A single crystal seamless copper tube production equipment and process for air conditioning and refrigeration

Abstract

A single crystal seamless copper tube production equipment and process for air conditioning and refrigeration, belonging to the technical field of metal processing equipment. The equipment consists of a melting furnace, an induction body, a casting furnace, a casting mold, a heating device, a cooling device, a coiler and a coiling machine. The process is to put the copper billet into the melting furnace, and the induction body at the bottom of the melting furnace performs induction heating on the copper billet to melt it to form copper liquid, and keep it warm; under the action of the communicating vessel, the copper liquid enters the furnace chamber of the casting furnace and stands for a specified time, when the copper tube is extruded from the casting mold, it enters the heating device for gradient heating, so that the grains grow in one direction to form a single crystal structure, and is further cooled in the cooling device. Finally, after being coiled and fixed to length by the coiler, the copper tube is transferred to the coiling machine for high-speed stretching and forming. The equipment of the present invention is simple, energy-saving, and has high production efficiency; it can directly carry out reprocessing processes such as drawing and forming; thereby solving the shortcomings of too long a process and high energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of metal processing equipment, and in particular to a single crystal seamless copper tube production equipment for air conditioning and refrigeration and a process thereof. Background Art

[0002] Copper metal has excellent electrical and thermal conductivity and good ductility. It is easy to process and shape, and is widely used in various sectors such as production, life and national economy. Copper pipe is one of the important copper processing products, mainly used in air conditioning, refrigeration, power generation, construction, etc.

[0003] The existing copper tube manufacturing process mainly includes the following solutions:

[0004] 1. Upward drawing method: This production method is to directly draw the copper tube upward after the electrolytic copper is melted, and produce fine equiaxed crystal batches. It needs to go through rolling and other processes for recrystallization before subsequent processing. However, the disadvantage is that the tube structure is loose, not resistant to high pressure, and is only suitable for the production of small-sized air-conditioning copper tubes.

[0005] 2. Continuous casting and rolling method: This production method is to directly cast equiaxed hollow copper after electrolytic copper is melted, and then produce copper tubes through planetary rolling. The advantages of copper tubes produced by this process are: high production efficiency. Disadvantages are: long production process, low yield rate, simple management difficulty, high energy consumption, and the tube is loose and cannot withstand high pressure. The continuous casting and rolling copper tube production method is the main production method for seamless copper tubes for air conditioning and refrigeration at home and abroad, and is the main development direction of seamless copper tubes for air conditioning and refrigeration.

[0006] 3. Continuous casting extrusion method: This production method is to melt electrolytic copper and then cast copper ingots, and then use a large extruder to extrude copper tubes after secondary heating. The advantages of copper tubes produced by this process are: the best quality, fine structure, high density, high pressure resistance, large bending deformation, suitable for working environments with frequent cold and heat exchange and large temperature differences, and can produce large-sized copper tubes. Disadvantages are: low yield, high energy consumption, and high production cost. At present, this process is used to produce seamless copper tubes for air conditioning and refrigeration only for some products with large diameters, small batches, and high requirements. Ordinary products are not competitive and are gradually eliminated by the market.

[0007] In the continuous casting and rolling copper tube manufacturing process, the production and processing of copper ingots usually adopts a horizontal continuous casting furnace. However, due to structural design problems, the existing copper tube production equipment has the disadvantages of too long continuous casting and rolling copper tube production process and high energy consumption. Summary of the invention

[0008] Based on this, the purpose of the present invention is to overcome the shortcomings of the prior art and provide a single crystal seamless copper tube production equipment and process for air conditioning and refrigeration, which can realize the short-process preparation of single crystal seamless copper tubes, with simple equipment, energy saving and high production efficiency. The process using the production equipment can directly produce single crystal copper without the need for recrystallization processing, and can directly carry out reprocessing processes such as drawing and forming; thereby solving the shortcomings of the continuous casting and rolling copper tube production process being too long and having high energy consumption.

[0009] The single crystal seamless copper tube production equipment for air conditioning and refrigeration of the present invention comprises a melting furnace, an inductor, a casting furnace, a casting mold, a heating device, a cooling device, a coiler and a coiling machine; the inductor is arranged at the lower part of the melting furnace; the casting furnace is installed at the bottom of the melting furnace and is connected to the melting furnace through a connecting vessel; the casting mold is installed at the bottom of the casting furnace, a crystallizer is arranged inside the casting mold, and the inlet of the crystallizer is connected to the outflow of the casting furnace; the heating device is arranged at the outflow of the casting mold, the cooling device is arranged at the outflow of the heating device, and the centers of the casting mold, the heating device and the cooling device are on the same axis; the coiler is arranged between the cooling device and the coiling machine.

[0010] In order to achieve better technical effects, further technical improvements also include a horizontal conveying roller, which is arranged on the axis where the center of the casting mold, the heating device and the cooling device is located.

[0011] In order to achieve better technical effects, further technical improvements also include that the melting furnace includes a furnace door and a melting furnace chamber, and the furnace door is openably and closably fixed above the melting furnace chamber.

[0012] In order to achieve better technical effects, further technical improvements also include that the heating device includes an annular heating tube, a heating element and a sensing element; the sensing element is arranged on the inner circumferential wall of the annular heating tube, and the heating element is arranged on the inner circumferential wall of the sensing element.

[0013] In order to achieve better technical effects, further technical improvements also include that the cooling device includes a water-cooled copper sleeve and a water tank, and the water tank is arranged below the water-cooled copper sleeve.

[0014] In addition, the process of producing single crystal seamless copper tubes for air conditioning and refrigeration by the equipment of the present invention is as follows: placing the copper billet into a melting furnace, and the induction body at the lower part of the melting furnace induction heats the copper billet to melt it to form copper liquid, and keeps it warm; under the action of the communicating vessel, the copper liquid enters the furnace chamber of the casting furnace and stands for a specified time, and then the copper liquid after standing enters the crystallizer by its own weight pressure to solidify and cast a hollow; when the copper tube is extruded from the casting mold and enters the heating device for gradient heating, the grains grow in one direction to form a single crystal structure, and it is further cooled in the cooling device, and finally after being wound up and cut to length by the winding machine, the copper tube is transferred to the disc drawing machine for high-speed stretching and forming.

[0015] In order to achieve better technical effects, further technical improvements include: the temperature of the induction body is raised to 1180-1200℃ and the insulation temperature is 1120-1200℃.

[0016] In order to achieve better technical effects, further technical improvements include: the cooling device adopts a water-cooling method, the water flow rate during water cooling is 800-1200L / h, and the traction speed is 300-600mm / min.

[0017] In order to achieve better technical effects, further technical improvements include that the copper tube winding speed of the winding machine is 300m / min-500m / min.

[0018] In order to achieve better technical results, further technical improvements include that the copper tube of the coil drawing machine is stretched 6 times and the single-pass elongation coefficient of the copper tube is 1.5-2.5.

[0019] The advantages of the present invention are:

[0020] 1. The production equipment directly produces single crystal copper. Due to its single crystal structure, dense grain boundary-free structure, good ductility, low degree of work hardening, it does not need to undergo recrystallization processing and can be directly subjected to reprocessing processes such as drawing and forming. This solves the shortcomings of the continuous casting and rolling copper tube production process that is too long and has high energy consumption, and can realize the short-process preparation of single crystal seamless copper tubes, with simple equipment, energy saving and high production efficiency.

[0021] 2. The production process uses hot mold continuous casting to produce bright single crystal copper with a diameter of 30mm-60mm and a wall thickness of 1.5-3.0mm to replace the original horizontal continuous casting diameter of 80-100mm and a wall thickness of 20-25mm of the continuous casting and rolling copper tube. Due to the bright surface, there is no need to go through the milling process. Copper has a single crystal structure with good plastic deformation ability. It can be directly used as a billet on the disc drawing machine for multiple stretching to the corresponding size without going through the three-roll planetary rolling and three-combination drawing processes. After finishing, flaw detection, annealing and packaging, the finished products are put into storage. At the same time, the intermediate finished products produced by the high-speed inverted disc drawing machine can be directly used for internal thread forming production without the need for intermediate annealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of the single crystal seamless copper tube production equipment for air conditioning and refrigeration of the present invention;

[0023] Figure 2 Another schematic diagram of the single crystal seamless copper tube production equipment for air conditioning and refrigeration of the present invention;

[0024] Figure 3 It is a schematic structural diagram of the heating device of the present invention. DETAILED DESCRIPTION

[0025] To further illustrate each embodiment, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementation methods and advantages of the present invention.

[0026] Please also see Figures 1 to 3 .

[0027] The single crystal seamless copper tube production equipment for air conditioning and refrigeration of the present invention comprises a melting furnace 10, an inductor 20, a casting furnace 30, a casting mold 40, a heating device 50, a cooling device 60, a coiler and a coiling machine; the inductor 20 is arranged at the lower part of the melting furnace 10; the casting furnace 30 is installed at the bottom of the melting furnace 10, and is connected to the melting furnace 10 through a connecting vessel 11; the casting mold 40 is installed at the bottom of the casting furnace 30, and a crystallizer is arranged inside the casting mold 40, and the inlet of the crystallizer is connected to the outflow of the casting furnace 30; the heating device 50 is arranged at the outflow of the casting mold 40, and the cooling device 60 is arranged at the outflow of the heating device 50, and the centers of the casting mold 40, the heating device 50 and the cooling device 60 are on the same axis; the coiler is arranged between the cooling device 60 and the coiling machine. It also includes a horizontal conveying roller 12, which is arranged on the axis where the centers of the casting mold 40, the heating device 50 and the cooling device 60 are located. Preferably, the disk pulling machine is a high-speed inverted disk pulling machine.

[0028] Specifically, the melting furnace 10 includes a furnace door and a melting furnace chamber, and the furnace door can be opened and closed and fixed above the melting furnace chamber. The heating device 50 includes an annular heating cylinder 51, a heating element 52 and an induction element 53; the induction element 53 is arranged on the inner circumferential wall of the annular heating cylinder 51, and the heating element 52 is arranged on the inner circumferential wall of the induction element 53. The cooling device 60 includes a water-cooled copper sleeve and a water tank, and the water tank is arranged below the water-cooled copper sleeve. Preferably, the heating element is a resistive heating element.

[0029] Production process example 1:

[0030] The process of producing single crystal seamless copper tubes for air conditioning and refrigeration by the equipment of this embodiment is as follows:

[0031] a. The copper is prepared by hot mold continuous casting process. The diameter of the copper is 30mm and the wall thickness is 1.5mm. After passing through the coiler, each piece is loaded into the receiving basket at 1000kg;

[0032] b. The copper in step a is transferred to a high-speed inverted disc drawing machine, and after 6 passes of high-speed stretching, it is drawn into a 9.52*0.30 finished tube with an outer diameter of 9.52±0.02mm and a wall thickness of 0.30±0.02mm;

[0033] c. The finished copper tube in step b is subjected to finishing and flaw detection treatment at a finishing speed of 300m / min, divided into 120kg / roll, the roll height is 280±5mm, and the number of defects per roll is ≤5;

[0034] d. The coiled material in step c is subjected to finished product annealing at a temperature of 430°C for a holding time of 25 minutes, and then the finished product is packaged and stored.

[0035] In step a, hot mold continuous casting is carried out at a continuous casting machine, and copper with a diameter of 30 to 60 mm and a wall thickness of 1 to 3 mm is prepared by horizontal continuous casting of a hot and cold combined casting mold. The process is as follows: the melting temperature of the copper liquid is 1180 to 1200° C., the insulation temperature is 1120 to 1200° C., the hot mold temperature is 1150 to 1180° C., the hot mold section is heated by resistance heating, and the heating power is 10 to 16 kW; the cooling water flow rate of the cold mold water-cooled copper sleeve is 800 to 1200 L / h, and the traction speed is 300 to 600 mm / min;

[0036] In step b, the hot mold continuous casting is directly stretched through a coiler and then stretched in multiple passes at a high-speed inverted coil drawing machine, and the single-pass elongation coefficient of the copper tube is 1.5-2.5.

[0037] The winding speed of the copper tube stretched by the coiling machine in step c is 300m / min-500m / min.

[0038] In step d, the annealing temperature of the copper tube after finishing is 430° C., and the holding time is 25 min.

[0039] Production process embodiment 2:

[0040] The process of producing single crystal seamless copper tubes for air conditioning and refrigeration by the equipment of this embodiment is as follows:

[0041] a. The copper is prepared by hot mold continuous casting process. The diameter of the copper is 30mm and the wall thickness is 1.5mm. After passing through the coiler, each piece is loaded into the receiving basket at 1000kg;

[0042] b. The copper in step a is transferred to a high-speed inverted disc drawing machine, and after 6 passes of high-speed stretching, it is drawn into a 9.52*0.30 finished tube with an outer diameter of 9.52±0.02mm and a wall thickness of 0.30±0.02mm;

[0043] c. The finished copper tube in step b is subjected to high-speed internal thread forming spinning to form the inner wall thread, the spinning speed is 32000r / min, and the pulling speed is 60m / min;

[0044] d. The finished copper tube in step c is subjected to finishing and flaw detection treatment at a finishing speed of 400m / min, divided into 140kg / roll, the roll height is 300±5mm, and the number of defects per roll is ≤8

[0045] d. The coiled material in step c is subjected to finished product annealing at a temperature of 430°C for a holding time of 25 minutes, and then the finished product is packaged and stored.

[0046] In step a, hot mold continuous casting is carried out at a continuous casting machine, and copper with a diameter of 30 to 60 mm and a wall thickness of 1 to 3 mm is prepared by horizontal continuous casting of a hot and cold combined casting mold. The process is as follows: the melting temperature of the copper liquid is 1180 to 1200° C., the insulation temperature is 1120 to 1200° C., the hot mold temperature is 1150 to 1180° C., the hot mold section is heated by resistance heating, and the heating power is 10 to 16 kW; the cooling water flow rate of the cold mold water-cooled copper sleeve is 800 to 1200 L / h, and the traction speed is 300 to 600 mm / min;

[0047] In step b, the hot mold continuous casting is directly stretched through a coiler and then stretched in multiple passes at a high-speed inverted coil drawing machine, and the single-pass elongation coefficient of the copper tube is 1.5-2.5.

[0048] The winding speed of the copper tube stretched by the coiling machine in step c is 300m / min-500m / min.

[0049] In step d, the annealing temperature of the copper tube after finishing is 430° C., and the holding time is 25 min.

[0050] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A single crystal seamless copper tube production equipment for air conditioning and refrigeration, Features: The invention comprises a melting furnace, an inductor, a casting furnace, a casting mold, a heating device, a cooling device, a coiler and a coiling machine; the inductor is arranged at the lower part of the melting furnace; the casting furnace is installed at the bottom of the melting furnace and is connected with the melting furnace through a connecting vessel; the casting mold is installed at the bottom of the casting furnace, a crystallizer is arranged inside the casting mold, and the inlet of the crystallizer is connected with the outlet of the casting furnace; the heating device is arranged at the outlet of the casting mold, the cooling device is arranged at the outlet of the heating device, and the centers of the casting mold, the heating device and the cooling device are on the same axis. The coiler is arranged between the cooling device and the coiling machine; the coiler also includes a horizontal conveying roller, which is arranged on the axis where the centers of the casting mold, the heating device and the cooling device are located; the melting furnace includes a furnace door and a melting furnace chamber, and the furnace door can be opened and closed and fixed above the melting furnace chamber; the heating device includes an annular heating cylinder, a heating element and a sensing element; the sensing element is arranged on the inner circumferential wall of the annular heating cylinder, and the heating element is arranged on the inner circumferential wall of the sensing element; the cooling device includes a water-cooled copper sleeve and a water tank, and the water tank is arranged below the water-cooled copper sleeve.

2. A process for producing single crystal seamless copper tubes for air conditioning and refrigeration using the equipment described in claim 1, Features: The copper billet is placed in a melting furnace, and the induction body at the bottom of the melting furnace performs induction heating on the copper billet to melt it and form molten copper to keep it warm; under the action of the communicating vessel, the molten copper enters the furnace chamber of the casting furnace and stands for a specified time, after which the molten copper enters the crystallizer by its own weight pressure to solidify and cast a hollow; when the copper tube is extruded from the casting mold and enters the heating device for gradient heating, the grains grow in one direction to form a single crystal structure, and it is further cooled in the cooling device. Finally, after being wound up and fixed to length by the winding machine, the copper tube is transferred to the disc drawing machine for high-speed stretching and forming.

3. The process for producing a single crystal seamless copper tube for air conditioning and refrigeration according to claim 2, Features: The induction body is heated to 1180-1200℃ and the insulation temperature is 1120-1200℃.

4. The process for producing a single crystal seamless copper tube for air conditioning and refrigeration according to claim 2, Features: The cooling device adopts water cooling, the water flow rate is 800-1200L / h, and the traction speed is 300-600mm / min.

5. The process for producing a single crystal seamless copper tube for air conditioning and refrigeration according to claim 2, Features: The copper tube winding speed of the winding machine is 300m / min-500m / min.

6. The process for producing a single crystal seamless copper tube for air conditioning and refrigeration according to claim 2, Features: The copper tube drawing machine has 6 passes, and the single pass elongation coefficient of the copper tube is 1.5-2.5.

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