Tunnel drying oven and preheating laminar flow mechanism thereof

Abstract

The embodiment of the utility model provides a tunnel drying oven and a preheating laminar flow mechanism of the tunnel drying oven, and the tunnel drying oven comprises a box body outer cover which comprises a feed port and a discharge port; the airflow conveying assembly comprises an impeller device and a fan cover part, the airflow conveying assembly is arranged in the box body outer cover and is close to the top of the box body outer cover, and the impeller device is arranged in the fan cover part; the material conveying device penetrates through the box body outer cover and is located on the side, away from the top of the box body outer cover, of the airflow conveying assembly. The first filtering device is arranged on the side, away from the top of the box body outer cover, of the fan cover component. According to the tunnel oven, the impeller device is arranged in the fan cover component, the fan cover component can improve airflow guidance quality and has the function of a volute, the overall height of the tunnel oven is remarkably reduced, and the tunnel oven is suitable for places with different spaces.

Description

Technical Field

[0001] The utility model relates to the technical field of food and medicine ovens, in particular to a tunnel oven and a preheating laminar flow mechanism of a tunnel oven. Background Art

[0002] Due to their excellent physical and chemical properties, glass containers are widely used in product packaging. Effective drying of these glass containers filled with food or medicine has always been an important technical challenge in the industry. In traditional tunnel ovens, the volute fans are used. When the air flow flows inside the volute, it will be affected by factors such as the shape and size of the volute and its interaction with the impeller, resulting in relatively poor air flow stability, an increased possibility of generating turbulence, and it is difficult to form an ideal laminar flow. At the same time, the existing tunnel ovens usually have a large volume and heavy weight, which limits the layout of the space site and is inconvenient for transportation. Summary of the Utility Model

[0003] Therefore, in order to overcome at least some of the defects and deficiencies in the prior art, the embodiments of the present utility model provide a tunnel oven and a preheating laminar flow mechanism of a tunnel oven.

[0004] Specifically, on the one hand, the preheating laminar flow mechanism provided by the embodiment of the present utility model includes: an outer box cover, including a feed inlet and a discharge outlet. An air flow conveying component, including an impeller device and a wind hood component, the air flow conveying component is arranged inside the outer box cover and near the top of the outer box cover, and the impeller device is arranged inside the wind hood component. A material conveying device, passing through the outer box cover and located on one side of the air flow conveying component away from the top of the outer box cover. A first filtering device, arranged on one side of the wind hood component away from the top of the outer box cover.

[0005] In the embodiment of the present application, the preheating laminar flow mechanism further includes a second filtering device, and the second filtering device is arranged on the top surface of the outer box cover.

[0006] In the embodiment of the present application, the top of the wind hood component has an air inlet end, and the impeller device is arranged at the top air inlet end of the wind hood component.

[0007] In the embodiment of the present application, the impeller device includes a wind guide cylinder, a wind guide cylinder mounting plate and an impeller, and the impeller is arranged on one side of the wind guide cylinder away from the wind guide cylinder mounting plate; the wind guide cylinder is fixed to the wind guide cylinder mounting plate, and the wind guide cylinder mounting plate is connected to the position of the air inlet end at the top of the wind hood component.

[0008] In an embodiment of the present application, the impeller device further includes a motor and a motor mounting bracket; the motor is fixed on the motor mounting bracket and is disposed on a side of the impeller away from the top of the outer casing of the box; the output end of the motor is connected to the impeller.

[0009] In an embodiment of the present application, the air hood component includes an air hood body and an air hood mounting bracket; the air hood body includes a plurality of side walls and further includes an extension plate extending from the bottom of the side walls towards the middle of the outer casing of the box, and the air hood mounting bracket is fixed to the extension plate of the air hood body.

[0010] In an embodiment of the present application, the preheating laminar flow mechanism further includes a lifting device, one end of the lifting device is connected to the air hood component, and the other end is connected to the outer casing of the box; the lifting device is used to drive the air hood body to approach or move away from the first filtering device.

[0011] In an embodiment of the present application, one end of the lifting device is connected to the air hood component through the air hood mounting bracket.

[0012] In an embodiment of the present application, the lifting height of the lifting device is 0 mm to 30 mm.

[0013] On the other hand, a tunnel oven provided by an embodiment of the present utility model includes a heating laminar flow mechanism, a cooling laminar flow mechanism, and the preheating laminar flow mechanism as described in any one of the foregoing, and the preheating laminar flow mechanism, the heating laminar flow mechanism, and the cooling laminar flow mechanism are connected in sequence.

[0014] As can be seen from the above, the above technical features of the present utility model may have one or more of the following beneficial effects:

[0015] 1. The impeller device is disposed inside the air hood component. The air hood component can improve the air flow directivity and has the function of a volute. This design significantly reduces the overall height of the tunnel oven, making the requirements for space during installation and use of the oven lower and adapting to more different production environments.

[0016] 2. The air hood component can improve the flow state of the air flow, make the air flow more concentrated and orderly, replace the effect of the volute, achieve uniform distribution of the air flow, provide a stronger and more stable air flow, and ensure uniform temperature and air flow inside the oven.

[0017] 3. The efficient preheating laminar flow mechanism and the optimized design of the air flow conveying component can more accurately control the heat and air flow, reduce energy waste, and lower production costs. Description of the Drawings

[0018] To more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 Schematic structural diagram of a preheating laminar flow mechanism provided by an embodiment of the present application;

[0020] Figure 2 Partial structural diagram of the preheating laminar flow mechanism provided by an embodiment of the present application;

[0021] Figure 3 Schematic structural diagram of the air flow conveying component of the preheating laminar flow mechanism provided by an embodiment of the present application;

[0022] Figure 4 Schematic overall structural diagram of a tunnel oven provided by an embodiment of the present application.

[0023]

Description of the reference numerals

[0024] 1: Preheating laminar flow mechanism; 12: Air flow conveying component; 121: Air hood component; 121-1: Air hood body; 121-2: Air hood mounting frame; 121-3: Extension plate; 122: Impeller device; 122-1: Air guide cylinder; 122-2: Impeller; 122-3: Air guide cylinder mounting plate; 122-4: Motor; 122-5: Motor mounting frame; 13: Outer casing of the oven; 14: First filtering device; 15: Material conveying device; 16: Second filtering device; 17: Lifting device; 2: Heating laminar flow mechanism; 3: Cooling laminar flow mechanism. Specific embodiments

[0025] In order to make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings. Obviously, the described embodiments are only some embodiments of the present utility model, rather than all embodiments. Based on the embodiments described in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present utility model.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, top, bottom) in the embodiments of the present utility model are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture (as shown in the attached drawings). If the specific posture changes, the directional indications will also change accordingly. In addition, in the embodiments of the invention and the claims, the term "vertical" means that the included angle between two elements is 90° or there is a deviation of -5° to +5°, and the term "parallel" means that the included angle between two elements is 0° or there is a deviation of -5° to +5°.

[0027] In the embodiments of the present utility model, descriptions such as "first" and "second" are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features.

[0028] In the embodiments of the present application, a preheating laminar flow mechanism 1 of a tunnel oven provided by the embodiments of the present utility model is shown in Figure 1 Figure, and includes an outer casing 13 of the oven, an air flow conveying assembly 12, a material conveying device 15, and a first filtering device 14.

[0029] Specifically, the outer casing 13 of the oven includes a feed inlet and a discharge outlet. The feed inlet and the discharge outlet can be respectively arranged at both ends of the outer casing 13 of the oven. The front end of the material conveying device 15 is connected to the feed inlet, and the rear end is connected to the discharge outlet, realizing a continuous process of material input and output. Exemplarily, the outer casing 13 of the oven can be made of stainless steel.

[0030] The air flow conveying assembly 12 includes an impeller device 122 and a wind hood component 121. The air flow conveying assembly 12 is arranged inside the outer casing 13 of the oven and near the top of the outer casing 13. The impeller device 122 is arranged inside the wind hood component 121. The impeller device 122 is fixed to the wind hood component 121 and forms an integral structure. Exemplarily, the impeller device 122 can be a shell-less fan, and the wind hood component 121 can be made of stainless steel.

[0031] The material conveying device 15 passes through the outer casing 13 of the oven and is located on the side of the air flow conveying assembly 12 away from the top of the outer casing 13. Both ends of the conveyor belt of the material conveying device 15 are respectively connected to the feed inlet and the discharge outlet of the outer casing 13 of the oven to ensure that the container can smoothly enter the inside of the outer casing 13. Exemplarily, the material conveying device 15 can be a conveyor belt.

[0032] The first filtering device 14 is arranged on one side of the hood component 121 away from the top of the outer casing 13 of the box. Exemplarily, the first filtering device 14 can be made of fiberglass.

[0033] In this embodiment, the air flow passes through the preliminary filtration of the second filtering device 16 from the top of the outer casing 13 of the box, enters the impeller device 122 from the air guide cylinder 122-1, and combines with the hood component 121 to make the air flow have a certain guiding effect and be conveyed away from the top of the outer casing 13 of the box. Then it passes through the first filtering device 14 for re-filtration and reaches the material conveying device 15 in the cavity evenly and dispersedly, forming an ideal preheating laminar flow, so that each object to be dried is blown by the laminar flow gas to achieve the preheating and drying effect. In the preheating laminar flow mechanism 1 of the present application, the combination of the impeller device 122 and the hood component 121 in the air flow conveying assembly 12 is adopted, so that the generated laminar flow air can make the preheated air more evenly distributed in the cavity of the outer casing 13 of the box through which the material conveying device 15 passes, reduce the temperature gradient, and achieve a more stable preheating effect; and the impeller device 122 is arranged in the hood component 121, and the hood component 121 replaces the effect of the traditional volute, making the entire preheating laminar flow mechanism 1 more compact, which is beneficial to improving the space utilization rate in a limited space. At the same time, the first filtering device 14 can more effectively remove tiny particles, impurities and microorganisms in the air, reduce the impurities and dust on the surface of the object to be dried, and ensure the cleanliness of the object to be dried; and continuously filter the air in the preheating laminar flow mechanism 1, reduce the damage of dust and impurities to the equipment and internal components, reduce the frequency of equipment failures, and thus reduce the cost of maintenance and replacement of components.

[0034] In the embodiment of the present application, refer to Figure 2 As shown, the preheating laminar flow mechanism 1 further includes a second filtering device 16, and the second filtering device 16 is arranged on the top surface of the outer casing 13 of the box. Specifically, the air inlet of the preheating laminar flow mechanism 1 is located at the top of the outer casing 13 of the box, the second filtering device 16 is arranged at the air inlet of the outer casing 13 of the box, and is in the same vertical direction as the air flow conveying assembly 12. Exemplarily, the second filtering device 16 can be made of non-woven fabric, and the outer periphery is wrapped by stainless steel or aluminum alloy.

[0035] In this embodiment, the second filtering device 16 preliminarily filters the air entering the preheating laminar flow mechanism 1, reducing the dust content in the air and providing a sterile environment for the internal heating and drying processes. Moreover, it blocks large particle contaminants, reduces the wear and blockage of the internal air flow conveying component 12 of the preheating laminar flow mechanism 1, ensures the normal operation of the equipment, reduces the failure rate, maintains a good heat transfer efficiency, and saves energy consumption to a certain extent. At the same time, the second filtering device 16 has a relatively low cost, but it plays an important role in protecting the overall performance of the preheating laminar flow mechanism 1 and extending the service life of the first filtering device 14, and has a high cost performance. Secondly, setting the second filtering device 16 at the top of the outer casing 13 of the box is more aesthetically pleasing in terms of the overall structure.

[0036] In the embodiment of the present application, referring to Figure 2 As shown, the top of the air hood component 121 has an air inlet end, and the impeller device 122 is arranged at the air inlet end at the top of the air hood component 121. Specifically, the air hood component 121 is built inside the outer casing 13 of the box and is close to the air inlet at the top of the outer casing 13, and the impeller device is inside the air hood component. Exemplarily, the air hood component 121 can be made of stainless steel.

[0037] In this embodiment, the impeller device 122 is installed at the air inlet end at the top of the air hood component 121 to ensure that continuous, uniform, and stable air enters the preheating laminar flow mechanism 1, creating good conditions for heat exchange and air circulation inside the preheating laminar flow mechanism 1. Moreover, the air inlet speed and air volume can be reasonably controlled. Installing the impeller device 122 at the air inlet position makes it easier to inspect, maintain, and clean the impeller device 122, ensuring the normal operation and service life of the impeller device 122.

[0038] In the embodiment of the present application, referring to Figure 3As shown, the impeller device 122 includes a wind guide cylinder 122-1, a wind guide cylinder mounting plate 122-3, and an impeller 122-2. The impeller 122-2 is disposed on a side of the wind guide cylinder 122-1 away from the wind guide cylinder mounting plate 122-3. The wind guide cylinder 122-1 is fixed to the wind guide cylinder mounting plate 122-3, and the wind guide cylinder mounting plate 122-3 is connected to a position of the air inlet end at the top of the wind hood component 121. Specifically, the wind guide cylinder 122-1 is disposed at the air inlet end, fixed to the wind guide cylinder mounting plate 122-3, and integrally connected to the wind hood component 121. Airflow enters the impeller device 122 through the wind guide cylinder 122-1. The high-speed rotation of the impeller 122-2 promotes air flow, converts mechanical energy into kinetic energy of the air, thereby generating an air current, enabling the impeller device 122 to achieve the function of air supply or exhaust, and the rotation mode and the layout of the blades contribute to forming a relatively uniform and stable air current. Exemplarily, the wind guide cylinder 122-1 and the wind guide cylinder mounting plate 122-3 may be made of stainless steel.

[0039] In this embodiment, due to the function of the wind guide cylinder 122-1, the air intake volume is increased, the air renewal speed inside the outer casing 13 of the box is improved, which helps to discharge moisture and waste gas faster, and maintain a dry and sterile environment inside the outer casing 13 of the box. At the same time, by reasonably arranging the air intake through the wind guide cylinder 122-1, the uniform transfer of heat can be promoted, energy waste can be reduced, and the overall energy utilization efficiency inside the preheating laminar flow mechanism 1 can be improved.

[0040] In the embodiment of the present application, refer to Figure 3 As shown, the impeller device 122 further includes a motor 122-4 and a motor mounting bracket 122-5. The motor 122-4 is fixed on the motor mounting bracket 122-5 and is disposed on a side of the impeller 122-2 away from the top of the outer casing 13 of the box. Specifically, the motor 122-4 is fixed to the motor mounting bracket 122-5 and connected to a side wall of the impeller 122-2. Among them, the impeller 122-2 can be selectively directly or indirectly connected to the motor 122-4 through a shaft. The shaft of the motor 122-4 will be closely fitted with the central axis of the impeller and fixed by means of keys, splines, etc., to ensure that the rotation of the motor 122-4 can be accurately and stably transmitted to the impeller 1222-4, driving the impeller to rotate at a high speed. And the top of the impeller 122-2 is connected to and integrated with the wind guide cylinder 122-1. Exemplarily, the impeller 122-2 is a centrifugal impeller.

[0041] In this embodiment, refer to Figure 3As shown, the impeller device 122 includes a motor 122-4 and a motor mounting bracket 122-5, both of which are built inside the wind hood component 121. The wind hood component 121 can prevent external objects from accidentally colliding with the motor 122-4, the impeller 122-2 or other components, reducing the risk of damage and failure of the impeller device 122 caused by collisions. It helps to regulate and concentrate the airflow generated by the impeller 122-2, reducing the scattering and turbulence of the airflow, thereby ensuring that the airflow entering the outer casing 13 of the box is more stable and uniform, which is beneficial to the temperature uniformity and heat exchange efficiency inside the preheating laminar flow mechanism 1. It can block the propagation of noise generated during the operation of the motor 122-4 to a certain extent, improve the noise level of the working environment, and reduce the interference to the operator.

[0042] Among them, in the present utility model, the impeller device 122 is arranged inside the wind hood component 121. The wind hood component 121 can improve the airflow directivity. The wind hood component 121 replaces the function of the volute, which can reduce the turbulence and energy loss of the airflow, thereby improving the efficiency of the impeller device 122 and generating a larger air volume and higher air pressure under the same power input. Its structure is more compact, occupies less space, is easier to install and layout in a limited space, reduces the overall structure of the tunnel oven, and makes it suitable for places with limited space, saving space resources. Secondly, the lower height of the outer casing 13 of the box facilitates the daily maintenance and repair of the equipment by the operator; from the perspective of transportation and installation, the outer casing 13 with a reduced height is easier to handle and place, reducing the limitations and risks brought by excessive height during transportation, and at the same time reducing the requirements and costs for lifting equipment during installation.

[0043] Reference Figure 3 As shown, in the embodiment of the present application, the wind hood component 121 includes a wind hood body 121-1 and a wind hood mounting bracket 121-2; the wind hood body 121-1 includes a plurality of side walls, and further includes an extension plate 121-3 extending from the bottom of the side walls towards the middle of the outer casing 13 of the box. The wind hood mounting bracket 121-2 is fixed to the extension plate 121-3 of the wind hood body 121-1. Specifically, both ends of the wind hood body 121-1 have extension plates extending towards the middle of the outer casing 13 of the box, enclosing a cavity that is open at both the upper and lower ends; at a position near the air inlet of the wind hood, the air guide cylinder mounting plate 122-3 is seamlessly connected to the extension plate, forming only one air flow channel, namely the air guide cylinder 122-1.

[0044] In this embodiment, the extension plate design of the wind hood body 121-1 can further constrain and guide the air flow, making the air flow more concentrated and directional, improving the utilization efficiency and conveying effect of the air flow. It helps prevent the air flow from leaking out from one end of the air guide cylinder 122-1, thereby ensuring that sufficient air volume and pressure reach the predetermined position and improving the overall performance of the impeller device 122 system. Moreover, it can reduce the turbulence and eddy currents generated at the edge of the wind hood body 121-1, thereby reducing the generation of air flow noise and improving the acoustic conditions of the working environment. At the same time, it also increases the structural strength and stability of the wind hood body 121-1, enabling it to better withstand the pressure of the internal air flow and external interference, and reducing the vibration and deformation of the wind hood body 121-1.

[0045] Reference Figure 2 As shown, in the embodiment of the present application, the preheating laminar flow mechanism 1 further includes a lifting device 17. One end of the lifting device 17 is connected to the wind hood component 121, and the other end is connected to the outer casing 13 of the box; the lifting device is used to drive the wind hood body 121-1 to approach or move away from the first filtering device 14. Specifically, the first filtering device 14 is located on one side away from the air inlet end of the wind hood body 121-1. The wind hood mounting frame 121-2 is fixedly connected to the extension plate of the wind hood body 121-1, and the wind hood body 121-1 is fixed on the wind hood mounting frame 121-2. The lifting device 17 can drive the wind hood body 121-1 to form a certain lifting space.

[0046] In the embodiment of the present application, one end of the lifting device 17 is connected to the wind hood component 121 through the wind hood mounting frame 121-2.

[0047] In the embodiment of the present application, the lifting height of the lifting device 17 is 0 mm to 30 mm. It should be noted that when the lifting height is greater than 0 mm and about 10 mm, a certain space can be obtained to replace the first filtering device 14. When the lifting height is 0 mm, the wind hood body 121-1 presses the first filtering device 14.

[0048] In this embodiment, the lifting device 17 enables the hood body 121-1 to press tightly against the first filtering device 14, ensuring a tight fit between the first filtering device 14 and the hood body 121-1, effectively preventing the leakage of unfiltered air, thereby guaranteeing the air quality entering the preheating laminar flow mechanism 1 and improving the production quality and safety of the product. When the first filtering device 14 needs to be replaced, the lifting device 17 can raise the hood body 121-1, providing sufficient operating space for the operator and making the replacement process more convenient and efficient. This not only reduces the time required to replace the first filtering device 14 and the downtime of the equipment, thereby improving production efficiency, but also reduces the working difficulty and labor intensity of the operator. Moreover, this liftable design increases the flexibility and maintainability of the equipment, and first filtering devices 14 of different specifications and models can achieve good installation and sealing by adjusting the height of the hood body 121-1, improving the compatibility of the equipment with different filtering devices.

[0049] On the other hand, referring to Figure 4 As shown, a tunnel oven includes a heating laminar flow mechanism 2, a cooling laminar flow mechanism 3, and the preheating laminar flow mechanism 1 as described in any one of the foregoing. The preheating laminar flow mechanism 1, the heating laminar flow mechanism 2, and the cooling laminar flow mechanism 3 are connected in sequence. Specifically, the heating laminar flow mechanism 2 is to raise the temperature inside the oven to achieve effective drying and sterilization of the containers. The cooling laminar flow mechanism 3 is to rapidly reduce the temperature of the containers after heat treatment to meet the requirement that the container temperature cannot exceed a certain temperature value during subsequent filling processes. The containers are transported from the feed inlet of the material conveying device 15 into the tunnel oven, first entering the preheating laminar flow mechanism. The containers are protected from contamination under the laminar flow and are gradually heated to a certain temperature; then they enter the heating laminar flow mechanism, where the temperature is raised to a set high temperature to achieve the effect of drying and sterilizing the containers; finally, the containers after heat treatment enter the cooling layer, and the temperature of the containers is rapidly reduced to keep the temperature of the containers stable within a suitable temperature range.

[0050] The tunnel oven provided in this embodiment adopts the preheating laminar flow mechanism of the above embodiment and has the same effects as the above preheating laminar flow mechanism, which will not be elaborated here.

[0051] In addition, it can be understood that the foregoing embodiments are only exemplary descriptions of the present invention. On the premise that the technical features do not conflict, the structures are not contradictory, and the invention purpose of the present invention is not violated, the technical solutions of the various embodiments can be arbitrarily combined and used.

[0052] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, indirect couplings or communication connections of devices or units, which can be electrical, mechanical, or other forms.

[0053] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A preheating laminar flow mechanism (1) for a tunnel oven, characterized in that: include: The outer casing (13) includes a feed inlet and a discharge outlet; An airflow conveying assembly (12) comprising an impeller device (122) and a wind shield component (121), wherein the airflow conveying assembly (12) is arranged inside the outer casing (13) of the box body and close to the top of the outer casing (13), and the impeller device (122) is arranged inside the wind shield component (121); A material conveying device (15) passes through the outer casing (13) and is located on a side of the airflow conveying component (12) away from the top of the outer casing (13); The first filter device (14) is arranged on a side of the wind shield component (121) away from the top of the box outer cover (13).

2. The preheating laminar flow mechanism (1) according to claim 1, characterized in that: The preheating laminar flow mechanism (1) further comprises a second filtering device (16), wherein the second filtering device (16) is arranged on the top surface of the outer casing (13).

3. The preheating laminar flow mechanism (1) according to claim 1, characterized in that: The top of the wind shield component (121) is provided with an air inlet end, and the impeller device (122) is arranged at the top air inlet end of the wind shield component (121).

4. The preheating laminar flow mechanism (1) according to claim 3, characterized in that: The impeller device (122) comprises an air guide tube (122-1), an air guide tube mounting plate (122-3) and an impeller (122-2); the impeller (122-2) is arranged on a side of the air guide tube (122-1) away from the air guide tube mounting plate (122-3); the air guide tube (122-1) is fixed to the air guide tube mounting plate (122-3), and the air guide tube mounting plate (122-3) is connected to the air inlet end position of the top of the wind cover component (121).

5. The preheating laminar flow mechanism (1) according to claim 4, characterized in that: The impeller device (122) further comprises a motor (122-4) and a motor mounting frame (122-5); the motor (122-4) is fixed on the motor mounting frame (122-5) and is arranged on a side of the impeller (122-2) away from the top of the box outer cover (13).

6. The preheating laminar flow mechanism (1) according to claim 1, characterized in that: The wind shield component (121) comprises a wind shield body (121-1) and a wind shield mounting frame (121-2); the wind shield body (121-1) comprises a plurality of side walls, and also comprises an extension plate (121-3) extending from the bottom of the side wall toward the middle of the box outer cover (13); the wind shield mounting frame (121-2) is fixed to the extension plate (121-3) of the wind shield body (121-1).

7. The preheating laminar flow mechanism (1) according to claim 6, characterized in that: The preheating laminar flow mechanism (1) further comprises a lifting device (17), one end of the lifting device (17) being connected to the wind hood component (121), and the other end being connected to the outer cover of the box body (13); the lifting device is used to drive the wind hood body (121-1) to move closer to or away from the first filtering device (14).

8. The preheating laminar flow mechanism (1) according to claim 7, characterized in that: One end of the lifting device (17) is connected to the wind shield component (121) via the wind shield mounting frame (121-2).

9. The preheating laminar flow mechanism (1) according to claim 7, characterized in that: The lifting height of the lifting device (17) is 0 mm to 30 mm.

10. A tunnel oven, characterized in that: It comprises a heating laminar flow mechanism (2), a cooling laminar flow mechanism (3) and a preheating laminar flow mechanism (1) as described in any one of claims 1 to 9, wherein the preheating laminar flow mechanism (1), the heating laminar flow mechanism (2) and the cooling laminar flow mechanism (3) are connected in sequence.

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