Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals

Definitions

• the present invention relates to an impeller for molten metal and an agitator for molten metal.
• degassing is performed to remove impurities such as hydrogen gas or oxides contained in the molten metal (see, for example, Patent Documents 1 to 5).
• molten metal such as aluminum alloy stored in a degassing tank is stirred by rotating a molten metal stirrer, while an injection gas such as argon gas or nitrogen gas is injected into the molten metal.
• the injection gas is injected into the molten metal in the form of bubbles from the outer periphery of a molten metal impeller attached to the tip of the shaft of the molten metal stirrer.
• the rotation of the molten metal impeller breaks down the bubbles of the injection gas.
• the broken down bubbles capture impurities in the molten metal and cause them to float up. In this way, the impurities are removed from the molten metal.
• the molten metal impeller may be placed deep in the degassing tank. In this case, the molten metal may not be stirred sufficiently at shallower positions, which may reduce the efficiency of the degassing process for the molten metal.
• the present invention was made in consideration of these points, and aims to provide an impeller for molten metal and an agitator for molten metal that can improve the efficiency of degassing processing of molten metal.
• the present invention provides A molten metal impeller including a lower surface perpendicular to a rotation axis and an upper surface, a central portion including a through hole extending along the rotation axis from the lower surface to the upper surface; A plurality of stirring blades protruding radially outward from the central portion; A plurality of grooves are provided on the lower surface and extend from the through holes to corresponding tips of the stirring blades; Equipped with The stirring blade includes a first guide surface and a second guide surface connected to the upper surface and the lower surface, When viewed toward the lower surface, the first guide surface is located at a position advanced from the groove in the impeller circumferential direction, and the second guide surface is located at a position retreated from the groove in the impeller circumferential direction, The first guide surface is inclined with respect to the lower surface so as to proceed in the impeller circumferential direction from the lower surface toward the upper surface. It may be an impeller for molten metal.
• the present invention provides The second guide surface is inclined with respect to the lower surface so as to proceed in the impeller circumferential direction from the lower surface toward the upper surface.
• the impeller for molten metal may be as described in [1].
• the present invention provides When viewed toward the bottom surface, the impeller circumferential direction is a counterclockwise direction.
• the impeller for molten metal may be as described in [1] or [2].
• the present invention provides The upper surface is inclined with respect to the lower surface so as to move away from the lower surface from the tip of the stirring blade toward the central portion.
• the impeller for molten metal may be the impeller according to any one of [1] to [3].
• the present invention provides the groove includes a first side wall connected to the lower surface, a second side wall connected to the lower surface and located at a position retreated from the first side wall in the impeller circumferential direction, and a ceiling wall connected to the first side wall and the second side wall, The second side wall is inclined with respect to the lower surface so as to proceed in the impeller circumferential direction from the lower surface toward the ceiling wall.
• the impeller for molten metal may be the impeller according to any one of [1] to [4].
• the present invention relates to The first side wall is formed perpendicular to the lower surface.
• the impeller for molten metal may be as described in [5].
• the present invention relates to The number of the stirring blades is two.
• the impeller for molten metal may be the impeller according to any one of [1] to [6].
• the present invention relates to The central portion includes a protrusion that protrudes from the upper surface and extends through the through hole.
• the impeller for molten metal may be as described in [7].
• the present invention relates to The upper surface is inclined with respect to the lower surface so as to move away from the lower surface from the tip of the stirring blade toward the protruding portion.
• the impeller for molten metal may be as described in [8].
• the present invention relates to The direction in which the stirring blade protrudes from the central portion is defined as a blade protruding direction, In a direction perpendicular to the blade protruding direction, the dimension of the central portion is larger than the dimension of the tip of the stirring blade.
• the impeller for molten metal may be as described in any one of [7] to [9].
• the present invention relates to A shaft, An impeller for molten metal according to any one of [1] to [10] attached to a lower end of the shaft;
• the molten metal stirrer may be provided with:
• the present invention can improve the efficiency of degassing processing of molten metal.
• FIG. 1 is a schematic diagram showing a state in which an impeller for molten metal according to a first embodiment of the present invention is used in a degassing treatment device.
• FIG. 2 is a perspective view showing an impeller for molten metal according to a first embodiment of the present invention.
• FIG. 3 is a bottom view of the molten metal impeller shown in FIG. 2, viewed toward its lower surface.
• FIG. 4 is a cross-sectional view taken along line AA of FIG.
• FIG. 5 is a cross-sectional view taken along line BB of FIG.
• FIG. 6 is a perspective view showing an impeller for molten metal according to a second embodiment of the present invention.
• FIG. 7 is a bottom view of the molten metal impeller shown in FIG.
• FIG. 8 is a cross-sectional view taken along line CC of FIG.
• FIG. 9 is a perspective view showing a modified example of the impeller for molten metal shown in FIG.
• FIG. 10 is a bottom view showing a modified example of the impeller for molten metal shown in FIG.
• the degassing treatment device 1 is a device for carrying out a degassing treatment to remove impurities such as hydrogen gas or oxides contained in the molten metal before casting using a metal material such as an aluminum alloy.
• the degassing treatment device 1 includes a degassing treatment tank 2 for storing molten metal, and a molten metal stirrer 10 for stirring the molten metal stored in the degassing treatment tank 2.
• the molten metal stirrer 10 is attached to the degassing treatment tank 2 so as to be rotatable about a rotation axis X.
• the molten metal stirrer 10 is connected to a rotation drive device (not shown), and stirs the molten metal stored in the degassing treatment tank 2.
• the molten metal is indicated by the symbol M in FIG. 1 etc.
• the molten metal agitator 10 includes a shaft 11 extending along the rotation axis X, and an impeller 20 for molten metal.
• the impeller 20 for molten metal is attached to the lower end 11a of the shaft 11, and the shaft 11 and the impeller 20 for molten metal rotate together.
• the attachment structure of the shaft 11 and the impeller 20 for molten metal is arbitrary.
• the shaft 11 may be screwed to the impeller 20 for molten metal.
• the shaft 11 may be joined to the impeller 20 for molten metal using an adhesive or the like, or may be fixed to the impeller 20 for molten metal using a fitting structure.
• the molten metal impeller 20 is configured to blow an injection gas G, such as argon gas or nitrogen gas, into the molten metal.
• the shaft 11 includes a gas flow path 12 (see FIG. 4) connected to a gas supply device (not shown).
• the shaft 11 is inserted into a through hole 31 (described later) of the molten metal impeller 20.
• the lower end 11a of the shaft 11 is formed with an injection port 13 (see FIG. 3 and FIG. 4) that communicates with the gas flow path 12.
• the injection gas G that has passed through the gas flow path 12 is ejected from the injection port 13 and blown into the molten metal through a groove 50 (described later).
• the shaft 11 and the impeller 20 for molten metal can be formed separately from at least one of silicon nitride ceramics, sialon ceramics, silicon carbide ceramics, carbon ceramics, and carbon. More specifically, the shaft 11 and the impeller 20 for molten metal can be formed from silicon nitride ceramics or sialon ceramics obtained by sintering silicon nitride powder with a sintering aid, silicon carbide ceramics such as silicon carbide sintered bodies obtained by sintering silicon carbide powder with a sintering aid or silicon nitride-bonded silicon carbide sintered bodies containing 50% or more by weight of silicon carbide, or carbon ceramics obtained by mixing and sintering carbon, silicon carbide, boron carbide, etc.
• the molten metal impeller 20 includes a lower surface 21 perpendicular to the rotation axis X, and an upper surface 22.
• the upper surface 22 is inclined with respect to the lower surface 21, as will be described in detail later.
• the molten metal impeller 20 includes a central portion 30, a plurality of stirring blades 40, and a plurality of grooves 50.
• the central portion 30 includes a through hole 31.
• the through hole 31 extends along the rotation axis X from the lower surface 21 to the upper surface 22.
• the through hole 31 passes through the central portion 30.
• the lower end portion 11a of the shaft 11 described above is inserted into the through hole 31.
• the through hole 31 includes a first circular hole portion 32 and a second circular hole portion 33.
• the first circular hole portion 32 opens to the upper surface 22.
• the second circular hole portion 33 is located below the first circular hole portion 32 and opens to the lower surface 21.
• the first circular hole portion 32 and the second circular hole portion 33 may be formed in a cylindrical shape centered on the rotation axis X and formed concentrically.
• the diameter of the second circular hole portion 33 may be larger than the diameter of the first circular hole portion 32.
• the lower end 11a of the shaft 11 is inserted into the first circular hole portion 32.
• a female thread (not shown) may be formed on the wall surface of the first circular hole portion 32, and a male thread may be formed on the lower end 11a of the shaft 11.
• the shaft 11 screws into the central portion 30, and the shaft 11 and the molten metal impeller 20 can be screwed together.
• the wall height h1 of the first circular hole portion 32 may be 3% or more, or may be 5% or more, of the diameter d1 (see Figures 3 and 4) of the impeller 20 for molten metal.
• the wall height h1 of the first circular hole portion 32 may be 3% or more, or may be 5% or more, of the diameter d1 (see Figures 3 and 4) of the impeller 20 for molten metal.
• the stirring blades 40 are formed so as to protrude radially outward from the central portion 30.
• the number of stirring blades 40 constituting the molten metal impeller 20 according to this embodiment is eight. However, the number of stirring blades 40 may be any number as long as it is two or more.
• the stirring blades 40 are arranged at an equal angular pitch in the impeller circumferential direction D1 described later. In this embodiment, the stirring blades 40 are arranged at a 45° pitch.
• the width w1 of the stirring blade 40 may be 0.3 times or more and 0.8 times or less, or 0.4 times or more and 0.7 times or less, of the diameter d2 (see FIGS.
• the strength of the stirring blade 40 can be improved. Furthermore, by ensuring the width of the stirring blade 40, a flow of the blown gas G toward the radially outward direction can be formed inside the groove 50. A flow of the molten metal toward the outside in the radial direction can also be formed to accompany the flow of the blown gas G. By making the width w1 0.8 times or less the diameter d2, the strength of the impeller 20 for molten metal can be improved.
• the width w1 of the stirring blade 40 is the width of the stirring blade 40 at the lower surface 21.
• the width w1 of the stirring blade 40 may be constant along the radial direction.
• the agitator blade 40 includes a first guide surface 41 and a second guide surface 42.
• the first guide surface 41 and the second guide surface 42 are connected to the upper surface 22 and the lower surface 21.
• the lower edge of the first guide surface 41 is connected to the lower surface 21, and the upper edge is connected to the upper surface 22.
• the lower edge of the second guide surface 42 is connected to the lower surface 21, and the upper edge is connected to the upper surface 22.
• the first guide surface 41 is located at a position advanced from the groove 50 in the impeller circumferential direction D1 when viewed toward the lower surface 21.
• the second guide surface 42 is located at a position retreated from the groove 50 in the impeller circumferential direction D1 when viewed toward the lower surface 21.
• the second guide surface 42 is located on the opposite side to the first guide surface 41 when viewed in the radial direction along the stirring blade 40.
• the impeller circumferential direction D1 is one direction along a circumference centered on the rotation axis X.
• the impeller circumferential direction D1 may be a direction proceeding counterclockwise. In this embodiment, as shown in FIG.
• the impeller circumferential direction D1 when viewed toward the lower surface 21 is the rotation direction of the molten metal impeller 20.
• the first guide surface 41 is located further forward in the rotational direction than the second guide surface 42
• the second guide surface 42 is located further back in the rotational direction than the first guide surface 41.
• the direction from the second guide surface 42 toward the first guide surface 41 along the circumference centered on the rotation axis X is the rotational direction of the molten metal impeller 20.
• the first guide surface 41 is inclined with respect to the lower surface 21 so as to proceed in the impeller circumferential direction D1 from the lower surface 21 toward the upper surface 22. That is, the upper edge of the first guide surface 41 is inclined with respect to the lower surface 21 so as to be displaced in the impeller circumferential direction D1 relative to the lower edge of the first guide surface 41.
• the first guide surface 41 is inclined so as to be displaced to the left from the lower surface 21 toward the upper surface 22.
• the first guide surface 41 is formed so as to proceed in the rotational direction from the lower surface 21 toward the upper surface 22.
• the first guide surface 41 is configured to guide the molten metal downward when the molten metal impeller 20 rotates.
• the angle ⁇ 1 between the first guide surface 41 and the extension surface of the lower surface 21 can be set to any angle in the range of 30° or more and less than 90°.
• ⁇ 1 By setting ⁇ 1 to 30° or more, the stirring function of the molten metal can be improved.
• ⁇ 1 to less than 90° the rotational resistance of the molten metal impeller 20 can be reduced.
• the angle ⁇ 1 may be 45° or 60°.
• Figure 5 shows an example where the angle ⁇ 1 is 60°.
• the second guide surface 42 is inclined with respect to the lower surface 21 so as to proceed in the impeller circumferential direction D1 from the lower surface 21 toward the upper surface 22. That is, the upper edge of the second guide surface 42 is inclined with respect to the lower surface 21 so as to be displaced in the impeller circumferential direction D1 relative to the lower edge of the second guide surface 42.
• the second guide surface 42 is inclined so as to be displaced to the left from the lower surface 21 toward the upper surface 22.
• the second guide surface 42 is formed so as to proceed in the rotational direction from the lower surface 21 toward the upper surface 22.
• the second guide surface 42 is configured to draw in the molten metal from above when the molten metal impeller 20 rotates.
• the angle ⁇ 2 between the second guide surface 42 and the lower surface 21 can be set arbitrarily in the range of 30° or more and 90° or less. By setting ⁇ 2 to 30° or more, the stirring function of the molten metal can be improved. By setting ⁇ 2 to less than 90°, the rotational resistance of the molten metal impeller 20 can be reduced.
• the angle ⁇ 2 may be 45° or 60°.
• the angle ⁇ 2 may be equal to the angle ⁇ 1.
• FIG. 5 shows an example in which the angle ⁇ 2 is 60°.
• the angle ⁇ 2 may be set to an angle different from the angle ⁇ 1.
• the angle ⁇ 2 may be within ⁇ 10° or within ⁇ 5° of the angle ⁇ 1.
• the stirring function of the molten metal can be further improved.
• the stirring blade 40 includes a tip surface 43.
• the tip surface 43 is connected to the upper surface 22 and the lower surface 21, and is also connected to the first guide surface 41 and the second guide surface 42 described above.
• the tip surface 43 constitutes the outer peripheral end surface of the molten metal impeller 20.
• Figure 3 shows an example in which the tip surface 43 is formed to form part of a cylindrical surface centered on the rotation axis X. However, the tip surface 43 may extend linearly in a direction perpendicular to the radial direction when viewed toward the lower surface 21.
• the upper surface 22 of the impeller 20 for molten metal is inclined with respect to the lower surface 21 so as to move away from the lower surface 21 from the tip surface 43 of the impeller 40 toward the central portion 30.
• the upper surface 22 may be a generally gentle conical surface.
• the angle ⁇ 4 of the upper surface 22 with respect to the lower surface 21 may be 1° or more and 45° or less, 2° or more and 20° or less, or 3° or more and 10° or less. By setting the angle ⁇ 4 to 1° or more, it is possible to prevent the molten metal from remaining on the upper surface 22 when the molten metal is discharged from the degassing tank 2. By setting the angle ⁇ 4 to 45° or less, it is possible to prevent the thickness of the impeller 20 for molten metal at the central portion 30 from increasing, and space saving can also be achieved.
• the grooves 50 are provided on the underside 21 of the molten metal impeller 20.
• the grooves 50 are formed in each agitator blade 40, with one groove 50 formed for each agitator blade 40.
• the grooves 50 extend in the radial direction from the through hole 31 to the tip surface 43 of the corresponding agitator blade 40. More specifically, the grooves 50 extend from the second circular hole portion 33 described above to the tip surface 43 of the agitator blade 40. In this way, a plurality of grooves 50 are formed radially on the underside 21.
• the area occupied by all the grooves 50 on the bottom surface 21 (described later) of the molten metal impeller 20 may be 0.5 times or more and 10.0 times or less, or 1.5 times or more and 6.0 times or less, of the area occupied by the second circular hole portion 33 (described later) of the through hole 31.
• the area occupied by the grooves 50 10.0 times or less of the area occupied by the second circular hole portion 33, the retention of the blown gas G toward the outside in the radial direction inside the grooves 50 can be suppressed, and an efficient laminar flow can be formed.
• a flow toward the outside in the radial direction of the molten metal can also be formed in association with this flow of the blown gas G.
• the width w2 of the groove 50 may be 0.2 times or more and 0.8 times or less, or 0.3 times or more and 0.4 times or less, of the width w1 of the stirring blade 40.
• the width w2 0.2 times or more of the width w1 the area of the groove 50 on the lower surface 21 of the molten metal impeller 20 can be secured, and the degassing function can be improved.
• the width w2 0.8 times or less of the width w1 the strength of the molten metal impeller 20 can be improved.
• the width of the groove 50 may be constant along the radial direction, or may be different.
• the width of the groove 50 may be gradually narrowed or gradually widened from the through hole 31 toward the tip surface 43.
• the width of the groove 50 may change within the range of the above-mentioned numerical example.
• the width w2 of the groove 50 is defined as the "average value" of the widths measured at 10 equally spaced points from the connection point with the second circular hole portion 33 to the connection point with the tip surface 43. These 10 points include the connection point with the second circular hole portion 33 and the connection point with the tip surface 43.
• the width w2 is the width of the groove 50 on the lower surface 21.
• the depth h2 of the groove 50 may be 0.3 to 0.7 times, or 0.4 to 0.6 times, the thickness t1 (see FIG. 4) at the tip surface 43 of the stirring blade 40.
• the thickness t1 is the thickness at the center position of the tip surface 43 in the width direction of the groove 50.
• the groove 50 includes a first side wall 51, a second side wall 52, and a ceiling wall 53.
• the first side wall 51 and the second side wall 52 are connected to the lower surface 21.
• the first side wall 51 is located further in the impeller circumferential direction D1 than the second side wall 52. In other words, the first side wall 51 is located further in the rotational direction than the second side wall 52, and is located on the left side as shown in FIG. 5.
• the first side wall 51 may be formed perpendicular to the lower surface 21.
• the first side wall 51 may form a plane perpendicular to the lower surface 21.
• the perpendicular plane is not limited to a plane strictly perpendicular to the lower surface 21, but also includes a plane inclined at an angle of ⁇ 5° or less with respect to the perpendicular plane.
• the second side wall 52 is located at a position set back from the first side wall 51 in the impeller circumferential direction D1. In other words, the second side wall 52 is located at a position set back from the first side wall 51 in the rotational direction, and is located on the right side as shown in FIG. 5.
• the second side wall 52 may be inclined with respect to the lower surface 21 so as to proceed from the lower surface 21 toward the ceiling wall 53 in the impeller circumferential direction D1. That is, the upper edge of the second side wall 52 may be inclined with respect to the lower surface 21 so as to be displaced in the impeller circumferential direction D1 with respect to the lower edge of the second side wall 52.
• the upper edge of the second side wall 52 is connected to the ceiling wall 53, and the lower edge of the second side wall 52 is connected to the lower surface 21.
• the second side wall 52 is inclined so as to be displaced to the left from the lower surface 21 toward the ceiling wall 53.
• the second side wall 52 is formed so as to proceed in the rotation direction from the lower surface 21 toward the ceiling wall 53.
• the second side wall 52 may be a flat surface inclined with respect to the lower surface 21.
• the angle ⁇ 3 between the second side wall 52 and the extension of the lower surface 21 can be set arbitrarily in the range of 30° or more and less than 90°.
• the angle ⁇ 3 may be 45° or 60°.
• the angle ⁇ 3 may be equal to the angle ⁇ 2.
• the angle ⁇ 3 may be set to an angle different from the angle ⁇ 2. In this case, the angle ⁇ 3 may be shifted within a range of ⁇ 10°, ⁇ 5°, or ⁇ 3° with respect to the angle ⁇ 2.
• the angle ⁇ 3 By setting the angle ⁇ 3 in this range, the second guide surface 42 and the second side wall 52 can be arranged in a state close to parallel, and the change in thickness between the second guide surface 42 and the second side wall 52 can be suppressed. Therefore, damage due to temperature nonuniformity can be prevented, and the strength of the molten metal impeller 20 can be improved.
• FIG. 5 an example is shown in which the angle ⁇ 3 is equal to the angle ⁇ 2, 60°.
• the angle ⁇ 3 By setting the angle ⁇ 3 to less than 90°, a laminar flow of the blown gas G radially outward is easily formed inside the groove 50. Therefore, the flow rate of the blown gas G inside the groove 50 can be increased. From these viewpoints, the angle ⁇ 3 may be 35° or more and 80° or less, or 40° or more and 75° or less.
• the ceiling wall 53 is connected to the first side wall 51 and the second side wall 52.
• the ceiling wall 53 is disposed above the first side wall 51 and the second side wall 52.
• the ceiling wall 53 may be formed in a curved shape that is convex toward the upper surface 22.
• the ceiling wall 53 may be formed to form a part of a cylindrical surface.
• the molten metal such as aluminum alloy stored in the degassing tank 2 is stirred by rotating the molten metal stirrer 10.
• the molten metal impeller 20 rotates with the impeller circumferential direction D1 when viewed toward the bottom surface 21 as shown in FIG. 3. Since the first guide surface 41 of the stirring blade 40 is located at a position further forward in the rotation direction than the second guide surface 42, the molten metal present in the vicinity of the first guide surface 41 is guided downward as shown in FIG. 5. As a result, a downward flow of molten metal is formed near the molten metal impeller 20 as shown in FIG. 1, and the molten metal descends toward the bottom surface of the degassing tank 2.
• the blown gas G such as argon gas or nitrogen gas
• the blown gas G passes through the gas flow path 12 in the shaft 11, reaches the nozzle 13 formed on the lower surface 21 of the shaft 11, and is blown from the nozzle 13 into the second circular hole portion 33 of the molten metal impeller 20.
• the blown gas G is distributed from the second circular hole portion 33 to each groove 50 and flows radially outward in each groove 50.
• the molten metal enters the groove 50 due to the rotation of the molten metal impeller 20.
• the blown gas G that flows through the groove 50 becomes bubbles and is blown into the molten metal from the tip surface 43 of each stirring blade 40.
• the bubbles of the blown gas G are subjected to a shearing action from the rotating stirring blades 40 and are broken down into fine particles.
• the fine bubbles trap impurities in the molten metal, and the buoyancy of the bubbles and the flow of the molten metal cause the impurities to float up. In this way, the impurities can be removed from the molten metal.
• the first guide surface 41 of the stirring blade 40 of the molten metal impeller 20 is inclined with respect to the lower surface 21 so as to proceed from the lower surface 21 to the upper surface 22 in the impeller circumferential direction D1.
• the molten metal impeller 20 rotates with the impeller circumferential direction D1 as the rotation direction, the molten metal present in the vicinity of the first guide surface 41 can be guided downward.
• a downward flow of the molten metal can be formed, and a vertical circulating flow can be formed in the degassing treatment tank 2.
• the blown gas G that has passed through the groove 50 provided on the lower surface 21 of the molten metal impeller 20 can be blown into the stirred molten metal from the tip surface 43 of the stirring blade 40.
• the blown gas G can be blown into the entire molten metal, improving the efficiency of the degassing treatment of the molten metal.
• the second guide surface 42 is inclined with respect to the lower surface 21 so as to proceed from the lower surface 21 to the upper surface 22 in the impeller circumferential direction D1.
• the first guide surface 41 and the second guide surface 42 are inclined with respect to the lower surface 21 so as to proceed from the lower surface 21 to the upper surface 22 in the impeller circumferential direction D1. Therefore, when the molten metal impeller 20 is made of ceramics, it is possible to prevent thermal shock caused by uneven thickness during firing or use, and to prevent damage.
• the impeller circumferential direction D1 is a counterclockwise direction when viewed toward the bottom surface 21.
• the upper surface 22 of the molten metal impeller 20 is inclined relative to the lower surface 21 so as to move away from the lower surface 21 from the tip surface 43 of the stirring blade 40 toward the center portion 30. This makes it possible to prevent the molten metal from accumulating near the upper surface 22. In other words, if the molten metal remains on the upper surface 22 when the molten metal is discharged from the degassing treatment tank 2, the molten metal will cool and solidify on the upper surface 22, and work to remove the solid matter may be required. However, according to this embodiment, since the upper surface 22 is inclined relative to the lower surface 21, it is possible to prevent the molten metal from remaining on the upper surface 22. This reduces or eliminates the work of removing the solid matter of the molten metal remaining on the upper surface 22.
• the second side wall 52 of the groove 50 is located at a position set back in the impeller circumferential direction D1 from the first side wall 51, and is inclined with respect to the lower surface 21 so as to proceed from the lower surface 21 to the ceiling wall 53 in the impeller circumferential direction D1.
• the first side wall 51 of the groove 50 is formed perpendicular to the bottom surface 21. This makes it possible to prevent the blown gas G in the groove 50 from being released downward from the groove 50, and to maintain a flow path for the blown gas G flowing radially outward within the groove 50. This allows the blown gas G to flow smoothly radially outward, and the gas can be broken down into fine particles and blown into the molten metal from the tip surface 43 of each stirring blade 40.
• the impeller circumferential direction D1 is counterclockwise when viewed toward the bottom surface 21.
• the present invention is not limited to this, and the impeller circumferential direction D1 may be clockwise when viewed toward the bottom surface 21.
• the thick arrow indicating the impeller circumferential direction D1 shown in FIG. 5 points to the right, and the cross-sectional shape of the stirring blade 40 shown in FIG. 5 is reversed left and right.
• the first guide surface 41 is located at a position advanced from the groove 50 in the impeller circumferential direction D1
• the second guide surface 42 is located at a position retreated from the groove 50 in the impeller circumferential direction D1.
• the second embodiment shown in Figures 6 to 10 differs mainly in that the number of stirring blades that make up the molten metal impeller is two, and the rest of the configuration is substantially the same as the first embodiment shown in Figures 1 to 5. Note that in Figures 6 to 10, the same parts as those in the first embodiment shown in Figures 1 to 5 are given the same reference numerals and detailed descriptions are omitted.
• the number of stirring blades 40 constituting the molten metal impeller 20 according to this embodiment is two.
• the two stirring blades 40 protrude from the central portion 30 in opposite directions.
• the stirring blades 40 are arranged at a pitch of 180° and are arranged in a straight line.
• the direction in which each stirring blade 40 protrudes from the central portion 30 is the blade protruding direction D2.
• the blade protruding direction D2 is along the radial direction.
• the grooves 50 may extend along the blade protruding direction D2.
• the width w3 of the groove 50 may be 0.05 times or more and 0.9 times or less, or 0.1 times or more and 0.4 times or less, of the width w4 of the stirring blade 40 (see FIG. 7).
• the width w3 0.05 times or more of the width w4 the area of the groove 50 can be secured on the lower surface 21 of the molten metal impeller 20, and the degassing function can be improved.
• the width w3 0.9 times or less of the width w4 the strength of the molten metal impeller 20 can be improved.
• the width w3 of the groove 50 may be constant along the blade protruding direction D2, but may also be different.
• the width w3 of the groove 50 may be gradually narrowed or gradually widened from the through hole 31 toward the tip surface 43.
• the width w3 of the groove 50 may change within the range of the above-mentioned numerical example.
• the width w3 is the width of the groove 50 on the lower surface 21.
• the width w4 of the stirring blade 40 is the width of the stirring blade 40 at the lower surface 21.
• the width w4 of the stirring blade 40 may be constant along the radial direction.
• the dimension w5 of the central portion 30 may be equal to the width w6 of the tip surface 43 of the stirring blade 40 in the direction perpendicular to the blade protruding direction D2.
• the dimension w5 is the dimension of the central portion 30 at a position passing through the center (rotation axis X) of the through hole 31.
• the molten metal impeller 20 includes a pair of side surfaces 23. Each side surface 23 is connected to the lower surface 21 and the upper surface 22. As shown in FIG. 7, the side surface 23 may be formed along the blade protruding direction D2. That is, each side surface 23 may extend parallel to the blade protruding direction D2 or perpendicular to the lower surface 21.
• the side surface 23 is formed in the central portion 30, but may extend from the central portion 30 to the stirring blade 40. As shown in FIG. 6, the side surface 23 may be interposed between the guide surfaces 41, 42 and the upper surface 22 or the lower surface 21.
• the first guide surface 41 may be connected to the upper surface 22 via the side surface 23, and the second guide surface 42 may be connected to the lower surface 21 via the side surface 23.
• the width w6 is the overall width of the stirring blade 40.
• the central portion 30 includes a protruding portion 60 that protrudes upward from the upper surface 22.
• the protruding portion 60 is provided in a ring shape around the through hole 31, and extends the through hole 31 upward.
• the insertion depth of the shaft 11 into the first circular hole portion 32 of the through hole 31 can be increased.
• the wall height dimension of the first circular hole portion 32 in this embodiment may be the same as the wall height dimension h1 of the first circular hole portion 32 shown in Fig. 3.
• the upper surface 22 of the molten metal impeller 20 is inclined with respect to the lower surface 21 from the tip surface 43 of the stirring blade 40 toward the protruding portion 60, moving away from the lower surface 21.
• the thickness of the stirring blade 40 gradually increases from the tip surface 43 toward the central portion 30.
• the angle of the upper surface 22 with respect to the lower surface 21 may be the same as the angle ⁇ 4 shown in FIG. 4.
• a first chamfered surface 44 may be formed between the first guide surface 41 and the bottom surface 21 of the agitator blade 40.
• the first chamfered surface 44 is formed on the inner periphery of the first guide surface 41. This makes it possible to prevent the formation of sharp corners on the agitator blade 40.
• a second chamfered surface 45 may be formed between the second guide surface 42 and the bottom surface 21 of the agitator blade 40. The second chamfered surface 45 is formed on the inner periphery of the second guide surface 42.
• the number of stirring blades 40 constituting the molten metal impeller 20 is two. This allows the structure of the molten metal impeller 20 to be simplified and the weight of the molten metal impeller 20 to be reduced. It also allows the storage space to be reduced.
• the central portion 30 includes a protruding portion 60 that protrudes from the upper surface 22, and the protruding portion 60 extends the through hole 31.
• the shaft 11 to be inserted deeper into the through hole 31, and the attachment of the shaft 11 to the impeller for molten metal 20 can be stabilized.
• the stirring blade 40 can be made thinner, and the weight of the impeller for molten metal 20 can be reduced.
• the upper surface 22 of the molten metal impeller 20 is inclined relative to the lower surface 21 from the tip surface 43 of the stirring blade 40 toward the protruding portion 60 so as to move away from the lower surface 21.
• the molten metal will cool and solidify on the upper surface 22, and work to remove the solid matter may be required.
• the dimension w5 of the central portion 30 is equal to the width w6 of the tip surface 43 of the stirring blade 40 in the direction perpendicular to the blade protruding direction D2.
• the present invention is not limited to this.
• the dimension w5 of the central portion 30 may be greater than the width w6 of the tip surface 43 of the stirring blade 40 in the direction perpendicular to the blade protruding direction D2.
• the mechanical strength of the central portion 30 can be improved, and the attachment between the shaft 11 and the impeller 20 for molten metal can be stabilized.
• the rotational resistance of the impeller 20 for molten metal can be reduced.
• each side surface 23 of the impeller 20 for molten metal when viewed toward the lower surface 21 does not have to be aligned with the blade protruding direction D2.
• the side surface 23 may include two inclined side surfaces 23a formed from each stirring blade 40 toward the central portion 30 and away from the groove 50, and a cylindrical side surface 23b formed between the two inclined side surfaces 23a.
• the cylindrical side surface 23b may be formed concentrically with the first circular hole portion 32 and the second circular hole portion 33 of the through hole 31, forming a part of a cylindrical surface centered on the rotation axis X.
• the inclined side surface 23a and the cylindrical side surface 23b may be perpendicular to the lower surface 21.

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• Engineering & Computer Science (AREA)
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• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
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• 2023
  • 2023-12-25 JP JP2024570141A patent/JPWO2024150665A1/ja active Pending
  • 2023-12-25 CN CN202380090845.1A patent/CN120476220A/zh active Pending
  • 2023-12-25 WO PCT/JP2023/046468 patent/WO2024150665A1/ja not_active Ceased

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