JP2001026828A - Filter for measuring inclusion in molten aluminum - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a filter for measuring inclusion in molten aluminum in which a filter surface having a fixed area is secured and whose manufacture and fitting are facilitated. SOLUTION: The filter is arranged at the bottom wall of a vessel for holding the molten aluminum and the inclusion quantity in the molten aluminum can be obtd. from filtered quantity and filtering time. Further, the peripheral surface and the surface peripheral edge part of the filter body 11 having porous body structure through which the molten aluminum can pass are coated with a masking agent, and the filtering surface 13 having a fixed area for allowing the molten aluminum pass through is arranged at the center part of the surface. The non-filtering surface 14 with its surface peripheral edge part coated with the masking agent is preferably made coplanar with the filter surface 13. As the masking agent 12, alumina-silica-base cement such as alumina-cement, portland-cement, slag-cement can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter used for quantitatively measuring suspended matters and inclusions floating in a molten aluminum or aluminum alloy, and a method for producing the same.

[0002]

2. Description of the Related Art Aluminum or aluminum alloy melt (hereinafter referred to as aluminum melt) includes Al ₂ O _2.
3 , MgO, Al ₄ C _{4 and the} like are floating. Depending on the type of the molten aluminum, intermetallic compounds such as Cr, Mn, and Fe may float. Quantification of inclusions is important for knowing the cleanliness and properties of the molten aluminum.
Inclusions floating in the aluminum melt are determined by filtering the aluminum melt with a filter and determining the relationship between the amount of filtration and the filtration time. For example, as shown in FIG. 1, a molten aluminum 2 is charged into a container 1, and an inert gas 4 is injected from an upper portion of the container 1 while controlling the temperature of the molten aluminum 2 by a heater 3, so that the molten aluminum 2 is discharged. Apply pressure. A molten metal outflow pipe 6 provided with a filter 5 is provided on the bottom of the container 1. As the filter 5, a ceramic filter or the like is used, and is fixed to a through hole provided in the bottom of the container 1 with cement or the like prior to measurement. The pressurized molten aluminum 2 is filtered by a filter 5
Through the molten metal outflow pipe 6 to the recovery container 7.

[0003] When the molten aluminum 2 passes through the filter 5, inclusions floating in the molten aluminum 2 are captured by the filter 5. In addition, when filters having the same airflow resistance are used, the flow resistance is as follows.
The filtration time is generally longer as the amount of inclusions increases. Thus, the amount of inclusions captured by the filter 5 (filtration amount) and the time required for a certain amount of the molten aluminum 2 to pass through the filter 5 (filtration time) depend on the amount of inclusions in the molten aluminum 2. Therefore, the amount of inclusions in the molten aluminum 2 can be determined from the filtration amount and the filtration time. But,
If the state of the filter 5 and the filtration area fluctuate, even if the same amount of inclusions is measured, the amount of inclusions obtained from the measurement results will have different values. In addition, in order to obtain the amount of inclusions while maintaining the filter under a certain condition, it is required to use a filter having the same filtration area after every measurement.

[0004]

As a method for maintaining a constant filtration area, a predetermined filtration area on the filter surface is covered with a suitable masking agent, and then cement is applied to an exposed portion of the filter with a brush or the like, and then the container is filtered. There is a method of fixing to the bottom of the vehicle. However, it is necessary to fix the filter to the container at the same time as concealing the non-exposed portion, which increases the work load. In addition, there is a possibility that the cement may seep out to the filtration surface required for the measurement, and the filtration area may vary. Further, a filter that has been used once cannot be reused because inclusions remain on the surface and a part of the inside of the filter, and must be replaced every measurement. The present invention has been devised to solve such a problem, and provides a filter surface and a non-filter surface on the surface of the filter body by previously covering the peripheral surface and the peripheral edge of the filter with a concealing agent. It is an object of the present invention to provide a filter which is less likely to vary in filtration area and is easy to manufacture and fix to a container.

[0005]

According to the present invention, there is provided a filter provided on a bottom wall of a container for accommodating a molten aluminum and for determining an amount of inclusions of the molten aluminum from a filtration amount and a filtration time. The filter body having a porous structure through which the molten aluminum is permeable, the peripheral surface and the peripheral edge of the filter body being covered with a concealing agent, and a filtering surface having a certain area through which the molten aluminum passes are provided at the center of the surface. Features. It is preferable that the non-filtration surface whose peripheral edge is covered with a concealing agent is flush with the filtration surface.
As the concealing agent, alumina-silica cement such as alumina cement, Portland cement and slag cement is used.

In this filter for measuring the amount of inclusions, the center of the surface of the filter body is covered with a masking member or a masking agent, and cement is applied to the peripheral surface and the peripheral edge of the filter body. It is manufactured by forming a filter surface of a fixed area in the part. When covering the center of the surface of the filter body with the masking member, the masking member is pressed against the center of the surface of the filter body using an elastic body such as a spring to prevent cement from entering the gap between the filter body and the masking member. Is preferred.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a filter 10 according to the present invention, as shown in FIG. The filter body 11 is a porous body that allows the molten aluminum 2 to pass therethrough, and is made of a ceramic material such as porcelain, pottery, quartz, carbon, graphite, quartz glass, and alumina. When a short cylindrical filter body 11 is used, the upper surface of the filter body 11 is covered with a concealing agent 12 within a predetermined range from the periphery to form a non-filtering surface 14, and a fixed area not covered with the concealing agent 12 at the center of the surface. Is formed. As the concealing agent 12, an alumina-silica cement such as alumina cement, portland cement, slag cement or the like, which does not deteriorate even at a high temperature in contact with the molten aluminum 2, is preferably used. The bottom surface of the filter body 11 is a portion that does not directly contact the molten aluminum 2 and serves as an outlet for the filtered molten aluminum 2.
There is no need to cover with 2.

As an object to which the filter 10 is set,
FIG. 3 shows a flat plate-shaped filter base 20 having a stepped filter mounting hole 21 formed in the center thereof, but a container 1 having a filter mounting hole 21 of a similar shape formed on the bottom wall.
(FIG. 1) can of course be used. The filter mounting hole 21 has a step portion 24 between an insertion hole 22 having an inner diameter slightly larger than the diameter of the filter 10 and a support hole 23 having an inner diameter slightly smaller than the diameter of the filter 10. After the filter 10 is inserted into the insertion hole 22 and placed on the step portion 24, cement is filled between the peripheral surface of the filter 10 and the inner wall of the insertion hole 22, and the filter 10 is dried and hardened. Fix to 20. At this time, the rim of the upper surface of the filter 10
Even if cement adheres to the corner between the upper surface and the peripheral surface of the filter 10,
The cement does not seep to the filtration surface 13 to change the filtration area.

The filter 10 is covered, for example, with the concealing agent 12 in the step shown in FIG. That is, the cylindrical side wall member 32 is erected on the periphery of the worktable 31 having the nest insertion hole 31a formed in the center portion (a), and the nest 34 as a masking member is inserted into the nest insertion hole 31a via the spring 33. (B). An annular space defined by the work table 31, the side wall member 32 and the insert 34 is filled with cement 35 (c). Then
The filter main body 11 is positioned on the insert 34 and the cement 35 while being guided by the guide 36 in order to keep the filter main body 11 in an appropriate position (d).

The shielding member 37 is placed on the filter main body 11 (e), and the shielding member 37 is pushed down to
The filter body 11 is buried in the liquid (f). At this time, since the upper end surface of the nest 34 is in contact with the center part (the lower side in FIG. 4) of the front surface of the filter main body 11 and the shielding member 37 is in contact with the rear surface (the upper side in FIG. 4), the pressing is performed via the shielding member 37. The cement 35 spreads along the gap between the worktable 31, the side wall member 32 and the filter body 11,
The extension area is regulated by the nest 34 and the shielding member 37, so that the filter body 11 does not seep to the central part and the rear part of the front surface.
Therefore, although the peripheral edge of the surface of the filter main body 11 is covered with the cement 35, the filter surface 13 (FIG. 2) having a certain area is secured at the center of the surface. Further, since the nest 34 is inserted into the nest insertion hole 31a via the spring 33, the nest 34 is in close contact with the center of the surface of the filter main body 11, so that the filter surface 13 having a certain area is secured and the filter main body 11 is secured. A non-filtering surface 14 is formed in which a predetermined area of the surface is covered with cement 35.

After the cement 35 is spread on the peripheral surface and the peripheral edge of the surface of the filter body 11, the side wall member 32, the nest 3
4, filter body 1 together with guide 36 and shielding member 37
1 is separated from the work table 31 (g). At this time, since the nest 34 is released from the elasticity of the spring 33, it can be easily separated from the filter body 11. Then
The filter body 11 is dried in a state where the side wall member 32, the guide 36, and the shielding member 37 are removed from the filter body 11 and the nest 34 is in contact with the center of the surface (h). After drying, the nest 34 is removed and the filter surface 13
Is provided, and the filter 10 in which the peripheral portion and the peripheral portion surrounding the filtering surface 13 are covered with the concealing agent 12 is obtained. The formed filtering surface 13 has a constant surface area because the contour is regulated by the top surface of the nest 34.

According to this method, a filtering surface 13 having a fixed area can be easily formed at the center of the surface of the filter body 11. Moreover, there is no need to apply cement with a brush or the like, and by immersing a plurality of filter bodies 11 in the liquid of cement 35 at the same time, a large number of filters can be manufactured at once, and the manufacturing load is greatly reduced. Predetermined part is concealing agent 1
The filter 10 covered with 2 is set on a filter base 20 constituting the bottom wall of the container 1. And the filter 10
The space between the peripheral surface of the filter and the insertion hole 22 is filled with cement, and the filter 10 is fixed to the filter base 20. Part of the filled cement is also exuded on the surface of the filter 10. However, the non-filtering surface 14 covered with the concealing agent 12
Therefore, a constant filtering area is secured without the filtering surface 13 being covered with cement.

After fixing the filter 10, the filter base 2
The container side wall is erected on the periphery of 0 to construct a container 1 (FIG. 1) for accommodating the molten aluminum 2. Alternatively, the filter 10 is arranged in a filter mounting hole 21 provided in the bottom wall of a pre-constructed integrated container, and the filter 10 is fixed by filling with cement. When the filter 10 is fixed, even if cement slightly seeps into the surface of the filter 10, it stops on the non-filtering surface 14, so that the effective area of the filtering surface 13 does not change. The molten aluminum 2 is accommodated in the container 1 to which the filter 10 is fixed, and the molten aluminum 2 is
By passing through 0, the filtration amount and the filtration time required for quantifying the amount of inclusions in the aluminum melt 2 are measured.

In the above example, the filter body 1 has a short cylindrical shape.
1 has been described. However, the present invention is not limited to this, and may have any form such as a polygonal column, an elliptical column, and the like. The shape after being covered with the cement 35 is not particularly restricted. Further, instead of bringing the insert 34 into contact with the center of the surface of the filter body 11, a shielding agent that can be separated after covering the peripheral edge and the peripheral surface with the cement 35 is used as a masking agent.
Can be covered beforehand. As a separable shielding agent, as long as it does not adversely affect the porous structure of the filter main body 11, wax that sublimes and evaporates when the cement 35 is heated and dried, or decomposition and evaporation due to the retained heat of the aluminum melt 2 that passes through the filter 10 or There are resins and low melting point alloys that are melted and removed.

[0015]

As described above, in the filter for measuring the amount of inclusions according to the present invention, the peripheral surface and the peripheral edge of the surface are covered with the concealing agent, and the filtration surface having a constant surface area is provided at the center of the surface. Therefore, when the filter is fixed to the container, a binder such as cement does not adhere to the filtration surface and does not reduce the surface area of the filtration surface required for quantitative measurement. Moreover, when employing a method in which a masking member or a masking agent is brought into contact with the center of the surface to immerse the filter body in the cement liquid,
Since a plurality of filters having a filtration area of a fixed area can be manufactured at a time, the manufacturing load is greatly reduced, and the filter can be easily fixed to the measuring container.

[Brief description of the drawings]

FIG. 1 Inclusion amount measuring device in which a filter for measuring the amount of inclusions of aluminum melt is incorporated in a container.

FIG. 2 is a plan view (a) and a cross-sectional view (b) of the filter for measuring the amount of inclusions according to the present invention.

FIG. 3 is a filter table for fixing a filter.

FIG. 4 is a view showing a manufacturing process of an inclusion amount measuring filter according to the present invention.

[Explanation of symbols]

1: container 2: molten aluminum 3: heater
4: Inert gas 5: Filter 6: Molten outflow pipe
7: Collection container 10: Filter 11: Filter body 12: Concealing agent 13: Filtration surface 14: Non-filtration surface 20: Filter base 21: Filter mounting hole 22:
Insertion hole 23: Supporting hole 24: Step 31: Work table 31a: Nesting insertion hole 32: Side wall member 33: Spring 34: Nesting 35:
Cement 36: Guide 37: Shielding member

 ──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Yukio Kuramasu 1-34-1 Kambara, Kambara-cho, Abara-gun, Shizuoka Prefecture F-term in Nippon Light Metal Co., Ltd. Group Technology Center 4K001 AA02 BA23 EA06 GB11

Claims (4)

[Claims] 1. A filter which is provided on a bottom wall of a container for accommodating a molten aluminum and obtains an amount of inclusions of the molten aluminum from a filtration amount and a filtration time, wherein the filter body has a porous structure through which the molten aluminum permeates; A filter for measuring the amount of inclusions in the molten aluminum, wherein the peripheral surface and the peripheral edge of the surface are covered with a concealing agent, and a filtration surface having a fixed area through which the molten aluminum passes is provided at the center of the surface. 2. The filter for measuring the amount of inclusions in a molten aluminum according to claim 1, wherein the non-filtering surface whose peripheral edge is covered with a concealing agent is flush with the filtering surface. 3. The filter according to claim 1, wherein an alumina-silica cement is used as a concealing agent. 4. After covering the center of the surface of the filter body with a masking member or a masking agent and applying cement to the peripheral surface and the peripheral edge of the filter body, the cement is dried and hardened, and a predetermined area of filtration is applied to the center of the surface. A method for producing a filter for measuring the amount of inclusions in molten aluminum, comprising forming a surface.