Circulating printing oven

Abstract

The invention discloses a circulating printing oven, and relates to the technical field of printing equipment, the circulating printing oven comprises an oven cover and an oven body, one side of the oven cover is rotatably connected with one side of the oven body, the other side of the oven cover is movably connected with the other side of the oven body through an opening and closing air cylinder, and a plurality of air blowing openings evenly distributed in the length direction of the whole cover body are formed in the oven cover. The side edge of the drying oven body is provided with an opening allowing printed matter to pass through, the air blowing opening is connected to a heat collection box through an air inlet pipe, the heat collection box is connected to a centrifugal fan, the centrifugal fan is connected to a circulating air pipe, and the circulating air pipe is a three-way pipe and is connected to the space in the drying oven body and external air. And a waste discharge port is formed in the oven cover. The circulating printing drying oven is uniform and efficient in drying, the adjusting performance is improved, the circulating printing drying oven is provided with a heat energy circulating and heat recycling structure, heat loss is small, waste can be discharged, and accumulation of water vapor and toxic waste gas is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of printing equipment, and particularly relates to a circulating printing oven. Background Art

[0002] The drying devices supporting current printing machines have the following technical defects during operation: During the drying operation, due to uneven heat energy distribution, local temperature differences are likely to form on the surface of the printed matter, resulting in differential shrinkage of the substrate and thus causing wrinkling phenomena; existing drying equipment can only adjust the temperature and wind force when adjusting the drying firepower, but this adjustment has a delay, and the temperature reduction at the air outlet is not very immediate; the water vapor accumulated inside the closed oven cannot be effectively discharged, forming a heat and humidity circulation blockage effect, significantly reducing the heat energy utilization efficiency and prolonging the drying cycle; volatile organic compounds (VOCs) such as benzene and esters contained in the ink solvent escape rapidly in a high-temperature environment, generating toxic waste gases with pungent odors, causing double pollution to the workshop environment and the atmospheric ecosystem; due to structural problems in existing equipment, a lot of heat energy escapes uselessly, and the thermal efficiency is low, further pushing up the unit energy consumption cost. These technical bottlenecks severely restrict the finished product qualification rate of printed matter, production energy consumption cost, and the environmental compliance of enterprises. Summary of the Invention

[0003] Technical Problems to be Solved by the Invention

[0004] The technical problem to be solved by the present invention is to provide a circulating printing oven, which has uniform and efficient drying, improved adjustment performance, has a heat energy circulation and heat recovery structure, small heat loss, and can discharge waste to avoid the accumulation of water vapor and toxic waste gases.

[0005] Technical Solution

[0006] To solve the above problems, the technical solution provided by the present invention is as follows:

[0007] A circulating printing oven includes an oven cover and an oven body rotatably connected at one side, and the other sides of the oven cover and the oven body are movably connected by an opening and closing cylinder. A plurality of air blowing ports are provided inside the oven cover along the length of the overall cover body and are evenly distributed. An opening for passing printed matter is provided on the side of the oven body. The air blowing ports are connected to a heat collecting box through an air inlet pipe. The heat collecting box is connected to a centrifugal fan. The centrifugal fan is connected to a circulating air duct. The circulating air duct is a tee pipe and is respectively connected to the space inside the oven body and the outside air. A waste discharge port is provided on the oven cover.

[0008] The rotatably connected oven lid and opening / closing air cylinder allow the operator to conveniently open and close the oven, facilitating the loading and unloading of the printed materials to be dried. At the same time, it ensures the airtightness of the internal environment of the oven during the drying process, contributing to maintaining stable drying conditions. And the opening / closing air cylinder can control the distance between the air outlet and the printed materials in the semi-open state to efficiently and instantaneously control the temperature and wind force of the hot air blown onto the printed materials. The air outlets evenly distributed along the length of the oven lid can ensure that the hot air is evenly distributed on the surface of the printed materials to be dried, thus avoiding local overheating or insufficient temperature, reducing problems such as substrate deformation and wrinkles caused by temperature differences, and improving the quality of the finished product. The heat collection box centrally collects heat, while the centrifugal fan is used to force air flow and send the heated air into the oven through the air outlets. This design not only improves the utilization efficiency of thermal energy but also can more quickly adjust the drying temperature, overcoming the problem of adjustment delay in traditional equipment. The circulating air duct in the form of a tee is respectively connected to the internal space of the oven body and the external air, realizing the recycling of hot air and effectively reducing energy loss. In addition, fresh external air is introduced as needed to adjust the internal humidity and temperature, further optimizing the drying environment. The waste outlet can effectively discharge the water vapor accumulated inside the oven and the toxic waste gases (such as VOCs like benzene and esters) volatilized from the ink solvent, which not only improves the working environment, reduces the harm to human health, but also reduces the pollution to the external atmospheric environment.

[0009] Optionally, a guiding sliding shaft is provided beside the opening / closing air cylinder, and the guiding sliding shaft is connected to the oven lid and the oven body.

[0010] The guiding sliding shaft can ensure that the oven lid moves along a preset path during the opening and closing process, avoiding the shaking or misalignment phenomena that may be caused by the action of the air cylinder, making the operation more stable and reliable. Through the guiding function of the guiding sliding shaft, precise positioning between the oven lid and the oven body can be achieved, ensuring good contact of the sealing between the two, which is crucial for maintaining the stability of the drying environment (such as temperature, humidity and other conditions).

[0011] Optionally, there are two sets of the air outlets, the air inlet pipes, the heat collection box, the centrifugal fan and the circulating air duct, which are symmetrically and evenly distributed.

[0012] By setting two sets of symmetrically and evenly distributed air outlets inside the oven lid, it can ensure that the hot air more evenly covers the entire surface of the printed materials, effectively avoiding the situation of local overheating or overcooling, thus reducing problems such as substrate deformation and wrinkles caused by temperature differences, and further improving the quality of the finished product. The dual-group design means that even if one set of equipment fails, the other set can still continue to work, which not only improves the reliability and stability of the system but also reduces production interruptions caused by equipment failures, contributing to maintaining the continuity of production.

[0013] Optionally, a control valve structure is provided inside the pipe of the circulating air duct connecting to the outside air.

[0014] The control valve allows the operator to precisely adjust the amount of outside air entering the oven system as needed. This helps maintain ideal drying conditions, such as parameters like temperature and humidity, thus ensuring the quality of printed products. By flexibly adjusting the inflow of outside air, thermal energy usage can be managed more effectively, avoiding unnecessary energy waste. For example, reducing the introduction of fresh air when full power operation is not required can help save heating costs. Different production environments or requirements may call for different drying conditions. The control valve enables the system to make quick adjustments according to the actual situation, enhancing the equipment's adaptability to various operating conditions.

[0015] Optionally, a diverging diffuser is provided at the connection between the heat collection box and the centrifugal fan, and a diverging partition is provided inside the connecting pipe in a plane.

[0016] The diverging diffuser can make the heated air more evenly distributed throughout the oven interior. Compared with direct injection, the diffuser allows the hot air to enter the oven in a more dispersed manner, thus avoiding problems such as local overheating or uneven temperature, and ensuring that the surface of the printed product is heated more evenly. By optimizing the flow path of the hot air, the diverging design helps reduce energy loss. The presence of the partition enables the hot air to mix better when passing through the pipe, achieving a more stable temperature distribution, and thus improving the overall thermal energy utilization efficiency. The design of the diffuser and the diverging partition in the plane can also help reduce the noise generated when the air flow passes through. This is because they change the direction and speed of the air flow, reducing the possibility of high-speed air flow directly impacting the object surface, thereby reducing noise generation.

[0017] Optionally, the diffuser faces the heating pipe of the heat collection box, and the other end of the heat collection box is provided with a hot air outlet and connected to the air inlet pipe.

[0018] The diffuser and the diverging partition in the plane work together to ensure that the air can be dispersed in the best way after entering the heat collection box and make full contact with the heating pipe. This not only promotes the effective absorption of heat but also avoids problems such as local overheating or cold zones caused by uneven air flow.

[0019] Optionally, the side wall of the air outlet is an inclined wall, and the mouth of the air outlet is a slit.

[0020] The contraction joint design can increase the air flow velocity through the air outlet. According to Bernoulli's principle, when gas passes through a narrow space, its flow velocity increases while the pressure decreases. This helps to direct the hot air more concentratedly towards the surface of the printed matter, improving the local heating efficiency. The inclined wall design guides the air to form a more directional and concentrated air flow pattern, reducing the dispersion and disorder of the air flow. This can ensure that the hot air covers the printed matter to be dried more evenly, reducing the problem of inconsistent drying caused by uneven air flow. Since the air flow is more concentrated and faster, the heat can be transferred to the surface of the printed matter more effectively, reducing energy loss. At the same time, this design also helps to better control the drying temperature and time, further improving the energy use efficiency. The traditional straight wall air outlet may cause problems such as overheating or insufficient heating in the edge area. The design of combining the inclined wall with the contraction joint can effectively alleviate this phenomenon, enabling the entire surface of the printed matter to be evenly heated, and avoiding quality problems in the edge part.

[0021] Optionally, a number of partition layers that vertically divide the space are provided inside the air outlet, and the partition layer closer to the air inlet pipe is shorter.

[0022] Through the layered design, the air flow entering the air outlet can be distributed and directed in a predetermined manner. The shorter partition layer is closer to the air inlet pipe side, which helps to guide more air flow towards the middle or outer area of the air outlet, thus achieving a more uniform air flow distribution. This can avoid the problem of uneven drying caused by the air flow concentrating in a certain area. This design can ensure that the hot air is more evenly distributed along the entire length of the air outlet, rather than only concentrating on certain specific points or areas. Therefore, it can improve the consistency of the heat received by the entire surface of the printed matter, reduce the situation of local overheating or insufficient heating, and thus improve the finished product quality.

[0023] Optionally, the partition layer is inclined towards the air inlet pipe.

[0024] The inclined partition layer can more effectively guide the direction of the air flow, enabling the hot air entering from the air inlet pipe to flow more smoothly along the predetermined path towards the outlet of the air outlet. This design helps to reduce the turbulent flow and resistance of the air inside the air outlet, making the air flow more stable and orderly.

[0025] Optionally, the waste outlet is connected to the oven cover through a waste discharge transition air body, and the waste discharge transition air body is a cuboid and is reduced in diameter through an inclined shell at the waste outlet.

[0026] This design helps to guide the exhaust gas to flow more smoothly from the inside of the oven to the waste outlet. The inclined structure can reduce the air flow resistance, making the exhaust gas discharge more efficiently and avoiding the accumulation or formation of turbulence of the exhaust gas in the waste discharge transition air body. The reduced-diameter design at the waste outlet can accelerate the flow rate of the exhaust gas, which helps to more effectively discharge harmful gases, reduce their residence time in the oven, and thus reduce the impact on product quality.

[0027] Beneficial effects

[0028] Adopting the technical solution provided by the present invention, compared with the prior art, it has the following beneficial effects:

[0029] The technical solution provided by the present invention is provided with air blowing ports evenly distributed along the length of the overall cover, having uniform and efficient drying performance. The design combines a centrifugal fan with a heat collection box and a circulation air duct, improving the instant adjustment performance. It is also provided with a circulation air duct that can recycle some hot air again, having a heat energy circulation and heat recovery structure. A dedicated waste outlet is set up for effective exhaust of waste gas and water vapor, and by optimizing the equipment structure, heat loss is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 FIG. 1 is a perspective view of the structure of a circulating printing oven according to an embodiment of the present invention;

[0031] Figure 2 FIG. 2 is a perspective view of the structure of a circulating printing oven according to an embodiment of the present invention from another perspective;

[0032] Figure 3 FIG. 3 is a schematic view of the bottom structure of the oven cover of a circulating printing oven according to an embodiment of the present invention;

[0033] Figure 4 FIG. 4 is a sectional view of a circulating printing oven according to an embodiment of the present invention;

[0034] Figure 5 FIG. 5 is a sectional view of the air blowing port of a circulating printing oven according to an embodiment of the present invention;

[0035] Figure 6 FIG. 6 is a sectional view of the centrifugal fan and the heat collection box of a circulating printing oven according to an embodiment of the present invention;

[0036] Figure 7 FIG. 7 is a schematic view of the structure of the circulation air duct of a circulating printing oven according to an embodiment of the present invention;

[0037] 1. Oven lid; 2. Oven body; 3. Wind baffle; 4. Opening and closing cylinder; 5. Guide sliding shaft; 6. First centrifugal fan; 601. Diffusion air outlet; 7. First heat collecting box; 701. First hot air outlet; 702. Heating pipe; 8. Second centrifugal fan; 9. Second heat collecting box; 901. Second hot air outlet; 10. First circulation air duct; 11. Second circulation air duct; 12. First group of air inlet pipes; 13. Second group of air inlet pipes; 14. Waste discharge port; 15. Hinge; 16. Air blowing port; 1601. Inclined wall; 1602. Shrinkage joint; 17. First partition layer; 18. Second partition layer; 19. Third partition layer; 20. Air damper; 21. Handwheel air valve actuator; 22. Pin shaft; 23. Waste discharge transition air body. Detailed implementation mode

[0038] To further understand the content of the present invention, the present invention will be described in detail with reference to the accompanying drawings and embodiments.

[0039] Embodiment 1

[0040] Combined with the attached Figure 1 , a circulating printing oven includes an oven lid 1 and an oven body 2 that are rotatably connected at one side. The oven lid 1 and the oven body 2 are rectangular in shape. A hinge 15 is provided at the rotation connection. The hinge 15 plates are fixedly connected to the sides of the oven lid 1 and the oven body 2 by screws respectively. Wind baffles 3 are provided on the other two sides of the oven body 2. An opening is provided in the middle of the wind baffle 3 for passing printed products. The oven lid 1 and the oven body 2 are made of stainless steel or aluminum alloy to ensure structural strength and corrosion resistance. The outer wall of the box / cover: 1.5 mm, made of 304 stainless steel with a thickness of 3 mm, and lined with a 0.8 mm high-temperature aluminized steel plate (temperature resistance ≥ 300 °C). The hinge 15 uses high-strength stainless steel screws to fix the hinge 15 plates on the oven lid 1 and the oven body 2 to ensure the stability of long-term use. The hinge 15 plates are made of 10 mm thick Q235 steel plates and fixed by M8 stainless steel countersunk head screws.

[0041] Combined with the attached Figure 2 , the other side of the oven lid 1 and the oven body 2 is movably connected by an opening and closing cylinder 4. There are two symmetrically arranged opening and closing cylinders 4. The output end of the opening and closing cylinder 4 is hinged to the side of the oven body 2, and the piston end of the opening and closing cylinder 4 is hinged to the oven lid 1. A guide sliding shaft 5 is provided beside the opening and closing cylinder 4. The guide sliding shaft 5 is connected to the oven lid 1 and the oven body 2. In this embodiment, there is one guide sliding shaft 5, which is located in the middle of the opening and closing cylinder 4. One end of the guide sliding shaft 5 is hinged to the side of the oven body 2, and the guide sliding shaft 5 is slidably connected to a sliding sleeve, and the sliding sleeve is hinged to the side of the oven body 2. The guide sliding shaft 5 is a solid steel shaft with a diameter of about 30 mm, and its surface is hardened. The inner diameter of the sliding sleeve is slightly larger than the shaft diameter to reduce friction and ensure smooth movement.

[0042] Combined with the attached Figure 3, inside the oven cover 1, there are several air blowing openings 16 evenly distributed along the length of the overall cover body. In this embodiment, there are 8 air blowing openings 16, which are evenly distributed inside the oven cover 1. The length of the air blowing opening 16 is greater than 80% of the length of the oven cover 1 to ensure the uniformity of hot air blowing. Parameters of the air blowing opening 16: the length of a single air blowing opening 16 is 1600 mm (covering 80% of the length of the oven cover 1), and the width is 20 mm.

[0043] Combined with the attached Figure 1-2 , on the side of the oven body 2, there is an opening for passing printed matter. The air blowing opening 16 is connected to the heat collecting box through an air inlet pipe. The air inlet pipe is a bent pipe with a bending angle of 180°, and is connected to the hot air outlet.

[0044] The heat collecting box is connected to a centrifugal fan. The centrifugal fan is connected to a circulating air duct. The circulating air duct is a tee pipe and is respectively connected to the space inside the oven body 2 and the outside air. There is a waste discharge opening 14 on the oven cover 1. The air blowing opening 16, the air inlet pipe, the heat collecting box, the centrifugal fan and the circulating air duct are all provided with two groups and are symmetrically and evenly distributed. The diffuser opening 601 faces the heating pipe 702 of the heat collecting box. At the other end of the heat collecting box, there is a hot air outlet and it is connected to the air inlet pipe.

[0045] In this embodiment, there are two groups of air blowing openings 16, four in each group, which are respectively connected to the first group of air inlet pipes 12 and the second group of air inlet pipes 13. There are 4 first group of air inlet pipes 12 and 4 second group of air inlet pipes 13 respectively, arranged side by side at one end of the top of the oven cover 1. The first group of air inlet pipes 12 is connected to the first heat collecting box 7 through the first hot air outlet 701, and the second group of air inlet pipes 13 is connected to the second heat collecting box 9 through the second hot air outlet 901. The first heat collecting box 7 is connected to the first centrifugal fan 6, and the second heat collecting box 9 is connected to the second centrifugal fan 8. The first heat collecting box 7, the first centrifugal fan 6 and the second heat collecting box 9, the second centrifugal fan 8 are respectively arranged on both sides of the top of the oven cover 1. The first centrifugal fan 6 is connected to the first circulating air duct 10, and the second centrifugal fan 8 is connected to the second circulating air duct 11. The first circulating air duct 10 is on the oven cover 1 at the end of the opening and closing cylinder 4, and the second circulating air duct 11 is on the oven cover 1 at the end of the air inlet pipe. The centrifugal fan can not only extract the hot air inside the oven cover 1 and the oven body 2, but also extract air from the outside.

[0046] Air inlet pipe: diameter 150 mm, 180° bent pipe (bending radius 200 mm), flange connection (bolt M10×25, spacing 100 mm).

[0047] Combined with the attached Figure 4 , the side wall of the air blowing opening 16 is an inclined wall 1601, and the mouth of the air blowing opening 16 is a shrinkage joint 1602. The width of the shrinkage joint 1602 at the mouth is 5 mm (the inclination angle of the inclined wall 1601 is 30°).

[0048] Combined with the attached Figure 5, there are several partition layers inside the air outlet 16 that vertically divide the space, and the partition layer closer to the air inlet pipe is shorter. The partition layer inclines towards the air inlet pipe. The internal partition layer: a vertical stainless steel partition, with a decreasing height gradient (the highest layer is 100 mm, the lowest layer is 20 mm), inclining 15° towards the air inlet pipe. The partition layer includes the first partition layer 17, the second partition layer 18, and the third partition layer 19, with the lengths increasing in sequence.

[0049] Combined with the attached Figure 6 , at the connection between the heat collection box and the centrifugal fan, there is a diverging diffusion air outlet 601, and there are partitions that diverge in a plane inside the connecting pipe. The partition has two layers and is bent. Heat collection box: size 600×400×300 mm, with 6 groups of U-shaped electric heating tubes inside (each tube has a power of 4 kW, total power 24 kW). Diffusion air outlet 601: a diverging flow guiding partition (2 layers, 60° bend, spacing 50 mm), made of 310S stainless steel.

[0050] Combined with the attached Figure 7 , inside the pipe where the circulating air duct connects to the outside air, there is a control valve structure. The control valve structure is a damper 20 and a handwheel wind valve actuator 21. The damper 20 is circular and located inside the pipe. The middle of the damper 20 is fixedly connected to the pin shaft 22 by screws, and the pin shaft 22 is connected to the output end of the handwheel wind valve actuator 21. After the handwheel wind valve actuator 21 operates, the damper 20 can adjust the angle of the damper 20. Three-way circulating air duct: the main pipe has a diameter of 200 mm, the branch pipe has a diameter of 150 mm, the wall thickness is 1.2 mm, and it is flange-connected.

[0051] The waste outlet 14 is connected to the oven lid 1 through a waste discharge transition air body 23. The waste discharge transition air body 23 is a cuboid and has a reduced diameter through an inclined shell at the waste outlet 14. The waste outlet 14 is connected to another centrifugal fan, with high waste discharge efficiency. Through the negative pressure suction of the centrifugal fan, the waste discharge air speed ≥ 8 m / s.

[0052] Working principle:

[0053] Working state one: The damper 20 is closed, and the inside of the oven lid 1 and the oven body 2 circulates air through the centrifugal fan, heat collection box, air inlet pipe, and air outlet 16, minimizing heat loss as much as possible, and is used for drying printed materials with short-time energy conservation and no pollution.

[0054] Working state two: The damper 20 is opened or half-opened, introducing outside air during the circulation process, discharging waste while drying printed materials, and is used for drying printed materials that will produce pollution and waste gas.

[0055] Efficient and uniform heating: Multiple air outlets 16 + stratified flow guiding design, temperature difference ≤ ±3°C.

[0056] Energy-saving circulation: More than 70% of the hot air is internally circulated, reducing energy consumption by 20% - 30%.

[0057] Flexible control: The manual air valve is combined with automatic temperature control to adapt to different printing processes (such as UV curing, water-based ink drying).

[0058] The above is a schematic description of the present invention and its implementation manners. This description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it and design similar structural modes and embodiments without creative efforts without departing from the spirit of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A circulating printing oven, characterized in that, It includes an oven cover rotatably connected at one side and an oven body, and the other sides of the oven cover and the oven body are movably connected by an opening and closing cylinder. Inside the oven cover, there are several air blowing openings evenly distributed along the length of the overall cover body. On the side of the oven body, there is an opening for passing printed materials. The air blowing openings are connected to a heat collecting box through an air inlet pipe. The heat collecting box is connected to a centrifugal fan. The centrifugal fan is connected to a circulating air pipe. The circulating air pipe is a tee pipe and is respectively connected to the space inside the oven body and the outside air. There is a waste discharge port on the oven cover.

2. The circulating printing oven according to claim 1, characterized in that, There is a guiding sliding shaft beside the opening and closing cylinder, and the guiding sliding shaft is connected to the oven cover and the oven body.

3. A cyclic printing oven according to claim 1, characterized in that, There are two groups of the air blowing openings, the air inlet pipes, the heat collecting box, the centrifugal fan and the circulating air pipe, and they are symmetrically and evenly distributed.

4. The circulating printing oven according to claim 3, characterized in that, There is a control valve structure in the pipe of the circulating air pipe connecting to the outside air.

5. A cyclic printing oven according to claim 3, characterized in that, At the connection of the heat collecting box and the centrifugal fan, there is a diverging diffusion air outlet, and there are partitions diverging in a plane inside the connecting pipe.

6. The circulating printing oven according to claim 5, characterized in that, The diffusion air outlet faces the heating pipe of the heat collecting box, and the other end of the heat collecting box is provided with a hot air outlet and is connected to the air inlet pipe.

7. A circulating printing oven according to claim 1, characterized in that, The side wall of the air blowing opening is an inclined wall, and the mouth of the air blowing opening is a constricted seam.

8. A circulating printing oven according to claim 7, characterized in that, Inside the air blowing opening, there are several partition layers vertically dividing the space, and the partition layer closer to the air inlet pipe is shorter.

9. The circulating printing oven according to claim 8, characterized in that, The partition layer inclines towards the air inlet pipe.

10. A circulating printing oven according to claim 1, characterized in that, The waste discharge port is connected to the oven cover through a waste discharge transition air body. The waste discharge transition air body is a cuboid and is reduced in diameter through an inclined shell at the waste discharge port.

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