Low-temperature large air volume hot blast stove

Abstract

The utility model relates to a boiler technical field, concretely is a kind of low-temperature large air volume hot blast stove, including shell, the inside of shell is equipped with combustion chamber, three interlayers are sequentially arranged between the outside of combustion chamber and the inside of shell, the interlayer in middle is flue gas layer, the outside of flue gas layer is outer layer cold air layer, the inside of flue gas layer is inner layer cold air layer, one end of combustion chamber is equipped with burner, and the other end of combustion chamber is communicated with flue gas layer by fire hole. In the low-temperature large air volume hot blast stove, three interlayers between the outside of combustion chamber and the inside of shell are designed, and the communication of outer layer cold air layer and inner layer cold air layer is realized by wind hole, so that cold air is preliminarily heat exchanged by outer layer cold air layer, then further heat exchanged by inner layer cold air layer. The secondary heat exchange structure prolongs the heat exchange path and time of cold air and high-temperature flue gas, and simultaneously avoids the problem of high temperature caused by excessive heat absorption of cold air in single heat exchange channel.

Description

Technical Field

[0001] This utility model relates to the field of boiler technology, specifically to a low-temperature, high-volume hot air furnace. Background Technology

[0002] Hot air furnaces, as devices that provide hot air, are widely used in various fields such as agricultural drying, food processing, wood drying, and industrial heating. In practical applications, the temperature and air volume requirements of hot air vary significantly depending on the scenario. For example, in the initial stage of agricultural product drying, a relatively low temperature (e.g., 50-80℃) but large air volume of hot air is usually required to prevent localized overheating and deterioration of the material, while continuous airflow removes moisture, improving drying efficiency and quality.

[0003] However, existing hot blast stoves are often designed with a greater emphasis on high-temperature hot air output. Their structures typically employ a single combustion chamber directly connected to a heat exchange channel. This results in short contact time and limited heat exchange area between the cold air and the high-temperature flue gas during heat exchange, leading to excessively high hot air temperatures that fail to meet low-temperature requirements. Reducing fuel supply to lower the temperature would drastically decrease airflow, making it impossible to meet high-volume airflow demands. Furthermore, some low-temperature hot blast stoves employ complex multi-loop heat exchange structures to improve heat exchange efficiency. This not only increases equipment size and manufacturing costs but also makes them prone to uneven airflow distribution, leading to localized overheating and significant hot air temperature fluctuations, thus affecting performance. Utility Model Content

[0004] The purpose of this invention is to provide a low-temperature, high-volume hot air furnace to address the problem mentioned in the background art that hot air furnaces are often designed with an emphasis on the output of high-temperature hot air. Their structures often adopt a form in which a single combustion chamber is directly connected to a heat exchange channel. During the heat exchange process, the contact time between the cold air and the high-temperature flue gas is short and the heat exchange area is limited, resulting in a high hot air temperature that is difficult to meet the low-temperature requirements. If the temperature is lowered by reducing the fuel supply, the air volume will decrease significantly, making it impossible to meet the requirements of a large air volume.

[0005] To achieve the above objectives, this utility model provides a low-temperature, high-volume hot air furnace, including an outer shell. A combustion chamber is installed inside the outer shell. Three layers are sequentially arranged between the outer side of the combustion chamber and the inner side of the outer shell. The middle layer is a flue gas layer, the outer side near the flue gas layer is an outer cold air layer, and the inner side near the flue gas layer is an inner cold air layer. A burner is installed at one end of the combustion chamber, and the other end of the combustion chamber is connected to the flue gas layer through a fire port.

[0006] This design utilizes a three-layer interlayer structure between the outer shell and the combustion chamber (with the flue gas layer in the middle, and the inner and outer cold air layers on the inside and outside, respectively), forming a "flue gas-cold air" double-layer heat exchange structure. The high-temperature flue gas generated by the burner enters the flue gas layer through the flame-passing port at the end of the combustion chamber, while the cold air flows between the inner and outer cold air layers, exchanging heat with the flue gas layer through the interlayer walls.

[0007] Preferably, the top of the outer casing is provided with a flue gas outlet, which is connected to one end of the flue gas layer.

[0008] This feature connects the flue gas outlet at the top of the casing to the flue gas layer, forming a directional emission channel for the flue gas. This allows the flue gas to be discharged smoothly after heat exchange, preventing it from accumulating in the flue gas layer.

[0009] Preferably, a cold air inlet is provided on one side wall of the outer casing, and the inner side of the cold air inlet is connected to one end of the outer cold air layer. A hot air outlet is provided on the other side wall of the outer casing, and the inner side of the hot air outlet is connected to one end of the inner cold air layer.

[0010] This design allows cold air to enter the outer cold air layer through a cold air inlet on one side of the casing. After heat exchange, the air enters the inner cold air layer through a vent for further heat exchange, and finally exits through a hot air outlet on the other side, forming a "secondary heat exchange" path for the cold air.

[0011] Preferably, the outer and inner cold air layers are connected at the ends away from the burner via an air vent.

[0012] This feature connects the outer and inner cold air layers through an air vent at the end furthest from the burner, allowing the cold air to enter the inner layer for secondary heat exchange after completing the initial heat exchange in the outer layer, thus forming a continuous heat exchange process.

[0013] Preferably, the flue gas layer is equipped with spiral fins to slow down the flue gas velocity and facilitate heat exchange.

[0014] The spiral fins in the flue gas layer can increase the flow resistance of the flue gas, reduce its flow velocity, and increase the contact area between the flue gas and the interlayer wall.

[0015] Preferably, the outer cooling air layer has a plurality of outer fins installed inside, and the inner cooling air layer has a plurality of inner fins installed inside.

[0016] This feature, with its fins (outer and inner fins) in the outer and inner cold air layers, increases the contact area between the cold air and the interlayer wall, while also diverting and guiding the airflow.

[0017] Preferably, both the outer and inner fins are arranged at equal intervals along the airflow direction inside the shell.

[0018] This design arranges the outer and inner fins at equal intervals along the airflow direction, so that the cold air is evenly divided during the flow, forming multiple parallel airflows.

[0019] Preferably, a support is installed at the bottom of the housing.

[0020] This feature provides stable support to the bottom of the casing, ensuring the hot air furnace remains level during operation.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] This low-temperature, high-volume hot air furnace employs a three-layer sandwich design (flue gas layer, outer cold air layer, and inner cold air layer) between the outer combustion chamber and the inner shell. The outer and inner cold air layers are connected via a cross-vent, allowing the cold air to first undergo initial heat exchange in the outer layer before entering the inner layer for further heat exchange. This secondary heat exchange structure extends the heat exchange path and time between the cold air and the high-temperature flue gas, while avoiding the problem of excessive heat absorption by the cold air in a single heat exchange channel, which can lead to excessively high temperatures. Combined with the stable output of the burner, there is no need to reduce the temperature by decreasing the fuel supply. While ensuring a large air volume, the hot air temperature can be stably controlled within a low-temperature range of 50-80℃, perfectly meeting the needs of low-temperature, high-volume hot air in the initial stages of agricultural product drying and food processing. This effectively prevents localized overheating and deterioration of materials, improving drying or processing quality.

[0023] The spiral fins inside the flue gas layer reduce the flue gas flow velocity, allowing the high-temperature flue gas to remain within the layer for a longer period, increasing the heat exchange time with the cooling air layer. The numerous outer and inner fins (arranged at equal intervals along the airflow direction) within the outer and inner cooling air layers increase the contact area between the cooling air and the interlayer walls, and guide the airflow to a uniform distribution, avoiding uneven local heat exchange. Through the synergistic effect of the fin structure and the multi-layered interlayer, heat exchange efficiency is significantly improved, allowing the heat from the high-temperature flue gas to be fully utilized, reducing energy waste and lowering operating costs.

[0024] Compared to traditional complex multi-loop heat exchange structures, the three-layer sandwich design of this invention has a reasonable layout, which simplifies the overall structure and reduces equipment size and manufacturing costs while ensuring heat exchange efficiency. At the same time, the connections between components are stable (such as the combustion chamber and flue gas layer being connected through a fire port, and the cold air layer being directly connected to the inlet and outlet), and the airflow path is clear. Component damage or failure is less likely to occur during long-term operation, reducing maintenance difficulty and costs. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0026] Figure 2 This is a side view of the structure of this utility model;

[0027] Figure 3 This is a top view of the structure of this utility model;

[0028] The meanings of the labels in the diagram are as follows:

[0029] 1. Outer shell; 11. Flue gas outlet; 12. Cold air inlet; 13. Hot air outlet; 2. Combustion chamber; 3. Burner; 4. Support; 5. Flue gas layer; 51. Spiral fins; 6. Outer cold air layer; 61. Outer fins; 7. Inner cold air layer; 71. Inner fins; 8. Flame outlet; 9. Air outlet. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] This utility model provides a low-temperature, high-volume hot air furnace, such as... Figure 1 As shown, the device includes an outer shell 1, a combustion chamber 2 installed inside the outer shell 1, and three interlayers arranged sequentially between the outer shell 1 and the outer shell 2. The middle interlayer is a flue gas layer 5, the outer side of the flue gas layer 5 is an outer cold air layer 6, and the inner side of the flue gas layer 5 is an inner cold air layer 7. A burner 3 is installed at one end of the combustion chamber 2, and the other end of the combustion chamber 2 is connected to the flue gas layer 5 through a fire port 8.

[0032] Three layers are arranged between the outer shell 1 and the combustion chamber 2: the middle layer is the flue gas layer 5, the outer layer is the outer cold air layer 6, and the inner layer is the inner cold air layer 7, forming a "flue gas-cold air" double-layer heat exchange structure. The high-temperature flue gas generated by the burner 3 enters the flue gas layer 5 through the flame outlet 8 at the end of the combustion chamber 2. The cold air flows between the inner and outer cold air layers and exchanges heat with the flue gas layer 5 through the interlayer walls. The three-layer nested structure extends the heat exchange path between the cold air and the high-temperature flue gas, avoiding the excessive heat absorption problem of the traditional single channel. The double-layer cold air channel provides circulation space for large air volume, realizing the coordinated output of low temperature and large air volume.

[0033] In this embodiment, as Figure 1 As shown, the top of the outer casing 1 is provided with a flue gas outlet 11, which is connected to one end of the flue gas layer 5.

[0034] The flue gas outlet 11 at the top of the outer shell 1 is connected to the flue gas layer 5, forming a directional flue gas emission channel to ensure that the flue gas is smoothly discharged after heat exchange. This ensures the continuity of flue gas flow, prevents local overheating or reduced heat exchange efficiency caused by stagnation, facilitates subsequent centralized flue gas treatment, and reduces pollution.

[0035] Specifically, such as Figure 2 , Figure 3 As shown, a cold air inlet 12 is provided on one side wall of the outer casing 1, and the inner side of the cold air inlet 12 is connected to one end of the outer cold air layer 6. A hot air outlet 13 is provided on the other side wall of the outer casing 1, and the inner side of the hot air outlet 13 is connected to one end of the inner cold air layer 7.

[0036] Cold air enters the outer cold air layer 6 through the cold air inlet 12 on one side of the outer shell 1. After preliminary heat exchange, it enters the inner cold air layer 7 through the air vent 9 for further heat exchange, and finally exits from the hot air outlet 13 on the other side, forming a "secondary heat exchange" path. The staged heat exchange of cold air avoids a sudden temperature rise and precisely controls the temperature of the hot air; the inlet and outlet are located on opposite sides to ensure smooth airflow and provide a structural basis for large air volume output.

[0037] Furthermore, such as Figure 1 As shown, the outer cold air layer 6 and the inner cold air layer 7 are connected at the ends away from the burner 3 through the air inlet 9.

[0038] The outer cold air layer 6 and the inner cold air layer 7 are connected by an air inlet 9 at the end away from the burner 3, allowing the cold air to undergo preliminary heat exchange in the outer layer before entering the inner layer for secondary heat exchange, forming a continuous process. This achieves staged heat exchange of the cold air, improving heat utilization while avoiding excessively high temperatures and ensuring that the hot air remains stable in the low-temperature range of 50-80℃.

[0039] Furthermore, such as Figure 1 As shown, the interior of the flue gas layer 5 is equipped with spiral fins 51 to slow down the flue gas velocity and facilitate heat exchange.

[0040] The spiral fins 51 within the flue gas layer 5 increase the flow resistance of the flue gas to reduce the flow velocity, while simultaneously increasing the contact area with the interlayer wall. This prolongs the residence time of the flue gas within the flue gas layer 5, allowing heat to be fully transferred to the cold air layer and improving heat exchange efficiency. The spiral structure guides the flow direction of the flue gas, avoiding local dead zones and ensuring uniform heat exchange.

[0041] Furthermore, such as Figure 1 As shown, the outer cold air layer 6 has several outer fins 61 installed inside, and the inner cold air layer 7 has several inner fins 71 installed inside.

[0042] The outer fins 61 in the outer cold air layer 6 and the inner fins 71 in the inner cold air layer 7 increase the contact area between the cold air and the interlayer wall, and also divert and guide the airflow. This improves the heat exchange efficiency between the cold air and the wall, reduces heat loss, and the fins break up the airflow boundary layer, making the cold air more evenly heated and avoiding temperature fluctuations in the hot air.

[0043] Furthermore, such as Figure 1 As shown, the outer fins 61 and the inner fins 71 are arranged at equal intervals along the airflow direction inside the shell 1.

[0044] The outer fins 61 and inner fins 71 are arranged at equal intervals along the airflow direction inside the outer shell 1, uniformly dividing the cold air into multiple parallel airflows. This ensures that the cold air is evenly distributed within the interlayer, avoids excessive local heat exchange, and improves the stability of the hot air temperature; the equal spacing design facilitates processing and reduces production costs.

[0045] Furthermore, such as Figure 1 As shown, a support 4 is installed at the bottom of the outer casing 1.

[0046] The support 4 at the bottom of the outer casing 1 provides stable support for the equipment, ensuring it remains level during operation. This enhances the overall stability of the equipment, reduces component loosening or damage caused by vibration, and extends its service life; it also facilitates placement and fixing in different locations, improving installation flexibility.

[0047] In operation, the low-temperature, high-volume hot blast stove of this invention first starts the burner 3, which then burns fuel in the combustion chamber 2 to generate high-temperature flue gas. The flue gas flows along the interior of the combustion chamber 2 towards the end furthest from the burner 3, and then enters the intermediate flue gas layer 5 through the fire port 8. Within the flue gas layer 5, the spiral fins 51 slow down the flue gas flow rate, allowing the high-temperature flue gas to flow fully through the entire flue gas layer 5, and finally exit from the flue gas outlet 11 at the top of the outer shell 1.

[0048] Cold air entry and initial heat exchange: Outside cold air enters the outer cold air layer 6 through the cold air inlet 12 on one side of the outer shell 1. During the flow, the outer fins 61 inside the outer cold air layer 6 evenly distribute the cold air, increasing the contact area between the cold air and the outer wall of the flue gas layer 5. At this time, the cold air and the high-temperature flue gas inside the flue gas layer 5 undergo the first heat exchange through the wall surface, and the temperature initially rises.

[0049] Secondary heat exchange and hot air output: The cold air, having completed the initial heat exchange, enters the inner cold air layer 7 through the air vent 9 between the outer cold air layer 6 and the inner cold air layer 7. In the inner cold air layer 7, the inner fins 71 further guide the cold air flow and increase the heat exchange area, allowing the cold air to undergo a second heat exchange with the inner wall of the flue gas layer 5, further raising the temperature to a low-temperature range of 50-80℃. Finally, the hot air, after two heat exchanges, is discharged from the hot air outlet 13 on the other side of the outer shell 1, meeting the requirements for low-temperature, high-volume operation.

[0050] Overall stable operation: Throughout the entire operation, the support 4 at the bottom of the outer shell 1 ensures the stable placement of the equipment. The synergistic effect of the multi-layer sandwich and fin structure not only makes full use of heat but also avoids excessive heat absorption by cold air, which can lead to excessively high temperatures. At the same time, the dual-channel design ensures a large air volume flow, achieving efficient and stable low-temperature hot air output.

[0051] Finally, it should be noted that the electronic components in the burner 3 and other components in this embodiment are all general standard parts or parts known to those skilled in the art. Their structure and principle can be known to those skilled in the art through technical manuals or conventional experimental methods. In the idle part of this device, all the above-mentioned electrical components are connected by wires. The specific connection method should refer to the working order of each electrical component in the above working principle to complete the electrical connection. All of these are technologies known in the art.

[0052] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A low-temperature, high-volume hot-air furnace comprising a housing (1), characterized in that: The combustion chamber (2) is installed inside the outer shell (1). Three layers are arranged between the outside of the combustion chamber (2) and the inside of the outer shell (1). The middle layer is the flue gas layer (5), the outer side of the flue gas layer (5) is the outer cold air layer (6), and the inner side of the flue gas layer (5) is the inner cold air layer (7). A burner (3) is installed at one end of the combustion chamber (2), and the other end of the combustion chamber (2) is connected to the flue gas layer (5) through a fire port (8).

2. The low-temperature, high-volume, hot-air furnace according to claim 1, characterized in that: The top of the outer shell (1) is provided with a flue gas outlet (11), which is connected to one end of the flue gas layer (5).

3. The low-temperature, high-volume, hot-air furnace according to claim 1, characterized in that: A cold air inlet (12) is provided on one side wall of the outer shell (1), and the inner side of the cold air inlet (12) is connected to one end of the outer cold air layer (6). A hot air outlet (13) is provided on the other side wall of the outer shell (1), and the inner side of the hot air outlet (13) is connected to one end of the inner cold air layer (7).

4. The cryogenic high-volume air heater of claim 3, wherein: The outer cold air layer (6) and the inner cold air layer (7) are connected at the ends away from the burner (3) through the air inlet (9).

5. The cryogenic high-volume air heater of claim 1, wherein: The flue gas layer (5) is equipped with spiral fins (51) inside to slow down the flue gas velocity and facilitate heat exchange.

6. The cryogenic high-volume air heater of claim 1, wherein: The outer cold air layer (6) has several outer fins (61) installed inside, and the inner cold air layer (7) has several inner fins (71) installed inside.

7. The cryogenic high-volume air heater of claim 6, wherein: The outer fins (61) and inner fins (71) are arranged at equal intervals along the airflow direction inside the shell (1).

8. The cryogenic high-volume air heater of claim 1, wherein: A support (4) is installed at the bottom of the outer casing (1).

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