JP4925888B2 - Rotating body for molten metal stirring, and molten metal degassing apparatus using the same - Google Patents

Description

  The present invention relates to a molten metal for treating impurities such as hydrogen and non-metal oxides in a molten metal by rotating and stirring the molten metal while releasing nitrogen gas or argon gas into the molten metal of aluminum or an alloy thereof. The present invention relates to a metal stirring rotor and a molten metal degassing apparatus using the same.

In recent years, in order to improve fuel economy and reduce CO2 emissions due to increasing global environmental awareness, as a measure to reduce the weight of automobile components, molten molten aluminum or its alloys are poured into molds and cooled to a predetermined level. A casting method having the shape is adopted. And the demand for weight reduction of such component parts has become more severe in order to further improve fuel consumption and reduce CO2 emissions, and in order to reduce the weight of these component parts, it has become necessary to reduce the thickness. Yes.
However, since the mechanical strength is insufficient only by thinning the material of these component parts using aluminum or an alloy thereof, it is necessary to improve the mechanical strength of the material of the component parts in order to reduce the thickness. In order to improve the mechanical strength of the material of the component itself, it is conceivable to change the material or the manufacturing method. The simplest method is to reduce the amount of impurities contained in the material used for the component. The mechanical strength should be as close as possible to the theoretical strength of the material itself.

  In order to reduce the amount of impurities contained in the material used for this component, a raw material with few impurities may be used.However, if a raw material with few impurities is used, the price of the raw material itself becomes very high, and the component There was a problem that the price increased with this.

  In order to solve such a problem, for the purpose of treating impurities in the molten metal of aluminum or its alloy, a treatment gas is blown into the molten metal and stirred to disperse the treatment gas, and the bubbles of the treatment gas The degassing apparatus which processes by floating and separating an impurity is used.

  FIG. 3 is a front view showing a part of a conventional molten metal degassing apparatus broken away.

  The degassing apparatus 30 shown in FIG. 3 includes a container 34 for containing the molten metal 35, a shaft 31 for stirring the molten metal 35, a rotor 32 connected to one end of the shaft 31, The rotary shaft 37 is connected to the other end by a bolt 39 and a nut 40 via flange joints 38a and 38b, and a rotary drive mechanism 33 for rotating the rotary shaft 37.

  The flange joint 38b has a supply port 41 for supplying the processing gas (G) and a gas supply path 41a inside, and the shaft 31 has a gas supply path 31a communicating with the gas supply path 41a inside. is doing. The gas supply path 31 a communicates with the gas supply path 32 a of the rotor 32 connected to one end of the shaft 31, and the processing gas (G) passes through the molten metal 35 in the container 34 from the discharge port 42 of the rotor 32. To be released.

  The processing method for the impurities 36 in the molten metal 35 using the degassing apparatus 30 is that the shaft 31 and the rotor 32 immersed in the molten metal 35 in the container 34 are rotated by the rotational drive of the rotational drive mechanism 33, Process gas (G) is blown into the molten metal 35 from the discharge port 42 through the gas supply passages 41a, 31a, and 32a through the supply port 41, and is refined and dispersed by centrifugal force generated by rotation. In this method, impurities 36 such as metal oxides are taken in or attached to the bubbles and collected on the surface of the molten metal 35 to be efficiently treated.

  Conventionally, carbon has been mainly used as a material for the shaft 31 and the rotor 32 used in such a degassing apparatus 30, but when the impurities 36 are treated in the molten metal 35, the carbon is caused by the molten metal 35. In recent years, ceramic materials have been used instead of carbon due to the large consumption. However, since ceramic materials generally have a drawback that they are vulnerable to rapid thermal shock, the gas supply paths 41a, 31a, 32a heated by the molten metal 35 are caused by the processing gas (G) blown from the supply port 41. There was a problem that it was damaged rapidly without being able to withstand the thermal shock.

In order to solve such a problem, Patent Document 1 discloses a rotating body for stirring molten metal, which includes a vertical rotating shaft (shaft) having a hollow portion for gas supply and a rotor fixed to the lower end portion of the rotating shaft. The rotary shaft and rotor are made of a nitride, boride, or carbide ceramic material, and a gas supply blow pipe formed in a hollow cylindrical shape by a heat insulating material is formed in the rotary shaft through a gap. A rotating body for stirring molten metal that is coaxially inserted and fixed is disclosed. According to this rotating body for molten metal stirring, since the blow pipe formed in a hollow cylinder shape by a heat insulating material is used, the rotary shaft is prevented from being rapidly cooled by the low temperature gas flowing through the blow pipe, and the rotary shaft is cracked or damaged. Can be prevented in advance.
Japanese Utility Model Publication No. 4-452

  However, the rotating body for molten metal stirring disclosed in Patent Document 1 has no gas leakage prevention measures at the contact portion between the blowing pipe and the connection member provided with the gas supply port at the upper end of the rotating shaft. As a result, low-temperature gas leaks from the gap between the contact portions and flows into the gap between the blowing pipe and the rotating shaft, and the inner surface of the rotating shaft is cooled. As a result, the molten metal (molten metal) becomes hot. Due to the difference in thermal expansion from the outer surface of the rotating shaft, there is a problem that a large thermal stress acts on the rotating shaft and breaks.

  Further, in the embodiment of Patent Document 1, a solid carbon is used as a blowing tube, and a sealing member made of a refractory material such as Al2O3 is filled in a gap in the vicinity of the lower end of the rotating shaft in a ring shape. It is described that it sticks. According to this, although there is no risk of low temperature gas flowing into the gap in the vicinity of the lower end portion of the rotating shaft, the radial fixing of the blowing pipe in the rotating shaft is performed only by the sealing member at the lower end portion. Therefore, it is in an unstable state. In such a case, there is little risk of misalignment with a short blowing pipe, but the length of the blowing pipe is generally 0.5 to 1.5 m. When the tube is bent and contacts the inner surface of the rotating shaft, there is a problem that a blow tube or a part of the rotating shaft is damaged due to an impact at the time of contact.

  The present invention has been devised to solve the above-mentioned problems. The molten metal agitation is capable of preventing the gas supply pipe from being loosened due to rotational centrifugal force or the like, or preventing the shaft from being damaged due to leakage of the processing gas. An object of the present invention is to provide a rotating body for use. Another object of the present invention is to provide a highly reliable degassing apparatus capable of stably supplying a high-quality molten metal over a long period of time by using this molten metal stirring rotor.

Molten metal agitating rotary member of the present invention, with the rotor for stirring the molten metal is attached to an end portion of the hand, a shaft connector is attached to be connected to a rotary drive mechanism at the other end, and a gas supply pipe arranged in the same axial inside of the shaft, the rotor side and near the side near the coupler gap which is provided between the gas supply pipe and the shaft
Sealing fixing materials for fixing the shaft and the gas supply pipe are respectively disposed. The sealing fixing material is made of at least one of a fibrous material and a porous material, and has a porosity of 5 to 30%. and it is characterized in Rukoto to have a.

Furthermore, the molten metal stirring rotor according to the present invention may further include a sealing member between the seal fixing member in the vicinity of the rotor side and the seal fixing member in the vicinity of the connector side in any of the above configurations . The fixing member is arranged.

  Moreover, the molten metal stirring rotor according to the present invention is characterized in that, in any one of the above-described configurations, the gas supply pipe is made of ceramics.

  Moreover, the rotating body for stirring molten metal according to the present invention is characterized in that, in any of the above-mentioned configurations, the ceramic is made of any one of cordierite, mullite, steatite, alumina, and zirconia.

  In the degassing apparatus of the present invention, the molten metal stirring rotator of the present invention having any one of the above structures is connected to the rotation drive mechanism of the shaft via the connector, and the molten metal agitator It is characterized by being arranged.

According to the molten metal agitating rotary member of the present invention, with the rotor for stirring the molten metal on the end of the hand is attached, a shaft connector is attached to be connected to a rotary drive mechanism at the other end When, and a gas supply pipe arranged in the same axial inside of the shaft, a shaft and a gas supply pipe near the rotor side and near coupler side of the gap formed between the shaft and the gas supply pipe sealing restraints for fixing are arranged respectively, sealing restraints are made from at least one fibrous material and a porous material, and from Rukoto that having a porosity of 5-30%, the fixing seal Since both ends of the gas supply pipe can be firmly fixed by the material and the gap between the shaft and the gas supply pipe can be sealed, it can be caused by centrifugal force due to rotation of the shaft and expansion and contraction due to heat of the shaft. Fixing of the gas supply pipe is not easily loosened even, gas leakage is less likely to occur from the contact portion between the connector and the shaft with the gas supply pipe. Even if a gas leak occurs, the seal fixing material serves to prevent the gas from entering, so that the shaft can be prevented from being damaged due to the gas leak. Moreover, since the fixing material for sealing consists of at least one of a fibrous material and a porous material, and has a porosity of 5 to 30%, air existing in the voids of the fixing material for sealing has a heat insulating action. Heat transfer from the shaft to the gas supply pipe can be suppressed, and damage to the gas supply pipe due to thermal shock can be more effectively prevented.

Further, according to the molten metal stirring rotating body of the present invention, when the sealing fixing member is further disposed between the sealing fixing member near the rotor side and the sealing fixing material near the coupling side , Since the gas supply pipe can be fixed at multiple locations, it is possible to fix the gas supply pipe more firmly and coaxially with a gap inside the shaft, so that the processing gas can be removed from the contact portion between the gas supply pipe and the connector or shaft. It becomes difficult to leak, and a structure capable of enhancing the sealing effect against processing gas leakage can be achieved. Also, even if the seal fixing material at one location deteriorates due to long-term use, the gas supply pipe can be fixed by another seal fixing material as long as the seal fixing material is arranged at multiple locations. The sealing effect can be maintained.

  Further, according to the molten metal stirring rotor of the present invention, when the gas supply pipe is made of ceramics, the deformation of the gas supply pipe due to heat is small, and the occurrence of gas leakage due to loose fixing of the gas supply pipe is prevented. can do.

  Moreover, according to the rotating body for stirring molten metal according to the present invention, when the ceramic is made of any one of cordierite, mullite, steatite, alumina, and zirconia, it is not easily damaged by the thermal shock applied to the gas supply pipe. And the problem of deformation can be prevented.

  Further, according to the molten metal degassing apparatus of the present invention, the molten metal stirring rotating body of the present invention is connected to the shaft rotation drive mechanism via the coupler, and is disposed in the molten metal container. Therefore, it is possible to reduce the number of parts replacement due to gas leakage due to deformation of the gas supply pipe or damage to the gas supply pipe, so that maintenance costs can be reduced and good degassing treatment can be performed over a long period of time. it can.

  Hereinafter, the example of embodiment of the rotating body for molten metal stirring of this invention and the degassing apparatus of a molten metal using the same is demonstrated.

  FIG. 1 is a cross-sectional view showing an example of an embodiment of a rotating body for molten metal stirring according to the present invention.

  The rotating body 1 for stirring a molten metal of the present invention includes a shaft 4, a rotor 5 for stirring the molten metal 2 attached to one end of the shaft 4, and a rotation drive mechanism ( The connecting tool 3 is connected to a gas supply pipe 7 that is coaxially arranged with a gap 9 provided inside the shaft 4. Further, the connector 3 is provided with a gas supply port 6 connected to the gas supply pipe 7, and the projection 11 at the tip of the shaft 4 on the rotor 5 side is provided with a gas outlet 8 connected to the gas supply pipe 7.

  The method for treating impurities in the molten metal 2 using this rotating metal stirring rotor 1 rotates the shaft 4 and the rotor 5 immersed in the molten metal 2 contained in a container (not shown) as shown in FIG. While being rotated by the drive mechanism, the processing gas is blown from the gas supply port 6 through the gas supply pipe 7 into the molten metal 2 from the gas outlet 8 and is refined and dispersed by the centrifugal force generated by the rotation of the rotor 5. In this method, impurities such as hydrogen and non-metal oxide are taken in and attached to bubbles and floated on the surface of the molten metal 2 to be collected efficiently.

In the molten metal agitating rotary member 1 of the present invention having such a configuration, sheet Lumpur near the rotor 5 side and in the vicinity of connector 3 side of the gap 9 between the shaft 4 and the gas supply pipe 7 which is arranged coaxially use fixed member 10 that are disposed respectively. In this way, the gas supply pipe 7 arranged coaxially with the gap 9 provided inside the shaft 4 is filled with the sealing fixing material 10 and fixed at both ends, so that it is displaced by the centrifugal force due to rotation. Can be extremely low. Further, the gas supply pipe 7 is hardly loosened due to expansion or contraction of the shaft 4 due to heating or cooling from the molten metal 2, and the contact portion between the shaft 4 and the gas supply pipe 7 located on the connection tool 3 side, the connection tool. 3 and the gas supply pipe 7 and the contact portion between the shaft 4 located on the rotor 5 side and the gas supply pipe 7 can cause very little leakage of the processing gas. Further, even if gas leaks occur in those parts, the processing gas does not flow into the gap 9 between the shaft 4 and the gas supply pipe 7 in order for the sealing material 10 to serve as a sealing material, It becomes possible to prevent the shaft 4 from being damaged due to the influence of gas leakage.

The seal restraints 10 comprises at least one fibrous material 10a and the porous member 10b, that having a porosity of 5-30%. As the fibrous material 10a, for example, a commercially available ceramic fiber may be used. In particular, crystalline zirconia, alumina, and long and short fibers made of mullite used as an inner wall material of a firing furnace or the like are combined with a small amount of silica component. You can use something. Moreover, as the porous material 10b, for example, a slurry in which an aqueous or organic solvent, ceramic particles such as alumina, silica, zirconia, cordierite, mullite, and the like and an inorganic polymer are mixed is poured into the gap 9, and 100 to 150 What is necessary is just to use what was heated and solidified at ° C. In addition, since the fibrous material 10a is solid, workability is good, but it is difficult to cope with a complicated shape of the gap 9. On the other hand, the porous material 10b can be produced in the above-described manner and can cope with a complicated shape. However, since the porous material 10b is in a liquid state at the time of production, a member to be damped is required to be disposed at a desired position, or it is desired to fill the porous material 10b. Since the liquid raw material drips and adheres to the shaft 4 and the gas supply pipe 7 above the position, workability is poor. Therefore, it is preferable to select which material is used or combined depending on the shape of the gap 9 and the position where the sealing fixing material 10 is to be disposed.

Further, by making the porosity of the sealing restraints 10 and 5-30%, it becomes to have a moderate air permeability with sealing restraints 10 having good thermal insulation properties, a gas supply pipe 7 and the shaft 4 Deterioration of the sealing material 10 due to damage to the gas supply pipe 7 due to the difference in thermal expansion of the gas and the air in the gap 9 between the shaft 4 and the gas supply pipe 7 being thermally expanded and pressurizing the sealing material 10 Can be effectively prevented.

  If the porosity of the seal fixing material 10 is less than 5%, the heat insulation of the seal fixing material 10 becomes insufficient, and the heat of the shaft 4 heated to a high temperature is easily transmitted to the gas supply pipe 7 through the seal fixing material 10. Therefore, a large thermal stress acts on the gas supply pipe 7 due to a difference in thermal expansion between the outer surface of the gas supply pipe 7 in contact with the seal fixing material 10 and the inner surface of the gas supply pipe 7 through which the low-temperature processing gas flows. There is a risk of damage. Further, the air in the gap 9 between the shaft 4 and the gas supply pipe 7 rises in temperature and expands in volume when the shaft 4 is heated. Therefore, unless the sealing material 10 has air permeability and the expanded air is not discharged to the outside, pressure is applied to the sealing material 10 due to the expansion of air, which is not preferable. If the rate is less than 5%, the air permeability tends to be insufficient. On the other hand, if the porosity exceeds 30%, a low-temperature processing gas is generated from the gap in the seal fixing material 10 when a gas leakage of the processing gas occurs from the contact portion between the gas supply pipe 7 and the connector 3 or the shaft 4. Will suddenly flow into the gap 9 near the center of the shaft 4, which may cause a temperature difference between the outer surface and the inner surface of the shaft 4, which may be damaged due to a difference in thermal expansion.

  Of the fixing material 10 for sealing, the porosity of the fibrous material 10a can be controlled by adjusting the amount of silica component that binds the long and short fibers made of zirconia, alumina, and mullite together. is there. Further, the porosity of the porous material 10b can be controlled by adjusting the amount of the solvent and the inorganic polymer and the particle size of the ceramic particles. Further, the porosity of the porous material 10b is easier to control than the solid fibrous material 10a.

  Here, as a method for adjusting the porosity of the fibrous material 10a, for example, when trying to obtain a porosity of 10%, a ceramic fiber made of alumina fiber which is the source of the fibrous material 10a in a container with numerous holes in advance. And the porosity is measured using the Archimedes method together with the container. If the porosity is lower than 10%, the container is further filled with ceramic fiber and the porosity is measured until the porosity becomes 10%. If the porosity is higher than 10%, on the contrary, reducing the filling amount of the ceramic fiber in the container and measuring the porosity is repeated until the porosity becomes 10%. After adjusting the porosity in the form including the container in this way, the ceramic fiber is taken out from the container, the water adhering at the time of measuring the porosity is dried and evaporated, and then the ceramic fiber is removed from the container. Divide by volume to obtain the filling amount per unit volume. Thereby, as long as the filling volume is known, the filling amount is calculated, and the porosity of the fibrous material 10a can be adjusted.

  Further, as a method for adjusting the porosity of the porous material 10b, for example, when obtaining the porous material 10b having a porosity of 10%, an alumina raw material having a mean particle size in the range of 0.1 to 30 μm, a solvent, and an inorganic material A slurry is produced using a polymer, a part of the produced slurry is placed in a container and dried, and the porosity of the dried body is measured. When the porosity is lower than 10%, an alumina raw material having an average particle size larger than the average particle size of the used alumina raw material is added to the slurry. When the porosity is higher than 10%, a small average particle size is used. After adding the alumina raw material to the slurry, the slurry is well stirred to disperse the additional particles in the slurry. Thereafter, a part of the slurry is collected, placed in a container, dried, and the porosity is measured until the porosity becomes 10%, thereby obtaining a porous material 10b having a porosity of 10%. it can.

  Further, it is preferable that a plurality of sealing fixing materials 10 are annularly arranged in the gap 9 between the shaft 4 and the gas supply pipe 7. As a result, the gas supply pipe 7 can be fixed more coaxially with the gap 9 inside the shaft 4 to maintain the sealing effect. For example, in the example shown in FIG. 1, a seal fixing material 10 in which two sealing fixing materials 10 of an annular fibrous material 10a and an annular porous material 10b are arranged in the gap 9 in the vicinity of the connector 3 is buried. Therefore, even if one sealing fixing material 10 (fibrous material 10a or porous material 10b) is deteriorated, the fixing and sealing effect of the gas supply pipe 7 can be maintained by the other sealing fixing material 10. Further, in this example, since the gas supply pipe 7 can be fixed at a total of three locations including the sealing material 10 of the fibrous material 10a buried in the gap 9 near the rotor 5 side, the shaft 4 is stronger. It is possible to fix the gas supply pipe 7 to. The arrangement of the fibrous material 10a and the porous material 10b in the gap 9 is not limited to the arrangement as in this example, and various arrangements can be implemented.

  FIG. 2 is a cross-sectional view showing another example of the embodiment of the molten metal stirring rotor of the present invention. 2, the same reference numerals are assigned to the same components as those in FIG.

In this way, the seal fixing material 10 is disposed in a total of six locations in the gap 9 near the rotor 5 side and near the connector 3 side, in combination with an annular fibrous material 10a, porous material 10b, and fibrous material 10a. With the configuration in which the sealing material 10 is disposed , the gas supply pipe 7 can be firmly fixed coaxially by providing a gap 9 inside the shaft 4 and maintain a good sealing effect. be able to. However, if there are too many places to be fixed by the seal fixing material 10, the seal fixing material 10 receives heat from the shaft 4 and is heated to a high temperature, and the gas supply pipe 7 in contact with the seal fixing material 10 is heated. It is conceivable that a large thermal stress acts on the gas supply pipe 7 due to a difference in thermal expansion between the outer surface and the inner surface of the gas supply pipe 7 through which a low-temperature processing gas flows. Further, when the gap 9 is reduced, the heat insulation effect by the air between the shaft 4 and the gas supply pipe 7 is diminished, so that the volume ratio occupied by the seal fixing material 10 in the gap 9 between the shaft 4 and the gas supply pipe 7 is It is preferable to suppress it to about 45% or less.

  As a method of arranging the plurality of sealing fixing members 10 of the fibrous material 10a and the porous material 10b, for example, the fibrous material 10a is first attached to the gas supply pipe 7 corresponding to the vicinity of the rotor 5 side. Attach it into the shaft 4. Thereafter, the slurry to be the porous material 10b is poured into the gap 9 and heated to 100 to 150 ° C. using a spot type hot air dryer such as a dryer to evaporate the solvent in the slurry. Next, a plurality of fixing materials 10 for sealing can be arranged in the vicinity of the rotor 5 side by pushing the fibrous material 10a using a bar-shaped jig thinner than the gap 9. Furthermore, a plurality of fixing materials 10 for sealing can be arranged in the same procedure also in the vicinity of the connector 3 side.

  Here, as a material of the shaft 4 and the rotor 5 of the molten metal stirring rotor 1, silicon nitride, silicon carbide, zirconia, cordierite, or a composite thereof can be applied, but mechanical characteristics and thermal shock resistance are also applicable. In consideration of the porcelain characteristics such as aluminum and the wettability with respect to the molten metal 2 made of aluminum, aluminum alloy, or the like, it is preferably mainly composed of a silicon nitride sintered body.

  In addition, since the connection tool 3 is usually made of an inert gas such as argon as a processing gas and is not corrosive, it supports the load of the shaft 4, the rotor 5 and the gas supply pipe 7 and is driven to rotate. Metals and ceramics can be used as long as they have mechanical characteristics that can maintain the connection with the mechanism. However, considering the cost, it is possible to use a metal such as stainless steel or carbon tool steel. preferable.

  Further, regarding the gas supply pipe 7, when the molten metal stirring rotor 1 is immersed in the molten metal 2, the temperature of the gas supply pipe 7 itself rises to about 300 ° C., and therefore, ceramics with small deformation due to thermal expansion. It is preferable that This is because if the deformation due to thermal expansion is large as in the case of metal, stress is applied to the joint between the shaft 4 and the connector 3, and there is a risk of damage. Ceramics applicable when the gas supply pipe 7 is made of ceramics are cordierite, mullite, steatite, alumina and zirconia, and any one of these is preferable. All of them have a thermal expansion coefficient as low as half or less than that of metals, and are excellent in thermal shock resistance. Among them, cordierite and mullite have a particularly low thermal expansion coefficient of 5 × 10 −6 / ° C. or less. Since the deformation due to temperature rise is small, it is suitable as a material for the gas supply pipe 7.

  Next, an example of the manufacturing method of the rotating body for a molten metal stirring of this invention is demonstrated.

  First, the shaft 4 and the rotor 5 made of a silicon nitride sintered body are manufactured. A commercially available silicon nitride primary material having an average particle size of 0.5 to 10 μm, a predetermined amount of a sintering aid, a binder and a solvent are mixed to form a slurry, which is then spray granulated with a spray dryer to obtain a secondary material. . And the cylindrical molded object used as the shaft 4 and the disk-shaped molded object used as the rotor 5 are shape | molded by the isostatic press molding method (rubber press) using this secondary raw material. Thereafter, the molded body is subjected to cutting as necessary, and then fired at a temperature of 1800 to 2100 ° C. in a reducing atmosphere furnace, and subjected to grinding as necessary to form a silicon nitride sintered body. A shaft 4 and a rotor 5 are obtained.

  Next, the gas supply pipe 7 is produced. A commercially available synthetic cordierite having an average particle size of 0.5 to 10 μm, a predetermined amount of a binder and a solvent are mixed to form a slurry, and then spray granulated with a spray dryer to obtain a cordierite secondary material. And the cylindrical molded object used as the gas supply pipe 7 is shape | molded by an isostatic press molding method (rubber press) using this secondary raw material. After that, the formed body is subjected to cutting as necessary, and then fired at a temperature of 1300 to 1450 ° C. in an air atmosphere furnace, and subjected to grinding as necessary to form a cordierite sintered body. A gas supply pipe 7 is obtained.

  For the production of the gas supply pipe 7, a cordierite sintered body has been described as an example. In addition, for mullite, steatite, alumina and zirconia, the same production method as described above except for the raw materials used and the firing temperature Is applicable. Regarding the firing temperature, mullite and steatite are 1300 to 1500 ° C, and alumina and zirconia are 1500 to 1700 ° C.

  Moreover, about manufacture of the coupling tool 3, it grinds to a predetermined shape using a stainless steel ingot, and the coupling tool 3 is obtained.

  Further, a slurry that is a base of the porous material 10b that is the sealing fixing material 10 is prepared. An organic solvent such as isopropyl alcohol, acetone or toluene, alumina particles having an average particle diameter of 0.1 to 30 μm, a binder and an inorganic polymer are mixed using a small ball mill, and then discharged and stored in a sealed container. In addition, the amount of the solvent and the inorganic polymer and the particle size of the ceramic particles are adjusted in advance so that the porosity becomes 10% after the slurry is dried. Further, for the fibrous material 10a, a filling amount to obtain a porosity of 10% in the gap 9 to be filled in advance is calculated using a commercially available ceramic fiber made of alumina fiber.

Next, the assembly of the molten metal stirring rotor 1 of the present invention will be described with reference to the example of FIG. First, the convex portion 11 at one end of the shaft 4 and the concave portion provided at the central portion of the rotor 5 are fastened with screws. Thereafter, the gas supply pipe 7 is inserted into the shaft 4. At this time, the porosity of 10% of alumina fibers in which to place the sealing restraints 10 into the gap 9 of the rotor 5 side near the ceramic fiber of the fibrous material 10a made of resin to a predetermined position of the outer surface of the gas supply pipe 7 Insert with tape attached. This prevents the position of the fibrous material 10a disposed in the vicinity of the rotor 5 side from being displaced by friction generated between the outer surface of the gas supply tube 7 and the inner surface of the shaft 4 when the gas supply tube 7 is inserted.

Then, as the seal restraints 10 of connector 3 side near you annularly disposed a fibrous material 10a using a jig narrower than the gap 9 bar shape. Further, a slurry that becomes a porous material 10b prepared in advance and stored in a sealed container is poured into the gap 9 into the gap 9 on the side of the connector 3 formed by pushing the fibrous material 10a, and a spot type such as a dryer is used. By heating to 100-150 ° C. using a hot air dryer, the solvent in the slurry is evaporated to produce an annular porous material 10b having a porosity of 10%. In addition, by adjusting the viscosity of this slurry, the fibrous material 10a becomes a weir and does not sag to the rotor 5 side. And the connection tool 3 is attached with the volt | bolt to the other edge part of the shaft 4, and an assembly will be completed, and the rotary body 1 for molten metal stirring of this invention shown in FIG. 1 can be obtained.

Molten metal agitating rotary member 1 of the present invention thus prepared, together with the rotor 5 for stirring the molten metal 2 to the end portion of the hand is attached, connected to a rotary drive mechanism at the other end a shaft 4 that connector 3 is attached to, and a gas supply pipe 7 disposed in the axial inside of the shaft 4, a rotor of the gap 9 provided between the shaft 4 and the gas supply pipe 7 Since the seal fixing material 10 for fixing the shaft and the gas supply pipe is arranged in the vicinity of the 5 side and the connection tool 3 side, both ends of the gas supply pipe 7 are firmly fixed, and the shaft 4 Since the gap 9 between the gas supply pipe 7 and the gas supply pipe 7 can be sealed, the gas supply pipe 7 is not easily loosened by the centrifugal force caused by the rotation of the shaft 4 or the expansion or contraction caused by the heat of the shaft 4. 7 and connector 3 and sha It is an extremely small amount of gas leakage of the process gas from the contact portion with the bets 4 occurs. Even if a gas leak occurs, the sealing material 10 serves to prevent the processing gas from entering, so that the shaft 4 can be prevented from being damaged due to the gas leak.

  When the sealing fixing material 10 is composed of at least one of the fibrous material 10a and the porous material 10b and has a porosity of 5 to 30%, the gap of the sealing fixing material 10 is fixed while fixing the gas supply pipe 7. Since the air present in the gas has a heat insulating action, heat transfer from the shaft 4 to the gas supply pipe 7 can be suppressed, and damage to the gas supply pipe 7 due to thermal shock can be prevented.

When a sealing fixing member is further arranged between the sealing member 10 near the rotor side and the sealing material 10 near the connector side , the gas supply pipe 7 can be fixed at a plurality of locations. Therefore, it is possible to fix the gas supply pipe 7 in the shaft 4 more firmly in the shaft 4 with a gap 9 therebetween, so that the processing gas can be supplied from the contact portion between the gas supply pipe 7 and the connector 3 or the shaft 4. It becomes difficult to leak, and it can be set as the structure which can improve the sealing effect with respect to the gas leak of process gas. In addition, even if the seal fixing material 10 at one location deteriorates due to long-term use, if the seal fixing material 10 is arranged at multiple locations, the gas is supplied by the other seal fixing material 10. The fixing and sealing effect of the tube 7 can be maintained.

  In addition, since the gas supply pipe 7 is made of a cordierite sintered body having a small thermal expansion coefficient, deformation due to heat is small, and the occurrence of gas leakage due to loose fixing of the gas supply pipe 7 can be prevented.

  Furthermore, in the molten metal degassing apparatus of the present invention using the molten metal stirring rotor 1 of the present invention, the molten metal stirring rotor 1 can withstand long-term rotation and damage due to gas leakage of the processing gas. Since there is not, it can be set as the reliable degassing apparatus which can supply the high quality molten metal 2 stably.

  As mentioned above, although the example of embodiment of this invention was demonstrated, the rotary body 1 for molten metal stirring of this invention is not limited to the above-mentioned content, If it is in the range which does not deviate from the summary, it will be variously changed. Needless to say. For example, if a multi-layer structure such as a cylindrical tube is disposed between the shaft 4 and the gas supply pipe 7, the processing gas is more difficult to leak into the shaft 4. Since the pipe prevents leakage, a part of the shaft 4 can be prevented from being damaged.

  Examples of the present invention are shown below.

  Production of a rotating body 1 for stirring molten metal according to the present invention shown in FIG. 1 was carried out. First, a shaft 4 and a rotor 5 made of a silicon nitride sintered body were produced. A commercially available silicon nitride primary material having an average particle diameter of 1 μm, a binder, and a solvent were added to form a slurry, which was then spray granulated with a spray dryer to obtain a secondary material. And the cylindrical molded object used as the shaft 4 and the disk-shaped molded object used as the rotor 5 were shape | molded by the isostatic pressing method (rubber press) using this secondary raw material. Then, it cut and obtained the cylindrical shaft 4 which has the convex part 11 in one edge part, and the disk-shaped rotor 5 which has a recessed part in the center. Next, the shaft 4 and the rotor 5 were placed in a reducing atmosphere furnace and fired at a maximum temperature of 1950 ° C. to obtain a sintered body. After firing, by further grinding the surface of the sintered body, a cylindrical shaft 4 having an outer diameter of 65 mm, an inner diameter of 40 mm, a length of 970 mm and having a convex portion 11 at one end, and an outer diameter And a disc-shaped rotor 5 having a thickness of 30 mm and a recess in the center. A radial dispersion groove having a depth of 15 mm for dispersing the processing gas into the molten metal 2 was provided on the bottom surface of the rotor 5. Further, a male thread for fastening to the rotor 5 and the connector 3 was provided on the convex portion 11 at one end of the shaft 4 and the other end. Further, a female screw for fastening to the shaft 4 was provided in the central recess of the rotor 5.

  Next, a gas supply pipe 7 made of cordierite was produced. A commercially available synthetic cordierite raw material having an average particle diameter of 1 μm, a binder and a solvent were mixed to form a slurry, and then spray granulated with a spray dryer to obtain a cordierite secondary raw material. And the cylindrical molded object used as the gas supply pipe 7 was shape | molded by the isostatic press molding method (rubber press) using this secondary raw material. Thereafter, the gas supply pipe 7 made of a cordierite sintered body having an outer diameter of 30 mm, an inner diameter of 25 mm, and a length of 955 mm is obtained by firing in an air atmosphere furnace at a temperature of 1420 ° C. and grinding. It was.

  Next, a cylindrical body having an outer diameter of 80 mm, an inner diameter of 65 mm, and a length of 100 mm was cut out from the S45C ingot by grinding, and an internal thread was formed on the inner diameter portion to form the connector 3.

  Next, preparation for manufacturing the fixing material 10 for sealing was performed. As the fibrous material 10a, a ceramic fiber made of a commercially available alumina fiber is prepared, a ceramic fiber is filled in a container with innumerable holes in advance, and the porosity is measured using the Archimedes method. The calculation was performed by calculating the fiber filling amount per unit volume at which a rate of 10% was obtained.

  As the porous material 10b, a solvent, alumina having an average particle diameter of 0.5 μm, a binder, and an inorganic polymer were mixed using a ball mill, and then discharged and stored in a sealed container. The porosity of the porous material 10b was adjusted as follows. A part of the prepared slurry was put in a container and dried, and the porosity of the dried body was measured using Archimedes method. When the porosity is lower than 10%, an alumina raw material having an average particle size larger than the average particle size of the used alumina raw material is added to the slurry. When the porosity is higher than 10%, a small average particle size is used. After adding the alumina raw material to the slurry, the slurry was stirred well to disperse the additional particles in the slurry. Thereafter, a portion of the slurry was sampled, placed in a container, dried, and the porosity was measured until the porosity was 10%.

And the rotating body 1 for molten metal stirring was assembled. First, the male screw of the convex portion 11 at the tip of the shaft 4 and the female screw of the concave portion at the center of the rotor 5 were fastened. Then, a ceramic fiber fibrous material 10a made of alumina fiber having a porosity of 10% is fixed to the outer surface corresponding to the vicinity of the rotor 5 side of the gas supply pipe 7 with a resin tape. Inserted until the tip of reached. After the insertion, the fibrous material 10a is arranged so as to be pushed into the gap 9 in the range of 300 to 350 mm from the tip portion to which the coupling tool 3 of the shaft 4 is attached using a metal jig thinner than the 5 mm gap 9. It was. Furthermore, the slurry that becomes the porous material 10b that has been prepared and stored in the sealed container is poured into the gap 9 into the gap 9 on the side of the connector 3 formed by pushing the fibrous material 10a. A porous material 10b having a porosity of 10% was produced by heating to 100 ° C. or higher using a hot air dryer to evaporate the solvent in the slurry and solidify.

  Thereafter, the connector 3 and the shaft 4 were fastened with the female screw of the connector 3 and the male screw of the shaft 4 to obtain the molten metal stirring rotor 1 of the present invention.

Next, an example of the molten metal stirring rotating body 1 of the present invention in which the seal fixing material 10 is disposed in the vicinity of the rotor 5 side and the coupling 3 side of the gap 9, and the rotor 5 side as a comparative example. The molten metal stirring rotator in which the seal fixing material 10 was buried only in the vicinity thereof was installed in a molten metal degassing apparatus, and the molten metal 2 impurity removal operation was performed. As a result, in the rotating metal stirring rotor of the comparative example, the shaft 4 was damaged after several days of operation. This is probably because the gas supply pipe 7 is loosely fixed due to the centrifugal force due to rotation, and the gas supply pipe 7 is in contact with the inner surface of the shaft 4 and is damaged. On the other hand, the embodiment of the molten metal stirring rotor 1 of the present invention can continue to remove impurities in the molten metal 2 without being damaged even after one month of operation. Can be firmly fixed and sealed, so that the gas supply pipe 7 is hardly loosened due to the centrifugal force caused by the rotation of the shaft 4 or the expansion or contraction caused by the heat of the shaft 4. It was confirmed that the gas leakage of the processing gas was less likely to occur from the contact portion 3.

  Next, a test for confirming the effect of the porosity of the sealing material 10 was performed.

  First, a plurality of shafts 4, rotors 5, cordierite-made gas supply pipes 7, and S45C-made connectors 3 made of silicon nitride-based sintered bodies were produced in the same size by the same manufacturing method as in Example 1.

  Next, it is made of an alumina fiber in which the filling amount per unit volume is changed so that the porosity is 4, 5, 10, 20, 30, 35% in the vicinity of the rotor 5 side and the connection tool 3 side. Sample No. 1 of the rotating body 1 for stirring a molten metal in which a fibrous material 10a of ceramic fiber was embedded. 1-6 were prepared.

  Similarly, a slurry made of an alumina raw material, a solvent, and an inorganic polymer, adjusted so that the porosity is 4, 5, 10, 20, 30, 35% in the vicinity of the rotor 5 side and the connection tool 3 side. Sample No. 1 was filled and heated to evaporate the solvent to form porous material 10b. 7-12 were also prepared.

And sample no. 1 to 12 are actually installed in the molten metal degassing apparatus and immersed in the molten metal 2, the rotor 5 is rotated, and the operation is performed while injecting argon gas at room temperature into the gas supply pipe 7. 4 or the gas supply pipe 7 was subjected to a test for confirming whether or not there is a defect that causes cracks or breakage. The operating time is a maximum of 600 hours. After that, after 240 hours and 480 hours, check that there is no damage such as damage to the shaft 4 and the gas supply pipe 7, respectively, and then crack or damage to the shaft 4 and the gas supply pipe 7 Evaluation was made with a mark “x” when the problem occurred, and a mark “◯” when there was no problem. The results are shown in Table 1.

  As a result, as shown in Table 1, a sample No. 1 in which the sealing material 10 was a fibrous material 10a or a porous material 10b was used. In both cases 1 to 12, no cracks or breakage was confirmed in the confirmation after 240 hours. However, Sample Nos. 1 and 7 with a low porosity of 4% and Sample No. 1 with a high porosity of 35%. 6 and 12 showed cracks and breakage after 480 hours of operation.

  Sample Nos. 1 and 7 having a low porosity of 4% have a reduced heat insulating property of the fixing material 10 for sealing, transfer heat from the shaft 4 heated to a high temperature to the gas supply pipe 7, and the fibrous material 10a becomes Since only the part that is buried and is in contact with the gas supply pipe 7 becomes high temperature, it is considered that the gas supply pipe 7 is cracked due to the difference in thermal expansion from the other parts that are not in contact.

  Sample No. with a high porosity of 35%. 6 and 12 show that the argon gas leaked from the gap formed between the gas supply pipe 7 and the shaft 4 and the seal fixing material 10 after 480 hours of operation has a high porosity of the seal fixing material 10, so that the shaft 4 It is considered that the gas enters the gap 9 between the gas supply pipe 7 and a temperature difference is generated between the outer surface and the inner surface of the shaft 4 and the shaft 4 is damaged due to a difference in thermal expansion.

  Compared with these samples, sample Nos. With porosity in the range of 5-30%. As for 2-5, 7-11, there is no crack or breakage in the shaft 4 and the gas supply pipe 7 even in the confirmation after 600 hours, and it is reliable that the molten metal 2 with high quality can be stably supplied. It was confirmed that this is a highly degassing treatment device.

  Next, a test for confirming the effect of the material of the gas supply pipe 7 was performed.

  First, a gas supply pipe 7 made of cordierite, mullite, steatite, alumina, and zirconia is manufactured in the same size as in Example 1, and this is provided with alumina fibers at one location near the rotor 5 side and near the coupler 3 side. A sample No. 1 was prepared by embedding and assembling a ceramic fiber fibrous material 10a made of Prepared 13-17.

  Each gas supply pipe 7 is manufactured by wet mixing a commercially available primary raw material, a solvent, a binder, and a sintering aid with a ball mill, and spray granulating the resulting slurry with a spray dryer. The next raw material was formed into a predetermined size by a hydrostatic press molding method, subjected to cutting, fired at the firing temperature shown in Table 2, and then subjected to grinding.

  In addition, as a comparative example, a commercially available conventional carbon gas supply pipe was purchased, and a molten metal stirring rotator was prepared.

  These sample Nos. 13-17 and the sample of the comparative example were installed in the degassing apparatus as in Example 2, and operated for 600 hours. After the operation, the gas supply pipe 7 was taken out, and the amount of deformation was measured. The results are shown in Table 2.

The amount of deformation of the gas supply pipe 7 is measured by placing a cylindrical gas supply pipe 7 on the surface plate and laying the side with the gap gauge where the gap between the surface plate and the gas supply pipe 7 is the largest. The amount of deformation was determined.

  As a result of the test, as shown in Table 2, the sample of the comparative example using the conventional carbon gas supply pipe was damaged and the amount of deformation could not be measured.

  In comparison with this, sample No. For 13 to 17, the deformation is as small as 1.5 mm or less, and among them, cordierite and mullite having a low coefficient of thermal expansion are confirmed to be good because the firing temperature is relatively low. It was.

It is sectional drawing which shows an example of embodiment of the rotary body for molten metal stirring of this invention. It is sectional drawing which shows the other example of embodiment of the rotary body for molten metal stirring of this invention. It is a front view which fractures | ruptures and shows a part of conventional molten metal degassing processing apparatus.

Explanation of symbols

1: Rotating body for molten metal stirring 2: molten metal 3: connecting tool 4: shaft 5: rotor 6: gas supply port 7: gas supply pipe 8: gas injection port 9: gap
10: Fixing material for seal
10a: Fiber material
10b: Porous material
11: Convex

Claims (5)

With the rotor for stirring the molten metal is attached to an end portion of the hand, a shaft connector is attached to be connected to a rotary drive mechanism at the other end, they are arranged in the same axial inside of the shaft and a gas supply pipe, sealing restraints for securing said shaft and said gas supply pipe to the vicinity of rotor-side and near the coupling side of the gap provided between the gas supply pipe and the shaft There are arranged, the sealing fixing material, fibrous material and comprises at least one of the porous material, and the molten metal agitating rotary member, characterized in Rukoto that having a porosity of 5-30% . The molten metal according to claim 1, wherein a sealing fixing member is further disposed between the sealing fixing member in the vicinity of the rotor side and the sealing fixing material in the vicinity of the connector side. Rotating body for stirring. The rotating body for stirring a molten metal according to claim 1 or 2 , wherein the gas supply pipe is made of ceramics. The molten metal stirring rotor according to any one of claims 1 to 3 , wherein the ceramic is made of any one of cordierite, mullite, steatite, alumina, and zirconia. The molten metal stirring rotator according to any one of claims 1 to 4 is connected to the rotation drive mechanism of the shaft via the connector, and is disposed in a molten metal container. Degassing equipment for molten metal.

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