A tunnel furnace

Abstract

The present invention provides a tunnel oven, which comprises: a frame; an oven, which is mounted on the frame and has a baking cavity; a multi-layer conveyor belt, which is mounted on the frame and arranged at intervals along the height direction of the oven, and the extension paths of the multi-layer conveyor belts all pass through the baking cavity; and a heating device, which is mounted in the baking cavity. Since the tunnel oven has a multi-layer conveyor belt, the whole machine of the tunnel oven can be prevented from being too long, and production space can be saved.

Description

Technical Field

[0001] The invention relates to the technical field of surface printing layer drying, in particular to a tunnel furnace. Background Art

[0002] During the printing process of printed materials, the ink layer printed on the printed materials generally contains volatile solvents. In order to make the volatile solvents evaporate quickly, a drying device must be used to dry the ink layer on the printed materials to make the volatile solvents in the ink layer of the printed materials evaporate quickly. The tunnel furnace is a device used for drying and aging inks, which can dry the coatings printed on the surfaces of various materials. In actual production, the tunnel furnace needs to adapt to the drying needs of different batches and different customers. For example, some products need to maintain a longer baking time, and some products have a large batch number. Therefore, the tunnel furnace conveyor belt needs to ensure sufficient transmission length in the oven to meet the baking time. The tunnel furnace in the prior art is generally a single-layer conveyor belt structure with a large conveyor belt length. The whole machine needs to occupy a large space, which easily leads to insufficient manufacturing space and high production costs. Summary of the invention

[0003] The main purpose of the present invention is to provide a tunnel furnace, aiming to solve the problem in the prior art that the tunnel furnace is large in size and occupies a large space.

[0004] To achieve the above object, the present invention provides a tunnel furnace, which comprises: a frame;

[0005] An oven, the oven is mounted on the rack and a baking cavity is provided in the oven;

[0006] A multi-layer conveyor belt, wherein the multi-layer conveyor belt is installed on the frame and arranged at intervals along the height direction of the oven, and the extension paths of the multi-layer conveyor belt all pass through the baking cavity;

[0007] A heating device is installed in the baking cavity.

[0008] Optionally, the tunnel oven further comprises an air regulating member, which is arranged on the frame along the height direction of the oven and is located inside the oven, and the air regulating member is movably connected to the frame to adjust the size of the air flow passing through the air regulating member.

[0009] Optionally, the air regulating member includes a plurality of air regulating plates, each of which is provided with ventilation holes, and the plurality of air regulating plates partially or fully overlap, wherein some or all of the air regulating plates are movably connected relative to the frame to adjust the ventilation holes on different air regulating plates to overlap or stagger with each other.

[0010] Optionally, a receiving member is provided between adjacent conveyor belts, and the receiving member receives the incoming materials from the upper conveyor belt and transfers the incoming materials to the lower conveyor belt, wherein the conveying directions of the upper and lower adjacent conveyor belts are opposite.

[0011] Optionally, the receiving member includes a transfer platform and a baffle, the transfer platform is obliquely arranged between two adjacent conveyor belts, the baffle is located above the lower conveyor belt of the two adjacent conveyor belts, one end of the incoming material on the transfer platform is placed on the baffle, and the other end is detached from the upper conveyor belt and placed on the lower conveyor belt to move at a uniform speed following the lower conveyor belt.

[0012] Optionally, the baffle is a flexible baffle.

[0013] Optionally, the tunnel oven also includes a preheating element, a loading section is provided on the multi-layer conveyor belt, the loading section is located outside the oven, and the preheating element is installed in the oven and faces the first conveyor belt where the loading section is located to heat the incoming material entering the baking chamber from the loading section.

[0014] Optionally, the tunnel oven further comprises a temperature sensor and a controller, wherein the temperature sensor is installed in the baking chamber, and the temperature sensor and the preheating element are electrically connected to the controller.

[0015] Optionally, the tunnel oven also includes a filtering device and a fan, wherein the fan is installed on the oven and is located above the uppermost conveyor belt or below the lowermost conveyor belt, and the filtering device is installed between the uppermost conveyor belt and the fan or between the lowermost conveyor belt and the fan.

[0016] Optionally, the tunnel furnace further comprises a driving roller, the driving roller is provided with a groove, the multiple layers of the conveyor belt are provided with guide strips, and the guide strips are embedded in the groove to form a fit.

[0017] The technical solution of the present invention is that an oven is installed on a frame, a baking cavity is provided in the oven, a multi-layer conveyor belt is installed on the frame and arranged at intervals along the height direction of the oven, and the extension path of the multi-layer conveyor belt passes through the baking cavity, and a heating device is installed in the baking cavity. Since the tunnel oven has a multi-layer conveyor belt, the whole machine of the tunnel oven can be prevented from being too long, which can save production space. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram of an embodiment of a tunnel furnace of the present invention;

[0020] Figure 2 for Figure 1 A partial enlarged view of middle A;

[0021] Figure 3 It is a partial structural schematic diagram of the tunnel furnace of the present invention under another visual perspective.

[0022] Description of Figure Numbers:

[0023] Label name Label name 11 frame 30 oven 12 Conveyor Belt 311 Air outlet duct 121 Feeding section 312 Return air duct 122 Baking section 32 Air regulating plate 123 Cutting section 33 New outlet 13 Heating tube 34 Maintenance door 14 Switchboard 35 Wind deflector 15 Baffle 36 Insulation layer 16 Support bracket 37 Exhaust vent 17 Conveyor roller 38 Baking chamber 181 body 40 Controller 182 Wind wheel 50 Incoming Materials 19 Cooling fan 60 Filters 20 Preheating parts 70 Dust screen

[0024] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0027] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0028] like Figure 1 As shown, in order to achieve the above-mentioned purpose, the present invention proposes a tunnel oven, which includes: a frame 11; an oven 30, which is installed on the frame 11, and a baking cavity 38 is provided in the oven 30; a multi-layer conveyor belt 12, which is installed on the frame 11 and arranged at intervals along the height direction of the oven 30, and the extension paths of the multi-layer conveyor belts 12 all pass through the baking cavity 38; a fan, which is installed in the oven 30.

[0029] The tunnel oven proposed by the present invention can be applied to the surface drying of printed materials, such as mobile phone glass cover plates. The frame 11 is the installation base of the oven 30, the multi-layer conveyor belt 12 and the fan. The oven 30 is provided with a baking chamber 38. The extension path of the multi-layer conveyor belt 12 passes through the baking chamber 38 to bake the incoming material 50 placed on the multi-layer conveyor belt 12. During the baking process, the coating on the surface of the incoming material 50 gradually dries and ages, releasing the volatile substances therein. Different products have different baking time requirements. In actual production, the oven 30 often has multiple sections to increase the baking time. At this time, the multi-layer conveyor belt 12 passes through the multi-section oven 30 in parallel. A heating device is provided in the oven 30 to heat the air flow blown out by the fan. The fan has an air inlet side and an air outlet side. The wind enters the fan from the air inlet side of the fan and flows out of the fan from the air outlet side of the fan. The heating device is installed on the air outlet side of the fan to heat the air flow flowing out of the fan to maintain the temperature in the baking chamber 38. It can be understood that since the coating on the surface of the incoming material 50 will volatilize organic matter, in order to prevent the organic matter from entering the outside air, one or more filters 60 can be set in the baking chamber 38. The filter 60 can be located at one or more of the air inlet side, the air outlet side, and the top of the multi-layer conveyor belt 12 of the fan. The specific setting can be based on needs. The filter 60 can absorb volatile organic matter and filter dust to ensure that the baking chamber 38 is highly clean. The tunnel oven proposed in this embodiment also includes a controller 40, which is electrically connected to the heating device and the fan, and the controller 40 controls the start or shut down of the heating device and the fan. In addition, the multi-layer conveyor belt 12 is connected to the conveying drive assembly, and the conveying drive assembly is electrically connected to the controller 40, and the conveying speed of the multi-layer conveyor belt 12 is controlled by the controller 40. The fan can set the fuselage 181 outside the oven 30, and the output shaft of the fan extends into the baking cavity 38. The output shaft is equipped with a wind wheel 182, and the wind wheel 182 drives the air flow in the baking cavity 38. This setting method can reduce the volume of the baking cavity 38, which is conducive to heat preservation. The conveying drive assembly in this embodiment can be composed of a conveying roller 17 and a motor, and the heating device can be an electric heating pipe 13.

[0030] The multi-layer conveyor belt 12 is arranged at intervals along the height direction of the oven 30, and the extension path passes through the baking chamber 38 so that the incoming material 50 on the conveyor belt 12 can be baked. The number of layers of the conveyor belt 12 can be two or more. In practical applications, two, three, four or five layers may be used, which is determined according to needs. Taking the arrangement of three layers of conveyor belts 12 as an example, in this embodiment, the fan can be arranged above the top conveyor belt 12 or below the bottom conveyor belt 12, or at the side position along the conveying path of the conveyor belt 12. The fan drives the air flow to form a circulating wind in the baking chamber 38, and the circulation direction is perpendicular to the extension direction of the conveyor belt 12, such as Figure 3 As shown, the air flow direction includes an air flow direction perpendicular to the conveyor belt 12 vertically and an air flow direction perpendicular to the conveyor belt 12 horizontally. The air flow direction perpendicular to the conveyor belt 12 vertically exerts pressure on the incoming material 50 on the conveyor belt 12, which can prevent the incoming material 50 from drifting in the wind direction perpendicular to the conveyor belt 12 horizontally. Figure 3 The arrow along the height direction of the oven 30 indicates the wind direction perpendicular to the conveyor belt 12, and the arrow along the width direction of the oven 30 indicates the wind direction perpendicular to the conveyor belt. In addition, the conveyor belt 12 is a mesh structure so that the air flow can pass through the conveyor belt 12 to form a wind direction perpendicular to the conveyor belt 12. The conveyor belt 12 in this embodiment can be a Teflon mesh belt, which can withstand high temperatures and has a long service life.

[0031] The extension path of the multi-layer conveyor belt 12 passes through the baking chamber 38, which means that at least part of the belt length of each layer of the conveyor belt 12 is located in the baking chamber 38, wherein the multi-layer conveyor belt 12 has a loading section 121 and a unloading section 123, the loading section 121 is located outside the oven 30 for loading, and the unloading section 123 is located outside the oven 30 for unloading, that is, the conveyor belt 12 provided with the loading section 121 or the unloading section 123 needs to have a belt length located in the oven 30 and a belt length located in the baking chamber 38, and the conveyor belt 12 not provided with the loading section 121 or the unloading section 123 can be located entirely in the baking chamber 38 or only partially in the baking chamber 38, and the part located in the baking chamber 38 is the baking section 122. Taking the three-layer conveyor belt 12 set on the tunnel furnace as an example, the loading section 121 can be set on the top conveyor belt 12, and the unloading section 123 can be set on the bottom conveyor belt 12. Of course, the conveyor belt 12 outside the oven 30 can be used for loading or unloading. Therefore, when the required baking time is shorter, the loading section 121 and / or the unloading section 123 can also be set on the middle conveyor belt 12 or the bottom conveyor belt 12, which can be determined according to actual production conditions. Loading and unloading can be completed with a robot, which will not be described here.

[0032] The tunnel furnace proposed in this embodiment has a multi-layer conveyor belt 12, which can avoid the tunnel furnace being too long and save production space. For example, according to the original setting of a single-layer conveyor belt, in order to ensure the baking effect, the conveyor belt is often as long as 22 meters or longer. According to this embodiment, the conveyor belt 12 is arranged into multiple layers, so that the total length of the multi-layer conveyor belt 12 can reach 22 meters or longer, but the whole machine can be shortened to one third of the original length, which greatly saves the manufacturing land cost.

[0033] In actual production, a large number of incoming materials 50 are placed on the conveyor belt 12, so the incoming materials 50 need to move at a uniform speed following the conveyor belt 12. In the multi-layer conveyor belt 12 proposed in this embodiment, the conveying directions of the upper and lower adjacent conveyor belts 12 are opposite, so that the incoming materials 50 can flow from the upper conveyor belt 12 to the lower conveyor belt 12 and continue to enter the baking oven 30 for baking. In this case, if the speed of the incoming materials 50 changes when entering the lower conveyor belt 12 from the upper conveyor belt 12, it may cause the incoming materials 50 to accumulate. Therefore, in order to avoid this situation, a receiving piece is provided between the adjacent conveyor belts 12, such as Figure 1 , 2 As shown, one end of the receiving member is connected to the upper conveyor belt 12, and the other end is connected to or placed close to the lower conveyor belt 12, so as to transfer the incoming material 50 from the upper conveyor belt 12 to the lower conveyor belt 12, and the transfer rate is the same as the transfer rate of the upper conveyor belt 12 and the lower conveyor belt 12. In this embodiment, the receiving member and the multi-layer conveyor belts 12 can be powered by the same power source to ensure the same transfer rate, or they can be powered by different power sources. At this time, the consistency of the rate is ensured by the controller 40.

[0034] In a further embodiment, Figure 2 As shown, the receiving member includes a transfer platform 14 and a baffle 15. The transfer platform 14 is tilted between two adjacent conveyor belts 12. The baffle 15 is located above the lower conveyor belt 12 of the two adjacent conveyor belts 12. The incoming material 50 enters the transfer platform 14 after leaving the upper conveyor belt 12 of the two adjacent conveyor belts 12. The incoming material 50 has a front end and a rear end. The front end of the incoming material 50 leaves the transfer platform 14 and rests on the baffle 15. The rear end leaves the transfer platform 14 and rests on the two adjacent conveyor belts 12. On the lower conveyor belt 12 of the conveyor belt 12, that is, when the incoming material 50 completely leaves the transfer platform 14, the front end is placed on the baffle 15, and the rear end is placed on the lower conveyor belt 12 (most of it is placed on the lower conveyor belt 12, and a small part is placed on the baffle 15), so that the rear conveyor belt 12 will follow the movement of the lower conveyor belt 12, so that the entire piece of incoming material 50 moves at a uniform speed following the lower conveyor belt 12, so that the incoming material 50 flows smoothly between the upper and lower conveyor belts 12 without being stuck. This multi-layer conveyor belt 12 structure of the tunnel furnace can reduce the number of ovens 30 and reduce energy consumption.

[0035] The baffle 15 in this embodiment is a flexible baffle, such as Teflon high temperature cloth, which is the same material as the conveyor belt 12, and has a thickness of less than or equal to 0.3 mm, so that the baffle 15 can receive the front end of the incoming material 50 without hindering the incoming material 50 from following the uniform movement of the lower conveyor belt 12. If the thickness of the baffle 15 is too large, it will lead to insufficient flexibility, and the front end of the incoming material 50 will slide when it contacts the baffle 15, and it is easy to form an accumulation with other incoming materials 50. Of course, the baffle 15 is not limited to the Teflon high temperature cloth mentioned above, and flexible plastic sheets can be used. The temperature in the baking chamber 38 is generally greater than 100°C. The baffle 15 is arranged above two adjacent lower conveyor belts 12 by a receiving bracket 16. One end of the baffle 15 is connected to the receiving bracket 16, and the other end is placed on the lower conveyor belt 12. Since the thickness of the baffle 15 is very thin, although the part placed on the lower conveyor belt 12 is located between the incoming material 50 and the lower conveyor belt 12, it only contacts a small part of the incoming material 50, and therefore will not affect the uniform movement of the incoming material 50 following the lower conveyor belt 12.

[0036] The conveyor belt 12 disposed on the surface of the transfer platform 14 needs to have a certain friction force to prevent the incoming material 50 from sliding on the transfer platform 14. In this embodiment, a silicone transfer belt (not shown in the figure) is provided on the surface of the transfer platform 14, and the conveying speed of the silicone transfer belt is consistent with that of the conveyor belt 12.

[0037] The oven 30 can be formed by splicing multiple sections of boxes along the extension direction of the multi-layer conveyor belt 12. Each box is provided with the baking cavity 38. The multi-layer conveyor belt 12 passes through multiple parallel baking cavities 38, so that the tunnel oven can meet a sufficient baking time.

[0038] As an embodiment, the tunnel oven further includes an air regulating member, which is arranged on the frame 11 along the height direction of the oven 30 and is located in the oven 30. The arrangement along the height direction of the oven 30 includes arranging the air regulating member on both sides of the conveyor belt 12 or arranging the air regulating member between adjacent conveyor belts 12 (in this case, the conveyor belt 12 passes through the air regulating member). In a preferred embodiment, the air regulating member is arranged on both sides of the conveyor belt 12, and the air regulating member is movably connected to the frame 11. The movably connected mode includes a sliding connection or a rotating connection. The size of the air flow passing through the air regulating member can be adjusted along the path of the air regulating member.

[0039] The air regulating member may be used to regulate the size of the air flow, including but not limited to the following methods: leaving a gap between the end of the air regulating member and the inner wall of the oven 30, sliding or rotating the air regulating member to expand or reduce the size of the gap to achieve the purpose of regulating the air volume; or, the air regulating member may be configured as a plurality of air regulating plates 32, such as two air regulating plates 32, each of which has a ventilation hole (not shown in the figure), and at least one of the two air regulating plates 32 is slidably connected or rotatably connected to the frame 11. At this time, sliding or rotating the air regulating plate 32 can cause the two air regulating plates 32 to partially or completely overlap, and there is a maximum ventilation position on the movable path of the plurality of air regulating plates 32 relative to the frame 11. At the maximum ventilation position, the ventilation holes on the two air regulating plates 32 completely overlap, and at this time, the ventilation volume through the air regulating plates 32 reaches a maximum.

[0040] In an optional embodiment, the multi-layer conveyor belt 12 passes through two opposite sides of the oven 30, and a set of air regulating plates 32 are provided on both sides of two adjacent conveyor belts 12 to adjust the air volume passing through each conveyor belt 12 so that the temperature of each position in the oven 30 is uniform. In practical applications, since the wind speed near the fan is relatively high, the ventilation holes of the air regulating plates 32 near the fan can be smaller than the ventilation holes far from the fan, so that the air volume flowing through each conveyor belt 12 is consistent, ensuring the temperature of each position in the oven 30 is uniform. The tunnel oven proposed in this embodiment can maintain good temperature uniformity, and the temperature difference at each location is maintained within plus or minus 5°C. Under normal use, the temperature of the oven 30 is less than or equal to 150°C, and the controller 40 can adjust the temperature of the oven 30 according to specific baking requirements.

[0041] Since the baking chamber 38 needs to have an air flow perpendicular to the conveyor belt 12, an air distribution plate (not shown in the figure) can be installed between the fan and the conveyor belt 12. A through hole is provided on the air distribution plate for the air flow flowing out of the motor to pass through. In this embodiment, the air distribution plate is directly opposite to the conveyor belt 12. Therefore, the direction of the air flow through the air distribution plate is perpendicular to the conveyor belt 12, so that the incoming material 50 is subjected to the pressure of the air flow and will not drift. In one embodiment, the air distribution plate is installed above the top conveyor belt 12, and the fan and the heating device are installed between the top wall of the oven 30 and the air distribution plate. Since air regulating plates 32 are installed on both sides of the conveyor belt 12, and the two ends of the air distribution plate are fixed on the air regulating plates 32 on both sides of the air distribution plate, the air flow passes through the air distribution plate and then flows through the air regulating plate 32 to enter the air inlet side of the fan.

[0042] In addition, in order to separate the air inlet side of the fan from the air outlet side of the fan, and to prevent the air flow flowing through the conveyor belt 12 from flowing through the conveyor belt 12 again without being driven by the fan and heated by the heating device, a wind shield 35 is arranged between the fan and the filter element 60. The wind shield 35 is fixed between the wind balancing plate and the fan to separate the air duct between the wind balancing plate and the fan into the air inlet side air duct of the fan and the air outlet side air duct of the fan. The wind shield 35 is connected to the air regulating plate 32, and is surrounded by the inner wall of the oven 30 to form an air duct structure for guiding the air flow. This air duct structure can ensure that the temperature of each part in the baking chamber 38 is uniform, and the baking quality of the product is ensured. The heating device is located in the air outlet side air duct to heat the air flow flowing out of the fan. The heating device is provided with an installation cavity (not shown in the figure) and a heating tube 13 installed in the installation cavity, and the installation cavity is surrounded by an arc-shaped anti-wind plate (not shown in the figure). The heating tube 13 may be a stainless steel electric heating tube, and the installation cavity where the heating tube 13 is located is surrounded by an arc-shaped wind-reversing plate, so that the air flow can flow smoothly along the wall surface of the arc-shaped wind-reversing plate.

[0043] The air regulating plate 32 is installed in the baking chamber 38 and connected to the wind shield 35. The wind shield 35 and the air regulating plate 32 separate the baking chamber 38 into an outlet duct 311 and a return air duct 312, wherein the outlet duct 311 is connected to the outlet side duct of the fan, and the return air duct 312 is connected to the inlet side duct of the fan. The filter element 60 is installed on the air balancing plate and is located in the air outlet duct 311. When the air flow passes through the air balancing plate, it flows through the filter element 60, and the filter element 60 absorbs dust and volatile organic compounds in the air flow. The filter element 60 in this embodiment is detachably connected and can be fixed to the air regulating plate 32 or the oven 30 by screws, such as connecting both ends of the filter element 60 to the air regulating plates 32 on both sides of the conveyor belt 12. Of course, the detachable connection of the filter element 60 is not limited to the above-mentioned screw fixation. For example, the air equalizing plate can be set to a groove shape, and the filter element 60 can be placed in the groove-shaped air equalizing plate. The filter element 60 is restricted by the groove wall to be fixed.

[0044] The oven 30 is also provided with a fresh air inlet 33 and an exhaust outlet 37. The exhaust outlet 37 is located at the top of the oven 30, and the fresh air inlet 33 is located at the air inlet side of the fan. The air flow entering the oven 30 from the fresh air inlet 33 first enters the air inlet side duct of the fan and further enters the fan. A filter (not shown in the figure) is provided on the air inlet side or the air outlet side of the fan. The fresh air inlet 33 is set on the air inlet side of the fan so that the air can first pass through the filter and then flow through the conveyor belt 12 to filter dust and ensure the cleanliness of the baking chamber 38.

[0045] As an embodiment, the tunnel oven further includes a preheating member 20, and the layer of conveyor belt 12 where the material loading section 121 is located is named as the first conveyor belt. The preheating member 20 is installed in the oven 30 and faces the first conveyor belt to heat the incoming material 50 entering the baking chamber 38 from the material loading section 121. The preheating member 20 can be an infrared lamp tube, and for the incoming material 50 newly entering the oven cavity, the infrared lamp tube heats it to the average temperature in the baking chamber 38 so that the temperature in the baking chamber 38 is uniform everywhere.

[0046] The tunnel oven also includes a temperature sensor (not shown in the figure) arranged in the baking box 30. The temperature sensor is located above the first conveyor belt, or the temperature sensor can also be installed on the air inlet side of the fan. Of course, in order to make the temperature control more accurate, a temperature sensor can be installed above each layer of the conveyor belt 12. The output end of the temperature sensor is connected to the controller 40. The controller 40 controls the heating intensity of the preheating part 20 according to the temperature sensor. When the temperature sensor above the first conveyor belt detects that the temperature reaches the average temperature in the baking chamber 38, the controller 40 controls the preheating part 20 to turn off or reduce the heating intensity.

[0047] In a further embodiment, a heat-insulating layer 36 is provided on the inner wall of the oven 30 , and the heat-insulating layer 36 may be silica gel to prevent the outer wall of the oven 30 from getting hot.

[0048] The tunnel oven also includes a maintenance door 34, which is installed on the oven 30; a driving cylinder (not shown in the figure) is installed on the frame 11 and the plunger of the driving cylinder is connected to the maintenance door 34, the cylinder can be electrically connected to the controller 40, when the operator needs to open the maintenance door 34, directly operate the controller 40, the cylinder can automatically open the maintenance door 34; the cylinder may not be electrically connected to the controller 40, at this time the operator drives the switch of the cylinder to open the maintenance door 34.

[0049] The tunnel oven also includes a cooling fan 1918, which is installed at a position of the frame 11 corresponding to the unloading section 123, and is used to cool the incoming material 50 sent out from the baking chamber 38. The dustproof net 70 is provided above the unloading section 123 to prevent foreign matter from falling onto the already baked incoming material 50.

[0050] In a further embodiment, the tunnel oven further comprises a cooling belt, which is connected to the unloading section 123 and is installed below the oven 30 for cooling the incoming material 50 .

[0051] In addition, the tunnel furnace also includes a driving roller 17, on which a groove (not shown) is provided, and guide strips (not shown) are provided on the multiple layers of the conveyor belt 12, and the guide strips are embedded in the groove to form a fit. In actual practice, since there is a certain gap between the conveyor belt 12 and the tracks on both sides (not shown in the figure), the conveyor belt 12 often deviates during the transmission process. The conveyor belt 12 itself has a certain elasticity, so the deviation phenomenon will cause the elastic conveyor belt 12 to be tensioned and may be twisted into the transmission roller. The guide bar is set on the back of the conveyor belt 12 where the incoming material 50 is placed, and can be a plastic convex rib. There are multiple transmission rollers 17, and each transmission roller 17 is provided with a groove. During the transmission of the conveyor belt 21, the guide bar is always embedded in the groove to form a positioning fit, so that the conveyor belt can always be transmitted in the preset transmission direction to avoid deviation, so that the transmission direction of the conveyor belt 12 is accurately controllable, ensuring the service life of the conveyor belt 12, avoiding the phenomenon of the conveyor belt 12 being twisted into the transmission roller, and allowing the tunnel furnace to work stably for a long time. The preset transmission direction is consistent with the extension direction of the track set on the frame 1, and the track is located on both sides of the conveyor belt 12.

[0052] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A tunnel furnace, characterized in that: The tunnel furnace comprises: frame; An oven, the oven is mounted on the rack and a baking cavity is provided in the oven; A multi-layer conveyor belt, wherein the multi-layer conveyor belt is installed on the frame and arranged at intervals along the height direction of the oven, and the extension paths of the multi-layer conveyor belt all pass through the baking cavity; A heating device and a fan, wherein the heating device and the fan are installed in the baking chamber, the heating device is used to heat the air flow blown out by the fan; the fan drives the air flow to form circulating wind in the baking chamber, and the circulating direction is perpendicular to the extending direction of the conveyor belt, specifically including the air flow direction perpendicular to the conveyor belt vertically and the air flow direction perpendicular to the conveyor belt horizontally; Wherein, a receiving member is provided between adjacent conveyor belts, and the receiving member receives the incoming materials from the upper conveyor belt and transmits the incoming materials to the lower conveyor belt; wherein, the conveying directions of the upper and lower adjacent conveyor belts are opposite; specifically, the receiving member includes a transfer table and a baffle, and the transfer table is obliquely arranged between two adjacent conveyor belts, and the baffle is located above the lower conveyor belt of the two adjacent conveyor belts, and one end of the incoming materials on the transfer table is placed on the baffle, and the other end is detached from the upper conveyor belt and placed on the lower conveyor belt to move at a uniform speed following the lower conveyor belt.

2. The tunnel furnace according to claim 1, characterized in that: The tunnel oven also includes an air regulating member, which is arranged on the frame along the height direction of the oven and is located in the oven. The air regulating member is movably connected to the frame to adjust the size of the air flow passing through the air regulating member.

3. The tunnel furnace according to claim 2, characterized in that: The air regulating member comprises a plurality of air regulating plates, each of which is provided with ventilation holes, and the plurality of air regulating plates are partially or completely overlapped, wherein a portion or all of the air regulating plates are movably connected relative to the frame to adjust the ventilation holes on different air regulating plates to overlap or stagger with each other.

4. The tunnel furnace according to claim 1, characterized in that: The blocking piece is a flexible blocking piece.

5. The tunnel furnace according to claim 1, characterized in that: The tunnel oven also includes a preheating element. A loading section is provided on the multi-layer conveyor belt. The loading section is located outside the oven. The preheating element is installed in the oven and faces the first conveyor belt where the loading section is located to heat the incoming material entering the baking chamber from the loading section.

6. The tunnel furnace according to claim 5, characterized in that: The tunnel oven further comprises a temperature sensor and a controller. The temperature sensor is installed in the baking cavity. The temperature sensor and the preheating element are both electrically connected to the controller.

7. The tunnel furnace according to claim 1, characterized in that: The tunnel oven also includes a filtering device and a fan. The fan is installed on the oven and is located above the uppermost conveyor belt or below the lowermost conveyor belt. The filtering device is installed between the uppermost conveyor belt and the fan or between the lowermost conveyor belt and the fan.

8. The tunnel furnace according to claim 1, characterized in that: The tunnel furnace also includes a driving roller, on which a groove is arranged, and guide strips are arranged on the multiple layers of the conveyor belt, and the guide strips are embedded in the groove to form a fit.

Images