Hot air circulating device of tunnel type baking furnace

Abstract

The utility model discloses a hot air circulating device of a tunnel type baking oven, which comprises a circulating air duct, a circulating fan and a heat exchange component, the circulating air duct comprises an air inlet pipeline and an air return pipeline, and the air inlet pipeline is provided with a heat exchange chamber; the heat exchange assembly comprises a burner, a heat exchanger and a waste gas exhaust pipe, the burner is arranged outside the heat exchange cavity, the heat exchanger is arranged inside the heat exchange cavity, the input end of the heat exchanger is communicated with the burner, the output end of the heat exchanger is communicated with the waste gas exhaust pipe, and the output end of the waste gas exhaust pipe extends out of the heat exchange cavity. The hot air circulation device of the tunnel type baking furnace has the advantages of being uniform in baking effect and high in heat utilization rate, the production quality can be effectively improved, and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel furnaces, in particular to a hot air circulation device for a tunnel type baking furnace. Background Art

[0002] Food processing tunnel furnaces are tunnel-type mechanical equipment that bakes food through heat conduction, convection, and radiation. This type of tunnel furnace is mainly used in industrialized food enterprises. It is characterized by large-scale continuous or intermittent baking, continuous production, and high production efficiency. At present, tunnel baking furnaces mostly use multiple heating devices in the furnace to increase the temperature in the furnace and bake the materials. However, the baking temperature of materials closer to the heating device is higher, and the baking temperature of materials farther from the heating device is lower, resulting in uneven baking of the materials, poor production quality, and certain limitations. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies in the prior art and provide a hot air circulation device for a tunnel type baking furnace which has uniform baking effect, high heat utilization rate, can effectively improve production quality and reduce production costs.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] A hot air circulation device of a tunnel type baking oven, comprising a circulating air duct, a circulating fan for driving the gas in the circulating air duct to flow, and a heat exchange component for performing convection heat exchange with the gas in the circulating air duct, wherein the circulating air duct comprises an air inlet duct and a return air duct connected to a baking oven body, an input end of the circulating fan is connected to the return air duct, an output end of the circulating fan is connected to the air inlet duct, and a heat exchange chamber is provided on the air inlet duct;

[0006] The heat exchange assembly includes a burner, a heat exchanger and an exhaust gas pipe. The burner is arranged outside the heat exchange chamber, and the heat exchanger is arranged inside the heat exchange chamber. The input end of the heat exchanger is connected to the burner, and the output end of the heat exchanger is connected to the exhaust gas pipe. The output end of the exhaust gas pipe extends to the outside of the heat exchange chamber.

[0007] As a further improvement of the above technical solution:

[0008] The heat exchanger includes several groups of heat exchange tubes, input end covers, connecting end covers and output end covers. The heat exchange tubes include primary heat exchange tubes and secondary heat exchange tubes. The burner, the input end cover, the primary heat exchange tubes, the connecting end cover, the secondary heat exchange tubes, the output end cover and the exhaust gas pipe are connected in sequence.

[0009] The outer wall of the heat exchange tube is provided with multiple groups of heat dissipation fin structures.

[0010] The circulating fan is provided with a dehumidification port for discharging moisture from the gas in the circulating air duct.

[0011] The circulating fan is provided with a fresh air compensation port for replenishing fresh air into the circulating air duct.

[0012] The air inlet duct is provided with a lower air blowing pipe for branching and outputting to the lower part of the baking furnace body, and an upper air blowing pipe for branching and outputting to the upper part of the baking furnace body.

[0013] Compared with the prior art, the advantages of the utility model are:

[0014] The hot air circulation device of the tunnel baking furnace of the utility model comprises a circulating air duct, a circulating fan and a heat exchange component which are connected with the baking furnace body. The gas after baking the materials in the baking furnace body is transported to the circulating fan through the return air duct. Driven by the circulating fan, the gas is transported to the heat exchange chamber and performs convection heat exchange with the heat exchanger. The high-temperature gas after heat exchange is transported back to the baking furnace body through the air inlet duct for baking, thus forming a hot air circulation. External cold air will not flow into the furnace, so that the temperature field in the furnace is stable, the baking effect on the materials is uniform, the production quality is effectively improved, and the heat will not be lost to the outside of the furnace. The heat utilization rate is high, which can reduce energy consumption and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is an example diagram of a hot air circulation device applied to a tunnel baking oven.

[0016] Figure 2 Schematic diagram of the working principle of the hot air circulation device.

[0017] Figure 3 It is a structural schematic diagram of the circulation fan and heat exchange component.

[0018] Figure 4 This is a schematic diagram of the structure of the circulating fan and heat exchange component from another angle.

[0019] Figure 5 Schematic diagram of the working principle of the heat exchange component.

[0020] Legend:

[0021] 1. Circulating air duct; 101. Air inlet duct; 1011. Downward blowing air duct; 1012. Upward blowing air duct; 102. Return air duct; 103. Heat exchange chamber; 2. Circulating fan; 201. Dehumidification port; 202. Fresh air compensation port; 3. Heat exchange component; 301. Burner; 302. Heat exchanger; 3021. Heat exchange tube; 3022. Input end cover; 3023. Connecting end cover; 3024. Output end cover; 303. Exhaust pipe; 4. Primary heat exchange tube; 5. Secondary heat exchange tube. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0023] like Figure 1 and Figure 2 As shown, the hot air circulation device of the tunnel baking oven of this embodiment includes a circulating air duct 1, a circulating fan 2 for driving the gas flow in the circulating air duct 1, and a heat exchange component 3 for performing convective heat exchange with the gas in the circulating air duct 1. The circulating air duct 1 includes an air inlet duct 101 and a return air duct 102 connected to the baking furnace body, the input end of the circulating fan 2 is connected to the return air duct 102, the output end of the circulating fan 2 is connected to the air inlet duct 101, and a heat exchange chamber 103 is provided on the air inlet duct 101; the heat exchange component 3 includes a burner 301, a heat exchanger 302 and an exhaust gas pipe 303, the burner 301 is arranged outside the heat exchange chamber 103, the heat exchanger 302 is arranged inside the heat exchange chamber 103, the input end of the heat exchanger 302 is connected to the burner 301, the output end of the heat exchanger 302 is connected to the exhaust gas pipe 303, and the output end of the exhaust gas pipe 303 extends to the outside of the heat exchange chamber 103. The hot air circulation device of the tunnel baking furnace includes a circulating air duct 1, a circulating fan 2 and a heat exchange component 3 connected to the baking furnace body. The gas after baking the material in the baking furnace body is transported to the circulating fan 2 through the return air duct 102. Driven by the circulating fan 2, the gas is transported to the heat exchange chamber 103 and performs convection heat exchange with the heat exchanger 302. The high-temperature gas after heat exchange is re-transported into the baking furnace body through the air inlet duct 101 for baking, forming a hot air circulation. External cold air will not flow into the furnace, so that the temperature field in the furnace is stable, the baking effect on the material is uniform, and the production quality is effectively improved. Moreover, the heat will not be lost to the outside of the furnace, the heat utilization rate is high, and it can reduce energy consumption and reduce production costs.

[0024] like Figures 3 to 5As shown, preferably, the heat exchanger 302 includes several groups of heat exchange tubes 3021, an input end cover 3022, a connecting end cover 3023 and an output end cover 3024, the heat exchange tubes 3021 include a primary heat exchange tube 4 and a secondary heat exchange tube 5, the burner 301, the input end cover 3022, the primary heat exchange tube 4, the connecting end cover 3023, the secondary heat exchange tube 5, the output end cover 3024 and the exhaust gas pipe 303 are connected in sequence. In the present embodiment, a plurality of groups of heat exchange tubes 3021 are divided into primary heat exchange tubes 4 and secondary heat exchange tubes 5 according to their working process. The high-temperature flue gas (about 1000°C) generated by the combustion of the burner 301 enters the primary heat exchange tube 4 through the input end cover 3022, and undergoes the first convective heat exchange with the gas in the heat exchange chamber 103 through the primary heat exchange tube 4. Then, the high-temperature flue gas enters the secondary heat exchange tube 5 from the primary heat exchange tube 4 through the connecting end cover 3023, and undergoes the second convective heat exchange with the gas in the heat exchange chamber 103 through the secondary heat exchange tube 5. Finally, the flue gas enters the exhaust gas pipe 303 through the output end cover 3024 and is discharged to the outside, with high heat utilization rate. In other embodiments, a plurality of groups of heat exchange tubes 3021 can also be divided into tertiary heat exchange tubes for the third convective heat exchange with the gas in the heat exchange chamber 103, quaternary heat exchange tubes for the fourth convective heat exchange with the gas in the heat exchange chamber 103, and so on, and is not limited to the present embodiment.

[0025] It should be noted that in this example, the gas flow direction in the heat exchange chamber 103 is from the secondary heat exchange tube 5 to the primary heat exchange tube 4. The secondary heat exchange tube 5 uses the flue gas with a relatively low temperature after the first heat exchange to preheat the gas (80°C) in the heat exchange chamber 103, and then uses the high-temperature flue gas in the primary heat exchange tube 4 to heat the gas in the circulating air duct 1, thereby raising the temperature of the gas to 260°C-300°C and entering the air inlet duct 101.

[0026] Preferably, the outer wall of the heat exchange tube 3021 is provided with multiple groups of heat dissipation fin structures. When the gas in the heat exchange chamber 103 passes over the heat exchange tube 3021, the heat exchange area between the gas and the heat exchange tube 3021 can be increased, thereby effectively improving the heat exchange efficiency.

[0027] Preferably, the circulating fan 2 is provided with a dehumidification port 201 for discharging moisture from the gas in the circulating air duct 1. Products such as bread dough will evaporate moisture during the baking process. Excess moisture in the circulating air duct 1 can be discharged through the dehumidification port 201, thereby ensuring that the humidity in the baking furnace is maintained at a normal state and preventing excessive humidity from affecting the baking quality of the product.

[0028] Preferably, the circulating fan 2 is provided with a fresh air compensation port 202 for replenishing fresh air into the circulating air duct 1. The circulating fan 2 draws fresh air into the circulating air duct 1 through the fresh air compensation port 202, which can make the circulating air duct 1 and the baking furnace body reach a constant temperature and pressure state, which is beneficial to extending the service life of the equipment.

[0029] Preferably, the air inlet duct 101 is provided with a lower air blowing pipe 1011 for outputting to the lower part of the baking furnace body, and an upper air blowing pipe 1012 for outputting to the upper part of the baking furnace body. In this embodiment, the gas (260°C-300°C) in the air inlet duct 101 can pass through the lower air blowing pipe 1011 and the upper air blowing pipe 1012, and the lower and upper surfaces of products such as bread embryos can be evenly baked at the same time, with good baking effect, effectively improving product quality.

[0030] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and changes obtained without departing from the technical concept of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A hot air circulation device for a tunnel baking oven, characterized in that: The invention comprises a circulating air duct (1), a circulating fan (2) for driving the gas in the circulating air duct (1) to flow, and a heat exchange component (3) for performing convective heat exchange with the gas in the circulating air duct (1), wherein the circulating air duct (1) comprises an air inlet duct (101) and a return air duct (102) which are connected to a baking furnace body, an input end of the circulating fan (2) is connected to the return air duct (102), an output end of the circulating fan (2) is connected to the air inlet duct (101), and a heat exchange chamber (103) is provided on the air inlet duct (101); The heat exchange component (3) comprises a burner (301), a heat exchanger (302) and an exhaust gas pipe (303); the burner (301) is arranged outside the heat exchange chamber (103); the heat exchanger (302) is arranged inside the heat exchange chamber (103); the input end of the heat exchanger (302) is connected to the burner (301); the output end of the heat exchanger (302) is connected to the exhaust gas pipe (303); and the output end of the exhaust gas pipe (303) extends to the outside of the heat exchange chamber (103).

2. The hot air circulation device of the tunnel baking oven according to claim 1, characterized in that: The heat exchanger (302) comprises a plurality of groups of heat exchange tubes (3021), an input end cover (3022), a connecting end cover (3023) and an output end cover (3024); the heat exchange tubes (3021) comprise a primary heat exchange tube (4) and a secondary heat exchange tube (5); the burner (301), the input end cover (3022), the primary heat exchange tube (4), the connecting end cover (3023), the secondary heat exchange tube (5), the output end cover (3024) and the exhaust gas pipe (303) are sequentially connected.

3. The hot air circulation device of the tunnel type baking oven according to claim 2, characterized in that: The outer wall of the heat exchange tube (3021) is provided with multiple groups of heat dissipation fin structures.

4. The hot air circulation device of the tunnel baking oven according to claim 1, characterized in that: The circulating fan (2) is provided with a dehumidification port (201) for discharging moisture from the gas in the circulating air duct (1).

5. The hot air circulation device of the tunnel baking oven according to claim 1, characterized in that: The circulating fan (2) is provided with a fresh air compensation port (202) for replenishing fresh air into the circulating air duct (1).

6. The hot air circulation device of the tunnel baking oven according to claim 1, characterized in that: The air inlet duct (101) is provided with a lower air blowing pipe (1011) for branching the air to the lower part of the baking furnace body for output, and an upper air blowing pipe (1012) for branching the air to the upper part of the baking furnace body for output.

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