A heat exchanger for heating combustion air and a melting furnace

Abstract

The present application relates to the technical field of metallurgical equipment, and in particular to a heat exchanger and a melting furnace for heating combustion-supporting air, which include a heat exchange box and a heat exchange pipe; the heat exchange box is installed in the exhaust hood of the melting furnace and introduces high-temperature flue gas through the smoke inlet at the bottom thereof, and the smoke outlet pipe arranged at the top smoke outlet recycles or discharges the cooled flue gas; a guide pipe with an arc-shaped channel is arranged inside the heat exchange box, one end of the channel is connected to the smoke inlet and the other end is connected to the smoke outlet pipe; at the same time, the heating pipe passes through the heat exchange box horizontally and extends into the above-mentioned arc-shaped channel to realize efficient heat exchange. In addition, the multi-stage heating pipeline system is optimized and designed to improve the thermal energy utilization rate and the quality of combustion-supporting air. The present application achieves the purpose of effectively recovering the waste heat of flue gas and improving the combustion efficiency, while also having good cleanliness and maintainability.

Description

Technical Field

[0001] The present application relates to the technical field of metallurgical equipment, and in particular to a heat exchanger and a melting furnace for heating combustion-supporting air. Background Art

[0002] In industrial manufacturing, especially in the non-ferrous metal processing industry, such as in the production of aluminum products, gas-fired aluminum melting furnaces or holding furnaces are often used. The working principle of this type of equipment is to achieve the required process temperature by burning the heat generated by the gas. With the rising cost of energy and the increasing awareness of environmental protection, it is particularly important to use this energy more efficiently (for example, reducing energy consumption while ensuring that product quality is not affected). Therefore, it is crucial for modern manufacturing to take measures to improve energy utilization and reduce environmental pollution.

[0003] Traditional gas-fired melting furnaces or holding furnaces generally use a heat exchange device in the exhaust hood to recover part of the energy of the high-temperature exhaust gas to preheat the air, thereby increasing the combustion efficiency of the flame after the air and gas are mixed, and achieving the purpose of saving fuel. However, most existing heat exchange systems are not designed to fully consider various situations that may occur during long-term operation - for example, smoke accumulation may lead to reduced heat exchange efficiency, and sometimes even require shutdown for cleaning and maintenance, which undoubtedly brings many inconveniences to production.

[0004] Moreover, the heat exchangers commonly used at present are usually composed of multiple heat exchange tubes. Due to the structural design, dust is easily accumulated and difficult to be completely removed, which makes the heat exchange performance of the whole system significantly reduced over time. This phenomenon is particularly obvious under certain working conditions (such as long-term continuous operation), which not only limits the overall performance of the equipment, but also increases the cost burden of subsequent maintenance. Summary of the invention

[0005] The present application provides a heat exchanger and a melting furnace for heating combustion-supporting air, which have the advantages of high heat exchange efficiency and low smoke accumulation, and are helpful to improve work efficiency.

[0006] In a first aspect, the present application provides a heat exchanger for heating combustion-supporting air, which adopts the following technical solution:

[0007] A heat exchanger for heating combustion-supporting air comprises a heat exchange box and a heat exchange pipe;

[0008] The heat exchange box is used to be installed in the exhaust hood of the melting furnace; the heat exchange box is provided with a smoke inlet at the bottom and a smoke outlet at the top; a smoke outlet is provided at the smoke outlet, and the smoke outlet is provided inside the heat exchange box;

[0009] The heat exchange box is also provided with a guide pipe, which has an arc-shaped channel, one end of which is an air inlet end and communicates with the smoke inlet, and the other end of which is an air outlet end and communicates with the smoke outlet pipe;

[0010] The heat exchange pipeline comprises a heating pipe passing through the heat exchange box, and the heating pipe is horizontally placed and extends to the inside of the arc-shaped channel.

[0011] By adopting the above technical solution, the heat exchanger uses the high-temperature flue gas in the exhaust hood of the melting furnace as a heat source, and increases the temperature of the combustion-supporting air by preheating the air, thereby improving the combustion efficiency and reducing gas consumption. Specifically, the arc-shaped channel design in the heat exchange box is conducive to extending the contact path between the high-temperature flue gas and the heating tube, enhancing heat transfer, and the heating tube horizontally penetrates the heat exchange box and penetrates into the arc-shaped channel, increasing the heat exchange area and further improving the heat exchange efficiency. This design effectively avoids the problem of energy waste under traditional methods and achieves the purpose of energy saving and environmental protection.

[0012] Preferably, the guide tube is composed of an arc-shaped guide plate and a partition; the guide plate is arranged to bulge upward, and the partition is arranged vertically on the inner side of the guide plate, so as to form an arc-shaped channel between the guide plate and the partition;

[0013] The heating pipe is arranged inside the guide plate and located on the top of the partition, and the side wall of the heating pipe is fixedly connected to the partition.

[0014] By adopting the above technical solution, a guide tube consisting of an arc-shaped guide plate and a partition is provided, and an arc-shaped channel is formed between the guide plate and the partition. The heating tube is placed on the inner side of the guide plate and on the top of the partition, and is fixedly connected to the partition. This structure enables the high-temperature flue gas to fully contact the heating tube during the flow along the arc-shaped channel, thereby improving the heat exchange efficiency and reducing the deposition of smoke inside the heat exchanger, thereby reducing the cleaning frequency and improving the working efficiency of the entire device.

[0015] Preferably, the guide tubes are provided in plurality and are stacked vertically; the partition in the upper guide tube is fixedly connected to the top of the guide plate in the lower guide tube; and the guide plate in the lower guide tube is provided with an air vent, which is communicated with the air inlet end of the upper guide tube; the heating tubes are provided in plurality and are arranged one-to-one with the plurality of guide tubes.

[0016] By adopting the above technical scheme, the arrangement of multiple guide tubes and multiple guide tubes enhances the heat exchange area between the flue gas and the air and improves the heat exchange efficiency; the design of fixed connection between the partition in the upper guide tube and the top of the guide plate in the lower guide tube ensures the structural stability; the air holes on the guide plate allow the flue gas to pass through each layer of heating tubes in turn, ensuring the effective utilization of the flue gas heat, reducing heat loss, and further improving the heat exchange performance of the entire system.

[0017] Preferably, a plurality of vertically stacked flow guide pipes form a group of flow guide components; and two groups of flow guide components are provided in the heat exchange box and are respectively located on both sides of the smoke outlet pipe.

[0018] By adopting the above technical solution, multiple guide tubes are stacked vertically to form a group of guide components, and two groups of such guide components are set in the heat exchange box and arranged on both sides of the smoke outlet pipe respectively, thereby increasing the heat exchange area between the smoke and the heating tube and improving the heat exchange efficiency.

[0019] Preferably, the heating tube is rotatably connected with a drainage fan and a conductive brush; the conductive brush is in contact with the inner wall of the heating tube; the heating tube is a metal tube and is conductively connected to the conductive brush;

[0020] The conductive brush is fixedly connected to the drainage fan through a connecting piece and rotates synchronously.

[0021] By adopting the above technical solution, the drainage fan on the heating tube can produce a rotating motion during the flow of smoke, driving the conductive brush to remove the smoke and dust attached to the inner wall of the heating tube, preventing the accumulation of smoke and dust and reducing the heat exchange efficiency; at the same time, the conductive connection between the conductive brush and the heating tube can remove static electricity on the heat exchanger, further reduce dust accumulation, ensure good heat transfer performance, and improve the working efficiency and reliability of the heat exchanger.

[0022] Preferably, the drainage fan is configured as a powered fan or an unpowered fan.

[0023] By adopting the above technical solution, the drainage fan can effectively guide the gas flow and select the form of a powered fan or an unpowered fan according to the actual application scenario, so that the device can not only adapt to the needs of different working environments but also ensure a high heat exchange efficiency, thereby achieving the purpose of energy saving. In particular, when no external power supply is required, an unpowered fan can be used to reduce energy consumption while ensuring a good ventilation effect, avoiding smoke and dust accumulation and reducing maintenance frequency, thereby improving the operating stability and economy of the entire system.

[0024] Preferably, the heat exchange pipeline further comprises a front air intake box, the front air intake box having a wide diameter portion and a narrow diameter portion, and an air guide inclined plate is provided between the wide diameter portion and the narrow diameter portion;

[0025] The wide diameter portion is provided with an air inlet flange for connecting to a blower; the narrow diameter portion is connected to the air inlet end of the heating pipe.

[0026] By adopting the above technical solution, the front air intake box uses the wide diameter part to increase the air intake area, which is beneficial to increase the air flow rate, and then cooperates with the air guide inclined plate to achieve the effect of evenly distributing the gas flow direction, ensuring that the air flows smoothly and efficiently into the heating tube.

[0027] On the other hand, the present application provides a melting furnace, which adopts the following technical solution:

[0028] A melting furnace comprises a furnace body, a furnace cover, a fume hood and the heat exchanger for heating combustion-supporting air mentioned above;

[0029] A connecting plate is arranged on the peripheral side of the heat exchange box, and the heat exchange box is fixedly connected to the inner wall of the smoke hood through the connecting plate.

[0030] By adopting the above technical solution, the melting furnace uses an integrated heat exchanger to improve the preheating efficiency of the combustion air and reduce energy loss. Specifically, the heat exchange box in the heat exchanger is fixed in the exhaust hood through a connecting plate, ensuring an effective flow path for the flue gas, while using the heat released during the exhaust process to preheat the combustion air. The multi-stage structure design further enhances the heat exchange performance, improves the overall thermal efficiency of the system, reduces the problem of smoke accumulation, and thus significantly reduces energy consumption and improves combustion efficiency.

[0031] Preferably, when the furnace cover is closed and covers the furnace body, a gap is provided between the furnace cover and the furnace body, and the interior of the furnace body is communicated with the exhaust hood through the gap.

[0032] By adopting the above technical solution, the hot flue gas continues to rise from the gaps on both sides of the furnace cover, continuously heating the heating tubes of the heat exchanger, ensuring that the gas in the heating tubes can be heated all the time.

[0033] In summary, the present invention includes at least one of the following beneficial technical effects:

[0034] 1. By setting up the guide tube with an arc-shaped channel and the design of multiple heating tubes, the flue gas can effectively heat the combustion air, improve the combustion calorific value, and help reduce gas consumption;

[0035] 2. The specific structure of the guide pipe and the layout of the heating pipe are adopted to reduce the possibility of smoke and dust adhesion and avoid the problem of reduced heat exchange efficiency caused by smoke and dust accumulation;

[0036] 3. Through the design of the drainage fan and the conductive brush, the static electricity inside the heater can be automatically removed to a certain extent, reducing the adsorption of smoke and dust, thereby reducing the accumulation of smoke and dust. The conductive brush can also clean the dust inside the heat exchanger, reducing downtime and improving overall work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of the overall structure of the heat exchanger in Example 1 of the present application;

[0038] Figure 2 It is a cross-sectional view of the heat exchange box in Example 1 of the present application and is used to show the structure of the flue gas flow channel;

[0039] Figure 3 This is a schematic diagram of the structure of the heat exchanger after adding a conductive brush and a drainage fan in Example 1 of the present application;

[0040] Figure 4 is a schematic structural diagram of a melting furnace in Example 2 of the present application;

[0041] Figure 5 It is a schematic diagram of the structure of the smoke exhaust hood with a side sliding door added in Example 2 of the present application.

[0042] Markings in the attached figure: 1. heat exchange box; 11. smoke inlet; 12. smoke outlet; 13. smoke outlet pipe; 14. guide pipe; 141. guide plate; 142. partition; 143. vent; 2. heat exchange pipe; 21. heating pipe; 22. front air inlet box; 221. wide diameter part; 222. narrow diameter part; 223. air guide inclined plate; 224. air inlet flange; 23. tail air collecting box; 231. gas output flange; 3. guide fan; 4. conductive brush; 5. furnace body; 6. furnace cover; 61. gap; 7. exhaust hood; 71. flange interface; 72. automatic exhaust valve; 73. side sliding door. DETAILED DESCRIPTION

[0043] The following is combined with Figure 1-5 The present invention is described in further detail. Example

[0044] The heat exchanger for heating combustion-supporting air provided in the embodiment of the present application is referred to Figure 1 The heat exchanger includes a heat exchange box 1 and a heat exchange pipe 2.

[0045] Reference Figure 2 and Figure 3 The heat exchange box 1 has a smoke inlet 11 at the bottom and a smoke outlet 12 at the top, and a smoke outlet pipe 13 is arranged at the smoke outlet 12, and the smoke outlet pipe 13 is placed inside the heat exchange box 1; a guide pipe 14 is also arranged inside the heat exchange box 1, and the guide pipe 14 has an arc-shaped channel, one end of the channel is connected to the smoke inlet 11 as an air inlet end, and the other end is connected to the smoke outlet pipe 13 as an air outlet end; the heat exchange pipe 2 includes a heating pipe 21, and the heating pipe 21 passes through the heat exchange box 1 and extends to the inside of the arc-shaped channel, which effectively improves the heat exchange efficiency and reduces smoke accumulation.

[0046] Specifically, the guide pipe 14 includes an arc-shaped guide plate 141 and a partition 142; the guide plate 141 is arranged to bulge upward, and the partition 142 is vertically arranged on the inner side of the guide plate 141, thereby forming an arc-shaped channel between the guide plate 141 and the partition 142; the heating pipe 21 is arranged on the inner side of the guide plate 141 and located on the top of the partition 142, and the side wall of the heating pipe 21 is fixedly connected to the partition 142, ensuring that the flue gas can flow along the set path and effectively exchange heat through the heating pipe 21.

[0047] The heating tube 21 here can be, for example, a smooth copper tube or a threaded stainless steel tube. Both materials can ensure good thermal conductivity, and the threaded stainless steel tube can further increase the heat exchange area and improve the heat transfer efficiency due to the presence of surface threads.

[0048] Furthermore, multiple guide pipes 14 are provided and stacked vertically. Such a layout can make full use of space resources and increase the heat exchange area per unit volume. The partition 142 in the upper guide pipe 14 is fixedly connected to the top of the guide plate 141 in the lower guide pipe 14, and the guide plate 141 in the lower guide pipe 14 is provided with ventilation holes 143. These ventilation holes 143 are connected to the air inlet end of the upper guide pipe 14, so that the multiple guide pipes are connected to each other.

[0049] There are multiple heating tubes 21 and they are arranged one by one with multiple flow guide tubes 14. The group of heating tubes 21 arranged in this way can evenly distribute the flue gas in each heating tube 21, ensuring that each section of the heating tube 21 has enough time to exchange heat with the flue gas, thereby improving the heat exchange efficiency.

[0050] Multiple vertically stacked guide tubes 14 can be divided into a group of guide components, and there are two groups of guide components in the heat exchange box 1 and they are respectively located on both sides of the smoke outlet pipe 13. This not only balances the pressure difference of the smoke flow in the box, but also increases the heat exchange area, further improving the heat exchange efficiency.

[0051] In addition, the heating tube 21 is rotatably connected with a drainage fan 3 and a conductive brush 4; the conductive brush 4 is in contact with the inner wall of the heating tube 21, and the heating tube 21 is a metal tube and is conductively connected to the conductive brush 4; the conductive brush 4 is fixedly connected to the drainage fan 3 through a connecting piece and rotates synchronously, and the rotation of the drainage fan 3 drives the conductive brush 4 to remove dust on the inner wall of the heating tube 21, thereby maintaining the heat exchange efficiency.

[0052] Furthermore, the heating tube 21 can be connected to a metal wire, so as to cooperate with the conductive brush 4 to eliminate static electricity inside the heat exchanger and reduce the adsorption of smoke. The conductive brush 4 can be a rubber brush with a metal wire in the center, which has good flexibility, and the metal wire is extended to the outside of the rubber brush to ensure that the metal wire maintains a good conductive connection with the heat exchanger.

[0053] Specifically, the drainage fan 3 can be a turbine-type unpowered fan or a fan driven by a DC motor. The former rotates automatically based on wind pressure and is suitable for a relatively stable flue gas flow rate environment, while the latter can adjust the speed according to the actual working conditions and adapt to more complex usage scenarios. The selection of these two fans can meet the needs of different working conditions and improve the flexibility of equipment operation.

[0054] Reference Figure 1 Finally, the heat exchange pipe 2 also includes a front air intake box 22 and a rear air collection box 23. The front air intake box 22 has a wide diameter portion 221 and a narrow diameter portion 222, and an air guide inclined plate 223 is provided between the wide diameter portion 221 and the narrow diameter portion 222; an air intake flange 224 is provided on the wide diameter portion 221 for connecting to the blower; the narrow diameter portion 222 is connected to the air intake end of the heating pipe 21. This structure can guide the air to transition smoothly, reduce the pressure loss caused by the impact of the air flow, and improve the overall heat exchange efficiency.

[0055] The tail end gas collecting box 23 is connected to the gas outlet end of the heating tube 21, and a gas output flange 231 is provided on the tail end gas collecting box 23, which can be connected to a gas mixer, such as a Venturi mixer, so as to achieve mixing of air and gas.

[0056] The implementation principle of this embodiment is: through the effective management of the flue gas flow direction and the direct heat exchange between the flue gas and the air, efficient heat recovery and utilization are achieved. Through reasonable design and material selection, not only the smoke accumulation problem existing in the traditional heat exchanger is solved, but also the equipment operation efficiency and stability are greatly improved. Compared with the existing heat exchange technology, the solution proposed in this application improves the heat exchange efficiency while reducing the maintenance frequency, which is of great significance for energy conservation and emission reduction. Example

[0057] The melting furnace provided in this embodiment refers to Figure 4 , the heat exchanger for heating the combustion-supporting air described in the above-mentioned embodiment 1 is adopted, including a furnace body 5, a furnace cover 6, a smoke exhaust hood 7 and a heat exchanger for heating the combustion-supporting air, wherein a connecting plate is provided on the surrounding side of the heat exchange box 1, and the heat exchange box 1 is fixedly connected to the inner wall of the smoke hood through the connecting plate, ensuring that the heat exchanger can be firmly installed inside the smoke exhaust hood 7 and that the smoke can pass through the heat exchanger, thereby ensuring the heat exchange effect.

[0058] In the present application, if the size of a heat exchanger is too small to be effectively filled in the exhaust hood 7, multiple heat exchangers can be arranged in parallel to ensure that all high-temperature flue gases can be heat exchanged through the heat exchanger.

[0059] Thus, the high-temperature flue gas generated in the furnace body 5 enters the heat exchanger from the bottom of the exhaust hood 7 and heats the air in the heating tube 21, and then enters the upper part of the exhaust hood 7 through the exhaust pipe of the heat exchange box 1. An automatic exhaust valve 72 is provided at the top of the exhaust hood 7. When the automatic exhaust valve 72 is opened, the exhaust of the flue gas can be realized. When exhaust is not required, the automatic exhaust valve 72 can be closed to maintain the heat inside the exhaust hood 7, thereby continuously heating the air.

[0060] Furthermore, when the furnace cover 6 is closed and covers the furnace body 5, a gap 61 is provided between the furnace cover 6 and the furnace body 5, and the interior of the furnace body 5 is connected to the exhaust hood 7 through the gap 61, so that sufficient heat can be ensured in the exhaust hood 7, thereby ensuring the heating effect of the heat exchanger on the air.

[0061] In addition, refer to Figure 5 , an additional holding furnace can be provided, which also has a furnace body 5, and a furnace door is provided on the furnace body 5 for feeding materials; a smoke collecting hood is provided on the upper side of the furnace door, and the smoke collecting hood is connected to the smoke exhaust hood 7 through a pipeline. Such a design is conducive to the centralized collection of smoke escaping when the furnace door is opened, and introduces it into the heat exchanger to participate in the heat exchange process, further improving the utilization rate of thermal energy. In addition, the high-temperature smoke of the holding furnace and the melting furnace can be passed into the smoke exhaust hood 7, further improving the utilization rate of energy.

[0062] The implementation principle of this embodiment is: by integrating a high-efficiency heat exchanger in the melting furnace, the heat in the flue gas discharged from the furnace body 5 can be effectively recovered for preheating the combustion air, which greatly reduces energy consumption. At the same time, the unique structural design of the furnace body 5 makes the flue gas discharge smoother and more orderly, avoiding unnecessary heat energy loss, which is of great significance for improving the overall combustion efficiency and environmental protection indicators.

[0063] As a further improvement of the embodiment of the present application, Figure 5 As shown, the fume hood 7 is also provided with a feeding port, and a side sliding door 73 is further provided at the feeding port.

[0064] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A heat exchanger for heating combustion air, characterized in that: It comprises a heat exchange box (1) and a heat exchange pipe (2); The heat exchange box (1) is used to be installed in a smoke exhaust hood (7) of a melting furnace; a smoke inlet (11) is provided at the bottom of the heat exchange box (1), and a smoke outlet (12) is provided at the top; a smoke outlet pipe (13) is provided at the smoke outlet (12), and the smoke outlet pipe (13) is provided inside the heat exchange box (1); A flow guide pipe (14) is also provided in the heat exchange box (1), and the flow guide pipe (14) has an arc-shaped channel, one end of which is an air inlet end and communicates with the smoke inlet (11), and the other end of which is an air outlet end and communicates with the smoke outlet pipe (13); The heat exchange pipeline (2) comprises a heating pipe (21) passing through the heat exchange box (1), wherein the heating pipe (21) is horizontally placed and extends into the interior of the arc-shaped channel; The guide tube (14) is composed of an arc-shaped guide plate (141) and a partition plate (142); the guide plate (141) is arranged to protrude upward, and the partition plate (142) is arranged vertically on the inner side of the guide plate (141), so that an arc-shaped channel is formed between the guide plate (141) and the partition plate (142); The heating tube (21) is arranged inside the guide plate (141) and located on the top of the partition plate (142); the side wall of the heating tube (21) is fixedly connected to the partition plate (142), and the arc-shaped channel surrounds the circumference of the heating tube (21).

2. The heat exchanger for heating combustion air according to claim 1, characterized in that: The guide tubes (14) are provided in plurality and are stacked vertically; the partition plate (142) in the upper guide tube (14) is fixedly connected to the top of the guide plate (141) in the lower guide tube (14); and the guide plate (141) in the lower guide tube (14) is provided with an air vent (143), the air vent (143) being in communication with the air inlet end of the upper guide tube (14); and the heating tubes (21) are provided in plurality and are arranged one-to-one with the plurality of guide tubes (14).

3. The heat exchanger for heating combustion air according to claim 2, characterized in that: A plurality of vertically stacked flow guide pipes (14) form a group of flow guide components; two groups of flow guide components are provided in the heat exchange box (1) and are respectively located on both sides of the smoke outlet pipe (13).

4. The heat exchanger for heating combustion air according to claim 1, characterized in that: The heating tube (21) is rotatably connected to a drainage fan (3) and a conductive brush (4); the conductive brush (4) is in contact with the inner wall of the heating tube (21); the heating tube (21) is a metal tube and is conductively connected to the conductive brush (4); The conductive brush (4) is fixedly connected to the drainage fan (3) via a connecting piece and rotates synchronously.

5. The heat exchanger for heating combustion air according to claim 4, characterized in that: The drainage fan (3) is configured as a powered fan or an unpowered fan.

6. The heat exchanger for heating combustion air according to claim 1, characterized in that: The heat exchange pipe (2) further comprises a front air intake box (22), the front air intake box (22) comprising a wide diameter portion (221) and a narrow diameter portion (222), an air guide inclined plate (223) being provided between the wide diameter portion (221) and the narrow diameter portion (222); The wide diameter portion (221) is provided with an air inlet flange (224) for connection to a blower; the narrow diameter portion (222) is connected to the air inlet end of the heating tube (21).

7. A melting furnace, characterized in that: It comprises a furnace body (5), a furnace cover (6), a smoke exhaust hood (7), and a heat exchanger for heating combustion-supporting air as claimed in any one of claims 1 to 6; A connecting plate is provided on the peripheral side of the heat exchange box (1), and the heat exchange box (1) is fixedly connected to the inner wall of the smoke hood via the connecting plate.

8. The melting furnace according to claim 7, characterized in that When the furnace cover (6) is closed and covers the furnace body (5), a gap (61) is provided between the furnace cover (6) and the furnace body (5), and the interior of the furnace body (5) is communicated with the smoke exhaust hood (7) through the gap (61).

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