High-quality blank suspension smelting equipment with cold crucible descending function

Abstract

The utility model provides high-quality blank suspension smelting equipment with a cold crucible descending function, which comprises a vacuum chamber, a cold crucible device and an induction coil, the cold crucible device comprises a crucible body, a crucible pull rod, a driving device and a feeding device, and the crucible body is arranged in the vacuum chamber; the upper end of the crucible pull rod is combined with the water jacket of the crucible body, the lower end of the crucible pull rod is combined with the driving device, a combination structure combined with the driving device is installed at the lowermost end of the crucible pull rod, and the combination structure is provided with a movable combiner and a rotary combiner; the driving device comprises a linear moving device connected with the moving combiner and a rotating driving device connected with the rotating combiner; the feeding device supplements materials into the crucible body in the metal smelting and solidification process. In the solidification process of molten metal, a sequential crystallization condition from bottom to top can be formed by utilizing a cold crucible descending device, and a metal blank which is free of shrinkage cavities, pores, looseness and cracks and is compact in material is obtained.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of metal smelting, specifically is high -quality blank material suspension smelting equipment with cold crucible descending function. BACKGROUND

[0002] Suspension smelting technology is one of the most advanced smelting technologies in the contemporary, and this technology eliminates the pollution of crucible material to the melt, and can obtain very high smelting temperature. However, if special technical measures are not taken, this technology has the same problem as most smelting technologies - metallurgical defects such as shrinkage cavity and crack in the cast blank. The reason for the shrinkage cavity is that the cooling direction of the metal liquid in the casting mold comes from the bottom and the side, and the metal liquid at the bottom and the side solidifies first, and the shrinkage amount during solidification of them is supplemented by the metal liquid in the middle, while the metal liquid in the middle solidifies without liquid to fill. This process also produces pores and loose in the middle of the blank. The reason for the crack is similar - the metal liquid at the bottom and the side solidifies first to form a fixed hard shell, and when the continuous solidification process lacks metal liquid supplement, thermal stress is generated.

[0003] Special measures can make the metal liquid solidify from bottom to top to form a sequential crystallization process. In this process, the metal liquid above can continuously supplement the shrinkage amount of the metal solidified below until the surface of the blank. Therefore, such a process can eliminate metallurgical defects such as shrinkage cavity, thermal stress and crack, and obtain a blank with excellent material quality.

[0004] In order to obtain the condition of sequential crystallization from bottom to top, relatively complex technical measures are generally required. Therefore, in view of the special conditions of suspension smelting, it is urgent to design a relatively simple suspension smelting device which can also realize such crystallization conditions. SUMMARY

[0005] In order to solve the above problems, the utility model designs a cold crucible descending device for suspension smelting technology, which mainly includes a cold crucible, a water jacket, a crucible pull rod, a driving device and a feeding device. During the suspension smelting process, after the metal material is completely melted and the composition is uniform, the driving device is started to make the cold crucible descend at a constant speed. During the descending process of the crucible, the metal liquid at the bottom of the crucible is lowered to a position below the induction coil to start solidification. As the crucible continues to descend, the metal liquid above the initially solidified metal gradually solidifies from bottom to top to form a dense metal blank. By controlling the descending speed of the crucible, a directional crystalline structure or a single crystal can be formed in the blank. In this device, by increasing the height of the crucible, larger size and weight blanks can also be prepared under the conditions of small size crucible, small diameter vacuum chamber and small power supply.

[0006] The utility model provides a high-quality blank suspension smelting equipment with cold crucible descending function, including vacuum chamber, cold crucible device and induction loop, cold crucible device and induction loop are all installed in the vacuum chamber, and induction loop surrounds the outer peripheral side of cold crucible device setting,

[0007] Among them, the cold crucible device includes crucible body, crucible pull rod, drive arrangement and feeding device, the crucible body is installed in the vacuum chamber,

[0008] The upper end of the crucible pull rod is combined with the water jacket of the crucible body, and the lower end is combined with the drive arrangement, a combined structure combined with the drive arrangement is installed at the lowermost end of the crucible pull rod, and the combined structure is installed with a moving coupler and a rotating coupler,

[0009] The drive arrangement includes a linear moving device connected with the moving coupler and a rotating drive device connected with the rotating coupler,

[0010] The feeding device supplements the material in the crucible body during the metal smelting and solidification process.

[0011] Further, the crucible body includes a crucible wall, a crucible bottom and a water jacket,

[0012] Among them, the crucible wall is a cylindrical structure, and the crucible bottom is a structure sealing the bottom opening of the crucible wall.

[0013] Further, the crucible wall is composed of a plurality of petals with the same shape and size, the length direction of the petals is parallel to the height direction of the cold crucible device, and each petal is provided with a water channel for cooling water;

[0014] The crucible bottom is not cut, or the crucible bottom is cut along the height direction, and the number of the cut seams of the crucible bottom is equal to the number of the petals of the crucible wall, and the seam gap of the cut seam is aligned with the seam gap of the petal of the crucible wall.

[0015] The water jacket is an annular container, which is divided into two layers, one layer connects the water supply channel in the petal of the crucible wall, and the other layer connects the return water channel in the petal of the crucible wall.

[0016] Further, the height H of the crucible body is 1.0-3.0D, wherein D represents the inner diameter of the crucible body.

[0017] Or, the height H of the crucible body is 3.0-12D.

[0018] Further, the cross-sectional dimension P of the crucible petal is 0.05-0.3, preferably P=0.1-0.15.

[0019] And / or, the relationship between the height h of the cut seam area of the crucible bottom and the overall height h0 of the crucible bottom is h=0-0.9h0.

[0020] Further, the crucible pulling rod is composed of two coaxial pipes, the inner pipe is communicated with one layer of the water jacket, and the outer pipe is communicated with another layer of the water jacket.

[0021] The crucible pulling rod extends downward to below the bottom of the vacuum chamber through a vacuum dynamic seal, and the two pipes of the crucible pulling rod are respectively provided with a water interface pipe below the vacuum chamber, which is combined with the cooling system of the equipment.

[0022] Further, the water interface pipe of the crucible pulling rod is installed on the interface cylinder, the interface cylinder is sleeved on the surface of the pipe of the pulling rod, and a screw nut is installed on the upper and lower parts of the interface cylinder, and the screw nut is pressed inward to compress the sealing ring between the interface cylinder and the pipe of the pulling rod through the threads on the two ends of the interface cylinder.

[0023] Further, the linear moving device comprises a servo motor, a linear module and a moving output structure, wherein the moving output structure is combined with the moving combination of the pulling rod;

[0024] And / or, the rotary driving device comprises a servo motor and a rotary output structure, wherein the motor base of the servo motor is fixed on the crucible pulling rod, and the rotary output structure is combined with the rotary combination of the crucible pulling rod.

[0025] Further, the downward moving speed of the crucible body is in the range of 0.3-30 mm / min, and the optimal speed is 1-10 mm / min;

[0026] And / or, the rotary speed of the crucible body is in the range of 2-20 rpm, and the optimal speed is 3-5 rpm.

[0027] Further, the feeding device comprises a horizontal feeding cylinder installed on the upper part of the vacuum chamber, a spiral blade pusher installed in the horizontal feeding cylinder, a first driving mechanism installed on the outer side of the horizontal feeding cylinder to drive the spiral blade pusher to rotate, a feeding pipe installed on the end of the horizontal feeding cylinder and extending into the vacuum chamber from the top of the vacuum chamber, and a storage tank installed on the upper part of the horizontal feeding cylinder close to the driving device, wherein a vacuum plug valve is used to communicate between the storage tank and the horizontal feeding cylinder;

[0028] Or, the feeding device comprises a vertical feeding cylinder installed vertically on the upper part of the vacuum chamber and above the crucible body, a drum installed horizontally in the upper part of the vertical feeding cylinder, a second driving mechanism installed on the outer part of the vertical feeding cylinder to drive the drum to rotate through the shaft of the drum, and a vacuum plug valve installed between the vertical feeding cylinder and the vacuum chamber, wherein a cord with hanging material is wound on the drum, the vertical feeding cylinder is provided with a vacuum sealed cylinder door and a valve for vacuumizing and argon filling, and the vertical feeding cylinder is installed on the top of the vacuum chamber through a flange;

[0029] Or, the feeding device includes a vertical feeding cylinder, a vacuum plug valve, a feeding driver, a feeding rod and a hopper, wherein the feeding driver includes a linear module installed on the upper part of the vertical feeding cylinder and a servo motor driving the linear module, the upper end of the feeding rod is combined with a moving output mechanism of the linear module, the lower end is sealedly extended into the vertical feeding cylinder through the vacuum door, and the hopper installed on the lower end of the feeding rod is configured as a cylindrical structure with an open bottom or a claw-shaped structure with split parts.

[0030] Compared with the prior art, the utility model has the advantages that:

[0031] In the solidification process of the metal liquid, the downward sequential crystallization condition is formed by the cold crucible descending device, and the metal blank with no shrinkage, porosity, loose and crack and dense material is obtained;

[0032] Compared with other technologies for obtaining high-quality metal blanks, the device of the patent has simple structure and small technical difficulty;

[0033] By using the device of the patent, blanks with large size and weight can be prepared under the conditions of small-size crucible, small-diameter vacuum chamber and small-power power supply;

[0034] Compared with the casting technology of suspension smelting, the patent does not need a mold to obtain the metal blank, and all materials form the available blank, so that the material yield is high. BRIEF DESCRIPTION OF DRAWINGS

[0035] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the application. Moreover, the same reference numerals are used throughout the same figures. In the drawings:

[0036] Figure 1 It is a schematic diagram of the structure of the suspension smelting equipment;

[0037] Figure 2 It is a schematic diagram of the structure of the cold crucible device;

[0038] Figure 3 It is a structure example of the rotatable water interface of the crucible pulling rod;

[0039] Figure 4 It is an example of the combination of the crucible pulling rod and the driving device;

[0040] Figure 5 It is a schematic diagram of the structure of the screw feeder;

[0041] Figure 6 It is a schematic diagram of the structure of the roller feeder;

[0042] Figure 7 Structure diagram of hopper feeder;

[0043] Figure 8 Structure diagram of metal liquid solidification process in the process of crucible descending;

[0044] Figure 9 Structure diagram of metal liquid solidification process in the process of crucible descending under the condition of feeding material by feeder.

[0045] In the figure, 01 is a vacuum chamber, 02 is a cold crucible device, 03 is an induction power supply, 04 is an induction coil, 05 is a vacuum unit, 06 is a cooling system, 07 is a control system, 08 is a crucible body, 09 is a crucible pull rod, 10 is a driving device, 11 is a feeding device, 12 is a crucible wall, 13 is a crucible bottom, 14 is a water jacket, 15 is a petal, 16 is a waterway, 17 is a pipeline, 18 is a vacuum dynamic seal, 19 is a vacuum chamber bottom, 20 is a water interface pipe, 21 is a combination structure, 22 is an interface cylinder, 23 is a nut, 24 is a thread, 25 is a sealing ring, 26 is a servo motor, 27 is a linear module, 28 is a moving output structure, 29 is a moving combination, 30 is a rotating output structure, 31 is a motor base, 32 is a rotating combination, 33 is a horizontal feeding cylinder, 34 is a helical blade pusher, 35 is a first driving mechanism, 36 is a vacuum chamber top, 37 is a feeding pipe, 38 is a storage tank, 39 is a vacuum plug valve, 40 is a vertical feeding cylinder, 41 is a roller, 42 is a second driving mechanism, 43 is a cord, 44 is a cylinder door, 45 is a valve, 46 is a flange, 47 is material, 48 is a feeding rod, 49 is a hopper, 50 is a claw structure, 51 is solidified metal, and 52 is metal liquid. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is described and explained below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application. Based on the examples provided by the present application, all other examples obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0047] As Figures 1-2 shown, the present embodiment provides a high-quality billet suspension melting equipment with a cold crucible descending function, which comprises a vacuum chamber 01, a cold crucible device 02, an induction power supply 03, an induction coil 04, a vacuum unit 05, a cooling system 06 and a control system 07; wherein the cold crucible device 02 comprises a crucible body 08, a crucible pull rod 09, a driving device 10 and a feeding device 11.

[0048] Referring to Figure 2The crucible body 08 is installed in the vacuum chamber 01 and is a container for melting metal and a place for solidification of the molten metal. Specifically, the crucible body 08 includes a crucible wall 12, a crucible bottom 13 and a water jacket 14. The crucible wall 08 is a cylindrical structure made of red copper and is composed of a plurality of segments 15 of the same shape and size, the length direction of the segments 15 being parallel to the height direction of the cold crucible device 02. Each segment 15 is provided with a water channel 16 for cooling water. The crucible bottom 13 is a structure for closing the bottom opening of the crucible wall 08 and is also made of red copper. The crucible bottom 13 can be either not cut or cut along the height direction, but must be kept as a whole within a certain height range near the bottom surface. The number of cuts of the crucible bottom 13 is equal to the number of segments 15 of the crucible wall 12, and the gaps of the cuts are aligned with the gaps of the segments 15 of the crucible wall. The crucible bottom 13 is sealingly installed on the water jacket 14, which is a device for supplying water to the water channels of the crucible wall 12. The water jacket 14 is a ring-shaped container divided into two layers, one layer connecting the water supply channels of the segments 15 of the crucible wall and the other layer connecting the water return channels of the segments 15 of the crucible wall. The water jacket 14 is made of metal materials, such as red copper, brass and stainless steel.

[0049] In the crucible lowering technique, there are two design methods for the height of the crucible body 08. The first method is to design the height H of the crucible body 08 according to the standard crucible for suspension melting, i.e. H = 1.0 ~ 3.0D, where D represents the inner diameter of the crucible body 08. The second method is to design the height H according to the requirement of significantly increasing the height of the crucible, i.e. H = 3.0 ~ 12D, in order to produce large-size and heavy ingots under the conditions of basically the same crucible inner diameter, furnace body inner diameter and power of the power source. The cross-sectional size P of the segments 15 of the crucible can be designed according to the principle of P = 0.05 ~ 0.3 in relation to the inner diameter D of the crucible body 08, with 0.1 ~ 0.15 being the best. The relationship between the height h of the cut area of the crucible bottom 13 and the overall height h0 of the crucible bottom 13 is selected according to h = 0 ~ 0.9h0.

[0050] It should be noted that, in order to facilitate the removal of the ingot from the crucible body 08 after the melting and solidification processes are completed, the crucible body 08 (including the crucible wall, the crucible bottom and the water jacket) can be made and assembled as two half crucible bodies.

[0051] In combination with Figure 2 and Figure 4As shown, the crucible pulling rod 09 is a rod member for moving the crucible body 08, the upper end of which is combined with the water jacket 14 of the crucible body 08, and the lower end of which is combined with the driving device 10; the crucible pulling rod 09 is also a structure for supplying water to the crucible water jacket 14. In order to realize the function of water supply, the crucible pulling rod 09 is composed of two coaxial pipes 17, the inner pipe is in communication with one layer of the water jacket 14, and the outer pipe is in communication with another layer of the water jacket 14. The crucible pulling rod 09 extends downward through the vacuum dynamic seal 18 to below the bottom 19 of the vacuum chamber 01, and below the vacuum chamber 01, the two pipes of the crucible pulling rod 09 are respectively provided with a water interface pipe 20 combined with the cooling system 06 of the equipment; a combination structure 21 combined with the driving device 10 is installed at the lowermost end of the crucible pulling rod 09, and the combination structure 21 is installed with a moving combination 29 and a rotating combination 32.

[0052] Combination Figure 3 In order to realize the function of rotating the crucible body 08, the water interface pipe 20 is designed to be able to rotate relative to the crucible pulling rod 09 as the axis under the condition of maintaining the seal. As an embodiment, the water interface pipe 20 is installed on the interface cylinder 22, the interface cylinder 22 is sleeved on the surface of the pulling rod pipe 17, and a screw nut 23 is installed on the upper and lower parts of the interface cylinder 22, the screw nut 23 is pressed inward to the sealing ring 25 between the interface cylinder 22 and the pulling rod pipe 17 through the threads 24 at both ends of the interface cylinder 22, and the dynamic seal is realized. Thus, the condition that the crucible pulling rod 09 can slowly rotate under the condition that the water interface pipe 20 is fixed is provided.

[0053] Continuing to refer to Figure 4 The driving device 10 includes a linear moving device and a rotating driving device. The linear moving device includes a servo motor 26, a linear module 27 and a moving output structure 28. The moving output structure 28 is combined with the moving combination 29 of the pulling rod 09, and the bearing is an example of the moving combination 29, which is used to rotate the crucible pulling rod 09 during the moving process. If the crucible pulling rod 09 does not rotate, other structural ways can be used. The rotating driving device includes a servo motor 26 and a rotating output structure 30, and the motor base 31 of the servo motor 26 is fixed on the crucible pulling rod 09 to move synchronously with the crucible pulling rod 09. The rotating output structure 30 can be combined with the rotating combination 32 of the pulling rod in various ways such as gears, belt pulleys or synchronous belt pulleys.

[0054] It is worth mentioning that the moving speed and the rotating speed of the driving device 10 should be precisely adjusted. The moving speed of the crucible body 08 is controlled within the range of 0.3-30 mm / min, and 1-10 mm / min is the best, the larger the diameter of the crucible body 08, the smaller the moving speed should be; the rotating speed of the crucible body 08 is controlled within the range of 2-20 rpm, and 3-5 rpm is the best, the larger the diameter of the crucible body 08, the smaller the rotating speed should be.

[0055] The feeding device 11 is used to feed materials into the crucible body 08 during the melting and solidification of the metal. The feeding device 11 can have various structures, such as a screw feeder, a roller feeder and a hopper feeder, etc. They have a common feature that the material storage body is connected with the vacuum chamber 01, and the feeding process does not destroy the atmosphere condition in the vacuum chamber 01.

[0056] As an embodiment, as shown in Fig. 1, the screw feeder is mainly used to feed regular granular materials. Specifically, the screw feeder comprises a horizontal feeding cylinder 33 installed on the top of the vacuum chamber 01, a screw blade pusher 34 installed in the horizontal feeding cylinder 33, a first driving mechanism 35 installed on the outer side of the horizontal feeding cylinder 33 to drive the screw blade pusher 34 to rotate, a feeding pipe 37 installed on the end of the horizontal feeding cylinder 33 and extending into the vacuum chamber from the chamber top 36, and a storage tank 38 installed on the top of the horizontal feeding cylinder 33 close to the driving device 10. Figure 5 Among them, a vacuum plug valve 39 is used to connect the storage tank 38 and the horizontal feeding cylinder 33. Thus, a large amount of materials is stored in the storage tank 38 in advance, and a certain amount of materials is sent to the horizontal feeding cylinder 33 through the vacuum plug valve 39; when feeding is required, the screw feeder is started, and the rotation of the blade pushes the materials in the horizontal feeding cylinder 33 to the end of the cylinder, and then the materials are sent into the crucible body 08 through the feeding pipe 37; when the materials in the horizontal feeding cylinder 33 are close to being sent out, the vacuum plug valve 39 of the storage tank 38 is opened to supplement the materials to the horizontal feeding cylinder 33.

[0057] As another embodiment, as shown in Fig. 2, the roller feeder comprises a vertical feeding cylinder 40 vertically installed on the top of the vacuum chamber 01 and above the crucible body 08, a roller 41 horizontally installed in the upper part of the vertical feeding cylinder 40, a second driving mechanism 42 installed on the outer side of the vertical feeding cylinder 40 to drive the roller 41 to rotate in combination with the roller shaft, and a vacuum plug valve 39 installed between the vertical feeding cylinder 40 and the vacuum chamber 01. Among them, the roller 41 is wound with a material hanging rope 43, such as a steel wire rope, a metal wire, a string, etc.; the vertical feeding cylinder 40 is installed with a vacuum sealed cylinder door 44 and a valve 45 for vacuumizing and argon filling, and the vertical feeding cylinder 40 is installed on the chamber top 36 of the vacuum chamber through a flange 46 to realize vacuum sealing.

[0058] Figure 6 Among them, the roller 41 is wound with a material hanging rope 43, such as a steel wire rope, a metal wire, a string, etc.; the vertical feeding cylinder 40 is installed with a vacuum sealed cylinder door 44 and a valve 45 for vacuumizing and argon filling, and the vertical feeding cylinder 40 is installed on the chamber top 36 of the vacuum chamber through a flange 46 to realize vacuum sealing.

[0059] ​Therefore, when the second drive mechanism 42 is activated, the drum 41 rotates to release the cable 43 and lower the material 47, which is suspended below the drum by the cable 43, and sends it into the crucible body 08. The material melts under the heating effect of the electromagnetic field of the induction coil 04 and falls into the crucible body 08. If it is required to continue feeding, the cable 43 should be retracted upwards to the vertical feeding cylinder 40 using the drum 41, the vacuum gate valve 39 should be closed, and the cylinder door 44 should be opened to hang new material on the cable 43. Then, the cylinder door 44 should be closed, the vertical feeding cylinder 40 should be evacuated (argon can be purged if necessary), the vacuum gate valve 39 should be opened, and new material should be sent into the crucible body 08.

[0060] As another embodiment, such as Figure 7 As shown, the hopper feeder includes a vertical feeding cylinder 40, a vacuum gate valve 39, a feeding driver, a feeding rod 48, and a hopper 49. The feeding driver includes a linear module 27 mounted on the vertical feeding cylinder 40 and a servo motor 26 driving the linear module 27. The upper end of the feeding rod 48 is connected to the moving output mechanism 28 of the linear module 27, and the lower end extends into the vertical feeding cylinder 40 through a vacuum seal 18. The hopper mounted at the lower end of the feeding rod 48 can be a cylindrical structure with an openable bottom or a segmented claw-like structure 50. The claw-like structure 40 can pick up material by grabbing or scooping it; it can receive instructions to open its claws and feed material into the crucible body 08. The operation mode of this hopper feeder for the second feeding is similar to that of a drum feeder.

[0061] Therefore, as Figure 8 As shown, when the metal material in the crucible 08 is completely melted and homogeneous, and the molten metal is required to cool and solidify, the drive device 10 is activated while maintaining the power supply, causing the crucible 08 to descend and rotate at a constant speed. The molten metal at the bottom of the crucible 08 first descends to a position below the induction coil 04, where it begins to cool and solidify, forming solidified metal 51. As the crucible 08 continues to descend, the molten metal 52 above the initially solidified metal gradually cools and solidifies until all the molten metal in the crucible 08 has solidified. Because the solidification process of the molten metal always occurs from bottom to top, the shrinkage that occurs during solidification is constantly replenished by the molten metal. Therefore, shrinkage cavities, porosity, and looseness do not appear in the solidified metal. Furthermore, the low thermal stress reduces the tendency to crack, resulting in a very dense billet material. By controlling the descent speed of the crucible 08, directional crystallization structures or single crystals can be formed in the billet.

[0062] It is worth mentioning that the feature of the suspension melting is that the electromagnetic field produces a suspension force on the melt in the crucible body 08 during the melting process, so that the side of the melt around is separated from the crucible wall 12; when the crucible body 08 is lowered, the suspension force still exists within a certain distance below the induction coil 04, and the electromagnetic field also keeps a certain heating effect on the side of the melt, which eliminates the radial cooling of the melt, and provides a guarantee for the melt to obtain the self-upward cooling effect and the sequential crystallization organization. The speed of the lowering of the crucible body 08 cannot be too fast, if the crucible body 08 is lowered too fast, the melt is lowered to a lower position before solidification, and the melt is solidified under the condition of losing the suspension force and the heating effect, i.e. solidified from the periphery to the inside under the condition of the radial cooling of the crucible wall 12, so that the metallurgical defects such as shrinkage cavity and crack still occur. The condition for maintaining the self-upward sequential crystallization of the melt is that the isothermal surface at the position of the solid / liquid section below the induction coil 04 is kept as a plane perpendicular to the lowering direction, which requires that the temperature of the center of the melt and the periphery can be balanced through the heat conduction process.

[0063] The effect of driving the crucible body 08 to rotate during the lowering of the crucible body 08 is to balance the temperature around the melt section, eliminate the uneven distribution of the electromagnetic field in the melt section to form a temperature difference, and destroy the planar form of the isothermal surface.

[0064] When the ordinary ceramic crucible, metal crucible or graphite crucible is used, the side of the melt in the crucible body 08 always keeps in contact with the crucible wall 12. Therefore, when the crucible body 08 is lowered, the crucible wall 12 below the induction coil 04 starts to cool, which will produce a radial cooling effect on the side of the melt, cause radial solidification, and lead to the formation of metallurgical defects such as shrinkage cavity and crack.

[0065] If a longer billet is required to be prepared, a crucible body 08 with a large height is used. There are two operation modes to achieve this purpose:

[0066] The first mode is to add materials to the crucible body 08, and the height of the induction coil 04 is designed according to the requirement of the standard height of the crucible body 08, and is installed at the position covering the lower section area of the crucible body 08. During the melting process, the melting of the lower materials makes the loose materials lower the filling height in the crucible body 08. During the lowering process of the crucible body 08, the un-melted materials in the crucible body 08 will gradually fall into the position of the induction coil 04, and be heated and melted to combine with the materials already melted below.

[0067] In the second mode, the attachment Figure 9The initial amount of material added to crucible 08 is similar to or slightly more than that of a standard height crucible, and the height and position of induction coil 04 are the same as in the first method. After the material in crucible 08 melts and crucible 08 descends a certain distance, material 47 is added to crucible 08 using feeding device 11; the rate of material addition is based on maintaining the height of the liquid level in crucible 08. The reason for using this method is that in the first method, when the height of the material piled in crucible 08 is large, there is a possibility of material sticking to the wall, hanging, and bridging, and the process of the material falling from the top to the bottom of crucible 08 may be obstructed.

[0068] It is worth noting that while large-size and heavy-weight billets can also be prepared using a large-size crucible body 08, a large-diameter vacuum chamber 01, and a high-power power supply, the apparatus of this embodiment can prepare large-size and heavy-weight billets under the conditions of a small-size crucible body 08, a small-diameter vacuum chamber 01, and a low-power power supply. Moreover, the billet material is dense and free from common metallurgical defects.

[0069] To better understand this implementation method, some specific embodiments are also provided below:

[0070] Example 1:

[0071] In this embodiment, the suspension melting equipment consists of a vacuum chamber 01, a cold crucible device 02, a power supply 03-induction coil 04 device, a vacuum unit 05, a cooling system 06, and a control system 07. Figure 1 The vacuum chamber has a diameter of 1600mm, and the induction power supply has a power of 800kW.

[0072] The cold crucible device consists of a crucible body 08, a crucible pull rod 09, and a driving device 10. Figure 2 ).

[0073] The crucible body is housed within a vacuum chamber and consists of a crucible wall 12, a crucible bottom 13, and a water jacket 14. Figure 2 The crucible wall is a cylindrical structure with an inner diameter of 160 mm and a height of 300 mm, made of copper. It is composed of 24 segments 15, parallel to the height direction of the crucible along its length. Each segment contains a water channel 16 for cooling water. The crucible bottom is a structure that seals the bottom opening of the crucible wall, also made of copper. The outer diameter of the crucible bottom is 160 mm, and its height is 30 mm. It has 24 slits cut along its height, with no slits within 8 mm of the bottom surface. Both the crucible body and the crucible bottom are made of copper. The water jacket is made of brass and is a ring-shaped container with two layers: one layer connects to the water supply channels in the crucible wall segments, and the other layer connects to the water return channels in the crucible wall segments.

[0074] The crucible body is assembled from two half-crucibles, and the crucible wall of each half-crucible consists of 12 lobes.

[0075] The upper end of the crucible pull rod 9 is connected to the water jacket 14 of the crucible, and the lower end is connected to the driving device 10. The pull rod is composed of two coaxial pipes 17, which are connected to the upper and lower layers of the water jacket. The pull rod extends downward through a vacuum dynamic seal 18 to below the bottom 19 of the vacuum chamber, and below the vacuum chamber, the two pipes of the pull rod are respectively provided with a water connection pipe 20 connected to the cooling system of the equipment. A connecting structure 21 is provided at the lower end of the pull rod for connection with the driving device. Figure 4 ).

[0076] The driving device is a linear movement device composed of a servo motor 26, a linear module 27, and a movement output structure 28. The movement output structure is connected to the movement connector 29 of the pull rod ( Figure 4 ).

[0077] The crucible is filled with 36 kg of nickel metal, and the material is heated with a power of 500 kW. When the nickel metal in the crucible is completely melted, the composition is uniform after 10 minutes of holding, and the driving device is started under the condition of maintaining the power to make the crucible descend at a speed of 5 mm / min. The metal liquid at the bottom of the crucible is first lowered to a position below the induction coil, and begins to cool and solidify. As the crucible continues to descend, the metal liquid above the initially solidified metal gradually cools and solidifies until the metal liquid in the crucible is completely solidified ( Figure 8 ). After the process is completed, the vacuum chamber is opened, the crucible body is removed from the pull rod, the crucible body is taken out, the crucible body is split into two half-crucible bodies, and the nickel ingot blank is taken out.

[0078] The nickel ingot taken out from the crucible has a diameter of about 160 mm, a height of about 200 mm, and a weight of about 36 kg. The nickel ingot is cut along the centerline in the height direction, and it is found that there are no shrinkage holes, pores, loose and cracks from top to bottom in the ingot, and the material is very dense.

[0079] Example 2:

[0080] The equipment structure and melting and solidification process of this example are basically the same as those of Example 1.

[0081] The difference between this example and Example 1 is that two sets of driving devices are provided, and an additional rotary driving device is added, which is composed of a servo motor 26 and a rotary output structure 30. In order to use this device, a synchronous pulley 30 is installed at the lower end of the pull rod to connect with the synchronous pulley 32 of the rotary driving device. A bearing 29 is also installed at the lower end of the pull rod, and the output structure 28 of the movement driving device is a mechanism connected to the bearing housing ( Figure 4 ).

[0082] In order to make the water-pulling rod 09 have the function of rotation, a structure that the water interface pipe 20 can be fixed when the pulling rod rotates is designed: the water interface pipe is installed on the interface cylinder 22, the interface cylinder is sleeved on the surface of the pulling rod pipe 17, a screw nut 23 is installed on the upper and lower surfaces of the interface cylinder, the screw nut is pressed inward to the sealing ring 25 between the interface cylinder and the pulling rod pipe through the threads 24 on the two ends of the interface cylinder, and dynamic sealing is realized. Figure 3 )。

[0083] In the solidification process, the moving speed is set to be the same as that of the example, and the rotating speed is set to be 3 rpm.

[0084] After the solidification process is completed, the nickel ingot with no shrinkage, porosity, looseness and crack and dense material is also formed. Compared with the nickel ingot of the example 1, the crystal structure is more uniform, and the effect of directional crystallization is achieved.

[0085] Example 3:

[0086] The equipment structure and the melting and solidification process of this example are also basically the same as those of the example 1.

[0087] The difference between this example and the example 1 is that the height of the crucible body 08 is 550 mm, and a screw feeder is installed on the upper surface of the vacuum chamber 01. Figure 5 The structure of the feeder includes: a horizontal feeding cylinder 33, a screw blade pusher 34 installed in the cylinder, a driving mechanism 35 installed on the outer side of the cylinder to drive the pusher to rotate, a feeding pipe 37 installed on the end of the cylinder and extending into the vacuum chamber, and a storage tank 38 installed on the feeding cylinder and close to the driving device on one side.

[0088] 40 kg of metal nickel is pre-installed in the crucible. After the metal nickel in the crucible is completely melted and kept for 10 minutes, the crucible is started to be lowered, and when the crucible is lowered by 50 mm, the screw feeder is started to feed the nickel beans to each of the crucibles, and the feeding speed is controlled to keep the liquid surface of the nickel pool in the crucible constant. Figure 9 ) until the nickel beans in the feeder are completely fed into the crucible, and the crucible continues to be lowered until the nickel liquid in the crucible is completely solidified.

[0089] After the process is completed, the crucible is taken out, the crucible is disassembled, and the nickel rod is taken out. The nickel rod has a diameter of about 160 mm, a height of about 400 mm, a weight of about 72 kg, and dense material.

[0090] The above merely describes a preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A high-quality billet suspension melting apparatus with a cold crucible lowering function, characterized by, The cold crucible device and the induction coil are both installed in the vacuum chamber, and the induction coil surrounds the outer circumferential side of the cold crucible device; The cold crucible device comprises a crucible body, a crucible pull rod, a driving device and a feeding device, and the crucible body is installed in the vacuum chamber; The upper end of the crucible pull rod is combined with the water jacket of the crucible body, and the lower end is combined with the driving device; The driving device comprises a linear moving device connected with the moving combination connector and a rotating driving device connected with the rotating combination connector; The feeding device supplements materials into the crucible body during the metal smelting and solidification process.

2. The suspension smelting apparatus according to claim 1, characterized in that The crucible body comprises a crucible wall, a crucible bottom and a water jacket; The crucible wall is a cylindrical structure, and the crucible bottom is a structure sealing the bottom opening of the crucible wall.

3. The suspension smelting apparatus according to claim 2, characterized in that, The crucible wall is composed of a plurality of petals with the same shape and size, the length direction of the petals is parallel to the height direction of the cold crucible device, and each petal is provided with a water channel for cooling water; The crucible bottom is not slitted, or the crucible bottom is slitted along the height direction, and the number of slits of the crucible bottom is equal to the number of petals of the crucible wall, and the slit gap of the crucible bottom is aligned with the slit gap of the crucible wall petals. The water jacket is an annular container, which is divided into two layers, one layer connects the water supply channel in the crucible wall petals, and the other layer connects the return water channel in the crucible wall petals.

4. The suspension smelting apparatus defined in claim 1, characterised in that The height H of the crucible body is 1.0-3.0D, wherein D represents the inner diameter of the crucible body; Or, the height H of the crucible body is 3.0-12D.

5. The suspension smelting apparatus defined in claim 4, characterised in that The cross-sectional dimension P of the crucible petals is 0.05-0.3; And / or, the relationship between the height h of the slitted area of the crucible bottom and the overall height h0 of the crucible bottom is h=0-0.9h0.

6. The suspension smelting apparatus defined in claim 5, characterised in that The cross-sectional dimension P of the crucible petals is 0.1-0.

15.

7. The suspension smelting apparatus defined in claim 3, characterised in that The crucible pull rod is composed of two coaxial pipes, the inner pipe is connected with one layer of the water jacket, and the outer pipe is connected with the other layer of the water jacket; The crucible pull rod extends downward to below the bottom of the vacuum chamber through a vacuum dynamic seal, and the two pipes of the crucible pull rod are respectively provided with a water interface pipe combined with the cooling system of the equipment below the vacuum chamber.

8. The suspension smelting apparatus defined in claim 7, characterised in that The water interface pipe of the crucible pull rod is installed on the interface cylinder, the interface cylinder is sleeved on the surface of the pull rod pipe, and a screw cap is installed on the upper and lower parts of the interface cylinder, and the screw cap is pressed inward to the sealing ring between the interface cylinder and the pull rod pipe through the threads at both ends of the interface cylinder.

9. The suspension smelting apparatus defined in claim 1, characterised in that The linear moving device comprises a servo motor, a linear module and a moving output structure, wherein the moving output structure is combined with the moving combination connector of the pull rod; And / or, the rotating driving device comprises a servo motor and a rotating output structure, wherein the motor base of the servo motor is fixed on the crucible pull rod, and the rotating output structure is combined with the rotating combination connector of the crucible pull rod.

10. The suspension smelting apparatus defined in claim 1, characterised in that The downward moving speed of the crucible body is in the range of 0.3-30mm / min; And / or, the rotating speed of the crucible body is in the range of 2-20rpm.

11. The suspension smelting apparatus defined in claim 10, characterised in that The downward moving speed of the crucible body is in the range of 1-10mm / min.

12. The suspension smelting apparatus defined in claim 10, wherein The rotating speed of the crucible body is in the range of 3-5rpm.

13. The suspension smelting apparatus defined in claim 1, characterized in that The feeding device comprises a horizontal feeding cylinder installed on the top of the vacuum chamber, a screw blade pusher installed in the horizontal feeding cylinder, a first driving mechanism installed on the outer side of the horizontal feeding cylinder to drive the screw blade pusher to rotate, a feeding pipe installed on the end of the horizontal feeding cylinder and extending into the vacuum chamber from the top of the vacuum chamber, and a storage tank installed on the top of the horizontal feeding cylinder close to the driving device, wherein a vacuum plug valve is installed between the storage tank and the horizontal feeding cylinder to communicate; Alternatively, the feeding device comprises a vertical feeding cylinder installed vertically on the top of the vacuum chamber and above the crucible body, a roller installed horizontally in the upper part of the vertical feeding cylinder, a second driving mechanism installed on the outer side of the vertical feeding cylinder to drive the roller to rotate in combination with the shaft of the roller, and a vacuum plug valve installed between the vertical feeding cylinder and the vacuum chamber, wherein a rope for hanging the material is wound on the roller, the vertical feeding cylinder is provided with a vacuum sealed cylinder door and a valve for vacuumizing and argon filling, and the vertical feeding cylinder is installed on the top of the vacuum chamber through a flange; Alternatively, the feeding device comprises a vertical feeding cylinder, a vacuum plug valve, a feeding driver, a feeding rod and a hopper, wherein the feeding driver comprises a linear module installed on the top of the vertical feeding cylinder and a servo motor for driving the linear module, the upper end of the feeding rod is combined with the moving output mechanism of the linear module, the lower end of the feeding rod extends into the vertical feeding cylinder through a vacuum seal, and the hopper installed on the lower end of the feeding rod is configured as a cylindrical structure with an open bottom or a claw-shaped structure with split halves.

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