Horizontal infrared crosslinking furnace
By designing a horizontal infrared crosslinking furnace and adopting crosslinking technology of inert gas protection and electric heating, the limitations of the vertical infrared crosslinking furnace are solved, and efficient, safe and environmentally friendly PE-Xa pipe manufacturing is achieved.
Patent Information
- Application Number
- CN202422566684.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-10-22
AI Technical Summary
In the prior art, vertical infrared crosslinking furnaces have problems such as narrow specification range, low crosslinking efficiency, easy ignition, high energy consumption and difficult operation, and the synchronous crosslinking process of the plunger machine is low, high noise, and uneven pipe performance.
A horizontal infrared cross-linking furnace is designed, including a cross-linking box, a bottom box, an anti-bonding duct roller and a gas supply mechanism. It is protected by inert gas nitrogen, and a cross-linking furnace infrared heating pipe heated by an electric heating wire. The anti-bonding duct roller supports the PE-Xa hot melt pipe embryo and is supported by a duct roller bracket to adapt to pipe manufacturing of different specifications.
It has achieved extensive adaptation to the specifications of pipes, improved cross-linking efficiency, reduced fire risks, energy-saving and environmentally friendly, and has simple operation and good surface condition of the pipes.
Smart Images
Figure CN223236760U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of plastic processing, in particular to a horizontal infrared cross-linking furnace. Background Art
[0002] Polyethylene (PE) is one of the five most common plastics, ranking first among all synthetic resins in terms of production and consumption. It is widely used in industry, agriculture, and daily life. However, PE has poor high-temperature resistance. Its mechanical and chemical resistance sometimes fail to meet the requirements of practical use. Therefore, modifying PE has always been key to the development and application of PE products, and PE cross-linking technology is an important technology for improving its material properties. Cross-linked PE can significantly improve its performance, not only significantly enhancing its mechanical properties, environmental stress cracking resistance, chemical corrosion resistance, creep resistance, and electrical properties, but also significantly improving its temperature resistance. For example, ordinary PE pipes cannot transport media with temperatures exceeding 45°C, but after cross-linking modification, the temperature can be raised to 70°C, greatly expanding the application range of PE.
[0003] PE-Xa pipes have good heat resistance and creep resistance, and are mainly used in radiant heating, radiant cooling, domestic hot and cold water, and radiator connection pipes. Among all polyethylene products, they have one of the most stable performance series and have broad application prospects. The traditional production process of PE-Xa pipes is plunger machine synchronous cross-linking. This process has simple equipment, low initial investment, simple operation, and adaptability to a wide range of pipe specifications. However, its disadvantages are low efficiency, high noise, pulsed changes in pipe wall bulk density, uneven pipe performance, and easy bamboo knots. Currently, commercialized screw extrusion post-crosslinking PE-Xa pipes all use vertical infrared cross-linking furnaces. The vertical infrared post-crosslinking process of PE-Xa pipes has high production efficiency, uniform pipe wall bulk density, and stable performance, but it has the disadvantages of adapting to a narrow range of pipe specifications, low cross-linking efficiency, easy ignition, high energy consumption, and difficult operation. Utility Model Content
[0004] The purpose of the utility model is to provide a horizontal infrared cross-linking furnace to solve the problems existing in the above-mentioned prior art, which has the advantages of adapting to a wide range of pipe specifications, high cross-linking efficiency, low fire risk, energy saving and environmental protection, and easy operation.
[0005] To achieve the above purpose, the present invention provides the following solutions:
[0006] The utility model provides a horizontal infrared cross-linking furnace, comprising a cross-linking box, a bottom box, an anti-sticking tube roller and an air supply mechanism, wherein the cross-linking box is arranged on the top of the bottom box, and a horizontally extending cross-linking chamber is arranged inside the cross-linking box. The cross-linking box is also provided with a cross-linking furnace infrared heating tube for heating the PE-Xa hot-melt pipe embryo in the cross-linking chamber, the anti-sticking tube roller is used to support the PE-Xa hot-melt pipe embryo and is supported in the cross-linking chamber by a tube roller bracket, and the air supply mechanism is used to transport inert gas into the cross-linking chamber.
[0007] Preferably, both ends of the cross-linking box are respectively provided with a pipe inlet and a pipe outlet.
[0008] Preferably, the cross-linking box comprises a left box body and a right box body, the left box body and the right box body are symmetrically arranged and are controlled to open and close by an electric push rod arranged at the bottom.
[0009] Preferably, the infrared heating tube of the cross-linking furnace is embedded in the box wall of the cross-linking box, an electric heating wire is provided in the infrared heating tube of the cross-linking furnace, and the infrared heating tube of the cross-linking furnace is coated with a high-temperature resistant nano coating.
[0010] Preferably, casters are provided at the bottom of the bottom box, and the casters are matched with the track between the extruder and the sizing cooling device of the post-crosslinking PE-Xa pipe production line, and the casters are driven by a driving mechanism.
[0011] Preferably, the bottom end of the managed roller bracket is located in the bottom box, and the bottom end of the managed roller bracket is provided with a managed roller lifting push rod for controlling the height of the anti-sticking managed roller.
[0012] Preferably, there are at least two anti-sticking hosting rollers distributed along the length direction of the cross-linking chamber.
[0013] Preferably, the gas supply mechanism is a nitrogen generator, the gas outlet of the nitrogen generator is connected to a nitrogen main pipe, and the nitrogen main pipe is provided with a plurality of nitrogen branches connected to the cross-linking cavity.
[0014] Preferably, both ends of the bottom box are provided with cross-linking furnace center height adjustment bolts.
[0015] Preferably, the anti-sticking hosting roller is made of stainless steel, and the outside of the anti-sticking hosting roller is sprayed with a high-temperature resistant anti-stick coating.
[0016] Compared with the prior art, the utility model has achieved the following technical effects:
[0017] 1. Adapt to a wide range of pipe specifications: Compared with the vertical infrared cross-linking furnace, the horizontal infrared cross-linking furnace can adapt to the manufacture of most or even all specifications of pipes.
[0018] 2. High cross-linking efficiency: The furnace chamber is filled with nitrogen, which can effectively reduce the loss of cross-linking agent during the cross-linking process of PE-Xa tubes, improve cross-linking efficiency, and reduce the risk of thermal oxidation degradation on the surface of PE-Xa tube embryos.
[0019] 3. Low fire risk: The oxygen index of PE is 17%. In the post-crosslinking atmosphere of the PE-Xa pipe of the present invention, the oxygen concentration is controlled below 15%, thereby reducing the fire risk during the crosslinking process of the post-crosslinking PE-Xa pipe.
[0020] 4. Energy saving and environmental protection: The inner material of the infrared heating tube of the cross-linking furnace is electric heating wire, and the outer surface is coated with high-temperature resistant nano-coating, which improves the heating efficiency and saves energy.
[0021] 5. Prevent tube collapse: The furnace is equipped with a trustee roller, the height of which is adjustable and the surface is sprayed with a high-temperature resistant anti-stick coating to prevent the tube from collapsing.
[0022] 6. Easy to operate: When guiding the pipe, since the cross-linking furnace is placed horizontally, the operator does not need to climb up to complete the pipe guiding.
[0023] 7. Good surface condition of the pipe: The surface of the hosting roller is sprayed with a high-temperature resistant anti-stick coating, which effectively reduces the problem of adhesion of the pipe embryo and makes the surface of the prepared pipe uniform and complete. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. 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 these drawings without paying any creative work.
[0025] Figure 1 This is the main view of the horizontal infrared cross-linking furnace in the utility model;
[0026] Figure 2 This is a side view of the horizontal infrared cross-linking furnace in the utility model;
[0027] In the figure: 1. Pipe inlet; 2. Junction box; 3. Casters; 4. Nitrogen branch pipe; 5. Nitrogen generator; 6. Nitrogen main pipe; 7. Track; 8. Tube roller bracket; 9. Tube roller lifting push rod; 10. Electric push rod; 11. Pipe outlet; 12. Driving mechanism; 13. Cross-linking furnace center height adjustment bolt; 14. Cross-linking furnace infrared heating tube; 15. Anti-sticking tube roller; 16. Cross-linking box; 17. Furnace cavity; 18. Bottom box. DETAILED DESCRIPTION
[0028] 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 embodiments described 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 making creative efforts are within the scope of protection of the present invention.
[0029] The purpose of the utility model is to provide a horizontal infrared cross-linking furnace to solve the problems existing in the prior art.
[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0031] The horizontal infrared cross-linking furnace in this embodiment is as follows Figure 1-Figure 2 As shown, it includes a cross-linking box 16, a bottom box 18, an anti-sticking trustee roller 15 and an air supply mechanism. The cross-linking box 16 is arranged on the top of the bottom box 18. A horizontally extending cross-linking chamber is arranged inside the cross-linking box 16. The cross-linking box 16 is also provided with a cross-linking furnace infrared heating tube 14 for heating the PE-Xa hot melt pipe embryo in the cross-linking chamber. The anti-sticking trustee roller 15 is used to support the PE-Xa hot melt pipe embryo and is supported in the cross-linking chamber by the trustee roller bracket 8. The air supply mechanism is used to transport inert gas into the cross-linking chamber.
[0032] In this specific embodiment, a pipe inlet 1 and a pipe outlet 11 are respectively provided at both ends of the cross-linking box 16 . The PE-Xa hot melt pipe blank enters the cross-linking chamber through the pipe inlet 1 and leaves the cross-linking chamber through the pipe outlet 11 .
[0033] In this specific embodiment, the cross-linking box 16 includes a left box body and a right box body, which are symmetrically arranged and are controlled to open and close by an electric push rod 10 arranged at the bottom.
[0034] In this specific embodiment, the cross-linking furnace infrared heating tube 14 is embedded in the box wall of the cross-linking box 16. An electric heating wire is provided in the cross-linking furnace infrared heating tube 14. The cross-linking furnace infrared heating tube 14 is coated with a high-temperature resistant nano coating.
[0035] In this specific embodiment, casters 3 are provided at the bottom of the bottom box 18, and the casters 3 are cooperated with the track 7 between the extruder and the sizing cooling device of the post-cross-linking PE-Xa pipe production line. The casters 3 are driven by the driving mechanism 12, and the movement of the entire cross-linking furnace is controlled by the casters 3 and the driving mechanism 12 (which can be a motor gear driving mechanism 12).
[0036] In this specific embodiment, the bottom end of the managed roller bracket 8 is located in the bottom box 18, and the bottom end of the managed roller bracket 8 is provided with a managed roller lifting push rod 9 for controlling the height of the anti-sticking managed roller 15. The managed roller lifting push rod 9 can be an electric push rod 10 or a pneumatic push rod, etc., which controls the height of the anti-sticking managed roller 15 to adapt to different specifications of PE-Xa pipes.
[0037] In this specific embodiment, there are at least two anti-sticking trustee rollers 15 distributed along the length direction of the cross-linking chamber. The spacing between the anti-sticking trustee rollers 15 should ensure that the tube embryo does not leave the radiation heating hot spot of the horizontal cross-linking furnace after sagging.
[0038] In this embodiment, the air supply mechanism is a nitrogen generator 5. The nitrogen generator 5's outlet is connected to a nitrogen main pipe 6, which is equipped with several nitrogen branch pipes 4 that communicate with the crosslinking chamber. To improve crosslinking efficiency, reduce the oxidative degradation of the crosslinked polyethylene product by oxygen in the hot air, and prevent fires, nitrogen is supplied from the nitrogen generator 5 through the nitrogen main pipe 6 and then through the nitrogen branch pipes 4 into the furnace chamber 17, reducing the oxygen concentration in the furnace chamber 17 to below 15%.
[0039] In this specific embodiment, the cross-linking furnace center height adjustment bolts 13 are provided at both ends of the bottom box 18. The cross-linking furnace center height adjustment bolts 13 are used to support the cross-linking furnace, and then the height of the cross-linking furnace from the ground is adjusted so that the center of the cross-linking cavity is consistent with the center of the extruder die.
[0040] In this specific embodiment, the anti-sticking trustee roller 15 is made of stainless steel, and the outside of the anti-sticking trustee roller 15 is sprayed with a high-temperature resistant anti-stick coating.
[0041] In this specific embodiment, a plurality of junction boxes 2 are disposed outside the cross-linking box 16 .
[0042] The horizontal infrared cross-linking furnace in this embodiment is height-adjustable and equipped with anti-sticking tube rollers, which are height-adjustable and coated with a high-temperature resistant anti-stick coating. The cross-linked polyethylene pipes are transported horizontally within the furnace cavity via the anti-sticking tube rollers. Infrared heating tubes are installed on the four walls of the furnace, and the furnace temperature is adjustable to 500°C. The infrared heating tubes provide the heat required for the cross-linking process of the polyethylene pipes in the form of radiant heat and convection heat. To improve cross-linking efficiency, reduce the oxidative degradation of the cross-linked polyethylene products by oxygen in the hot air, and prevent fires, a nitrogen generator is used to deliver nitrogen to the furnace cavity through a nitrogen main and then a nitrogen branch pipe, reducing the oxygen concentration within the furnace cavity to below 15%. When the production rate of polyethylene pipes to be post-crosslinked is slow, a single horizontal infrared cross-linking furnace can be used. When the production rate of polyethylene pipes to be post-crosslinked is high, multiple horizontal infrared cross-linking furnaces can be connected in series to form an infrared cross-linking unit.
[0043] The specific operation process is as follows:
[0044] Place the infrared cross-linking furnace on the track 7 between the extruder and the sizing cooling device of the post-cross-linking PE-Xa pipe production line, adjust the center height adjustment bolt 13 of the cross-linking furnace to make the center of the cross-linking cavity consistent with the center of the extruder die, adjust the hosting roller lifting push rod 9 according to the specifications of the manufactured PE-Xa pipe to make the height of the hosting roller appropriate, install the guide rope, move the cross-linking furnace so that the cross-linking furnace inlet and the extruder die are kept at a convenient operating distance, close the cross-linking furnace, connect and start the power of the infrared cross-linking furnace, set the required start-up temperature, start the nitrogen generator 5, start the extruder, connect the pipe blank spitted out from the die to the guide rope, start the traction machine, and adjust the cross-linking furnace temperature, extrusion rate of the extruder, traction rate of the traction machine and the distance between the extruder die and the cross-linking furnace inlet according to the production requirements of PE-Xa pipes.
[0045] The PE-Xa tube blank that has completed the cross-linking process is introduced into a vacuum sizing cooling water tank for sizing and cooling, just like the manufacturing process of ordinary thermoplastic plastic pipes, and then pulled, cut, and collected.
[0046] The following are examples and comparative examples:
[0047] Example 1:
[0048] A horizontal infrared cross-linking furnace was set at 260°C, with an oxygen content of 15% in the air. A 15-ton anti-sticking tube roller was installed to cross-link DN16 PE-Xa pipe. The resulting PE-Xa pipe had a cross-linking degree of 80%, an oxidation induction period of 50 minutes at 200°C, and a smooth, burr-free surface with minimal ovality.
[0049] Example 2:
[0050] A horizontal infrared cross-linking furnace was set at 260°C, with an oxygen content of 13% in the air. A 15-roll anti-sticking tube was installed to cross-link DN16 PE-Xa pipe. The resulting PE-Xa pipe had a cross-linking degree of 83.2%, an oxidation induction period of 48 minutes at 200°C, and a smooth, burr-free surface with minimal ovality.
[0051] Example 3:
[0052] A horizontal infrared cross-linking furnace was set at 280°C, with an oxygen content of 15% in the air. A 15-ton anti-sticking tube roller was installed to cross-link DN16 PE-Xa pipe. The resulting PE-Xa pipe had a cross-linking degree of 81.2%, an oxidation induction period of 45 minutes at 200°C, and a smooth, burr-free surface with minimal ovality.
[0053] Comparative Example 1:
[0054] A horizontal infrared cross-linking furnace was set at 260°C, with an oxygen content of 23% in the air. A 15-roll anti-sticking tube was installed to cross-link DN16 PE-Xa pipe. The resulting PE-Xa pipe had a cross-linking degree of 72%, an oxidation induction period of 40 minutes at 200°C, and a smooth, burr-free surface with minimal ovality.
[0055] Comparative Example 2:
[0056] In a horizontal infrared cross-linking furnace set at 260°C and an oxygen content of 23%, without the use of a 15-roller anti-sticking tube, DN16 PE-Xa tubing was cross-linked. The tubes exhibited severe sag and were prone to breakage, preventing further testing.
[0057] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.
Claims
1. A horizontal infrared cross-linking furnace, characterized in that: It includes a cross-linking box, a bottom box, an anti-sticking trustee roller and an air supply mechanism. The cross-linking box is arranged on the top of the bottom box. A horizontally extending cross-linking cavity is arranged inside the cross-linking box. The cross-linking box is also provided with a cross-linking furnace infrared heating tube for heating the PE-Xa hot melt pipe embryo in the cross-linking cavity. The anti-sticking trustee roller is used to support the PE-Xa hot melt pipe embryo and is supported in the cross-linking cavity by the trustee roller bracket. The air supply mechanism is used to transport inert gas into the cross-linking cavity.
2. The horizontal infrared cross-linking furnace according to claim 1, characterized in that: The two ends of the cross-linking box are respectively provided with a pipe inlet and a pipe outlet.
3. The horizontal infrared cross-linking furnace according to claim 1, characterized in that: The cross-linking box comprises a left box body and a right box body, the left box body and the right box body are symmetrically arranged and are controlled to open and close by an electric push rod arranged at the bottom.
4. The horizontal infrared cross-linking furnace according to claim 1, characterized in that: The infrared heating tube of the cross-linking furnace is embedded in the box wall of the cross-linking box, an electric heating wire is arranged in the infrared heating tube of the cross-linking furnace, and the infrared heating tube of the cross-linking furnace is coated with a high-temperature resistant nano coating.
5. The horizontal infrared cross-linking furnace according to claim 1, characterized in that: The bottom of the bottom box is provided with casters, which are matched with the track between the extruder and the sizing cooling device of the post-crosslinking PE-Xa pipe production line, and the casters are driven by a driving mechanism.
6. The horizontal infrared cross-linking furnace according to claim 1, characterized in that: The bottom end of the managed roller bracket is located in the bottom box, and the bottom end of the managed roller bracket is provided with a managed roller lifting push rod for controlling the height of the anti-sticking managed roller.
7. The horizontal infrared cross-linking furnace according to claim 1, characterized in that: There are at least two anti-sticking trustee rollers distributed along the length direction of the cross-linking cavity.
8. The horizontal infrared cross-linking furnace according to claim 1, characterized in that: The gas supply mechanism is a nitrogen generator, the gas outlet of the nitrogen generator is connected to the nitrogen main pipe, and the nitrogen main pipe is provided with a plurality of nitrogen branches connected to the cross-linking cavity.
9. The horizontal infrared cross-linking furnace according to claim 1, characterized in that: Both ends of the bottom box are provided with cross-linking furnace center height adjustment bolts.
10. The horizontal infrared cross-linking furnace according to claim 1, characterized in that: The anti-sticking hosting roller is made of stainless steel, and the outside of the anti-sticking hosting roller is sprayed with a high-temperature resistant anti-stick coating.