.

[0030] Example 2

[0031] Based on Embodiment 1, in order to achieve stability in the connection between the intermediate frequency furnace body 1 and the waste heat collection hood 2 and to ensure long-term use, a fixing ring 7 is fixed at the outlet of the intermediate frequency furnace body 1. An annular groove 9 is formed at the top of the intermediate frequency furnace body 1, located within the inner ring of the fixing ring 7. A groove 8 is formed at the bottom of the waste heat collection hood 2, and the groove 8 of the waste heat collection hood 2 is inserted into the fixing ring 7. The groove 8 is an annular groove. The fixing ring 7 has an annular cross-section. A vacuum cavity is provided on the inner wall of the outer ring of the waste heat collection hood 2, and the vacuum cavity is located outside the groove 8. A protective mechanism is installed on the inner ring of the waste heat collection hood 2. The protective mechanism includes a connecting base 10, a flow guide hood 11, a heat insulation skirt 13, and a pressure ring 12. The connecting base 10 is fixed to the inner ring of the outlet of the medium frequency furnace body 1. The connecting base 10 has a ring-shaped cross-section. The flow guide 11 is fixed to the upper surface of the inner ring of the connecting base 10. The flow guide 11 is inclined and has a ring-shaped cross-section. The heat insulation skirt 13 is fixed to the inner ring of the inlet of the waste heat collection hood 2. The heat insulation skirt 13 has an "L"-shaped cross-section and is ring-shaped. The bottom plate of the heat insulation skirt 13 is located in the ring groove 9. The pressure ring 12 is fixed to the inner ring of the heat insulation skirt 13. The pressure ring 12 has an arc-shaped cross-section and is ring-shaped. When the medium frequency furnace body 1 and the waste heat collection hood 2 are connected, the pressure ring 12 is tangent to the outer ring of the flow guide 11.

[0032] Specifically, when the medium-frequency furnace body 1 is connected to the waste heat collection hood 2, the fixing ring 7 will be inserted into the groove 8 to achieve quick and accurate positioning and avoid installation misalignment. As the groove 8 is engaged, the annular groove 9 fits against the bottom plate of the heat insulation skirt 13. At this time, the pressure ring 12 presses down on the outer ring of the guide hood 11. Due to the action of the connecting base 10, the guide hood 11 tilts inward to a certain extent, forcing the flue gas at the furnace mouth to concentrate upward, reducing overflow and diffusion. The annular inclined surface of the guide hood 11 can also form a preliminary barrier against the high-temperature flames, preventing the high-temperature flames from burning the connection between the medium-frequency furnace body 1 and the waste heat collection hood 2. At the same time, the heat insulation skirt 13 forms a heat insulation barrier around the furnace mouth, reducing the heat conducted to the connection point and preventing overheating damage to the fixing ring 7 and the collection hood 2. The inner wall of the outer ring of the waste heat collection hood 2 is also provided with a vacuum cavity to further isolate heat and reduce heat conduction, ensuring that the entire connection is both firm and sealed, and achieves safe and durable waste heat collection.

[0033] To reiterate, the heat insulation skirt 13 is made of high-temperature resistant composite ceramic fiber board material, which has an extremely low thermal conductivity, excellent heat insulation performance, and high strength; the connecting base 10 is made of high-temperature heat-resistant alloy steel, such as the 25Cr20Ni series, which still maintains a certain degree of plasticity and ductility at high temperatures, and will not crack under pressure, allowing the top of the flow guide to deform slightly with the action of the pressure ring 12.

[0034] During use, when the medium-frequency furnace body 1 is connected to the waste heat collection hood 2, the fixing ring 7 will smoothly insert into the groove 8, thereby achieving quick and accurate positioning and avoiding installation misalignment. As the groove 8 is engaged, the annular groove 9 fits against the bottom plate of the heat insulation skirt 13. At this time, the pressure ring 12 presses down on the outer ring of the guide hood 11. Due to the action of the connecting base 10, the guide hood 11 tilts inward to a certain extent, forcing the flue gas at the furnace opening to concentrate upward, reducing overflow and diffusion. The annular inclined surface of the guide hood 11 can also form a preliminary barrier against the high-temperature flames, preventing the high-temperature flames from burning the connection between the medium-frequency furnace body 1 and the waste heat collection hood 2. At the same time, the heat insulation skirt 13 forms a heat insulation barrier around the furnace opening, reducing the heat conducted to the connection point and preventing overheating damage to the fixing ring 7 and the collection hood 2. The inner wall of the outer ring of the waste heat collection hood 2 is also provided with a vacuum cavity to further isolate heat and reduce heat conduction, ensuring that the entire connection is both firm and sealed, and achieves safe and durable waste heat collection.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A waste heat recovery device for a medium-frequency furnace used in cast iron pot production, comprising a medium-frequency furnace body (1) and a waste heat collection hood (2) mounted on the top of the medium-frequency furnace body (1) by screws, characterized in that: The outlet of the medium frequency furnace body (1) is fixed with a fixing ring (7), and the bottom end of the waste heat collection cover (2) is provided with a groove (8). The groove (8) of the waste heat collection cover (2) is inserted into the fixing ring (7), and a protective mechanism is installed on the inner ring of the waste heat collection cover (2).

2. The waste heat recovery device for a medium-frequency furnace used in cast iron pot production according to claim 1, characterized in that: The bottom end of the waste heat collection cover (2) is fixed with a fixing seat (6). There are four sets of fixing seats (6), all located on the side of the waste heat collection cover (2). The fixing seat (6) is fixed to the upper surface of the medium frequency furnace body (1) by screws.

3. The waste heat recovery device for a medium-frequency furnace used in cast iron pot production according to claim 1, characterized in that: The bottom of the waste heat collection hood (2) is an inverted frustum-shaped structure, and the inlet at the bottom of the waste heat collection hood (2) is an annular structure.

4. The waste heat recovery device for an intermediate frequency furnace used in cast iron pot production according to claim 1, characterized in that: The top of the medium frequency furnace body (1) is provided with an annular groove (9), which is located in the inner ring of the fixed ring (7).

5. The waste heat recovery device for a medium-frequency furnace used in cast iron pot production according to claim 1, characterized in that: The groove (8) is an annular groove, and the fixing ring (7) has an annular cross-section.

6. The waste heat recovery device for an intermediate frequency furnace used in cast iron pot production according to claim 1, characterized in that: The outer ring inner wall of the waste heat collection cover (2) is provided with a vacuum cavity, and the vacuum cavity is located outside the groove (8).

7. The waste heat recovery device for a medium-frequency furnace used in cast iron pot production according to claim 4, characterized in that: The protective mechanism includes a connecting base (10), a flow guide (11), a heat insulation skirt (13), and a pressure ring (12). The connecting base (10) is fixed to the inner ring of the outlet of the medium-frequency furnace body (1). The connecting base (10) has a ring-shaped cross-section. The flow guide (11) is fixed to the upper surface of the inner ring of the connecting base (10). The flow guide (11) is inclined and has a ring-shaped cross-section. The heat insulation skirt (13) is fixed to the waste heat collection... The inner ring of the inlet of the cover (2) has an "L" shaped cross-section and an annular structure. The bottom plate of the heat insulation skirt (13) is located in the annular groove (9). The pressure ring (12) is fixed in the inner ring of the heat insulation skirt (13) and has an arc-shaped cross-section. When the medium frequency furnace body (1) and the waste heat collection cover (2) are connected, the pressure ring (12) is tangent to the outer ring of the flow guide cover (11).

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