Internal circulation shrinkage furnace

Abstract

The invention discloses an internal circulation shrinkage furnace which comprises a heat preservation shell, a furnace body and a furnace cover. The air cavity inner shell is arranged in the installation channel, a heating air cavity is formed between the heat preservation shell and the air cavity inner shell, a thermal shrinkage channel is formed in the air cavity inner shell, and air holes communicating the heating air cavity with the thermal shrinkage channel are formed in the side portion and the bottom of the air cavity inner shell; the heater is arranged in the heating air cavity and used for heating air; the air supply device is arranged at the top of the air cavity inner shell and used for conveying air in the thermal shrinkage channel into the heating air cavity, and air internal circulation between the heating air cavity and the thermal shrinkage channel is achieved; and the conveying device is used for conveying the products into and out of the thermal shrinkage channel. According to the scheme, internal circulation of hot air in the whole shrinkage furnace is achieved, heat dissipation is reduced, then energy waste is reduced, and meanwhile the temperature in the thermal shrinkage channel is more easily controlled to be the target temperature.

Description

Technical Field

[0001] The present application relates to the field of packaging technology, and in particular to an internal circulation shrinking furnace. Background Art

[0002] Heat shrink film will shrink when exposed to heat, thus tightly wrapping the product. Based on this characteristic, heat shrink film is widely used in the packaging and transportation of various foods, medicines and daily necessities, and can provide stability, covering and protection for the products.

[0003] On the heat shrink film product packaging line, the heat shrink film is generally wrapped around the periphery of the product first, and then the product is conveyed to the shrink furnace for heating by a conveyor belt. The high temperature environment in the shrink furnace is used to shrink the heat shrink film, and then it is tightly attached to the periphery of the product. China's authorized patent CN203172940U discloses a heat shrink film machine, which uses a fan set in a hot air furnace to continuously blow the hot air in the furnace to the product to achieve heat shrink film heating. However, in this solution, the fan continuously pumps low-temperature air in the environment into the hot air furnace, and the hot air blown to the surface of the product is directly dissipated into the environment. In addition to being unable to reuse the heated air, resulting in energy waste, it is also difficult to ensure that the temperature of the hot air blown to the surface of the product can meet the working requirements, affecting the packaging quality. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide an internal circulation shrinking furnace, which can solve the above-mentioned problems existing in the prior art.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] An internal circulation shrinking furnace, comprising:

[0007] A heat-insulating shell having a mounting channel formed therein;

[0008] An air cavity inner shell is arranged in the installation channel, a heating air cavity is formed between the heat-insulating shell and the air cavity inner shell, a heat shrink channel is formed inside the air cavity inner shell, and air holes for connecting the heating air cavity and the heat shrink channel are provided on the side and bottom of the air cavity inner shell;

[0009] A heater, disposed in the heating air cavity, for heating the air;

[0010] An air supply device, arranged at the top of the air cavity inner shell, for conveying the air in the heat shrink channel to the heating air cavity, so as to realize the internal circulation of air between the heating air cavity and the heat shrink channel;

[0011] A conveying device is used to convey the product into and out of the heat shrink channel.

[0012] Optionally, the insulation shell includes an insulation upper shell and an insulation base, the insulation upper shell can be detachably installed on the insulation base, the air cavity inner shell is installed in the insulation upper shell or in the insulation base, and the heater and the air supply device can be inspected and maintained by opening the insulation upper shell.

[0013] Optionally, one side of the heat-insulating upper shell is hinged to the heat-insulating base via a hinge, and the other side is connected and fixed to the heat-insulating base via a lock, and the heat-insulating upper shell can be flipped open by unlocking the lock.

[0014] Optionally, the wind cavity inner shell includes a wind cavity upper shell and a wind cavity bottom plate, the wind cavity upper shell is installed in the thermal insulation upper shell, and the wind cavity bottom plate is installed on the thermal insulation base, and by covering the thermal insulation upper shell, the two sides of the wind cavity upper shell and the two sides of the wind cavity bottom plate are joined to enclose and form the wind cavity inner shell.

[0015] Optionally, the wind cavity upper shell includes a first wind cavity side panel, a wind cavity top panel, and a second wind cavity side panel which are sequentially connected to form a U-shaped structure, a first side wind cavity is formed between the first wind cavity side panel and the thermal insulation upper shell, a second side wind cavity is formed between the second wind cavity side panel and the thermal insulation upper shell, and the heater is arranged in the first side wind cavity and the second side wind cavity.

[0016] Optionally, the air holes are provided on the air cavity bottom plate, and a lower air cavity is formed between the air cavity bottom plate and the thermal insulation base. The first side air cavity and the second side air cavity are respectively provided with first air volume adjusting components on one side close to the lower air cavity, and the ventilation volumes between the first side air cavity and the second side air cavity and the lower air cavity are respectively adjusted by the first air volume adjusting components, thereby adjusting the air volume of the air holes on the air cavity bottom plate.

[0017] Optionally, the first air cavity side plate and the second air cavity side plate are respectively connected to a support plate extending outward and abutting against the inner wall of the thermal insulation upper shell on one side near the air cavity bottom plate, and ventilation holes are provided on the support plate. The first air volume adjusting component is movably mounted on the support plate, and a first adjustment hole corresponding to the ventilation hole is provided on the first air volume adjusting component. The overlap degree between the first adjustment hole and the ventilation hole is adjusted by moving the first air volume adjusting component, thereby adjusting the ventilation volume between the first side air cavity and the second side air cavity and the lower air cavity.

[0018] Optionally, the air holes are respectively arranged on the first air cavity side plate and the second air cavity side plate, and second air volume adjusting components are respectively arranged on the inner sides of the first air cavity side plate and the second air cavity side plate, and the air volumes of the air holes on the first air cavity side plate and the second air cavity side plate are respectively adjusted by the second air volume adjusting components.

[0019] Optionally, the second air volume adjusting components on both sides are movably installed on the inner side of the first air cavity side panel or the second air cavity side panel respectively, and the second air volume adjusting components are provided with second adjustment holes corresponding to the air holes. The overlap between the second adjustment holes and the air holes is adjusted by moving the second air volume adjusting components, thereby adjusting the air output of the air holes on the first air cavity side panel and the second air cavity side panel.

[0020] Optionally, the air supply device includes a connected air guide ring and a fan, the air guide ring is arranged between the air cavity top plate and the thermal insulation upper shell, the air cavity top plate is provided with a vent corresponding to the air guide ring, the fan draws the air in the heat shrink channel into the air guide ring through the vent, and the air guide ring guides the air into the first side air cavity and the second side air cavity.

[0021] Optionally, a middle partition is provided in the heating air cavity which divides the heating air cavity into a medium-temperature air cavity and a high-temperature air cavity, and the heater includes a first heating tube arranged in the medium-temperature air cavity and a second heating tube arranged in the high-temperature air cavity; the area in the heat shrinkage channel corresponding to the medium-temperature air cavity is a preheating expansion area, and the area corresponding to the high-temperature air cavity is a high-temperature heat shrinkage area.

[0022] Optionally, the conveying device includes a conveyor mesh belt and two conveyor wheels respectively arranged at both ends of the heating pipe, the two ends of the conveyor mesh belt are mounted outside the two conveyor wheels, and the upper part of the conveyor mesh belt passes through the interior of the heat shrink channel, and the lower part is located below the insulation shell.

[0023] The beneficial effects of the present application are as follows: the present invention provides an internal circulation shrinkage furnace, an air cavity inner shell is arranged in the installation channel of the insulation shell, and a heater is arranged in the heating air cavity between the air cavity inner shell and the insulation shell. When working, the air supply device continuously draws the air in the heat shrinkage channel in the air cavity inner shell into the heating air cavity for heating, and the hot air in the heating air cavity enters the heat shrinkage channel through the air holes arranged on the air cavity inner shell, thereby achieving the purpose of continuously conveying hot air to the heat shrinkage channel and maintaining a constant temperature in the heat shrinkage channel, and the product with the heat shrink film is conveyed into the heat shrinkage channel by the conveying device for heating and shrinking, and then the product is output out of the heat shrinkage channel.

[0024] In this solution, air holes are provided on the sides and bottom of the inner shell of the air cavity, and the hot air in the heat shrink channel can enter from both sides and the bottom of the heat shrink channel at the same time, ensuring the uniformity of the temperature of the entire heat shrink channel, and at the same time blowing hot air to the product from all directions, so that all positions of the heat shrink film on the product can shrink at the same time, avoiding the occurrence of undesirable phenomena such as wrinkles and uneven shrinkage caused by different shrinkage speeds at different positions of the heat shrink film due to uneven temperature. In addition, the hot air in the heat shrink channel will not be directly dissipated into the environment, and the air supply device directly pumps the air in the heat shrink channel back into the heating air cavity for heating, realizing the internal circulation of the hot air in the entire shrinking furnace, reducing heat dissipation, thereby reducing energy waste, and making it easier to control the temperature in the heat shrink channel at the target temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present application is further described in detail below based on the drawings and embodiments.

[0026] Figure 1 This is one of the three-dimensional structural schematic diagrams of the internal circulation shrinking furnace described in the embodiment of the present application;

[0027] Figure 2 This is the second schematic diagram of the three-dimensional structure of the internal circulation shrinking furnace described in the embodiment of the present application;

[0028] Figure 3 It is a vertical cross-sectional view of the internal circulation shrinking furnace described in the embodiment of the present application;

[0029] Figure 4 This is a transverse cross-sectional view of the internal circulation shrinking furnace described in the embodiment of the present application;

[0030] Figure 5 for Figure 4 A magnified schematic diagram of the middle A area;

[0031] Figure 6 This is a schematic diagram of the internal structure of the internal circulation shrinkage furnace described in an embodiment of the present application.

[0032] In the figure:

[0033] 1. Insulation shell; 11. Insulation upper shell; 12. Insulation base; 13. Hinge; 14. Lock; 2. Machine base; 3. Air cavity inner shell; 31. Air cavity upper shell; 311. First air cavity side panel; 312. Second air cavity side panel; 313. Air cavity top panel; 32. Air cavity bottom panel; 33. Air hole; 34. Middle partition; 4. Conveying device; 5. Air supply device; 51. Fan; 52. Air guide ring; 6. Heater; 7. First air volume regulating component; 8. Second air volume regulating component; 10. Heat shrink channel; 20. Heating air cavity; 201. First side air cavity; 202. Second side air cavity; 203. Lower air cavity. DETAILED DESCRIPTION

[0034] In order to make the technical problems solved by this application, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the embodiments of this application are further described in detail below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0035] In the description of this application, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0037] like Figure 1-6 As shown, this embodiment provides an internal circulation shrinking furnace, comprising:

[0038] The heat-insulating shell 1 has a mounting passage formed therein;

[0039] The air cavity inner shell 3 is arranged in the installation channel, a heating air cavity 20 is formed between the heat-insulating shell 1 and the air cavity inner shell 3, a heat shrink channel 10 is formed inside the air cavity inner shell 3, and air holes 33 for connecting the heating air cavity 20 and the heat shrink channel 10 are provided on the side and bottom of the air cavity inner shell 3;

[0040] A heater 6 is disposed in the heating air cavity 20 and is used to heat the air;

[0041] The air supply device 5 is arranged at the top of the air cavity inner shell 3, and is used to transport the air in the heat shrink channel 10 to the heating air cavity 20, so as to realize the internal circulation of air between the heating air cavity 20 and the heat shrink channel 10;

[0042] The conveying device 4 is used to convey the product into and out of the heat shrink channel 10 .

[0043] Specifically, when the internal circulation shrinkage furnace of this embodiment is working, the air supply device 5 continuously draws the air in the heat shrinkage channel 10 in the air cavity inner shell 3 into the heating air cavity 20 for heating, and the hot air in the heating air cavity 20 enters the heat shrinkage channel 10 through the air holes 33 arranged on the air cavity inner shell 3, thereby achieving the purpose of continuously conveying hot air to the heat shrinkage channel 10 and maintaining a constant temperature in the heat shrinkage channel 10. The product with the heat shrinkage film is conveyed to the heat shrinkage channel 10 by the conveying device 4 for heating and shrinkage, and then the product is output from the heat shrinkage channel 10.

[0044] In this solution, air holes 33 are provided on the sides and bottom of the air cavity inner shell 3, and the hot air in the heat shrink channel 10 can enter from both sides and the bottom of the heat shrink channel 10 at the same time, ensuring the uniformity of the temperature of the entire heat shrink channel 10, and at the same time achieving hot air blowing to the product from all directions of the product, so that all positions of the heat shrink film on the product can shrink at the same time, avoiding the occurrence of undesirable phenomena such as wrinkles and uneven shrinkage caused by different shrinkage speeds at different positions of the heat shrink film due to uneven temperature. In addition, the hot air in the heat shrink channel 10 will not be directly dissipated into the environment, and the air supply device 5 directly pumps the air in the heat shrink channel 10 back to the heating air cavity 20 for heating, realizing the internal circulation of the hot air in the entire shrinking furnace, reducing heat dissipation, and thus reducing energy waste, and at the same time making it easier to control the temperature in the heat shrink channel 10 at the target temperature. The heat preservation effect of the insulation shell 1 can effectively reduce the heat dissipation in the heating air cavity 20, further reducing energy consumption.

[0045] The heater 6 and the air supply device 5 are arranged in the heat preservation shell 1. When a fault occurs, it is difficult to repair the heater 6 and the air supply device 5. Therefore, this solution takes the following measures to solve this problem:

[0046] The insulation shell 1 includes an insulation upper shell 11 and an insulation base 12. The insulation upper shell 11 can be detachably installed on the insulation base 12. The wind cavity inner shell 3 is installed in the insulation upper shell 11 or in the insulation base 12. The heater 6 and the air supply device 5 can be inspected by opening the insulation upper shell 11.

[0047] Specifically, the insulation shell 1 is configured to be a detachable insulation upper shell 11 and an insulation base 12. When the internal heater 6 or the air supply device 5 needs to be repaired, the insulation upper shell 11 can be directly opened. At this time, the heating air cavity 20 and the heat shrinkage channel 10 are open, and the staff can easily inspect and replace the internal heater 6 and the air supply device 5.

[0048] In some embodiments, one side of the insulation upper shell 11 is hinged to the insulation base 12 via a hinge 13, and the other side is connected and fixed to the insulation base 12 via a lock 14. By unlocking the lock 14, the insulation upper shell 11 can be flipped open.

[0049] Specifically, under normal use, the lock 14 locks the insulation upper shell 11 and the insulation base 12, and the insulation upper shell 11 is fixed on the insulation base 12 to ensure the sealing of the insulation shell 1 and avoid air leakage; when maintenance is required, the lock 14 is opened, and the insulation upper shell 11 is flipped to the side where the hinge 13 is located, and the internal components can be repaired. This solution uses a hinge to connect the insulation upper shell 11 and the insulation base 12. When opening the insulation upper shell 11, it only needs to be simply flipped, and after the maintenance is completed, the insulation upper shell 11 can be quickly flipped back, which facilitates the rapid opening and closing operation of the insulation upper shell 11. Specifically, compared with disassembling and removing the entire insulation upper shell 11, this method does not require cumbersome procedures such as hoisting and positioning the insulation upper shell 11.

[0050] Furthermore, the internal circulation shrinking furnace of the present scheme includes a machine base 2, and the insulation base 12 and the conveying device 4 are fixedly installed on the machine base 2. After the insulation upper shell 11 is flipped open, the insulation upper shell 11 will not contact the ground and cause impact damage.

[0051] Regarding the structure of the wind cavity inner shell 3, refer to Figure 3 The wind cavity inner shell 3 includes a wind cavity upper shell 31 and a wind cavity bottom plate 32. The wind cavity upper shell 31 is installed in the thermal insulation upper shell 11, and the wind cavity bottom plate 32 is installed on the thermal insulation base 12. By covering the thermal insulation upper shell 11, the two sides of the wind cavity upper shell 31 and the two sides of the wind cavity bottom plate 32 are joined to enclose and form the wind cavity inner shell 3.

[0052] Similarly, the air cavity inner shell 3 adopts a detachable structure. When the heat-insulating upper shell 11 is opened, the air cavity upper shell 31 inside it is opened accordingly, and the air cavity bottom plate 32 is fixed on the heat-insulating base 12. At this time, the air supply device 5 located at the top of the air cavity upper shell 31 is exposed, and the staff can directly inspect the air supply device 5 in the air cavity upper shell 31. In addition, in normal operation, under the transportation of the conveying device 4, the product passes through the heat shrink channel 10 inside the air cavity inner shell 3, that is, the conveying device 4 is to pass through the inside of the air cavity inner shell 3, specifically, the conveying device 4 needs to pass above the air cavity bottom plate 32, and the flipping and opening of the air cavity upper shell 31 of this solution will not drive the air cavity bottom plate 32 to move, so when opening the air cavity upper shell 31, there is no need to remove the conveying device 4, which simplifies the disassembly and assembly process of the inspection operation.

[0053] Reference Figure 4The air cavity upper shell 31 includes a first air cavity side plate 311, an air cavity top plate 313 and a second air cavity side plate 312 which are sequentially connected to form a U-shaped structure, a first side air cavity 201 is formed between the first air cavity side plate 311 and the thermal insulation upper shell 11, a second side air cavity 202 is formed between the second air cavity side plate 312 and the thermal insulation upper shell 11, and the heater 6 is arranged in the first side air cavity 201 and the second side air cavity 202.

[0054] Heaters 6 are respectively arranged in the first side air cavity 201 and the second side air cavity 202 to ensure that the temperature of the wind blown from the first side air cavity 201 and the second side air cavity 202 to the heat shrink channel 10 has high consistency, so that the peripheral temperature of the product in the heat shrink channel 10 is uniform, and the entire heat shrink film shrinks synchronously, avoiding the problem of wrinkles caused by different local shrinkage speeds.

[0055] Specifically, the heater 6 includes a plurality of heating tubes arranged in the first side wind cavity 201 and the second side wind cavity 202. In order to fix the heating tubes, a plurality of fixing clips are arranged on the inner wall of the thermal insulation upper shell 11, and the heating tubes are installed on the fixing clips. When the thermal insulation upper shell 11 is flipped open, the fixing screws of the wind cavity upper shell 31 can be removed and the wind cavity upper shell 31 can be taken out from the thermal insulation upper shell 11. After that, the heating tubes fixed on the inner wall of the thermal insulation upper shell 11 can be easily inspected and replaced.

[0056] Reference Figure 4-5 The air holes 33 are arranged on the air cavity bottom plate 32, and a lower air cavity 203 is formed between the air cavity bottom plate 32 and the heat preservation base 12. The first side air cavity 201 and the second side air cavity 202 are respectively provided with first air volume regulating components 7 on one side close to the lower air cavity 203. The ventilation volumes between the first side air cavity 201 and the second side air cavity 202 and the lower air cavity 203 are respectively adjusted by the first air volume regulating components 7, thereby adjusting the air volume of the air holes 33 on the air cavity bottom plate 32.

[0057] Among them, the two sides of the lower wind chamber 203 are respectively connected to the first side wind chamber 201 and the second side wind chamber 202. The first side wind chamber 201 and the second side wind chamber 202 on both sides can be directly used to provide hot air to the lower wind chamber 203, so there is no need to set a heater 6 in the lower wind chamber 203. At the same time, in order to facilitate the control of the air volume of the air holes 33 on the air cavity bottom plate 32 located at the bottom of the product, the present scheme sets a first air volume adjusting component 7 at the connection between the first side air cavity 201 and the second side air cavity 202 and the lower air cavity 203. The air volume entering the lower air cavity 203 is adjusted by the first air volume adjusting component 7, thereby adjusting the air volume of the air holes 33 on the air cavity bottom plate 32. In this method, the width of the first side air cavity 201 and the second side air cavity 202 is relatively small, so the size of the first air volume adjusting component 7 is relatively small. Compared with directly setting the air volume adjusting component on the air cavity bottom plate 32, the structure of this method consumes less materials and has lower cost. At the same time, it will not occupy the space on the air cavity bottom plate 32, thereby avoiding interference with the setting of the conveying device 4.

[0058] Regarding the setting method of the first air volume adjusting component 7, in some embodiments, the first air cavity side plate 311 and the second air cavity side plate 312 are respectively connected to a support plate extending outward and abutting the inner wall of the thermal insulation upper shell 11 on one side close to the air cavity bottom plate 32, and the support plate is provided with ventilation holes. The first air volume adjusting component 7 is movably mounted on the support plate, and the first air volume adjusting component 7 is provided with a first adjustment hole corresponding to the ventilation hole. The overlap degree of the first adjustment hole and the ventilation hole is adjusted by moving the first air volume adjusting component 7, thereby adjusting the ventilation volume between the first side air cavity 201 and the second side air cavity 202 and the lower air cavity 203.

[0059] Specifically, the support plate, in addition to supporting the first air volume adjusting component 7, also cooperates with the first air volume adjusting component 7 to realize the air volume adjustment function. The greater the overlap between the first adjustment hole and the ventilation hole, the greater the ventilation volume of the first side air cavity 201 and the second side air cavity 202 to the lower air cavity 203. When the first adjustment hole completely avoids the ventilation hole, the ventilation channel of the first side air cavity 201 and the second side air cavity 202 to the lower air cavity 203 is closed. At this time, no hot air is blown toward the product from the lower air cavity 203.

[0060] Among them, the support plate is preferably formed by directly bending the side ends of the first air cavity side plate 311 and the second air cavity side plate 312 outward through a sheet metal process. There is no fixed connection between the support plate and the insulation shell 1, which facilitates the removal of the entire air cavity upper shell 31 from the insulation upper shell 11.

[0061] In order to adjust the movement of the first air volume adjusting component 7, an adjusting screw can be set at one end of the first air volume adjusting component 7, and a nut matching the adjusting screw is set on the first air volume adjusting component 7. By rotating the adjusting screw, the first air volume adjusting component 7 can be driven to move linearly.

[0062] Furthermore, the air holes 33 are respectively provided on the first air cavity side plate 311 and the second air cavity side plate 312, and second air volume adjusting components 8 are respectively provided on the inner sides of the first air cavity side plate 311 and the second air cavity side plate 312, and the air volumes of the air holes 33 on the first air cavity side plate 311 and the second air cavity side plate 312 are respectively adjusted by the second air volume adjusting components 8.

[0063] Similarly, the second air volume adjustment member 8 is provided to adjust the air volume on both sides of the product. In this way, in actual use, the staff can freely adjust the air volume on both sides and the bottom of the product according to the heating requirements of each part, thereby controlling the temperature of each side of the product, and then controlling the shrinking speed of the heat shrink film on each side of the product, so as to meet the packaging requirements of products with different structures.

[0064] The working principle of the second air volume adjusting components 8 on both sides is similar to that of the first air volume adjusting component 7. The second air volume adjusting components 8 are movably installed on the inner side of the first air cavity side plate 311 or the second air cavity side plate 312 respectively. The second air volume adjusting component 8 is provided with a second adjustment hole corresponding to the air hole 33. The overlap between the second adjustment hole and the air hole 33 is adjusted by moving the second air volume adjusting component 8, thereby adjusting the air volume of the air holes 33 on the first air cavity side plate 311 and the second air cavity side plate 312.

[0065] Specifically, support frames are respectively provided on the inner sides of the first air chamber side plate 311 and the second air chamber side plate 312, and the second air volume adjustment member 8 passes through the support frames to be movably mounted on the first air chamber side plate 311 and the second air chamber side plate 312. To adjust the movement of the second air volume adjustment member 8, an adjustment screw can be provided at one end of the second air volume adjustment member 8, and a nut matched with the adjustment screw can be provided on the second air volume adjustment member 8, and the second air volume adjustment member 8 can be driven to move linearly by rotating the adjustment screw.

[0066] Reference Figure 6The air supply device 5 includes a connected air guide ring 52 and a fan 51. The air guide ring 52 is arranged between the air cavity top plate 313 and the thermal insulation upper shell 11. The air cavity top plate 313 is provided with a vent corresponding to the air guide ring 52. The fan 51 draws the air in the heat shrink channel 10 into the air guide ring 52 through the vent. The air guide ring 52 guides the air to the first side air cavity 201 and the second side air cavity 202.

[0067] Specifically, based on the setting of the air guide ring 52, the air can be smoothly pushed to the first side air cavity 201 and the second side air cavity 202 on both sides, so as to promote the circulation of the internal air. The air guide ring 52 includes an air gathering ring and a plurality of air guide fins connected to the outer periphery of the air gathering ring. The air gathering ring is provided with a plurality of air outlets on both sides facing the first side air cavity 201 and the second side air cavity 202, and each air outlet has an air guide fin on both sides. All the air guide fins are arranged in a star-shaped shape. Driven by the fan 51, the air in the heat shrink channel 10 continuously enters the air gathering ring and gathers. After the air in the air gathering ring is blown out from the air outlets on both sides thereof, it is continuously diffused to the first side air cavity 201 and the second side air cavity 202 on both sides under the guidance of the air guide fins.

[0068] In some of the embodiments, the heating air cavity 20 is provided with a middle partition plate 34 which divides the heating air cavity 20 into a medium-temperature air cavity and a high-temperature air cavity, and the heater 6 includes a first heating tube arranged in the medium-temperature air cavity and a second heating tube arranged in the high-temperature air cavity; the area in the heat shrink channel 10 corresponding to the medium-temperature air cavity is a preheating expansion area, and the area corresponding to the high-temperature air cavity is a high-temperature heat shrinkage area.

[0069] Specifically, in the existing heat shrinking equipment, the product covered with the heat shrink film is usually directly transported to a high temperature environment for heating and shrinking. However, since the heat shrink film is originally in a relaxed state, there will be folds in the local position of the heat shrink film. When the heat shrink film is directly heated and the heat shrink film shrinks as a whole, wrinkles will be generated in the originally folded area, affecting the appearance of the packaged product. For this reason, in this scheme, a preheating expansion zone and a high-temperature heat shrinking zone are set in the heat shrinking channel 10. The temperature of the preheating expansion zone has not yet reached the heat shrinking temperature of the heat shrink film. After the product covered with the heat shrink film enters the preheating expansion zone, due to the increase in temperature, the air in the heat shrink film expands and then the heat shrink film is propped up and stretched, eliminating the poor folding phenomenon on the heat shrink film; then enters the high-temperature heat shrinking zone, the temperature reaches the heat shrinking temperature of the heat shrink film, and the heat shrink film is preheated and shrunk as a whole and tightly wrapped on the product. Among them, the heat shrink film is originally provided with an exhaust hole, and when shrinking, the air in the heat shrink film is discharged from the exhaust hole. The temperature control of the preheating expansion zone and the high-temperature heat shrinking zone can be achieved by controlling the power of the first heating tube and the second heating tube respectively.

[0070] Regarding the setting of the conveying device 4, the conveying device 4 includes a conveying mesh belt and two conveying wheels respectively arranged at the two ends of the heating pipe, the two ends of the conveying mesh belt are sleeved outside the two conveying wheels, and the upper part of the conveying mesh belt passes through the inside of the heat shrink channel 10, and the lower part is located below the insulation shell 1.

[0071] The conveyor belt has mesh holes, and the hot air blown out from the air holes 33 on the wind chamber bottom plate 32 can be blown to the lower surface of the product through the mesh holes. This solution uses a conveyor belt structure to transport products, which has the advantages of simple structure and low cost.

[0072] In the description of this article, it should be understood that the terms "upper", "lower", "left", "right", etc., and other directions or positional relationships are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of this application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0073] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0074] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0075] The technical principles of the present application are described above in conjunction with specific embodiments. These descriptions are only for explaining the principles of the present application and cannot be interpreted as limiting the scope of protection of the present application in any way. Based on the explanations herein, those skilled in the art can think of other specific implementation methods of the present application without creative work, and these methods will fall within the scope of protection of the present application.

Claims

1. An internal circulation shrinking furnace, characterized in that: include: A heat-insulating shell (1) having a mounting channel formed therein; An air cavity inner shell (3) is arranged in the installation channel, a heating air cavity (20) is formed between the heat-insulating shell (1) and the air cavity inner shell (3), a heat shrink channel (10) is formed inside the air cavity inner shell (3), and air holes (33) are provided on the side and bottom of the air cavity inner shell (3) for connecting the heating air cavity (20) and the heat shrink channel (10); A heater (6) is disposed in the heating air cavity (20) and is used to heat the air; An air supply device (5) is arranged at the top of the air cavity inner shell (3) and is used to transport the air in the heat shrink channel (10) to the heating air cavity (20) to achieve internal circulation of air between the heating air cavity (20) and the heat shrink channel (10); A conveying device (4) is used to convey the product into and out of the heat shrink channel (10).

2. The internal circulation shrinking furnace according to claim 1, characterized in that: The heat-insulating shell (1) comprises a heat-insulating upper shell (11) and a heat-insulating base (12); the heat-insulating upper shell (11) can be detachably mounted on the heat-insulating base (12); the wind cavity inner shell (3) is mounted in the heat-insulating upper shell (11) or in the heat-insulating base (12); and the heater (6) and the air supply device (5) can be inspected and maintained by opening the heat-insulating upper shell (11).

3. The internal circulation shrinking furnace according to claim 2, characterized in that: One side of the heat-insulating upper shell (11) is hinged to the heat-insulating base (12) via a hinge (13), and the other side is connected and fixed to the heat-insulating base (12) via a lock (14); by unlocking the lock (14), the heat-insulating upper shell (11) can be flipped open.

4. The internal circulation shrinking furnace according to claim 2, characterized in that: The wind cavity inner shell (3) comprises a wind cavity upper shell (31) and a wind cavity bottom plate (32); the wind cavity upper shell (31) is installed in the heat-insulating upper shell (11), and the wind cavity bottom plate (32) is installed on the heat-insulating base (12); by covering the heat-insulating upper shell (11), two sides of the wind cavity upper shell (31) and two sides of the wind cavity bottom plate (32) are joined to enclose and form the wind cavity inner shell (3).

5. The internal circulation shrinking furnace according to claim 4, characterized in that: The wind cavity upper shell (31) comprises a first wind cavity side plate (311), a wind cavity top plate (313) and a second wind cavity side plate (312) which are sequentially connected to form a U-shaped structure; a first side wind cavity (201) is formed between the first wind cavity side plate (311) and the thermal insulation upper shell (11); a second side wind cavity (202) is formed between the second wind cavity side plate (312) and the thermal insulation upper shell (11); and the heater (6) is arranged in the first side wind cavity (201) and the second side wind cavity (202).

6. The internal circulation shrinking furnace according to claim 5, characterized in that: The air holes (33) are arranged on the air cavity bottom plate (32), a lower air cavity (203) is formed between the air cavity bottom plate (32) and the heat-insulating base (12), and first air volume regulating components (7) are respectively arranged on the side of the first side air cavity (201) and the second side air cavity (202) close to the lower air cavity (203), and the ventilation volume between the first side air cavity (201) and the second side air cavity (202) and the lower air cavity (203) is respectively adjusted by the first air volume regulating components (7), thereby adjusting the air volume of the air holes (33) on the air cavity bottom plate (32).

7. The internal circulation shrinking furnace according to claim 6, characterized in that: The first air cavity side plate (311) and the second air cavity side plate (312) are respectively connected to a support plate extending outward and abutting against the inner wall of the thermal insulation upper shell (11) on one side close to the air cavity bottom plate (32), and the support plate is provided with a ventilation hole. The first air volume adjusting component (7) is movably mounted on the support plate, and the first air volume adjusting component (7) is provided with a first adjustment hole corresponding to the ventilation hole. The overlap between the first adjustment hole and the ventilation hole is adjusted by moving the first air volume adjusting component (7), thereby adjusting the ventilation volume between the first side air cavity (201) and the second side air cavity (202) and the lower air cavity (203).

8. The internal circulation shrinking furnace according to claim 5, characterized in that: The air holes (33) are respectively arranged on the first air cavity side plate (311) and the second air cavity side plate (312), and second air volume adjusting components (8) are respectively arranged on the inner sides of the first air cavity side plate (311) and the second air cavity side plate (312), and the air volumes of the air holes (33) on the first air cavity side plate (311) and the second air cavity side plate (312) are respectively adjusted by the second air volume adjusting components (8).

9. The internal circulation shrinking furnace according to claim 8, characterized in that: The second air volume adjusting components (8) on both sides are movably mounted on the inner side of the first air cavity side plate (311) or the second air cavity side plate (312), respectively; the second air volume adjusting components (8) are provided with second adjusting holes corresponding to the air holes (33); the overlap between the second adjusting holes and the air holes (33) is adjusted by moving the second air volume adjusting components (8), thereby adjusting the air volume of the air holes (33) on the first air cavity side plate (311) and the second air cavity side plate (312).

10. The internal circulation shrinking furnace according to claim 5, characterized in that: The air supply device (5) comprises a connected air guide ring (52) and a fan (51); the air guide ring (52) is arranged between the air cavity top plate (313) and the heat-insulating upper shell (11); a ventilation opening corresponding to the air guide ring (52) is arranged on the air cavity top plate (313); the fan (51) draws the air in the heat shrink channel (10) into the air guide ring (52) through the ventilation opening; the air guide ring (52) guides the air into the first side air cavity (201) and the second side air cavity (202).

11. The internal circulation shrinking furnace according to any one of claims 1 to 10, characterized in that: The heating air cavity (20) is provided with a middle partition (34) for dividing the heating air cavity (20) into a medium-temperature air cavity and a high-temperature air cavity; the heater (6) comprises a first heating tube arranged in the medium-temperature air cavity and a second heating tube arranged in the high-temperature air cavity; the area in the heat shrink channel (10) corresponding to the medium-temperature air cavity is a preheating expansion area, and the area corresponding to the high-temperature air cavity is a high-temperature heat shrink area.

12. The internal circulation shrinking furnace according to any one of claims 1 to 10, characterized in that: The conveying device (4) comprises a conveying mesh belt and two conveying wheels respectively arranged at the two ends of the heating pipe, the two ends of the conveying mesh belt are sleeved outside the two conveying wheels, and the upper part of the conveying mesh belt passes through the interior of the heat shrink channel (10), and the lower part is located below the insulation shell (1).

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